A novel homozygous variant of the thrombomodulin gene causes a hereditary bleeding disorder.

We report a 19-year-old Vietnamese woman who experienced several life-threatening bleeding events, including ovarian hemorrhage. Blood analysis revealed a decreased fibrinogen level with markedly elevated fibrinogen/fibrin degradation products and D-dimer levels. Despite hemostatic surgery and administration of several medications, such as nafamostat mesylate, tranexamic acid, and unfractionated heparin, the coagulation abnormalities were not corrected, and the patient experienced repeated hemorrhagic events. We found that administration of recombinant human thrombomodulin (rhTM) remarkably improved the patient's pathophysiology. Screening and sequencing of the TM gene (THBD) revealed a previously unreported homozygous variation: c.793T>A (p.Cys265Ser). Notably, the Cys265 residue forms 1 of 3 disulfide bonds in the epidermal growth factor (EGF)-like domain 1 of TM. Transient expression experiments using COS-1 cells demonstrated markedly reduced expression of TM-Cys265Ser on the plasma membrane relative to wild-type TM. The TM-Cys265Ser mutant was intracellularly degraded, probably because of EGF-like domain 1 misfolding. The reduced expression of TM on the endothelial cell membrane may be responsible for the disseminated intravascular-coagulation-like symptoms observed in the patient. In summary, we identified a novel TM variant, c.793T>A (p.Cys265Ser). Patients homozygous for this variant may present with severe bleeding events; rhTM should be considered a possible treatment option for these patients.

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.

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.

Platelet production using adipose-derived mesenchymal stem cells: Mechanistic studies and clinical application.

Megakaryocytes (MKs) are platelet progenitor stem cells found in the bone marrow. Platelets obtained from blood draws can be used for therapeutic applications, especially platelet transfusion. The needs for platelet transfusions for clinical situation is increasing, due in part to the growing number of patients undergoing chemotherapy. Platelets obtained from donors, however, have the disadvantages of a limited storage lifespan and the risk of donor-related infection. Extensive effort has therefore been directed at manufacturing platelets ex vivo. Here, we review ex vivo technologies for MK development, focusing on human adipose tissue-derived mesenchymal stem/stromal cell line (ASCL)-based strategies and their potential clinical application. Bone marrow and adipose tissues contain mesenchymal stem/stromal cells that have an ability to differentiate into MKs, which release platelets. Taking advantage of this mechanism, we developed a donor-independent system for manufacturing platelets for clinical application using ASCL established from adipose-derived mesenchymal stem/stromal cells (ASCs). Culture of ASCs with endogenous thrombopoietin and its receptor c-MPL, and endogenous genes such as p45NF-E2 leads to MK differentiation and subsequent platelet production. ASCs compose heterogeneous cells, however, and are not suitable for clinical application. Thus, we established ASCLs, which expand into a more homogeneous population, and fulfill the criteria for mesenchymal stem cells set by the International Society for Cellular Therapy. Using our ASCL culture system with MK lineage induction medium without recombinant thrombopoietin led to peak production of platelets within 12 days, which may be sufficient for clinical application.

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.

Major cardiovascular and bleeding events with long-term use of aspirin in patients with prior cardiovascular diseases: 1-year follow-up results from the Management of Aspirin-induced Gastrointestinal Complications (MAGIC) study.

Aspirin should be used for the prevention of cardiovascular (CV) events by the risk-benefit balance. This study was conducted to clarify CV and bleeding events in Japanese aspirin users with a history of CV diseases. This study was a prospective, nationwide, multicenter cooperative registry of Japanese patients with CV diseases at risk of thromboembolism who were taking aspirin (75-325 mg) for at least 1 year. We observed major CV and bleeding events during follow-up. Patients with history of ischemic stroke (IS), transient ischemic attack (TIA), coronary artery disease (CAD), atrial fibrillation (AF), and venous thromboembolism (VTE) were included and analyzed in this sutdy. CV events included IS, TIA, CAD, CV death, angioplasty or stenting, and hospitalization because of CV disease. Bleeding events included major bleeding requiring hospitalization and/or blood transfusion. A total of 1506 patients were categorized into IS/TIA (N = 540), CAD (N = 632), and AF/VTE (N = 232). Among them, 101 patients had two or more categories. CV and bleeding events occurred in 61 (3.82%/year) and 15 patients (0.93%/year), respectively. The annual rates of CV and bleeding events were 2.81% and 0.93% in IS/TIA, 5.32% and 0.75% in CAD, 1.15% and 1.15% in AF/VTE, and 6.44% and 0.91% in two or more disease categories, respectively. The Management of Aspirin-induced Gastrointestinal Complications (MAGIC) study clarified the rates of major CV and bleeding events with long-term use of aspirin in patients with prior CV diseases in real-world clinical practice. The risk-benefit balance of aspirin was acceptable in patients with IS/TIA, CAD, and multiple CV diseases but not in those with AF/VTE.Trial Registration: The MAGIC Study is registered at UMIN Clinical Trial Registry (www.umin.ac.jp/ctr/index-j.htm), number UMIN000000750.

