BACKGROUND: Transcatheter edge-to-edge mitral valve repair is now available in many countries and has achieved favourable therapeutic outcomes. However, there have been no reported cases of clip opening while locked (COWL) during the acute phase using the MitraClip G4 system (Abbott, Abbott Park, IL, USA). CASE SUMMARY: We present two cases of COWL occurring at different phases: one immediately after clip release and the other 2 days post-procedure. In both cases, the initial treatment involved the use of the XTW system. Subsequently, an additional XT system was deployed for the deterioration of mitral regurgitation caused by COWL, without any complications. DISCUSSION: The MitraClip G4 system offers four size variations, providing a larger grasping area and increased flexibility for accessing complex lesions. Furthermore, the complication rate decreased with increasing operator experience and device generation. However, it has been reported that COWL can occur after the clip is deployed during TEER. Although the mechanism of COWL is unclear, the nature and mobility of the valve leaflets and the product specificity of the MitraClip may be involved.

BACKGROUND: There are a few case reports regarding transcatheter aortic valve implantation (TAVI) for deteriorated surgical homograft. CASE SUMMARY: We present a case of severe structural valve deterioration (SVD) of homograft surgical aortic valve presenting severe aortic regurgitation in an 84-year-old man with decompensated heart failure. We performed TAVI in homograft valve using 23 mm SAPIEN3 Ultra RESILIA. The resulting grade of paravalvular regurgitation was trace, the post-operative effective orifice area (EOA) was 1.66 cm2 (index EOA: 1.19 cm2/m2), and device success was achieved. DISCUSSION: Stented bioprosthetic valves are more commonly implanted than mechanical and stentless bioprosthetic valves. In the 1980s and the early 1990s, homografts became particularly popular as alternatives to stented valves. There are several reports of TAVI for homograft SVD, but the paravalvular leakage grade is worse than that of redo-surgical aortic valve replacement, although the mortality rate is lower. However, the valves used in these reports were from older valves such as SAPIEN XT or SAPIEN3. There are no reports using SAPIEN3 Ultra RESILIA with a significant reduction in paravalvular leak due to an external textured polyethylene terephthalate skirt extending 40% higher above the valve inflow than the classical SAPIEN3, which is now available. Transcatheter aortic valve implantation using SAPIEN3 Ultra RESILIA showed good therapeutic efficacy.

Recent studies have showed that asymptomatic cerebral infarction (ACI) developed in a reasonable number of patients after cardiac catheterization. However, no study has investigated the long-term prognostic impact of ACI after cardiac catheterization. We investigated whether ACI after cardiac catheterization affects long-term mortality and subsequent cardiovascular events.We retrospectively enrolled patients who underwent cardiac catheterization before cardiac surgery and cerebral diffusion-weighted magnetic resonance imaging (DWI). The incidence and clinical features of ACI were investigated. The long-term prognosis, including all-cause mortality and subsequent major cardiovascular events (MACE; all-cause mortality, stroke, acute myocardial infarction, fatal arrhythmia, and hospitalized heart failure), was also assessed.A total of 203 patients were enrolled. Of these, 10.3% had ACI diagnosed by DWI. There were no differences in baseline characteristics between patients with and without ACI, except more frequent history of symptomatic stroke in patients with ACI. In the Kaplan-Meier analysis during a median follow-up of 1009 days, the patients with ACI showed worse mortality and a slightly higher occurrence of MACE compared with those without ACI (P = 0.01 and P = 0.08, respectively). In addition, ACI was a prognostic marker independent of age, surgery type, and history of stroke.ACI after cardiac catheterization frequently developed and was also associated with long-term prognosis. It may be an independent prognostic marker in high-risk patients who underwent subsequent cardiac surgery.

BACKGROUND: Early prediction of aorta-related events is important for determining subsequent treatment strategies in patients with acute aortic dissection. However, most studies evaluated long-term aortic growth rates by annual assessment. The purpose of our study was to determine whether the in-hospital growth rate of aortic volume was associated with aorta-related events. METHODS: We studied 116 patients with uncomplicated type B acute aortic dissection. We analyzed whether changes in aortic volume were associated with aorta-related events during a 5-year follow-up. According to the growth rate from admission to discharge, patients were divided into two groups: Increase >0 (aortic volume: n = 59, aortic diameter: n = 43) and Reduction ≤0 (aortic volume: n = 57, aortic diameter: n = 73) in maximum aortic diameter or aortic volume. The primary endpoint was the discriminative ability of the growth rate of aortic volume for aorta-related events. RESULTS: According to the evaluation of aortic volume changes, the Increase group had significantly higher aorta-related event rates than those in the Reduction group (49.2 % vs. 3.5 %, respectively; p < 0.001). Receiver operating characteristics analysis showed that the growth rate of aortic volume had a clearly useful discrimination, with an area under the curve of 0.84, whereas the discriminative ability of the growth rate of maximum aortic diameter was poor (area under the curve: 0.53). Multivariate analysis showed that the growth rate of aortic volume from admission to discharge was an independent predictor of aorta-related events (hazard ratio, 26.3; 95 % confidence interval, 2.04-286.49; p = 0.001). CONCLUSIONS: In-hospital evaluation of aortic volume was helpful to predict long-term aorta-related events in patients with uncomplicated type B acute aortic dissection.

BACKGROUND: Recently, mechanical support obtained with the combination of venoarterial extracorporeal membrane oxygenation (VA-ECMO) and an Impella device, together referred to as ECPELLA, has been shown to be effective for acute myocardial infarction with cardiogenic shock. However, methods for withdrawing VA-ECMO in acute myocardial infarction cases complicated by right ventricular dysfunction are yet to be established. Here, we report the effective use of inhaled nitric oxide during the weaning of VA-ECMO from the ECPELLA management of a patient with acute myocardial infarction with cardiogenic shock. CASE SUMMARY: An 81-year-old man with an acute extensive anterior wall myocardial infarction with cardiogenic shock was supported with ECPELLA to improve his haemodynamics. During ECPELLA, the Impella device could not maintain sufficient flow. Echocardiography revealed a small left ventricle and an enlarged right ventricle, indicating acute right heart failure. Inhaled nitric oxide was initiated to reduce right ventricle afterload, which decreased pulmonary artery pressure from 34/20 to 27/13 mmHg, improved right and left ventricle sizes, and stabilized the Impella support. Afterward, VA-ECMO could be withdrawn because the Impella alone was sufficient for haemodynamic support. DISCUSSION: Inhaled nitric oxide improved right ventricle performance in a patient with severe myocardial infarction with right heart failure supported by ECPELLA. Thus, we suggest that inhaled nitric oxide facilitates the weaning of VA-ECMO from patients with refractory right ventricular dysfunction who are supported by ECPELLA.

Recent studies showed that preoperative functional assessment with fractional flow reserve (FFR) could predict a long-term patency of arterial bypass grafts in patients with coronary artery bypass grafting (CABG). Quantitative flow ratio (QFR) is a novel angiography-based approach to estimate FFR. This study aimed to investigate whether preoperative QFR could discriminate arterial bypass function at 1 year after surgery. The PRIDE-METAL registry was a prospective, multicenter observational study that enrolled 54 patients with multivessel coronary artery disease. By protocol, left coronary stenoses were revascularized by CABG with arterial grafts, whereas right coronary stenoses were treated with coronary stenting. Follow-up angiography at 1 year after surgery was scheduled to assess arterial graft patency. QFR was performed using index angiography by certified analysts, blinded to bypass graft function. The primary end point of this sub-study was the discriminative ability of QFR for arterial graft function, as assessed by receiver-operating characteristic curve. Among 54 patients enrolled in the PRIDE-METAL registry, index and follow-up angiography was available in 41 patients with 97 anastomoses. QFR were analyzed in 35 patients (71 anastomoses) with an analyzability of 85.5% (71/83). Five bypass grafts were found to be non-functional at 1 year. The diagnostic performance of QFR was substantial (area under the curve: 0.89; 95% confidence interval: 0.83 to 0.96) with an optimal cutoff of 0.76 to predict functionality of bypass grafts. Preoperative QFR is highly discriminative for predicting postoperative arterial graft function.Trial registration: Clinical.gov reference: NCT02894255.

AIMS: In recent large trials, sacubitril/valsartan demonstrated favorable effects in patients with HF. However, many patients do not achieve the target dose of treatment. This study investigated the factors linked to up-titration of sacubitril/valsartan in patients with heart failure and preserved ejection fraction (HFpEF). METHODS: Using a multicenter retrospective database, 204 consecutive patients with HFpEF (left ventricular ejection fraction ≥ 40%) who were treated with sacubitril/valsartan between October 2020 and March 2022 were analyzed. Up-titration was defined as an increase in dosage above 24/26 mg BID beyond 12 weeks after the initiation of sacubitril/valsartan. RESULTS: Among the patients, 55% underwent up-titration, and 8% discontinued the drug. The baseline systolic blood pressure (SBP) was higher in patients with up-titration than in those with no up-titration; SBP values similar to that at baseline were observed between the 2 groups at 2 to 4 weeks and at 12 weeks after the commencement of sacubitril/valsartan treatment. The majority of those who discontinued sacubitril/valsartan did so because of hypotension. The multivariable logistic regression model showed that a history of hypertension, history of atrial fibrillation, baseline SBP, and baseline estimated glomerular filtration rate <60 mL/min/1.73 m2 were associated with sacubitril/valsartan up-titration. CONCLUSION: Approximately half of all patients did not undergo up-titration, and 8% of those with HFpEF discontinued the sacubitril/valsartan therapy. For aggressive up-titration and continuation of sacubitril/valsartan, patients with lower baseline SBP, renal dysfunction, absence of a history of hypertension, and presence of atrial fibrillation may require more careful monitoring.

