Blood Pressure Level and Variability During Long-Term Prasugrel or Clopidogrel Medication After Stroke: PRASTRO-I.

BACKGROUND AND PURPOSE: High blood pressure increases bleeding risk during treatment with antithrombotic medication. The association between blood pressure levels and the risk of recurrent stroke during long-term secondary stroke prevention with thienopyridines (particularly prasugrel) has not been well studied. METHODS: This was a post hoc analysis of the randomized, double-blind, multicenter PRASTRO-I trial (Comparison of Prasugrel and Clopidogrel in Japanese Patients With Ischemic Stroke-I). Patients with noncardioembolic stroke were randomly assigned (1:1) to receive prasugrel 3.75 mg/day or clopidogrel 75 mg/day for 96 to 104 weeks. Risks of any ischemic or hemorrhagic stroke, combined ischemic events, and combined bleeding events were determined based on the mean level and visit-to-visit variability, including successive variation, of systolic blood pressure (SBP) throughout the observational period. These risks were also compared between quartiles of mean SBP level and successive variation of SBP. RESULTS: A total of 3747 patients (age 62.1±8.5 years, 797 women), with a median average SBP level during the observational period of 132.5 mm Hg, were studied. All the risks of any stroke (146 events; hazard ratio, 1.318 [95% CI, 1.094-1.583] per 10-mm Hg increase), ischemic stroke (133 events, 1.219 [1.010-1.466]), hemorrhagic stroke (13 events, 3.247 [1.660-6.296]), ischemic events (142 events, 1.219 [1.020-1.466]), and bleeding events (47 events, 1.629 [1.172-2.261]) correlated with increasing mean SBP overall. Similarly, an increased risk of these events correlated with increasing successive variation of SBP (hazard ratio, 3.078 [95% CI, 2.220-4.225] per 10-mm Hg increase; 3.051 [2.179-4.262]; 3.276 [1.172-9.092]; 2.865 [2.042-4.011]; 2.764 [1.524-5.016], respectively). Event rates did not differ between the clopidogrel and prasugrel groups within each quartile of SBP or successive variation of SBP. CONCLUSIONS: Both high mean SBP level and high visit-to-visit variability in SBP were significantly associated with the risk of recurrent stroke during long-term medication with either prasugrel or clopidogrel after stroke. Control of hypertension would be important regardless of the type of antiplatelet drugs. Registration: URL: https://www.clinicaltrials.jp; Unique identifier: JapicCTI-111582.

DA-EPOCH-R combined with high-dose methotrexate in patients with newly diagnosed stage II-IV CD5-positive diffuse large B-cell lymphoma: a single-arm, open-label, phase II study.

CD5-positive diffuse large B-cell lymphoma (CD5+ DLBCL) is characterized by poor prognosis and a high frequency of central nervous system relapse after standard immunochemotherapy. We conducted a phase II study to investigate the efficacy and safety of dose-adjusted (DA)- EPOCH-R (etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin, and rituximab) combined with high-dose methotrexate (HD-MTX) in newly diagnosed patients with CD5+ DLBCL. Previously untreated patients with stage II to IV CD5+ DLBCL according to the 2008 World Health Organization classification were eligible. Four cycles of DA-EPOCH-R followed by two cycles of HD-MTX and four additional cycles of DAEPOCH- R (DA-EPOCH-R/HD-MTX) were planned as the protocol treatment. The primary end point was 2-year progression-free survival (PFS). Between September 25, 2012, and November 11, 2015, we enrolled 47 evaluable patients. Forty-five (96%) patients completed the protocol treatment. There were no deviations or violations in the DA-EPOCH-R dose levels. The complete response rate was 91%, and the overall response rate was 94%. At a median follow up of 3.1 years (range, 2.0-4.9 years), the 2- year PFS was 79% [95% confidence interval (CI): 64-88]. The 2-year overall survival was 89% (95%CI: 76-95). Toxicity included grade 4 neutropenia in 46 (98%) patients, grade 4 thrombocytopenia 12 (26%) patients, and febrile neutropenia in 31 (66%) patients. No treatment-related death was noted during the study. DA-EPOCH-R/HD-MTX might be a first-line therapy option for stage II-IV CD5+ DLBCL and warrants further investigation. (Trial registered at: UMIN-CTR: UMIN000008507.).

Safety and Efficacy of Prasugrel in Elderly/Low Body Weight Japanese Patients with Ischemic Stroke: Randomized PRASTRO-II.