Pharmacodynamic assessment of prasugrel and clopidogrel in patients with non-cardioembolic stroke: a multicenter, randomized, active-control clinical trial.

Prasugrel, a novel P2Y12 receptor antagonist, has been shown to be more effective than clopidogrel for preventing cardiovascular events in patients with acute coronary syndromes undergoing percutaneous coronary intervention. We investigated the dose-response antiplatelet effects of prasugrel compared with clopidogrel in Japanese patients with non-cardioembolic stroke. The influence of cytochrome P450 (CYP) polymorphisms on the antiplatelet effects of both drugs was also compared. In this multicenter randomized active-control comparative study, patients were randomized to receive prasugrel 2.5 mg, 5 mg, or 7.5 mg (double blind) or clopidogrel 75 mg (open label) once daily for 14 days. The primary endpoint was inhibition of platelet aggregation (IPA) in response to adenosine diphosphate 20 µM within 8 h of study drug administration on day 14. Of the 66 patients randomized, data from 63 (prasugrel 2.5 mg, 5 mg, and 7.5 mg groups, n = 14, 16, and 18, respectively; clopidogrel group, n = 15) were used in the pharmacodynamic assessment. IPA (arithmetic mean ± SD) after prasugrel administration increased dose-dependently (33 ± 9%, 44 ± 11%, and 53 ± 14%, at 2.5 mg, 5 mg, and 7.5 mg, respectively) and was higher in these groups than after clopidogrel (23 ± 16%). In a subgroup of CYP2C19 intermediate metabolizers, IPA was higher in the prasugrel 5 mg and 7.5 mg groups than in the clopidogrel group. No death or serious adverse events were reported. Prasugrel was well tolerated at doses up to 7.5 mg/day and had antiplatelet effects higher than those of clopidogrel 75 mg/day. CYP2C19 polymorphisms may have reduced clopidogrel-induced IPA.

Influence of blood pressure on the effects of low-dose asprin in elderly patients with multiple atherosclerotic risks.

OBJECTIVE: We examined whether the efficacy of low-dose acetylsalicylic acid (aspirin) for primary prevention of cardiovascular events is influenced by blood pressure (BP) using data from patients aged 60-85 years with hypertension, dyslipidemia, and/or diabetes, but without cardiovascular disease of the Japanese Primary Prevention Project. METHODS: All patients had received aspirin (100 mg/day) or no aspirin. BP subgroups were defined as low (average SBP from the baseline to the year of the events <130 mmHg), moderate (≥130 and <140 mmHg), and high (≥140 mmHg). The mean duration of follow-up was 5.02 years. RESULTS: In hypertensive patients (n = 12 278) aspirin had no significant impact on the primary outcome of death from cardiovascular disease, nonfatal stroke, and nonfatal myocardial infarction. On the other hand, aspirin increased the incidence of serious extracranial hemorrhage [hazard ratio, 1.81; 95% confidence interval (CI), 1.18-2.77; P = 0.0064] and tended to increase hemorrhagic stroke (hazard ratio, 1.75; CI, 0.99-3.07; P = 0.053). Aspirin had no effect on the primary outcome in any of the BP subgroups, and was associated with increased hemorrhagic stroke in the high BP group (hazard ratio, 3.51; CI, 1.29-9.51; P = 0.014); serious extracranial hemorrhage was elevated or tended to elevate in the moderate (hazard ratio, 2.53; CI, 1.18-5.45; P = 0.017) and high (hazard ratio, 2.14; CI, 1.00-4.56; P = 0.050) BP groups. CONCLUSION: In aged Japanese hypertensive patients, these data demonstrated no overall benefit of low-dose aspirin therapy although treatment was associated with an elevated risk of hemorrhagic events.