AIM: Psychological distress is associated with poor prognosis in patients with cardiovascular disease (CVD). However, factors related to psychological distress in elderly patients with CVD is less understood. We aimed to investigate the rate of psychological distress in elderly patients with CVD in comparison with that of patients without CVD and to examine the clinical, socioeconomic, and lifestyle factors associated with this condition. METHODS AND RESULTS: Data from a nationwide population-based study in Japan of patients aged ≥ 60 years were extracted, and 1:1 propensity score matching was conducted of patients with and without CVD. Psychological distress was assessed using the K6 scale, on which a score ≥ 6 was defined as psychological distress. Of the 24,388 matched patients, the rate of psychological distress was significantly higher among patients with CVD compared to those without CVD (29.8% vs. 20.5%, p < 0.0001). The multivariate analysis revealed that female sex, comorbidities except hypertension, current smoking, daily sleep duration of < 6  h versus ≥ 8  h, home renter versus owner, retired status, having a walking disability, and lower monthly household expenditure were independently associated with psychological distress. Walking disability was observed in greatest association with psychological distress (odds ratio 2.69, 95% confidence interval 2.46-2.93). CONCLUSION: Elderly patients with CVD were more likely to have psychological distress compared to those without CVD. Multiple factors, including clinical, socioeconomic, and lifestyle variables, were associated with psychological distress. These analyses may help health care providers to identify high risk patients with psychological distress in a population of older adults with CVD.

BACKGROUND: Cardiovascular disease and cancer share a number of risk factors and pathophysiologic mechanisms. Although risk management and early detection of cancer in patients with cardiovascular disease are important, preventive efforts in cardiology and oncology have been relatively disconnected. This study aimed to investigate the rate of cancer screening in a population of older adults with cardiovascular disease. METHODS: This study used data from the 2019 Comprehensive Survey of Living Conditions. Data on participants aged 60 years or older were extracted. The rate of cancer screening and cancer type were investigated between participants with and without cardiovascular disease. RESULTS: Of the 132,442 individuals, participants with cardiovascular disease had a significantly lower rate of cancer screening than those without cardiovascular disease [male: 4401 of 7972 participants (55.2%) vs. 33,744 of 52,106 participants (64.8%), p < 0.001; female: 2500 of 4984 participants (50.2%) vs. 41,319 of 67,380 participants (61.3%), p < 0.001]. The rate of cancer screening was significantly lower in participants with cardiovascular disease than in those without cardiovascular disease, regardless of cancer type, including gastric, colorectal, lung, breast, and gynecologic cancer screening. A history of cardiovascular disease was a negative factor for cancer screening (odds ratio 0.71, 95% confidence interval 0.67-0.74 in male participants; odds ratio 0.80, 95% confidence interval, 0.75-0.85 in female participants). CONCLUSIONS: The rate of cancer screening in elderly participants with cardiovascular disease was lower than that in participants without cardiovascular disease. Physicians should raise awareness regarding early cancer detection in patients with cardiovascular disease.

BACKGROUND: We evaluated malignancy according to the characteristics of pericardial fluid in symptomatic Japanese patients undergoing pericardiocentesis and computed tomography (CT). METHODS: This was a retrospective, single-center, observational study of 125 symptomatic patients undergoing pericardiocentesis. The patients were classified into two groups: a malignancy group and a non-malignancy group, according to the primary disease and cytology of the pericardial effusion (PE). We compared the pericardial fluid sample and CT measurements between both groups. RESULTS: All patients were diagnosed as having exudative PE by Light's criteria. PE with malignant cells was demonstrated in 76.8% of the malignancy group patients. Pericardial to serum lactate dehydrogenase (LDH) ratio > 0.6, as one of Light's criteria, was associated with malignancy (p = 0.017). Lower serum brain natriuretic peptide (BNP) concentration was also associated with malignancy (BNP: 126.9 ± 89.8 pg/ml vs 409.2 ± 97.7 pg/ml, malignancy vs non-malignancy groups, respectively; p = 0.037). A significant difference was observed in pericardial fluid glucose level between the malignancy and non-malignancy groups (pericardial fluid glucose: 78.24 ± 48.29 mg/dl vs 98.41 ± 44.85, respectively; p = 0.048). Moreover, CT attenuation values (Hounsfield units (HU)) tended to be higher in the malignancy group vs the non-malignancy group (22.7 [interquartile range (IQR), 17.4-26.0] vs 17.4 [IQR, 13.7-26.4], respectively; p = 0.08). The sensitivity and specificity of pericardial fluid glucose level ≤ 70 mg/dl and CT attenuation values > 20 HU were 40.9% and 89.6%, respectively, in the malignancy group. The positive- and negative predictive values of pericardial fluid glucose level ≤ 70 mg/dl and CT attenuation values > 20 HU were 85.7% and 50.0%, respectively, in the malignancy group. Pericardial fluid glucose level ≤ 70 mg/dl and CT attenuation values > 20 HU were cutoff values associated with malignancy (p = 0.012). CONCLUSIONS: Lower pericardial fluid glucose level with higher CT attenuation values may suggest malignancy-related PE.

BACKGROUND: There is a paucity of data comparing the long-term outcomes after inferior vena cava (IVC) filters placement for patients with acute venous thromboembolism (VTE) between those with and without active cancer. METHODS: In the COMMAND VTE Registry, we evaluated the effects of IVC filter use on the long-term clinical outcomes stratified by the presence and absence of active cancer. RESULTS: Among 2,626 patients with acute symptomatic VTE, there were 604 patients with active cancer, and 2022 patients without active cancer. IVC filters were placed and not retrieved in 455 patients (17%) in the entire cohort, in 150 patients (24.8%) in the active cancer stratum, and in 305 patients (15.1%) in the non-cancer stratum. In the entire cohort, non-retrieved IVC filter placement was not associated with a lower adjusted risk for PE recurrence (HR 0.59, 95% CI 0.30-1.15, P = 0.122), but with an increased adjusted risk for DVT recurrence (HR 2.27, 95% CI 1.43-3.60, P<0.001). In the non-cancer stratum, the non-retrieved IVC filter placement was associated with a decreased risk for PE (HR 0.29, 95% CI 0.09-0.93, P = 0.037), but not with an increased risk for DVT (HR 1.73, 95% CI 0.89-3.38, P = 0.108), while in the active cancer stratum, it was associated with an increased risk for DVT (HR 2.47, 95% CI 1.24-4.91, P = 0.010), but not with a decreased risk for PE (HR 0.82, 95% CI 0.34--1.96, P = 0.650). CONCLUSIONS: There were some differences in the risk-benefit balance between VTE patients with and without active cancer.

BACKGROUND: Although the incidence of very late stent failure (VLSF) is reduced with newer generation drug-eluting stent (DES), the mechanism of VLSF has not been fully explored.Methods and Results:This study evaluated both local vascular healing using coronary angioscopy and systemic factors determined by platelet reactivity at long-term follow-up after 2nd- and 3rd-generation DES implantation in patients with acute coronary syndrome. Coronary angioscopy was performed to assess neointimal coverage (NIC), yellow color (YC) grade and presence of thrombus. The obtained findings were compared with 2nd- and 3rd-DES. Platelet aggregation was assessed by light transmittance aggregometry. 100 consecutive patients were prospectively enrolled: 2nd- (n=50) and 3rd-DES (n=50). 3rd-DES patients had significantly higher NIC grade and lower YC grade compared with 2nd-DES. The presence of thrombus was tended to be lower with 3rd-DES than with 2nd-DES (8% vs. 18%, P=0.11). Patients with thrombus had significantly higher maximum platelet aggregation and higher prevalence of high on-treatment platelet reactivity (HPR) than those without thrombus. Multivariable analysis showed stent strut exposure and HPR as independent predictors of thrombus. CONCLUSIONS: Newer generation DES contribute to better vascular healing depending on the degree of neointimal coverage. In addition to local factors at the stented lesion, systemic factors such as degree of platelet reactivity might also contribute to VLSF.

Endovascular therapy (EVT) was performed in two cases with chronic total occlusion (CTO) of superficial femoral artery. In these cases, angioscopy was deployed in the backyard of the CTO lesion from popliteal artery retrogradely, then the guidewire was advanced from antegrade. When the wire crossed the distal of the CTO lesion, the wire penetration was clearly visualized by the retrograde-angioscopy. Therefore, wire crossing of CTO into the distal true lumen was certainly confirmed, and EVT was successful. .