INTRODUCTION: The safety of prasugrel in elderly and/or low body weight Japanese patients with ischemic stroke who have a relatively high bleeding risk with antiplatelet therapy remains unknown. OBJECTIVE: We aimed to investigate the safety and efficacy of long-term prasugrel monotherapy for stroke prevention compared with clopidogrel in elderly and/or low body weight Japanese patients with non-cardioembolic ischemic stroke. METHODS: In this randomized, double-blind, comparative, phase III study, elderly (age ≥75 years) and/or low body weight (≤50 kg) Japanese patients with a previous history of non-cardioembolic ischemic stroke were assigned to a prasugrel 3.75 mg (PRA3.75) group, a prasugrel 2.5 mg (PRA2.5) group, or a clopidogrel 50 mg (CLO50) group and followed up for 48 weeks. The primary safety endpoint was the combined incidence of primary safety events, defined as life-threatening, major, and other clinically relevant bleeding. The efficacy endpoint was a composite of ischemic stroke, myocardial infarction, and death from other vascular causes. RESULTS: A total of 654 patients (age 76.4 ± 7.3 years, body weight 55.6 ± 9.3 kg, women 43.9%) from 74 medical institutions within Japan were enrolled. The combined incidence (95% CI) of primary safety events was 4.2% (1.9-7.8%), 1.9% (0.5-4.7%), and 3.6% (1.6-6.9%) in the PRA3.75 group (n = 216), PRA2.5 group (n = 215), and CLO50 group (n = 223), respectively (hazard ratios [HR] PRA3.75/CLO50, 1.13 [0.44-2.93]; PRA2.5/CLO50, 0.51 [0.15-1.69]). The incidences of bleeding leading to treatment discontinuation (95% CI) were 2.3% (0.8-5.3%), 0.9% (0.1-3.3%), and 2.2% (0.7-5.2%) in the PRA3.75, PRA2.5, and CLO50 groups, respectively (HRs PRA3.75/CLO50, 1.01 [0.29-3.48]; PRA2.5/CLO50, 0.41 [0.08-2.12]). There was no significant difference in all bleeding events between groups. The incidence of ischemic stroke, myocardial infarction, and death from other vascular causes was lower, but not significantly so, in patients treated with prasugrel than in patients treated with clopidogrel: PRA3.75, 0.0% (0/216); PRA2.5, 3.3% (7/215); and CLO50, 3.6% (8/223; HRs PRA3.75/CLO50, 0.00 [0.00-0.00]; PRA2.5/CLO50, 0.90 [0.32-2.47]). CONCLUSIONS: Elderly and/or low body weight -Japanese patients with previous non-cardioembolic ischemic stroke who received PRA3.75 showed similar results in terms of primary safety endpoint, and a numerically lower incidence of ischemic stroke, myocardial infarction, and death from other vascular causes, compared with those who received CLO50.

Echocardiographic Assessment of Cardiac Structural and Functional Abnormalities in Patients With End-Stage Renal Disease Receiving Chronic Hemodialysis.

BACKGROUND: The aim of this study was to assess the echocardiographic characteristics of chronic hemodialysis (HD) patients with end-stage renal disease (ESRD) in a multicenter prospective cohort study.Methods and Results:Three hundred and fifteen patients with ESRD (67.9±10.6 years, 47.6% male) on chronic HD for ≥1 year were examined on transthoracic echocardiography, including Doppler-derived aortic valve area (AVA) measurement. Only 11.5% and 3.4% of all patients had normal left ventricular (LV) geometry and normal LV filling pattern, respectively. The majority of patients had aortic and mitral valvular calcification, and approximately 50% of all 315 patients had aortic valve narrowing with AVA <2.0 cm2. Patients were divided into 3 groups according to AVA index tertile: group 1, highest tertile; group 2, middle tertile; and group 3, lowest tertile. Group 3 was older, had a greater cardiothoracic ratio on chest X-ray, higher plasma brain natriuretic peptide and total LV afterload, and lower stroke volume index than the other 2 groups. Age and intact parathyroid hormone (PTH) level were independently associated with low AVA index. CONCLUSIONS: Patients with ESRD on chronic HD have a high prevalence of cardiac structural and functional abnormalities including calcified aortic sclerosis. High age and PTH were associated with aortic valve narrowing in these patients.