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.

Megakaryocytes and platelets from a novel human adipose tissue-derived mesenchymal stem cell line.

The clinical need for platelet transfusions is increasing; however, donor-dependent platelet transfusions are associated with practical problems, such as the limited supply and the risk of infection. Thus, we developed a manufacturing system for platelets from a donor-independent cell source: a human adipose-derived mesenchymal stromal/stem cell line (ASCL). The ASCL was obtained using an upside-down culture flask method and satisfied the minimal criteria for defining mesenchymal stem cells (MSCs) by The International Society for Cellular Therapy. The ASCL showed its proliferation capacity for ≥2 months without any abnormal karyotypes. The ASCL was cultured in megakaryocyte induction media. ASCL-derived megakaryocytes were obtained, with a peak at day 8 of culture, and ASCL-derived platelets (ASCL-PLTs) were obtained, with a peak at day 12 of culture. We observed that CD42b+ cells expressed an MSC marker (CD90) which is related to cell adhesion. Compared with peripheral platelets, ASCL-PLTs exhibit higher levels of PAC1 binding, P-selectin surface exposure, ristocetin-induced platelet aggregation, and ADP-induced platelet aggregation, as well as similar levels of fibrinogen binding and collagen-induced platelet aggregation. ASCL-PLTs have lower epinephrine-induced platelet aggregation. The pattern of in vivo kinetics after infusion into irradiated immunodeficient NOD.Cg-PrkdcscidIl2rgtm1Wjl/SzJ mice was similar to that of platelet concentrates. ASCL-PLTs have similar characteristics to those of peripheral platelets and might have an additional function as MSCs. The establishment of the ASCL and its differentiation into ASCL-PLTs do not require gene transfer, and endogenous thrombopoietin is used for differentiation. The present protocol is a simple method that does not require feeder cells, further enhancing the clinical application of our approach.

Low-Dose Aspirin for Primary Prevention of Cardiovascular Events in Elderly Japanese Patients with Atherosclerotic Risk Factors: Subanalysis of a Randomized Clinical Trial (JPPP-70).

INTRODUCTION: This post hoc subanalysis of the randomized Japanese Primary Prevention Project investigated whether once-daily low-dose aspirin versus no aspirin reduced the risk of cardiovascular events (CVEs) in patients aged ≥ 70 years with atherosclerotic risk factors. METHODS: Patients aged < 70 years (young-old) or ≥ 70 years (old) with hypertension, dyslipidemia, or diabetes participated between 2005 and 2007. Patients were randomized 1:1 to receive 100 mg enteric-coated aspirin once daily or no aspirin plus standard of care. The primary outcome was a composite of death from cardiovascular causes plus nonfatal stroke and nonfatal myocardial infarction. The secondary outcome was a composite of the primary outcome plus transient ischemic attack, angina pectoris, and arteriosclerotic disease requiring medical or surgical intervention. Old (n = 7971) and young-old (n = 6493) patients were followed up for a median 5.02 years. RESULTS: Aspirin did not reduce the risk of primary (hazard ratio [HR] 0.92 [95% confidence interval {CI} 0.74-1.16]; P = 0.50) or secondary (0.85 [0.70-1.04]; P = 0.11) outcomes in patients aged ≥ 70 years. In old men with high-density lipoprotein < 40 mg/dL, treatment with low-dose aspirin was associated with a reduction in the incidence of the primary endpoint compared with the group not receiving aspirin (10/260 vs 22/250; HR 0.44 [95% CI 0.20-0.93]; P = 0.03). This subgroup was also found to contain significant larger proportions of patients with elevated body mass index, patients with diabetes mellitus, and smokers (P < 0.001). Old patients also showed differences in bleeding outcomes. Serious extracranial hemorrhage requiring transfusion or hospitalization occurred significantly more frequently in the aspirin-treated group than in the non-aspirin-treated group (35 [0.88%] vs 18 [0.45%]; HR 1.96 [1.11-3.46]; P = 0.020). Gastrointestinal hemorrhage occurred significantly more frequently in the aspirin-treated group than the non-aspirin-treated group (63 [1.58%] vs 18 [0.45%]; relative risk [RR] 3.5 [2.08-5.90]; P < 0.0001). Cerebral hemorrhage (intracranial hemorrhage) tended to occur more frequently in the aspirin-treated group than the non-aspirin-treated group (22 [0.55%] vs 11 [0.28%]; RR 2.01 [0.97-4.14]; P = 0.058). Cerebral hemorrhage occurred significantly more frequently in old patients than in young-old patients (33 [0.41%] vs 10 [0.15%]; HR 2.7 [1.34-5.53]; P = 0.0055). Gastrointestinal hemorrhage occurred in a slightly higher proportion of old patients compared with young-old patients (81 [1.02%] vs 53 [0.82%]; RR 1.2 [0.88-1.76]; P = 0.21). DISCUSSION/CONCLUSIONS: Aspirin did not reduce the risk of the primary or secondary outcomes in old patients. Aspirin treatment may have reduced CVEs within a high CVE risk elderly population subgroup. Aspirin treatment in such a group requires caution, because of the increased risk of intracranial hemorrhage, severe extracranial hemorrhage requiring hospitalization or transfusion, and gastrointestinal bleeding in old patients receiving aspirin therapy. CLINICAL TRIAL REGISTRATION: The study is registered at ClinicalTrials.gov [NCT00225849].