The instantaneous wave-free ratio (iFR) is used for assessing the hemodynamic severity of a lesion, as an alternative to the fractional flow reserve (FFR). We evaluated the relationship between iFR and FFR in detail and the clinical significance of iFR in patients with mild to intermediate coronary artery stenosis. We recruited consecutive 323 patients (421 lesions) with lesions exhibiting 30% to 80% diameter stenosis on angiography in whom FFR and iFR were measured. In the total lesions, mean diameter stenosis was 48.6% ± 9.0%, and physiological significance, defined by FFR of 0.80 or less or by iFR of 0.92 or less, was observed in 32.5% or 33.5%, respectively. Mismatch between iFR and FFR was observed in 18.1% of the lesions. Clinical factors did not predict FFR value; however, gender, diabetes mellitus, aortic stenosis, anemia, high-sensitivity CRP value, and renal function predicted iFR value. In multivariate logistic analysis after adjustment for FFR value, gender (p < 0.001), diabetes mellitus (p = 0.005), aortic stenosis (p = 0.016), high-sensitivity CRP (p < 0.001), and renal function (p = 0.003) were all independent predictors of iFR value. In Kaplan-Meier analysis, the baseline iFR predicted the subsequent major cardiovascular events (MACE) (hazard ratio, 2.40; 95% CI, 1.16-4.93; p = 0.018) and the results of the iFR-guided strategy for predicting rates of MACE and myocardial infarction/revascularization were superior to those of the FFR-guided strategy. In conclusion, significant clinical factors predicted iFR value, which affected the prognostic capacity. The iFR-guided strategy may be superior in patients with mild to intermediate stenosis.

BACKGROUND: Visual-functional mismatch between coronary angiography and fractional flow reserve (FFR) has been reported, and the underlying reason remains poorly understood. Therefore, the relationship between angiographic measurements and FFR was evaluated, and predictors for FFR in intermediate coronary artery stenosis were determined. METHODS: Consecutive 314 patients (405 lesions) with a lesion of 30-80% angiographic diameter stenosis who underwent invasive FFR were recruited. The myocardial area supplied by the coronary artery distal to the stenosis was evaluated using a modified version of the Bypass Angioplasty Revascularization Investigation (BARI) score. Participants underwent follow-up, and major cardiovascular events (MACE), including all-cause death, myocardial infarction (MI), and unplanned revascularization were recorded. RESULTS: Although % diameter stenosis was correlated with FFR (R = 0.279, P < 0.001), diameter stenosis-FFR mismatch was observed in 37.8% of the lesions. Although FFR values were not associated with clinical factors, such as age, sex, and comorbidities, it was correlated with minimal lumen diameter (MLD), diffuse lesion, presence of proximal lesion, and BARI score. In addition, the lesions in left anterior descending (LAD) coronary artery showed low FFR values compared with those in the left circumflex coronary artery or right coronary artery. In multivariate logistic analysis, MLD (β coefficient = 0.330), diffuse lesion (β coefficient = -0.266), proximal lesion (β coefficient = -0.144), BARI score (β coefficient = -0.219), and LAD lesion (β coefficient = -0.293) were all independent predictors for FFR value. The estimated FFR value based on these factors showed smaller mismatch and higher sensitivity. No difference was observed in the event rates for MACE and MI or revascularization between the FFR-guided and estimated FFR-guided strategies. CONCLUSIONS: MLD, diffuse lesion, proximal lesion, BARI score, and lesion vessel were independent predictors for FFR in intermediate coronary stenosis. Not only the extent of local lesion stenosis but also the amount of myocardial supply and the lesion location may determine the physiological significance and explain the visual-functional mismatch. The estimation of FFR by these factors may be useful in clinical practice.

The relationship between activation of the sympathetic nervous system (SNS) and improvement of left ventricular (LV) function and how this correlates with clinical outcomes are not fully explored in Takotsubo syndrome (TS). The purpose of this study is to evaluate the relationship between activation of the SNS and LV function improvement and how this correlates with clinical outcomes in TS. Patients with TS were retrospectively identified. Patients were divided into two groups according to the timing of LV function improvement: < 1 month (S group) and ≥ 1 month (L group). Activation of the SNS was assessed by plasma catecholamine measurement and Iodine-123 meta-iodobenzylguanidine (I123-MIBG) scintigraphy. In-hospital complications included heart failure, cardiogenic shock, the use of invasive or noninvasive ventilation, life-threatening arrhythmia, cerebrovascular event and all-cause death. A total of 90 patients with TS were enrolled. Of these, 39 patients were in the S group and 51 in the L group. There were no significant differences between the two groups in clinical demographics. The L group was characterized by enhanced SNS activation, including higher levels of catecholamines and lower late heart-mediastinum ratio followed by higher washout rate in I123-MIBG scintigraphy, compared with the S group. In-hospital complications were increased in the L group (56% vs. 33.3%, p = 0.03), including higher rates of heart failure (45% vs. 23%, p = 0.03) and in-hospital death (8.0% vs. 0%, p = 0.03). In patients with TS, high activity of the SNS was observed in patients with delayed LV function recovery, which was associated with in-hospital adverse outcomes.

Catheter ablation (CA) targeting premature ventricular contraction (PVC) from Purkinje fibers can be an effective therapy for refractory ventricular fibrillation (VF) after myocardial infarction (MI). We experienced two cases in which catheter ablation targeting PVC initiating VF after percutaneous coronary intervention (PCI) in post-MI patients was effective despite transient early recurrences of VF. The first patient (a 68-year-old woman with MI) developed drug-refractory VF 3 days after PCI to the left anterior descending artery (LAD) and left circumflex artery. CA targeting Purkinje potential preceding PVC at the infarcted area eliminated both the PVCs and VF. Three days after the procedure, the VF attacks relapsed by a different type of PVC. However, the VF responded to conventional treatments and disappeared thereafter. In the second patient (an 83-year-old woman with old MI), refractory VF attacks occurred after PCI to the LAD. CA targeting Purkinje potential preceding two distinct types of PVC successfully suppressed the VF. Although the VF relapsed 2 days after CA, it was suppressed by conventional treatment and disappeared the next day. .

Statin-related myopathy (SRM) is a clinically important adverse reaction. Recent pharmacogenetic research, mainly in non-Asian populations, have indicated clinical relevance of some of genetic biomarkers to SRM, but predictive markers for SRM in Asian populations including Japanese has not yet been established. This study was aimed to identify clinically important genetic markers associated with SRM in Japanese patients. Allele frequencies of the three reported candidate markers - SLCO1B1 rs4149056, RYR2 rs2819742, and GATM rs9806699 - and carrier frequencies of HLA types were compared between patients with SRM patients (n = 52) and healthy Japanese subjects (n = 2878 or 86 (for rs9806699) as controls). No significant association of RYR2, SLCO1B1, and GATM variants with SRM were observed in our Japanese patients, but a significant association was detected for HLA-DRB1*04:06 with SRM (odds ratio: 3.19; 95% confidence interval: 1.53-6.66). This study suggested that HLA-DRB1*04:06 might be associated with SRM onset in a Japanese population. Further studies are required to validate these results.

Although patients with impaired glucose tolerance (IGT) are at increased atherothrombotic risk, it is unclear how antiplatelet drugs act in patients with IGT. The aim of this study was to investigate the pharmacodynamic response to clopidogrel in patients with IGT and insulin resistance (IR). A 75 g oral glucose tolerance test was performed in 65 coronary artery disease (CAD) patients on aspirin and clopidogrel therapy. Platelet function tests were assessed at 3 time-points by light transmittance aggregometry using ADP (5 and 20 μmol/L) stimuli. 30 patients had IGT and 35 normal glucose tolerance (NGT). Among them, 13 patients showed IR. Following ADP stimuli, patients with IGT showed significantly higher maximal platelet aggregation at each time point than those with NGT patients. This resulted in greater high on-treatment platelet reactivity (HPR) rates at each time point in IGT patients (53.3-36.7 vs. 14.3-11.4 %, p < 0.05). A multivariable logistic regression analysis showed that IGT status was the strongest predictor of HPR (odds ratio 7.54, 95 % CI 1.95-29.1, p = 0.003). Following a glucose load, profiles of platelet reactivity varied according to IR status, with minimal changes over time in patients with IR, while there was a significant reduction in the non-IR patients. In aspirin and clopidogrel-treated patients with CAD, IGT is associated with enhanced platelet reactivity and increased rates of HPR compared with NGT patients. These findings suggest the presence of platelet dysfunction in patients with IGT, which may be attributed to the presence of IR.