Influence of cytochrome P450 polymorphisms on the antiplatelet effects of prasugrel in patients with non-cardioembolic stroke previously treated with clopidogrel.

This randomized double-blind crossover study aimed to investigate the influence of cytochrome P450 (CYP) 2C19 polymorphisms on the antiplatelet effects of prasugrel in patients with non-cardioembolic stroke treated with clopidogrel. Patients received clopidogrel 75 mg/day for > 4 weeks. Subsequently, patients received prasugrel 3.75 mg/day (group A; n = 64) or 2.5 mg/day (group B; n = 65) for 4 weeks followed by a 4 week switched-dose regimen. To assess the influence of CYP2C19 polymorphisms, patients were classified as extensive metabolizers (EMs), intermediate metabolizers (IMs), and poor metabolizers (PMs). The primary endpoint was P2Y12 reaction units (PRU) at the end of each 4 week treatment. A significant reduction in PRU was noted after treatment with prasugrel 3.75 mg/day compared with the pre-dose value (after treatment with clopidogrel) (p < 0.0001). By CYP2C19 phenotypes, a significant reduction in PRU was noted in IMs and PMs after treatment with prasugrel 3.75 mg/day and in PMs after treatment with prasugrel 2.5 mg/day, as compared with the pre-dose value (p < 0.0001). The plasma concentration of the active metabolite of clopidogrel was relatively low in PMs compared to EMs and IMs; prasugrel was similar across all CYP2C19 phenotypes. No major or clinically significant hemorrhagic adverse events occurred. By CYP2C19 phenotype, the antiplatelet effects of prasugrel were greater with 3.75 mg/day in IMs and PMs, and with 2.5 mg/day in PMs compared with clopidogrel 75 mg/day, without safety concerns. CYP2C19 polymorphisms did not affect the plasma concentration of the active metabolite of prasugrel or its antiplatelet effects. (JapicCTI-101044).

Developmental Changes in Neonatal and Infant Skin Structures During the First 6 Months: In Vivo Observation.

BACKGROUND/OBJECTIVES: Developmental changes of structures in neonatal and infant skin have not been well characterized. The purpose of this study was to clarify changes in skin structures during neonatal and infant growth in vivo. METHODS: Fifteen healthy, full-term neonates (seven girls, eight boys) were studied. The measurements were performed 4 to 7 days (neonate) and 1, 3, and 6 months after birth on the buttock, upper thigh, and ventral forearm skin using a confocal laser scanning microscope. Developmental changes in dermoepidermal junction structures, stratum corneum thickness, epidermal thickness, and microvascular development were investigated. RESULTS: A significant decrease in stratum corneum thickness was observed over the 3 months after birth. Dermal papillae were not observed in neonatal skin but were observed gradually over the next 3 months. Epidermal thickness, determined from the skin surface to the bottom of the epidermal layer, increased significantly from 4 to 7 days to 1 month of age, indicating the formation of dermal papillae and rete ridges. Complicated microvascular structures were observed in neonatal skin but disappeared gradually and were observed only at the dermal papillae at 3 months of age. CONCLUSIONS: Our results reveal that infant skin is in a developmental stage structurally up to 3 months of age, paralleling skin functional and developmental maturation.

Impact of Arterial Access Route on Bleeding Complications in Japanese Patients Undergoing Percutaneous Coronary Intervention- Insight From the PRASFIT Trial.

BACKGROUND: Few large-scale studies have examined the relationship between bleeding events not related to coronary artery bypass grafting (CABG), and the vascular access route used in acute coronary syndrome (ACS) or in elective treatment of coronary artery disease (CAD). METHODS AND RESULTS: We compared the incidence of bleeding events occurring up to 3 days after percutaneous coronary intervention (PCI) or loading dose of prasugrel or clopidogrel in 2 studies of Japanese patients (PRASFIT-ACS, femoral and radial routes, n=683 and 531; PRASFIT-Elective, femoral and radial routes, n=135 and 508). Rates of periprocedural bleeding, bleeding not related to CABG, and puncture site bleeding were consistently lower in the radial access route group than in the femoral access route group in both studies. Risk factors for periprocedural bleeding included sex, body weight, age, and access route in PRASFIT-ACS (femoral access: hazard ratio [HR], 3.739; 95% confidence interval [CI]: 1.727-8.094; radial access: HR, 0.288; 95% CI: 0.128-0.65), and body weight, age, and access route in PRASFIT-Elective (femoral access: HR, 12.32; 95% CI 1.282->100; radial access: HR, 0.125; 95% CI: 0.013-1.205). CONCLUSIONS: The incidence of periprocedural bleeding is lower with a radial access route than with a femoral access route for PCI in Japanese patients with ACS or those undergoing elective PCI for CAD.