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).

Effects of daily aspirin on cancer incidence and mortality in the elderly Japanese.

BACKGROUND: Long-term follow-up of studies to investigate preventive effects of aspirin on arterial thrombosis indicate that aspirin reduces the incidence and mortality of some cancers in Western populations. OBJECTIVES: To explore the effects of aspirin on cancer incidence and mortality in the elderly Japanese. PATIENTS/METHODS: Patients aged 60 to 85 years, presenting with hypertension, dyslipidemia, or diabetes mellitus (n = 14 601, 7297 in the aspirin group and 7304 in the no-aspirin group) participated the Japanese Primary Prevention Project (JPPP), a multicenter, open-label, randomized, parallel-group trial. A subanalysis of JPPP was performed to analyze the incidence of newly diagnosed cancer and death related to cancer. RESULTS: The cumulative incidence of newly diagnosed cancer was 5.60% (4.65-6.64%) in the aspirin group and 4.14% (3.67-4.66%) in the no-aspirin group. The hazard ratio for newly diagnosed cancer was 1.24 (1.06-1.46), and the cancer incidence was significantly higher in the aspirin group. The cumulative cancer mortality was 1.96% (1.65-2.31%) in the aspirin group and 1.87% (1.56-2.22%) in the no-aspirin group, with no statistically significant difference. The Fine and Gray model suggested that the difference in the incidence of newly diagnosed cancer between the two groups decreased year by year. CONCLUSIONS: Low-dose aspirin use did not reduce the cancer incidence or cancer mortality during a 5-year-average study period in the elderly Japanese. The cancer incidence in the aspirin group might decrease, however, to less than that in the no-aspirin group after the study period. Aspirin use might have led to earlier cancer diagnosis in our study.

A noninferiority confirmatory trial of prasugrel versus clopidogrel in Japanese patients with non-cardioembolic stroke: rationale and study design for a randomized controlled trial - PRASTRO-I trial.

BACKGROUND: This comparison of PRAsugrel and clopidogrel in Japanese patients with ischemic STROke (PRASTRO)-I trial investigates the noninferiority of prasugrel to clopidogrel sulfate in the prevention of recurrence of primary events (ischemic stroke, myocardial infarction, and death from other vascular causes), and the long-term safety of prasugrel in Japanese patients with non-cardioembolic stroke. RESEARCH DESIGN AND METHODS: This was an active-controlled, randomized, double-blind, double-dummy, parallel-group study conducted between July 2011 and March 2016 at multiple centers around Japan. Patients had to meet eligibility criteria before receiving 3.75 mg prasugrel or 75 mg clopidogrel orally once daily for a period of 96-104 weeks. RESULTS: A total of 3747 patients were included in this trial; 1598 in the 3.75 mg prasugrel group and 1551 in the 75 mg clopidogrel group completed the study. During the study period, 287 (15.2%) patients in the prasugrel group and 311 (16.7%) in the clopidogrel group discontinued treatment. Baseline characteristics, safety, and efficacy results are forthcoming and will be published separately. CONCLUSIONS: This article presents the study design and rationale for a trial investigating the noninferiority of prasugrel to clopidogrel sulfate with regards to the inhibitory effect on primary events in patients with non-cardioembolic stroke.