BACKGROUND: Several studies have shown that patients with diabetes mellitus (DM) exhibit an impaired response to clopidogrel. This may contribute to their increased risk of recurrent atherothrombotic events, despite the use of dual-antiplatelet therapy. The mechanisms for impaired clopidogrel response in DM patients have not been fully elucidated. OBJECTIVES: The aim of this study was to explore the mechanisms for impaired clopidogrel-mediated platelet inhibition in patients with DM using a comprehensive methodological approach embracing both pharmacokinetic (PK) and pharmacodynamic (PD) assessments as well as ex vivo and in vitro investigations. METHODS: Patients (DM, n = 30; non-DM, n = 30) with stable coronary artery disease taking aspirin 81 mg/day and P2Y12 antagonist naive were enrolled. Blood was collected before and at various times (0.5, 1, 2, 4, 6, and 24 h) after a 600-mg loading dose of clopidogrel. PD assessments included vasodilator-stimulated phosphoprotein, light transmission aggregometry, and VerifyNow P2Y12 ex vivo, before and after dosing and following in vitro incubation with escalating concentrations (1, 3, and 10 μM) of clopidogrel's active metabolite (Clop-AM). Exposure to Clop-AM was also determined. RESULTS: PD assessments consistently showed that during the overall 24-h study time course, residual platelet reactivity was higher in DM patients compared with non-DM patients. In vitro incubation with Clop-AM revealed altered functional status of the P2Y12 signaling pathway in DM platelets as measured by vasodilator-stimulated phosphoprotein, but not with other PD assays. Clop-AM exposure was ∼40% lower in DM patients than in non-DM patients. CONCLUSIONS: The present study suggests that among DM patients, impaired P2Y12 inhibition mediated by clopidogrel is largely attributable to attenuation of clopidogrel's PK profile. This is characterized by lower plasma levels of Clop-AM over the sampling time course in DM patients compared with non-DM patients and only modestly attributed to altered functional status of the P2Y12 signaling pathway.

OBJECTIVE: This study was carried out to examine the difference in effects between rosuvastatin and pravastatin on neointimal formation after the placement of a drug-eluting stent (DES). MATERIALS AND METHODS: Forty patients who underwent placement of a DES in our hospital were prospectively randomized to receive rosuvastatin (n=20) or pravastatin (n=20), and analyzed by optical coherence tomography at the chronic stage. The main outcome measure was comparison of neointimal coverage analyzed at a strut level. RESULTS: A significant reduction in total cholesterol, low-density lipoprotein, and white blood cell count was observed during the study in the rosuvastatin group (total cholesterol, from 4.82±0.90 to 4.43±0.77 mmol/l, P=0.038; low-density lipoprotein, from 2.85±0.76 to 2.34±0.57 mmol/l, P=0.006; white blood cell count, from 5810±1399 to 5355±1257/µl, P=0.048), but not in the pravastatin group. Although not statistically significant, C-reactive protein was lower in the rosuvastatin than in the pravastatin group at the chronic stage (1.14±1.21 vs. 7.67±13.67 mg/l, P=0.051). Malapposed and uncovered struts were significantly less frequent in the rosuvastatin group than in the pravastatin group (malapposed, 0.06 vs. 0.60%, P<0.001; uncovered, 6.49 vs. 11.29%, P<0.001). The difference in uncovered struts was maintained even when stent types were analyzed separately (everolimus-eluting stent, 4.81 vs. 6.21%, P=0.007; sirolimus-eluting stent, 14.40 vs. 20.86%, P<0.001). Comparison of neointimal thickness between the rosuvastatin and the pravastatin groups showed inconsistent results depending on the stent types analyzed. CONCLUSION: Compared with pravastatin, the use of rosuvastatin resulted in lower frequency of uncovered and malapposed struts after the placement of a DES, which might be mediated through improved inflammatory and lipid profiles.

OBJECTIVES: The goal of this study was to investigate the differential efficacy of clopidogrel or aspirin monotherapy according to smoking status in patients with atherosclerotic vascular disease. BACKGROUND: Smoking enhances clopidogrel-induced platelet inhibition, which may explain the higher relative benefit among smokers observed in trials evaluating dual antiplatelet therapy. Whether smoking has an impact on clinical outcomes in patients requiring a single antiplatelet agent remains unknown. METHODS: This was a post-hoc analysis of the CAPRIE (Clopidogrel Versus Aspirin in Patients at Risk of Ischemic Events) trial that compared clopidogrel and aspirin monotherapy in patients (N = 19,184) with atherosclerotic vascular disease. RESULTS: Current smokers (n = 5,688) had an increased risk of ischemic events compared with never smokers (n = 4,135; hazard ratio [HR]: 1.24 [95% confidence interval (CI): 1.08 to 1.42]) and ex-smokers (n = 9,381; HR: 1.32 [95% CI: 1.18 to 1.47]) (p < 0.001). Clopidogrel was associated with a reduction in ischemic events among current smokers (8.3% vs. 10.8%; HR: 0.76 [95% CI: 0.64 to 0.90]), whereas no benefit over aspirin was seen in the combined group of ex-smokers/never-smoked patients (10.4% vs. 10.6%; HR: 0.99 [95% CI: 0.89 to 1.10]; p = 0.01 for interaction). Among current smokers, clopidogrel also reduced myocardial infarction, vascular death, and death from any cause compared with aspirin. No interaction between smoking status and study treatment was observed for bleeding events. CONCLUSIONS: In a post-hoc analysis of the CAPRIE population, current smokers appeared to have enhanced benefit with clopidogrel therapy for secondary prevention compared with aspirin. These results should be considered hypothesis generating for future prospective studies assessing the impact of specific platelet-inhibiting strategies according to smoking status.

BACKGROUND: Although drug-eluting stents (DES) reduce restenosis, the best strategy for DES implantation in small vessels has not been established. PURPOSE: We investigated the clinical usefulness of low-pressure implantation of a 2.5-mm DES for small vessels less than 2.5mm in diameter. METHODS: In 118 patients, a 2.5-mm DES was implanted for small vessels less than 2.5mm in diameter between 2007 and 2009 in our hospital. The patients were divided into two groups by initial deployment pressure: low-pressure (LP; n=46) and nominal-pressure (NP; n=72). RESULTS: Patients with impaired glucose tolerance were more frequent (p=0.02) and the target vessel diameter was significantly smaller (p=0.01) in the LP group than in the NP group. A smaller minimum lumen diameter (MLD) was obtained (LP: 2.22±0.27mm vs. NP: 2.34±0.26mm, p=0.02) after DES implantation with a smaller balloon-to-artery ratio (p=0.03) in the LP group. However, at mid-term follow-up (7.7±3.9 months), MLD (p=0.55) and the binary restenosis rate (LP: 2.6% vs. NP: 11.1%, p=0.12) were not significantly different between the LP and NP groups. Furthermore, by Kaplan-Meier analysis, the incidence of major adverse cardiac events was not different between the groups during the long-term follow-up (32.4±8.6 months). CONCLUSION: The present study indicates that low-pressure implantation of 2.5-mm DES for very small vessels may be feasible with regard to short- and long-term clinical outcomes.

Increased body weight is independently associated with impaired clopidogrel pharmacodynamic (PD) response. Prasugrel has more potent PD effects compared with clopidogrel, although its PD effects in obese patients are unknown. The aim of this prospective, randomised, study was to compare the PD effects of standard-dose prasugrel [60 mg loading dose (LD)/10 mg daily maintenance dose (MD)] with high-dose clopidogrel (900 mg LD/150 mg daily MD) in non-diabetic obese [body mass index (BMI) ≥30 kg/m²] patients, with coronary artery disease (CAD) on aspirin therapy. PD assessments (baseline, 2 hours post-LD and 6 ± 2 days after MD) were conducted using four platelet function assays, and the platelet reactivity index (PRI) assessed by VASP was used for sample size estimation. A total of 42 patients with a BMI of 36.42 ± 5.6 kg/m² completed the study. There were no differences in baseline PD measures between groups. At 2 hours post-LD, prasugrel was associated with lower PRI compared with clopidogrel (24.3 ± 5.5 vs 58.7 ± 5.7, p≤0.001), with consistent findings for all assays. At one-week, PRI values on prasugrel MD were lower than clopidogrel MD without reaching statistical significance (34.7 ± 5.8 vs 42.9 ± 5.8, p=0.32), with consistent findings for all assays. Accordingly, rates of high on-treatment platelet reactivity were markedly reduced after prasugrel LD, but not after MD. In conclusion, in non-diabetic obese patients with CAD, standard prasugrel dosing achieved more potent PD effects than high-dose clopidogrel in the acute phase of treatment, but this was not sustained during maintenance phase treatment. Whether an intensified prasugrel regimen is required in obese patients warrants investigation.

Diabetes mellitus (DM) is the most important predictor of chronic kidney disease (CKD), and pharmacodynamic (PD) studies have shown that DM patients with impaired renal function are characterized by reduced clopidogrel response. However, post-hoc PD studies conducted in unselected cohorts, composed of both DM and non-DM patients, have reached controversial findings on the effects of CKD on clopidogrel response, likely attributed to patient heterogeneity. The impact of renal function on clopidogrel response in non-DM patients remains unexplored and represented the aim of this prospective investigation. We conducted a prospective PD investigation in non-DM patients with and without CKD defined as an estimated glomerular filtration rate (eGFR) below or above 60 mL/min, respectively. All patients had known coronary artery disease and were on maintenance aspirin therapy. PD assessments were assessed at baseline and 2 and 24 h after a 600 mg loading dose of clopidogrel. PD assays included light transmission aggregometry (LTA) using 5 and 20 μmol ADP with and without PGE1 and flow cytometric assessment of the phosphorylation status of the vasodilator-stimulated phosphoprotein (VASP) to determine the platelet reactivity index. A total of 60 patients were studied (n = 30 eGFR ≥60 mL/min; n = 30 eGFR <60 mL/min). At baseline there were no differences between groups. Following clopidogrel loading dose administration, levels of on-treatment platelet reactivity were similar between groups at 2 and 24 h as measured with LTA and VASP. Accordingly, there were no differences in rates of high on-treatment platelet reactivity between groups. In non-DM patients with CAD, the presence of impaired renal function is not associated with differences in clopidogrel-induced antiplatelet effects compared with patients with preserved renal function.