Apixaban for the Treatment of Japanese Subjects With Acute Venous Thromboembolism (AMPLIFY-J Study).

BACKGROUND: Anticoagulation is recommended as standard of care for venous thromboembolism (VTE) (pulmonary embolism [PE]/deep vein thrombosis [DVT]), for which unfractionated heparin (UFH) and warfarin are used in Japan. In the multi-regional AMPLIFY study, a fixed-dose regimen of apixaban alone was non-inferior to conventional therapy for treatment of PE/DVT and was associated with significantly fewer bleeding events. METHODS AND RESULTS: Japan phase 3 study (AMPLIFY-J), randomized, active-controlled, open-label study in Japanese subjects with acute PE/DVT, was designed based on AMPLIFY. Key objectives were to investigate safety and efficacy of apixaban in symptomatic PE/DVT subjects during 24-week treatment. UFH/warfarin was used as control treatment. Apixaban was initiated at 10 mg twice daily for 7 days, followed by 5 mg twice daily for 23 weeks. All endpoints and imaging for thrombotic burden were assessed by an event adjudication committee. Eighty subjects were randomized, 33 subjects (41.3%) were aged <65 years. Proportion of major/clinically relevant non-major bleeding was lower in apixaban (7.5%) compared with well-controlled UFH/warfarin (28.2%; median TTR, 70.4%). [corrected]. Recurrent VTE occurred in no subjects in apixaban and in 1 subject in UFH/warfarin. Thrombotic burden results were similar in both groups. Proportions of subjects with adverse events was generally similar in both groups. CONCLUSIONS: Apixaban was well-tolerated and had a favorable safety profile. No clinically important efficacy difference compared with UFH/warfarin was observed.

Effect of combination therapy of ezetimibe and rosuvastatin on regression of coronary atherosclerosis in patients with coronary artery disease.

Ezetimibe has been reported to provide significant incremental reduction in low-density-lipoprotein cholesterol (LDL-C) when added to a statin; however, its effect on coronary atherosclerosis has not yet been evaluated in detail. The aim of this study was to investigate the add-on effect of ezetimibe to a statin on coronary atherosclerosis evaluated by intravascular ultrasound (IVUS).In this prospective randomized open-label study, a total of 51 patients with stable coronary artery disease (CAD) requiring percutaneous coronary intervention (PCI) were enrolled, and assigned to a combination group (n = 26, rosuvastatin 5 mg/day + ezetimibe 10 mg/day) or a monotherapy group (n = 25, rosuvastatin 5 mg/day). Volumetric IVUS analyses were performed at baseline and 6 months after the treatment for a non-PCI site. LDL-C level was significantly reduced in the combination group (-55.8%) versus that in the monotherapy group (-36.8%; P = 0.004). The percent change in plaque volume (PV), the primary endpoint, appeared to decrease more effectively in the combination group compared with the monotherapy group (-13.2% versus -3.1%, respectively, P = 0.050). Moreover, there was a significant group × time interaction in the effects of the two treatments on PV (P = 0.021), indicating the regressive effect of the combination therapy on PV was greater than that of monotherapy for subtly different values of baseline PV in the two treatment groups. Moreover, percent change in PV showed positive correlations with percent change of LDL-C (r = 0.384, P = 0.015).Intensive lipid-lowering therapy with ezetimibe added to usual-dose statin may provide significant incremental reduction in coronary plaques compared with usual-dose statin monotherapy.

Sarpogrelate hydrochloride, a serotonin 5HT2A receptor antagonist, ameliorates the development of chronic hypoxic pulmonary hypertension in rats.