Platelets from patients with diabetes mellitus (DM) are hyper-reactive and whether cangrelor, a potent intravenous P2Y(12) receptor blocker, has differential pharmacodynamic (PD) effects according DM status is unknown. The aim of this investigation was to evaluate the in vitro PD effects of cangrelor in coronary artery disease (CAD) patients with and without DM. This prospective study enrolled 120 clopidogrel-naïve patients with CAD on aspirin therapy. PD assessments using cangrelor (500 nmol/l) in vitro included vasodilator-stimulated phosphoprotein assay to obtain the P2Y(12) reactivity index (PRI), and multiple electrode aggregometry (MEA). In a 20 patients subgroup, dose-dependent response was assessed following exposure to escalating concentrations (baseline, 5, 50, 500 and 5,000 nmol/l); thrombin generation processes were evaluated by thromboelastography (TEG). PD data were evaluable in 103 patients. No differences in baseline PD parameters were observed in DM (n = 48) and non-DM (n = 45) subjects. Cangrelor reduced PRI values irrespective of DM status (p < 0.0001), yielding no difference in patients with and without DM (16.1 ± 12.3 vs. 16.8 ± 11.3; p = 0.346). All MEA values were significantly reduced, although this was of greater magnitude with purinergic compared to non-purinergic agonists. A trend analysis showed a dose-dependent effect on platelet inhibition, with no interaction due to DM status, whereas no significant dose-dependent effect was observed for TEG-derived parameters. Therefore, in vitro cangrelor provides potent and dose-dependent blockade of the platelet P2Y(12) receptor, with no differential effect in DM and non-DM patients. In addition, in vitro cangrelor exerts moderate inhibitory effects on non-purinergic platelet signaling pathways, without modulating platelet-derived thrombin generation processes.

BACKGROUND: In patients on dual antiplatelet therapy with aspirin and clopidogrel, the adjunctive use of cilostazol is associated with enhanced platelet inhibition. However, if cilostazol exerts different pharmacodynamic (PD) effects according to levels of on-treatment platelet reactivity remains unknown. This study aimed to determine the PD effects of cilostazol in patients with and without high on-clopidogrel platelet reactivity (HPR) according to diabetes mellitus (DM) status. METHODS: This is a post-hoc analysis derived from patients (n = 79) enrolled in a prospective, randomized, double-blind, double-dummy, crossover study comparing cilostazol with placebo in stable coronary artery disease patients on aspirin and clopidogrel therapy. In the present analysis, patients were divided according to the presence or absence of HPR (HPR and non-HPR). HPR was defined as a P2Y12 units (PRU) > 240 as assessed by the VerifyNow P2Y12 assay. The PD effects of cilostazol were evaluated in patients with and without HPR according to DM status. RESULTS: Significant absolute changes in PRU values were observed after adjunctive cilostazol in both HPR [53.4 (95% CI 24.7-82.1), P = 0.001] and non-HPR [40.8 (95% CI 28.7-52.8), P < 0.0001] patients. This difference was statistically significant in HPR patients with DM (P = 0.001), but not without DM (P = 0.24), and in non-HPR patients with and without DM (P = 0.0001 for both). The greatest mean reduction in PRU was observed in HPR patients with DM (72.9; 95% CI 33.7-112.0). Thrombin generation was not affected by cilostazol, irrespective of HPR status. CONCLUSION: Cilostazol reduces platelet reactivity both in HPR and non-HPR patients, although these PD effects are enhanced in HPR patients with DM. Nevertheless, larger studies are needed to better evaluate possible differential effects of cilostazol on platelet reactivity by diabetes status.

Patients with type 2 diabetes mellitus (T2DM) have impaired clopidogrel-induced antiplatelet effects, which may be in part attributed to their reduced sensitivity to insulin and consequently, results in upregulation of the P2Y12 signalling pathway. It has been hypothesised that insulin sensitising strategies may enhance clopidogrel-mediated P2Y12 inhibitory effects. The aim of this pilot pharmacodynamics (PD) study was to assess the impact of pioglitazone on clopidogrel-mediated P2Y12 inhibitory effects in patients with T2DM. This was a prospective, randomised, double-blind, placebo-controlled, cross-over PD study. Patients with T2DM and stable coronary artery disease on maintenance aspirin and clopidogrel were randomised to receive either pioglitazone 30 mg or matching placebo daily for 14 days. PD assessments were measured at baseline, 14 days after randomisation, at the end of the wash-out period, and 14 days after cross-over. The primary endpoint measure was maximal platelet aggregation (MPA) to 20 μM adenosine diphosphate (ADP) as assessed by light transmittance aggregometry (LTA). Flow cytometric analysis of vasodilator-stimulated phosphoprotein phosphorylation (VASP-PRI), and VerifyNow P2Y12 testing were also performed. A total of 15 randomised patients completed the study. MPA to 20 μM ADP (primary endpoint) was not significantly different with pioglitazone compared with placebo (49.53 ± 4.76 vs. 52.52 ± 3.89%; p = 0.594). Similarly, other PD measures did not differ significantly between the groups. In conclusion, in patients with T2DM on maintenance aspirin and clopidogrel therapy, the adjunctive use of pioglitazone does not result in enhanced inhibition of platelet P2Y12 mediated signalling.

OBJECTIVES: The purpose of this study is to assess the pharmacodynamic effects of different prasugrel dosing regimens in patients on maintenance prasugrel therapy. BACKGROUND: There are a growing number of patients on chronic prasugrel therapy regimens, leading to questions about the dosing regimen of prasugrel to administer if percutaneous coronary intervention is required. METHODS: This is a prospective pharmacodynamic study in patients (n = 64) receiving maintenance prasugrel therapy who were randomly allocated to a 10 mg, 30 mg, or 60 mg dose of prasugrel. Pharmacodynamic assessments using multiple assays were conducted at 3 timepoints (baseline and 1 h and 4 h after dosing). RESULTS: Intragroup comparisons showed that a 60 mg dose reduced the platelet reactivity index (PRI) after 1 h (p = 0.004) and 4 h (p < 0.001, primary endpoint; p = 0.002 between 1 h and 4 h). A 30 mg dose also reduced PRI levels at 1 h (p = 0.006) and 4 h (p < 0.001; p = 0.044 between 1 h and 4 h). A 10 mg dose was associated with modest pharmacodynamic effects. Intragroup comparisons showed similar findings with VerifyNow-P2Y12 and light transmission aggregometry. Intergroup comparisons showed that a 60 mg dose achieved lower PRI levels than 30 mg at 4 h (p = 0.05), and a numerical trend toward better pharmacodynamic effects at 1 h (p = 0.171). Intergroup comparisons were similar with VerifyNow-P2Y12, but not light transmission aggregometry. CONCLUSIONS: For patients on maintenance prasugrel therapy, a 60 mg dosing strategy is associated with faster and higher platelet inhibition compared with lower doses, as assessed by P2Y(12) specific assays. (Impact of Prasugrel Re-load on Platelet Aggregation in Patients on Chronic Prasugrel Therapy; NCT01201772).

OBJECTIVES: This study sought to assess the presence of a dose-response effect of cigarette smoking and its impact on high on-treatment platelet reactivity (HPR) in patients with diabetes mellitus treated with clopidogrel. BACKGROUND: Cigarette smoking is an inducer of cytochrome P450 1A2, a hepatic enzyme involved in clopidogrel metabolism. If cigarette smoking is associated with a dose-response effect on pharmacodynamic measures in clopidogrel-treated patients is unknown. METHODS: A total of 134 type 2 diabetes mellitus patients on maintenance aspirin and clopidogrel therapy were studied. Patients were divided into 3 groups according to cotinine levels: <3 ng/ml (nonsmokers), 3 to 199 ng/ml (light smokers), and ≥ 200 ng/ml (heavy smokers). Platelet function was assessed by light transmittance aggregometry, VerifyNow P2Y12 assay (Accumetrics, San Diego, California), and vasodilator-stimulated phosphoprotein. Rates of HPR were defined using established cutoff values. RESULTS: A dose-response effect was observed for all pharmacodynamic parameters tested. Serum cotinine levels were inversely associated with platelet reactivity as assessed by light transmittance aggregometry using 5 and 20 μmol/l adenosine diphosphate (p < 0.0001 for all). Accordingly, platelet disaggregation increased with levels of serum cotinine (p < 0.0001). Similar results were found with P2Y(12) reaction units (p < 0.0001) and inhibition of platelet aggregation (p = 0.005) as defined by VerifyNow P2Y12 testing, and platelet reactivity index (p = 0.002) as assessed by vasodilator-stimulated phosphoprotein. Higher serum cotinine levels were significantly associated with lower rates of HPR, as defined according to various pharmacodynamic cutoff measures. CONCLUSIONS: Cigarette smoking is associated with a dose-response effect on clopidogrel-induced antiplatelet effects and lower rates of HPR in diabetes mellitus patients.

BACKGROUND: Although the advancement of the equipment and the presence of innovative techniques, percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) continues to be affected by lower procedural success in comparison with non occluded vessel PCI. OBJECTIVE: We describe a new technique for the treatment of coronary CTO which utilizes a new generation of polymeric wires. METHODS AND RESULT: From March 2009 to June 2010 different strategies were adopted as "bail out" after an initial attempt failed in 117 consecutive CTO lesions. Among these, conventional strategies (CS) such as parallel wire, sub-intimal tracking and re-entry (STAR), microchannel technique, intracoronary ultrasound guided revascularization and anchor balloon, were used in 75 cases (64.1%), while in the remaining a new technique, the "mini-STAR," was used (39.9%). Although no substantial differences were observed regarding the distribution of clinical features and angiographic lesions characteristics between the populations, mini-STAR was able to achieve a higher rate of procedural success in comparison with other CS (97.6% vs. 52%, P < 0.001) with lower contrast agent use (442 ± 259 cm(3) vs. 561 ± 243 cm(3), P = 0.01) and shorter procedural and fluoroscopy times (122 ± 61 vs. 157 ± 74 min, P = 0.009 and 60 ± 31 min vs. 75 ± 38 min, P = 0.03, respectively). No differences were observed in term of peri-procedural complications such as procedural myocardial infarction, coronary perforations, and contrast-induced nephropathy between mini-STAR and CS. CONCLUSION: The mini-STAR technique is a promising strategy for the treatment of CTO lesions, achieving a high procedural success rate and low occurrence of procedural adverse events.

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Activated platelets stimulate thrombus formation in response to rupture of an atherosclerotic plaque or endothelial cell erosion, promoting atherothrombotic disease. Multiple pathways contribute to platelet activation. Aspirin, an irreversible inhibitor of thromboxane A2 synthesis, in combination with clopidogrel, an inhibitor of P2Y(12) adenosine diphosphate platelet receptors, represent the current standard-of-care of antiplatelet therapy for patients with acute coronary syndrome and for those undergoing percutaneous coronary intervention. Although these agents have demonstrated significant clinical benefit, the increased risk of bleeding and the recurrence of thrombotic events represent substantial limitations. Thrombin is one of the most important platelet activators. The inhibition of protease-activated receptor 1 showed a good safety profile in preclinical studies. In fact, phase II studies with vorapaxar (SCH530348) and atopaxar (E5555) showed no increase of bleeding events in addition to the current standard-of-care of antiplatelet therapy. Although the results of phase III trials for both drugs are awaited, this family is a promising new addition to the current clinical practice for patients with atherothrombotic disease, not only as an alternative, but also as additional therapy.

Cilostazol is a platelet inhibitor which when added to aspirin and clopidogrel has shown to reduce the risk of recurrent ischaemic events without an increase in bleeding. These clinical benefits have shown to be more pronounced in patients with diabetes mellitus (DM). However, it remains unknown whether cilostazol exerts different pharmacodynamic effects in patients with and without DM. This was a randomised, double-blind, placebo-controlled, cross-over pharmacodynamic study comparing platelet function in patients with and without DM on aspirin and clopidogrel therapy. Patients (n=111) were randomly assigned to either cilostazol 100 mg or placebo twice daily for 14 days and afterwards crossed-over treatment for another 14 days. Platelet function was performed at baseline, 14 days post-randomisation, and 14 days post-cross-over. Functional testing to assess P2Y12 signalling included flow cytometric analysis of phosphorylation status of vasodilator-stimulated phosphoprotein measured by P2Y12 reactivity index (PRI), light transmittance aggregometry and VerifyNow. Thrombin generation processes were also studied using thrombelastography. Significantly lower PRI values were observed following treatment with cilostazol compared with placebo both in DM and non-DM groups (p < 0.0001). The absolute between-treatment differences of PRI between groups was a 35.1% lower in patients with DM (p=0.039). Similar results were obtained using all other functional measures assessing P2Y12 signalling. Thrombin generation was not affected by cilostazol. Cilostazol reduces platelet reactivity both in patients with and without DM, although these pharmacodynamic effects are enhanced in patients with DM. Despite the marked platelet inhibition, cilostazol does not alter thrombin-mediated haemostatic processes, which may explain its ischaemic benefit without the increased risk of bleeding.

OBJECTIVES: The aim of this study was to evaluate the impact of the phosphodiesterase (PDE) inhibitor pentoxifylline on platelet function profiles in patients receiving dual antiplatelet therapy (DAPT). BACKGROUND: Previous studies have shown that, in patients receiving DAPT, the adjunctive use of a PDE inhibitor enhances platelet inhibition, particularly in those presenting with diabetes mellitus (DM). However, the pharmacodynamic (PD) effects of the PDE inhibitor pentoxifylline on platelet function profiles in DM patients receiving DAPT are unknown. METHODS: This was a prospective, randomized, double-blind, parallel design study conducted in DM patients with stable coronary artery disease receiving DAPT. Patients were randomly assigned to either pentoxifylline 400 mg or placebo 3 times daily for 14 days. The PD effects were assessed by vasodilator-stimulated phosphoprotein phosphorylation assay, light transmittance aggregometry, VerifyNow P2Y12 assay (Accumetric, Inc., San Diego, California), and multiple electrode aggregometry at baseline and 14 days. The PD effects were also assessed according the presence or absence of high on-treatment platelet reactivity status. RESULTS: A total of 40 patients were available for analysis. At 14 days, there were no differences in the P2Y(12) reactivity index as assessed by vasodilator-stimulated phosphoprotein phosphorylation between treatment groups (primary endpoint; p = 0.93). Intra-group comparisons also failed to show any differences between baseline and 14-day P2Y(12) reactivity index assessment in the placebo and pentoxifylline arms (p = 0.61). There were no significant inter- and intra-group differences in all other PD measures. The PD effects did not vary according the presence or absence of high on-treatment platelet reactivity. CONCLUSIONS: Adjunctive treatment with pentoxifylline is not associated with increased platelet inhibitory effects in DM patients with coronary artery disease receiving DAPT.

Patients with end-stage renal disease (ESRD) have abnormalities in the cellular and plasmatic systems regulating blood homeostasis, which may contribute to their risk for thrombotic and bleeding complications. However, their relative contributions in this population are poorly understood. The aim of this study was to evaluate the distribution of enzymatic and cellular abnormalities in ESRD patients on haemodialysis as assessed by thromboelastography (TEG®). Whole blood samples were analysed by TEG in ESRD patients (n=70) and in a control group (n=70) of subjects with coronary artery disease. Profiles were constructed considering the maximum amplitude (MA), a marker of platelet function, and reaction time (R), a marker of thrombin generation, values. R values were higher in ESRD patients compared with the control group (8.2 ± 2.8 vs. 5.7 ± 1.9 minutes [min], p <0.0001), while there were no differences in MA (66.7 ± 8.1 vs. 66.2 ± 6.6 mm, p=0.562). Normal manufacturer defined coagulation (2-8 min) and aggregation (51-69 mm) parameters were present in 31% of ESRD patients compared with 56% of controls (p=0.006). A hypocoagulable status was observed in 42.9% of ESRD patients compared with 8.9% in the control group (p<0.0001). There were no differences in platelet function, which showed a hyperaggregable status in 41.4% versus 35.7% of cases (p=0.603). Abnormalities in both parameters were observed in 15.7% of ESRD patients versus 1.4% in the control group (p= 0.004), which were more common among older patients (p= 0.005). In conclusion, patients with ESRD have an elevated prevalence of abnormal haemostatic profiles, which may contribute to their elevated risk of bleeding and thrombotic complications.

OBJECTIVES: The aim of this study was to assess the association between genetic variants of the insulin receptor substrate (IRS)-1 gene, platelet function, and long-term outcomes in patients with type 2 diabetes mellitus (DM) and stable coronary artery disease while on aspirin and clopidogrel therapy. BACKGROUND: The effects of pharmacogenetic determinants on platelet function and cardiovascular outcomes in type DM patients are unknown. METHODS: The association between IRS-1 genetic variants, platelet function, and the risk of major adverse cardiac events (MACE) at 2 years was assessed in 187 patients with type 2 DM and stable coronary artery disease on maintenance aspirin and clopidogrel therapy. RESULTS: Seven tag single nucleotide polymorphisms were selected. Individuals with high platelet reactivity were more frequent among carriers of the C allele (GC and CC genotypes; approximately 20% of population) of the rs956115 marker (44.4% vs. 20.5%; odds ratio: 3.1, 95% confidence interval [CI]: 1.44 to 6.67; p = 0.006). These patients were at higher risk of MACE (28.0% vs. 10.9%; hazard ratio: 2.90, 95% CI: 1.38 to 6.11; p = 0.005). The C allele carriers of the rs956115 marker were more commonly associated with a hyperreactive platelet phenotype. This was confirmed in an external validation cohort of patients with type 2 DM but not in an external validation cohort of patients without DM. Carriers of the C allele of the rs956115 marker also had a significantly higher risk of MACE compared with noncarriers (30.6% vs. 11.4%; hazard ratio: 2.88, 95% CI: 1.35 to 6.14; p = 0.006). CONCLUSIONS: Type 2 DM patients who are carriers of the C allele of the rs956115 marker of the IRS-1 gene have a hyperreactive platelet phenotype and increased risk of MACE.