PURPOSE: The purpose of the present study was to determine if sarpogrelate hydrochloride (SPG), a serotonin 5HT2A receptor antagonist, prevented the development of chronic hypoxia-induced pulmonary hypertension (PH) and hypertensive pulmonary vascular remodeling. METHODS: Forty-one male Sprague-Dawley rats were exposed to hypobaric hypoxia (380 mmHg, 10 % oxygen) or room air and administered 50 mg/kg SPG or vehicle by gavage once daily from day -2 to day 14. The mean pulmonary artery pressure (PAP) and right ventricular hypertrophy (RVH) were measured. Hypertensive pulmonary vascular remodelings were assessed morphometrically by light microscopy. Serotonin-induced contraction was determined in isolated pulmonary artery rings from 24 rats. In another set of rats, Western blotting, real-time polymerase chain reaction and immunofluorescent staining (n = 9) for lung tissue were performed. RESULTS: Chronic hypoxia induced a rise in mean PAP and RVH, increased the percentage of muscularized arteries in peripheral pulmonary arteries and medial wall thickness in small muscular arteries, and potentiated serotonin-induced contraction, each of which was significantly (p < 0.05) ameliorated by SPG. Chronic hypoxia significantly increased the expression of endothelial nitric oxide synthase (eNOS) and phosphorylated eNOS (peNOS) protein levels, cyclic guanosine monophosphate, and matrix metalloproteinase-13 (MMP-13) mRNA levels in whole lung tissues. SPG increased peNOS expression in the immunofluorescent staining of peripheral pulmonary arteries from chronic hypoxic rats and decreased the MMP-13 mRNA in lung tissue in chronic hypoxic rats. CONCLUSIONS: The administration of SPG ameliorated the development of chronic hypoxic PH and hypertensive pulmonary vascular changes.

Optimal duration of dual antiplatelet therapy following treatment with the endeavor zotarolimus-eluting stent in real-world Japanese patients with coronary artery disease (OPERA): study design and rationale.

BACKGROUND: In patients with coronary artery disease (CAD), there is an increasing therapeutic need among interventional cardiologists to conduct dual antiplatelet therapy (DAPT) whose duration is shorter than current guideline-recommended 6-12 months after the implantation of drug-eluting stents. However, no clinical grounds sufficient to rationalize the need are available. OBJECTIVES: To define the optimal duration of DAPT and to examine the safety and efficacy of the Endeavor zotarolimus-eluting stent (E-ZES) in real-world Japanese patients with CAD. STUDY DESIGN: The present prospective, nonrandomized, multicenter, controlled study is uniquely designed to examine the analysis set to be formulated after integrating two different databases consisting of the following two study arms: the 3-month DAPT arm, in which 1,210 patients were consecutively enrolled at 106 medical institutions; and the 12-month DAPT arm, in which 1,210 patients will be consecutively extracted from the Endeavor Japan post-marketing surveillance at 60 medical institutions. The primary endpoint is "net adverse cardiac and cerebrovascular events-death, myocardial infarction, cerebrovascular accident, and major bleeding)" at 12 months after implantation. The secondary endpoints are as follows: major adverse cardiac events at 1, 3, 6, 9, and 12 months after implantation; target vessel revascularization and target lesion revascularization at 9 and 12 months after implantation; and stent thrombosis, DAPT compliance, and bleeding events at 12 months after implantation. Noninferiority in the E-ZES's profiles between the study arms will be investigated. CONCLUSIONS: The present study will provide insight into the optimal duration of DAPT after the E-ZES implantation in individual, real-world patients with CAD.

Prasugrel, a third-generation P2Y12 receptor antagonist, in patients with coronary artery disease undergoing elective percutaneous coronary intervention.

BACKGROUND: Prasugrel is being developed in Japan as an antiplatelet therapy for use during percutaneous coronary intervention (PCI). Up to 70% of Japanese patients with coronary artery disease undergo elective PCI. The PRASugrel For Japanese PatIenTs with Coronary Artery Diseases Undergoing Elective PCI (PRASFIT-Elective) study investigated the efficacy and safety of different prasugrel dosing regimens in Japanese patients undergoing elective PCI. METHODS AND RESULTS: A total of 742 patients scheduled for elective coronary artery stenting were enrolled. Patients were randomized to receive either prasugrel (20/3.75 mg, loading/maintenance dose) or clopidogrel (300/75 mg) in a double-blind manner. Endpoints, including cardiovascular events and bleeding, were assessed at weeks 24-48. The incidence rate of major cardiovascular events (cardiovascular death, non-fatal myocardial infarction, or non-fatal ischemic stroke) up to week 24 was 4.1% (15/370) and 6.7% (25/372) in the prasugrel and clopidogrel groups, respectively. Other incidence rates were: non-coronary artery bypass graft-related major bleeding, 0% and 2.2%; major/minor bleeding, 1.6% and 3.0%; and all bleeding events, 38.1% and 34.4% in the prasugrel and clopidogrel groups, respectively. The incidence rate of bleeding-related adverse events was similar in both groups, being 40.8% and 35.8% in the prasugrel and clopidogrel groups, respectively. CONCLUSIONS: These results support the risk-benefit profile of an adjusted dosing regimen of prasugrel in Japanese patients undergoing PCI. Larger studies are required to confirm these findings.

Efficacy and safety of adjusted-dose prasugrel compared with clopidogrel in Japanese patients with acute coronary syndrome: the PRASFIT-ACS study.

BACKGROUND: Prasugrel is an antiplatelet agent that shows more prompt, potent, and consistent platelet inhibition than clopidogrel. The objective of this study was to confirm the efficacy and safety of prasugrel at loading/maintenance doses of 20/3.75 mg. METHODS AND RESULTS: Japanese patients (n=1,363) with acute coronary syndrome undergoing percutaneous coronary intervention were randomized to either prasugrel (20/3.75 mg) or clopidogrel (300/75 mg), both in combination with aspirin (81-330 mg for the first dose and 81-100 mg/day thereafter), for 24-48 weeks. The primary efficacy endpoint was the incidence of major adverse cardiovascular events (MACE) at 24 weeks, defined as a composite of cardiovascular death, nonfatal myocardial infarction, and nonfatal ischemic stroke. We compared the incidence of MACE between the 2 groups using point estimates. Safety outcomes included the incidence of bleeding events until 2 weeks after the last dose. The incidence of MACE at 24 weeks was 9.4% in the prasugrel group and 11.8% in the clopidogrel group (risk reduction 23%, hazard ratio 0.77, 95% confidence interval 0.56-1.07). The incidence of non-coronary artery bypass graft-related major bleeding was similar in both groups (1.9% vs. 2.2%). CONCLUSIONS: Prasugrel 20/3.75 mg was associated with a low incidence of ischemic events, similar to the results of TRITON-TIMI 38, and with a low risk of clinically serious bleeding in Japanese ACS patients.

[Antiplatelet drugs].

Antiplatelet therapy is widely used with proven benefit for the prevention of further ischemic complications in patients with coronary heart disease and stroke. Treatment guidelines for acute coronary syndrome and percutaneous coronary intervention now recommend the use of oral antiplatelet agents including clopidogrel in combination with aspirin (dual antiplatelet therapy: DAPT) for the prevention of recurrent ischemic events. The limitations of DAPT with clopidogrel include the potential for low response to clopidogrel identified through platelet reactivity or genetic testing, or slower return to normal platelet activity in patients who received clopidogrel prior to emergent or planned surgical procedures. This review will discuss the pharmacologic properties and clinical studies about new antiplatelet drugs including prasugrel, ticagrelor and PAR-1 inhibitors.

Relationship between CYP2C19 loss-of-function polymorphism and platelet reactivities with clopidogrel treatment in Japanese patients undergoing coronary stent implantation.

BACKGROUND: CYP2C19 loss-of-function genotype (*2 and/or *3 alleles) is related to low responsiveness to clopidogrel, which is a risk factor for ischemic cardiac events. The contribution of these genotypes to platelet reactivity in Japanese patients in a steady state receiving dual antiplatelet therapy after coronary stenting was evaluated. METHODS AND RESULTS: A total of 155 Japanese patients were classified according to their CYP2C19 loss-of-function genotype. Platelet reactivity was assayed by plasma levels of soluble P-selectin and platelet-derived microparticles, light transmittance aggregometry induced by ADP (ADP-LTA), shear stress-induced platelet aggregometry, vasodilator-stimulated phosphoprotein phosphorylation (VASP) index and the VerifyNow-P2Y12 assay. Linear and logistic regression models were used to assess the associations between CYP2C19 loss-of-function genotype and high on-treatment platelet reactivity. In total, 62 patients (40.0%) were extensive metabolizers (EMs), 70 (45.2%) were intermediate metabolizers (IMs) and 23 (14.8%) were poor metabolizers (PMs). ADP-specific assays (ADP-LTA, the VASP index and VerifyNow-P2Y12) differed according to CYP2C19 genotype, with a significant gene-dose effect (PMs>IMs>EMs). CYP2C19 loss-of-function carrier status was associated with more frequent high platelet reactivity. CYP2C19 loss-of-function genotype alone could explain 12.2%, 14.3%, and 14.7% of the variability in the ADP-LTA, VASP and VerifyNow-P2Y12 assays, respectively. CONCLUSIONS: CYP2C19 loss-of-function genotype is associated with more frequent high platelet reactivity, as assessed by ADP-specific platelet function tests, in Japanese patients.