BACKGROUND: Safety concerns have recently emerged based on a drug interaction between clopidogrel and proton pump inhibitors leading to reduced pharmacodynamic effects. However, whether such drug interaction is a class effect or a drug effect and if this can be modulated by timing of drug administration remains a matter of debate. The aim of this study was to assess the impact of high-dose pantoprazole therapy, a proton pump inhibitor with low potential to interfere with clopidogrel metabolism, administered concomitantly or staggered, on clopidogrel-mediated pharmacodynamic effects. METHODS AND RESULTS: This was a prospective, randomized, crossover study conducted in 20 healthy volunteers. Subjects were randomly assigned to receive pantoprazole (80 mg daily) administered concomitantly (CONC) or staggered by 8 to 12 hours (STAG) for 1 week on a background of clopidogrel therapy (600-mg loading dose followed by a 75-mg maintenance dose during all phases) in a crossover fashion with a 2- to 4-week washout period between treatments. All subjects had a 1-week treatment phase with a clopidogrel-only regimen with a 2- to 4-week washout period from randomization sequence. Platelet function was assessed by flow cytometric analysis of the status of phosphorylation of the vasodilator-stimulated phosphoprotein, light transmittance aggregometry after adenosine diphosphate stimuli, and VerifyNow P2Y(12) system at 3 time points: baseline, 24 hours after loading dose, and 1 week after maintenance dose. The primary end point was the comparison of P2Y(12) reactivity index assessed by vasodilator-stimulated phosphoprotein at 1 week. After 1 week, there were no significant difference in P2Y(12) reactivity index between the CONC and STAG regimens (least-squares mean±SEM, 56.0±3.9% versus 56.1±3.9%; P=0.974), as well as when compared with the clopidogrel-only regimen (61.0±3.9%; P=0.100 versus CONC and P=0.107 versus STAG). Further, no differences were observed at baseline and 24 hours between regimens. Concordant results were obtained by light transmittance aggregometry and VerifyNow P2Y(12) assays. CONCLUSIONS: Pantoprazole therapy used at high doses is not associated with modulation of the pharmacodynamic effects of clopidogrel, irrespective of timing of drug administration. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01170533.

Antiplatelet therapy represents the cornerstone of treatment for the short- and long-term prevention of atherothrombotic disease processes, in particular in high-risk settings such as in patients with acute coronary syndrome and those undergoing percutaneous coronary intervention. Currently, dual antiplatelet therapy with aspirin and clopidogrel represents the most commonly used treatment regimen in these settings. However, a considerable number of patients continue to experience adverse outcomes, including both bleeding and recurrent ischemic events. Numerous investigations have demonstrated that this phenomenon may be, in part, attributed to the broad variability in individual response profiles to this standard antiplatelet treatment regimen, as identified by various assays of platelet function testing. In addition, recent studies have demonstrated that genetic polymorphisms may also have an important role in determining levels of platelet inhibition and may be considered as a tool to identify patients at risk of adverse events. This article provides an overview on antiplatelet drug response variability, an update on definitions, including the role of pharmacodynamic testing, underlying mechanisms - with emphasis on recent understandings on pharmacogenetics and drug-drug interactions - and current and future perspectives on individualized antiplatelet therapy.

BACKGROUND: Patients with type 2 diabetes mellitus (T2DM) have reduced aspirin-induced pharmacodynamic effects. This may be attributed to increased platelet turnover rates resulting in an increased proportion of non-aspirin-inhibited platelets during the daily dosing interval. The hypothesis of this study was that an increase in the frequency of drug administration [twice daily (bid) versus once daily (od)] may provide more effective platelet inhibition in T2DM patients. METHODS AND RESULTS: T2DM patients with stable coronary artery disease were prospectively recruited. Patients modified their aspirin regimen on a weekly basis according to the following scheme: 81 mg/od, 81 mg/bid, 162 mg/od, 162 mg/bid, and 325 mg/od. Pharmacodynamic assessments included light-transmittance aggregometry after arachidonic acid, collagen and adenosine diphosphate stimuli; VerifyNow-Aspirin assay; and serum thromboxane B(2) (TXB(2)) levels. Twenty patients were analyzed. All patients were sensitive and compliant to aspirin irrespective of dose, as assessed by arachidonic acid-induced aggregation. When aspirin was administered once daily, there was no significant effect on platelet reactivity by increasing the once-daily dosing using aspirin-sensitive assays (collagen-induced aggregation and VerifyNow-Aspirin). An increase in aspirin dose by means of a second daily administration was associated with a significant reduction in platelet reactivity assessed by collagen-induced aggregation and VerifyNow-Aspirin between 81 mg/od and 81 mg/bid (P<0.05 for both assays) and between 81 mg/od and 162 mg/bid (P<0.05 for both assays). There was no impact of aspirin dosing regimens on adenosine diphosphate-induced aggregation. A dose-dependent effect of aspirin was observed on serum TXB(2) levels (P=0.003). CONCLUSIONS: Aspirin dosing regimens are associated with different pharmacodynamic effects in platelets from T2DM patients and stable coronary artery disease, with a twice-daily, low-dose aspirin administration resulting in greater platelet inhibition than once-daily administration as assessed by aspirin-sensitive assays and a dose-dependent effect on serum TXB(2) levels. The clinical implications of a modified aspirin regimen tailored to T2DM patients warrant further investigation. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01201785.

Platelets have a key role in normal hemostasis and in the pathogenesis of atherothrombotic events, such as acute coronary syndrome. Following plaque rupture, platelets adhere to the subendothelial matrix, become activated and then aggregate to form a prothrombotic surface that promotes clot formation and subsequently vascular occlusion. Multiple pathways are involved in platelet activation, including those activated by adenosine diphosphate (ADP), thromboxane A2, epinephrine, serotonin, collagen, and thrombin. Currently, two groups of inhibitors of platelet activation are approved for clinical use in patients with acute coronary syndromes: cyclooxygenase-1 inhibitors, namely aspirin, and oral ADP receptor antagonists such as clopidogrel. These agents have shown improved short- and long-term clinical outcomes but are associated with increased bleeding risk, and the rates of recurrent ischemic events remain high. These considerations underscore the need for novel antiplatelet agents that can provide greater reduction in recurrent atherothrombotic events without increasing the risk of bleeding. Several novel antiplatelet agents are currently under clinical development, such as more potent ADP receptor antagonists and protease-activated receptor-1 antagonists. This article provides an overview of the basic principles of platelet biology and the current status of knowledge on available oral antiplatelet therapy, as well as those under clinical development.

BACKGROUND: A drug interaction between clopidogrel and omeprazole resulting in impaired platelet inhibition has been reported. It has been suggested that staggering administration of clopidogrel and omeprazole may overcome this pharmacodynamic (PD) interaction. METHODS AND RESULTS: This prospective, open-label, 3-period, randomized crossover study was performed in 20 healthy volunteers. Subjects were randomly selected to receive omeprazole (40 mg daily) concomitantly (CONC) or staggered by 8 to 12 hours (STAG) for 1 week on a background of clopidogrel therapy in a crossover fashion, with a 2- to 4-week washout period between treatments. After another 2- to 4-week washout period, all subjects were treated for 1 week with clopidogrel alone. Clopidogrel was administered as a 600-mg loading dose followed by a 75-mg maintenance dose during all phases. PD effects were assessed by vasodilator-stimulated phosphoprotein phosphorylation assay, VerifyNow P2Y(12) system, and light transmittance aggregometry at baseline, 24 hours, and 1 week. The primary end point was the comparison of P2Y(12) reactivity index assessed by vasodilator-stimulated phosphoprotein phosphorylation assay at 1 week between CONC and STAG regimens. No significant difference in the primary end point was observed (least squares mean ± SEM, 56.1 ± 3.5% for CONC versus 61.6 ± 3.4% for STAG; P = 0.08). P2Y(12) reactivity index values were significantly lower in the clopidogrel regimen (48.8 ±3.4%) than in the CONC (P = 0.02) and STAG (P = 0.001) regimens. No PD differences were observed between regimens at baseline and 24 hours. Concordant results were obtained by P2Y(12)-specific assessments using VerifyNow but not with light transmittance aggregometry. CONCLUSIONS: Omeprazole impairs clopidogrel-induced antiplatelet effects in the maintenance phase of treatment irrespective of timing of their administration.

Antiplatelet drugs represent the cornerstone of treatment for cardiovascular atherothrombotic disease. Dual oral antiplatelet therapy with aspirin and oral ADP-receptor antagonists, such as clopidogrel, has been the standard choice for prevention of ischemic events in patients with acute coronary syndrome and in those undergoing percutaneous coronary intervention. However, due to the limitations of clopidogrel, such as interindividual-response variability, drug-drug interactions, slow onset of action and irreversible inhibitory effects, novel antiplatelet agents are under clinical development. Cangrelor is a reversible, potent, competitive inhibitor of the ADP P2Y(12) receptor that is administered intravenously and rapidly achieves near complete inhibition of ADP-induced platelet aggregation. These pharmacological properties make cangrelor a promising drug for clinical use. However, recent large-scale Phase III clinical investigations failed to show significant clinical benefit on the primary end point with cangrelor. This article provides an overview of the current status of knowledge on cangrelor, focusing on its pharmacologic properties and clinical development.

Atherothrombotic disease is the leading cause of death worldwide. Currently, dual antiplatelet therapy with aspirin and ADP receptor antagonists has shown improved short- and long-term clinical outcomes but is associated with increased bleeding risk, and the rates of recurrent ischemic events still remain high. Selective inhibition of the principal protease-activated receptor (PAR)-1 for thrombin, the most potent platelet activator, represents a promising novel strategy to reduce ischemic events without increasing the risk of bleeding. Two PAR-1 antagonists are currently being tested in clinical trials: SCH 530348 and E5555. Both have demonstrated an antiplatelet effect without increasing bleeding time in preclinical trials. Results of Phase II trials showed that SCH 530348, in addition to standard antiplatelet therapy, was well tolerated and not associated with increased bleeding risk. The safety and tolerability of E5555 is being evaluated in patients with coronary artery disease and non-ST-segment elevation acute coronary syndrome in four Phase II clinical trials. Two large-scale Phase III trials assessing the efficacy of SCH 530348 in addition to the standard of care are currently ongoing. This article provides an overview of the current status of knowledge on platelet thrombin receptor antagonists, focusing on pharmacologic properties and clinical development.

Antiplatelet drug therapy represents the cornerstone of treatment for cardiovascular atherothrombotic disease processes. Dual antiplatelet therapy with aspirin and oral ADP-receptor antagonists such as clopidogrel are currently the standard care for prevention of ischemic events in patients with acute coronary syndrome and who are undergoing percutaneous coronary intervention. However, despite the clinical benefit associated with clopidogrel therapy, this drug has several limitations, including a broad interindividual response variability, drug-drug interactions, slow onset of action and irreversible platelet inhibition, emphasizing the need for novel P2Y(12)-receptor antagonists. Elinogrel (PRT060128) is a reversible, potent and competitive inhibitor of the P2Y(12) receptor with a fast onset and offset of action that can be administered by both oral and intravenous routes and rapidly achieves near complete platelet inhibition. Preclinical and early-phase clinical testing have shown promising results with this novel compound, which awaits further testing in outcome-driven clinical trials. This article provides an overview of the current level of knowledge regarding elinogrel, focusing on its pharmacologic properties and preclinical and early-phase clinical development.

Platelet activation and subsequent accumulation at sites of vascular injury are the first steps in hemostasis. Excessive platelet activation after atherosclerotic plaque rupture or endothelial cell erosion may also lead to the formation of occlusive thrombi, which are responsible for acute ischemic events. Multiple pathways are involved in platelet activation, including those activated by adenosine diphosphate (ADP), thromboxane A(2) (TXA(2)), serotonin, collagen, and thrombin. Antiplatelet agents used for prevention of atherothrombosis have focused on blocking the formation of TXA(2) (eg, aspirin) and interfering with ADP stimulation mediated by the P2Y(12) receptor (eg, clopidogrel). These agents, used alone or in combination, significantly decrease the risk for atherothrombotic events, but a significant residual risk for recurrent ischemic events remains. This has been, in part, attributed to persistence of elevated platelet reactivity despite the use of these agents. Several novel antiplatelet agents are currently under clinical development, with the goal of achieving more efficacious platelet inhibition. These include agents that more efficiently block TXA(2)-mediated effects, as well as more potent P2Y(12) receptor antagonists. In addition, inhibition of the protease-activated receptor-1 platelet activation pathway stimulated by thrombin has emerged as a rational target for clinical development. An overview of the basic principles of platelet biology is given and currently available antiplatelet agents, as well as those under clinical development, are reviewed.

OBJECTIVES: We sought to assess the impact of renal function on platelet reactivity in patients with diabetes mellitus (DM) and coronary artery disease on aspirin and clopidogrel therapy. BACKGROUND: Diabetes mellitus is a key risk factor for chronic kidney disease (CKD). In aspirin-treated DM patients the presence of moderate/severe CKD is associated with reduced clinical efficacy of adjunctive clopidogrel therapy. Whether these findings may be attributed to differences in clopidogrel-induced effects is unknown. METHODS: This was a cross-sectional observational study in which DM patients taking maintenance aspirin and clopidogrel therapy were studied. Patients were categorized into 2 groups according to the presence or absence of moderate/severe CKD. Platelet aggregation after adenosine diphosphate (ADP) and collagen stimuli were assessed with light transmittance aggregometry and defined patients with high post-treatment platelet reactivity (HPPR). Markers of platelet activation, including glycoprotein IIb/IIIa activation and P-selectin expression, were also determined using flow cytometry. RESULTS: A total of 306 DM patients were analyzed. Patients with moderate/severe CKD (n = 84) had significantly higher ADP-induced (60 +/- 13% vs. 52 +/- 15%, p = 0.001) and collagen-induced (49 +/- 20% vs. 41 +/- 20%, p = 0.004) platelet aggregation compared with those without (n = 222). After adjustment for potential confounders, patients with moderate/severe CKD were more likely to have HPPR after ADP (adjusted odds ratio: 3.8, 95% confidence interval: 1.7 to 8.5, p = 0.001) and collagen (adjusted odds ratio: 2.4; 95% confidence interval: 1.1 to 5.4; p = 0.029) stimuli. Markers of platelet activation were significantly increased in patients with HPPR. CONCLUSIONS: In DM patients with coronary artery disease taking maintenance aspirin and clopidogrel therapy, impaired renal function is associated with reduced clopidogrel-induced antiplatelet effects and a greater prevalence of HPPR.

In patients with acute coronary syndromes and undergoing percutaneous coronary intervention, numerous large-scale clinical trials have shown that adjunctive treatment with the P2Y(12) receptor antagonist clopidogrel in addition to aspirin reduces ischemic events. These studies underscore the importance of blockade of the P2Y(12) signaling pathway in these settings. However, recent findings have shown that clopidogrel therapy may have some shortcomings. These include its broad range of interindividual-response profiles, where patients with low P2Y(12) inhibitory effects have an increased risk of recurrent ischemic events, including stent thrombosis, and its irreversible mechanism of action. These observations underscore the need for novel antiplatelet agents overcoming these limitations. Cangrelor (AR-C69931MX) is an intravenous, direct-acting and reversible P2Y(12) receptor antagonist. Cangrelor has a rapid onset and offset of action and achieves significantly greater degrees of platelet inhibition compared with clopidogrel. This article provides an overview of the current status of knowledge on cangrelor, focusing on its pharmacologic properties, clinical development and potential future applications.

BACKGROUND: Acute myocardial infarction (MI) stems from a disruption of the plaque in the coronary artery. Based on postmortem examinations, such plaque disruption has been classified as either a rupture or an erosion. Unfortunately, it has been difficult to clinically identify plaque ruptures and plaque erosions during the development of acute MI. To elucidate the relationships between clinical features and the morphological characteristics of the infarct-related lesions, we observed the culprit lesions in patients with acute MI by coronary angioscopy and intravascular ultrasound. METHODS: We examined culprit lesions in 107 patients with acute MI using coronary angioscopy and intravascular ultrasound immediately before performing percutaneous coronary intervention. The lesions were then classified as plaque ruptures or nonruptured erosions, and their clinical features were compared. RESULTS: Among the lesions studied, 44 were classified as plaque ruptures, 28 were classified as plaque erosions, and 35 were unclassified. Patients with nonruptured eroded plaques had more preinfarction angina before the onset of MI than those with ruptured plaques (53.6% vs 22.7%, P = .0074). They also had less ST-segment elevation MI (71.4% vs 93.2%, P = .0185), lower peak creatine kinase levels (2029 +/- 1517 vs 4033 +/- 2699 IU/L, P = .0009), less distal embolization after percutaneous coronary intervention (3.6% vs 36.4%, P = .0014), and less Q-wave MI 1 month after onset (40.7% vs 88.4%, P < .0001). CONCLUSION: Patients with eroded plaque lesions have smaller infarctions than those with ruptured plaque lesions, suggesting that an eroded plaque is less potently thrombogenic than a ruptured plaque.

医局登録番号 497

医局登録番号 496