Incidence of stroke, systemic embolism and bleeding events in patients without anticoagulation based on real-world data in Japan: a retrospective cohort study.

OBJECTIVES: To examine the incidence of stroke or systemic embolic events (SSEs) and bleeding events in untreated patients with non-valvular atrial fibrillation (NVAF) after widespread use of direct oral anticoagulant agents (DOACs). DESIGN: Multicentre, non-interventional, observational, retrospective cohort study using real-world data in Japan (2016-2018). SETTING: The Mie, Musashino University study of NVAF, which used the Mie-Life Innovation Promotion Center Database. This is a regional clinical database involving one university hospital and eight general hospitals in Mie Prefecture in Japan. PARTICIPANTS: Japanese patients with NVAF (n=7001). PRIMARY AND SECONDARY OUTCOME: The incidence of SSEs and bleeding events. RESULTS: A total of 7001 patients with NAVF were registered, and 53.0% were treated with DOACs, 10.6% were treated with warfarin and 36.4% had no treatment. Additionally, 29.5% of patients with a CHADS2 (congestive heart failure, hypertension, age≥75 years, diabetes, previous stroke or transient ischemic attack) score of 3-6 were untreated. In the no treatment group, the SSE rates by the CHADS2 score (0, 1, 2 and 3-6) were 1.4%, 1.4%, 3.2% and 8.0%, respectively. The rates of bleeding events by the CHADS2 score (0, 1, 2 and 3-6) in the no treatment group were 0.7%, 1.0%, 1.2% and 2.9%, respectively. A multivariate analysis of SSEs in components of the CHADS2 showed that the adjusted HRs were 2.32 for heart failure, 1.66 for an age ≥75 years, 1.81 for diabetes mellitus and 5.84 for prior stroke or transient ischaemic attack. CONCLUSIONS: Approximately one-third of the patients do not receive any anticoagulation in the modern DOAC era in Japan. The SSE rate increases by the CHADS2 score. The SSE rate is low in patients with a CHADS2 score <1, supporting no indication of anticoagulation in current guidelines. In patients with a CHADS2 score >1, the use of anticoagulant drug therapy is recommended because of a higher risk of stroke.

Efficacy and Safety of Prasugrel by Stroke Subtype: A Sub-Analysis of the PRASTRO-I Randomized Controlled Trial.

AIMS: The efficacy of antiplatelet therapy may vary among different disease subtypes. Prasugrel is generally a more potent, consistent, and fast-acting platelet inhibitor than clopidogrel. This sub-analysis of the phase III comparison of PRAsugrel and clopidogrel in Japanese patients with ischemic STROke (PRASTRO-I) trial aimed to assess the differences in efficacy of these treatments for each stroke subtype. METHODS: In the PRASTRO-I trial, a total of 3,753 patients with ischemic stroke were recruited from 224 centers throughout Japan and randomized (1:1) to prasugrel (3.75 mg/day) or clopidogrel (75 mg/day) for 96 weeks. For the sub-analysis, strokes were classified as large-artery atherosclerosis, small-artery occlusion (lacunar), stroke of other etiology, and stroke of undetermined etiology. The cumulative incidence of primary events (ischemic stroke, myocardial infarction, and death from other vascular cause) and hazard ratios (HRs) were calculated for each subgroup. RESULTS: For patients with large-artery atherosclerosis, the primary event incidence was 3.8% in the prasugrel group and 4.8% in the clopidogrel group (HR 0.79; 95% confidence interval [CI] 0.45-1.41). For patients with small-artery occlusion, the incidence was 3.3% in the prasugrel group and 3.9% in the clopidogrel group (HR 0.82; 95% CI 0.45-1.50). For patients with stroke of undetermined etiology, the incidence was 4.6% in the prasugrel group and 3.0% in the clopidogrel group (HR 1.56; 95% CI 0.90-2.72). The incidence of bleeding was similar across subtypes. CONCLUSIONS: Although statistical significance was not reached, the efficacy of prasugrel was potentially different between stroke subtypes, warranting further studies.

Association between High Platelet Reactivity Following Dual Antiplatelet Therapy and Ischemic Events in Japanese Patients with Coronary Artery Disease Undergoing Stent Implantation.

AIM: Although high on-treatment platelet reactivity (HTPR) with dual antiplatelet therapy (DAPT) correlates with long-term adverse outcomes in patients undergoing percutaneous coronary intervention, the correlation in Japanese patients remains unclear. Therefore, we examined the relationship between platelet reactivity during DAPT with aspirin and clopidogrel and 1-year clinical outcomes following successful coronary stent implantation. METHODS: A prospective, multicenter registry study (j-CHIPS) was conducted in patients undergoing coronary stenting and receiving aspirin and clopidogrel at 16 hospitals in Japan. A VerifyNow point-of-care assay was used to assess platelet reactivity, and a cutoff value to define HTPR was established. RESULTS: Between February 2011 and May 2013, 1047 patients were prospectively enrolled, of which 854 patients with platelet function evaluation at 12-24 h after PCI were included in the final analysis. After 1 year of follow-up, the incidence of the primary endpoint (a composite of all-cause mortality, myocardial infarction, stent thrombosis, and ischemic stroke) was significantly higher in patients with HTPR than in those without (5.9% vs. 1.5%, p=0.008), and HTPR showed a modest ability to discriminate between patients who did and did not experience major adverse cardiac and cerebrovascular events (area under the curve, 0.60; 95% confidence interval, 0.511-0.688, p=0.039). HTPR status did not identify patients at risk for major or minor bleeding events. CONCLUSION: HTPR was significantly associated with adverse ischemic outcomes at 1 year after PCI in Japanese patients receiving maintenance DAPT, indicating its potential as a prognostic indicator of clinical outcomes in this high-risk patient population.

Comparison of prasugrel and clopidogrel in patients with non-cardioembolic ischaemic stroke: a phase 3, randomised, non-inferiority trial (PRASTRO-I).

BACKGROUND: The effect of prasugrel in terms of the prevention of recurrence of ischaemic stroke is unknown. We investigated the non-inferiority of prasugrel to clopidogrel for prevention of ischaemic stroke, myocardial infarction, and death from other vascular causes in Japanese patients with non-cardioembolic stroke. METHODS: In this phase 3 randomised, double-blind, non-inferiority trial, patients aged 20-74 years who had had a non-cardioembolic stroke in the previous 1-26 weeks were recruited from 224 hospitals in Japan. Eligible patients were randomly assigned (1:1) to receive prasugrel (3·75 mg/day) or clopidogrel (75 mg/day) orally for 96-104 weeks. Randomisation was stratified according to stroke subtype. The randomisation schedule was generated by an independent statistician who created a computer-generated random number sequence. Patients, investigators, and the funder were masked to treatment allocation. The primary endpoint was combined incidence of ischaemic stroke (fatal and non-fatal), myocardial infarction (fatal and non-fatal), and death from other vascular causes in the intention-to-treat population. The safety endpoint was incidence of bleeding events, comprising life-threatening bleeding, major bleeding, and clinically relevant bleeding. The safety analysis was done in the population excluding trial patients with serious Good Clinical Practice violations, and those who had not taken the trial drug. The predefined non-inferiority margin was an upper 95% CI limit for the risk ratio (RR) of 1·35. The trial was registered with the Japan Pharmaceutical Information Center (JapicCTI-111582). FINDINGS: Patients were recruited between Sept 1, 2011, and June 12, 2015. 3747 patients (797 [21%] women) were enrolled, with a mean age of 62·1 (SD 8·5) years. 3753 patients were randomly assigned to treatment and, of these patients, 1885 in the prasugrel group and 1862 in the clopidogrel group were confirmed to have taken the trial drug at least once, and six patients withdrew from the trial before administration of the trial drug. Thus, a total of 3747 patients were included in the full analysis set. 73 (4%) of 1885 patients in the prasugrel group and 69 (4%) of 1862 patients in the clopidogrel group reached the primary endpoint (RR 1·05, 95% CI 0·76-1·44). The incidence of bleeding events was not significantly different between treatment groups; life-threatening bleeding was observed in 18 (1%) patients in the prasugrel group and 23 (1%) patients in the clopidogrel group (RR 0·77, 0·41-1·42). INTERPRETATION: The non-inferiority of prasugrel to clopidogrel for the prevention of ischaemic stroke, myocardial infarction, and death from other vascular causes was not confirmed in Japanese patients with non-cardioembolic stroke. No safety concerns were identified. FUNDING: Daiichi Sankyo.