Risk of bleeding and repeated bleeding events in prasugrel-treated patients: a review of data from the Japanese PRASFIT studies.

Prasugrel is a third-generation thienopyridine that achieves potent platelet inhibition with less pharmacological variability than other thienopyridines. However, clinical experience suggests that prasugrel may be associated with a higher risk of de novo and recurrent bleeding events compared with clopidogrel in Japanese patients undergoing percutaneous coronary intervention (PCI). In this review, we evaluate the risk of bleeding in Japanese patients treated with prasugrel at the doses (loading/maintenance doses: 20/3.75 mg) adjusted for Japanese patients, evaluate the risk factors for bleeding in Japanese patients, and examine whether patients with a bleeding event are at increased risk of recurrent bleeding. This review covers published data and new analyses of the PRASFIT (PRASugrel compared with clopidogrel For Japanese patIenTs) trials of patients undergoing PCI for acute coronary syndrome or elective reasons. The bleeding risk with prasugrel was similar to that observed with the standard dose of clopidogrel (300/75 mg), including when bleeding events were re-classified using the Bleeding Academic Research Consortium criteria. The pharmacodynamics of prasugrel was not associated with the risk of bleeding events. The main risk factors for bleeding events were female sex, low body weight, advanced age, and presence of diabetes mellitus. Use of a radial puncture site was associated with a lower risk of bleeding during PCI than a femoral puncture site. Finally, the frequency and severity of recurrent bleeding events during continued treatment were similar between prasugrel and clopidogrel. In summary, this review provides important insights into the risk and types of bleeding events in prasugrel-treated patients.Trial registration numbers: JapicCTI-101339 and JapicCTI-111550.

Residual Ischemic Risk and Its Determinants in Patients With Previous Myocardial Infarction and Without Prior Stroke or TIA: Insights From the REACH Registry.

BACKGROUND: Although the rate of in-hospital ischemic events after myocardial infarction (MI) has dramatically decreased, long-term residual risk may remain substantial. However, most of the information on current residual risk is derived from highly selected randomized trials. HYPOTHESIS: In patients with previous MI and no prior ischemic stroke/transient ischemic attack (TIA), residual ischemic risk increases over time. METHODS: Using the international Reduction of Atherothrombosis for Continued Health (REACH) registry, we analyzed baseline characteristics and 4-year follow-up of patients with previous MI and no history of stroke/TIA to describe annual rates of recurrent ischemic events globally and by geography. The primary outcome was the composite of cardiovascular death, MI, or stroke. Multivariate analysis identified risk factors associated with recurrent ischemic events. RESULTS: Data from 16 770 patients enrolled at 5587 sites in 44 countries were analyzed. The rate of the primary outcome increased annually from 4.7% during year 1 to reach a 4-year rate of 15.1%. Compared with North America, Japan experienced lower ischemic event rates (P < 0.01), whereas Eastern Europe (P < 0.01) and the Middle East (P = 0.01) experienced higher ischemic event rates. The presence of congestive heart failure, polyvascular disease, diabetes, atrial fibrillation or flutter, and older age were associated with increased residual risk (all P < 0.01). Statin use was associated with lower ischemic risk (P < 0.01). CONCLUSIONS: In this study, residual ischemic risk after MI accrued progressively up to 4 years of follow-up, emphasizing the value of intensive secondary prevention strategies to minimize residual risk.

Phospholipase Cß1 induces membrane tubulation and is involved in caveolae formation.

Lipid membrane curvature plays important roles in various physiological phenomena. Curvature-regulated dynamic membrane remodeling is achieved by the interaction between lipids and proteins. So far, several membrane sensing/sculpting proteins, such as Bin/amphiphysin/Rvs (BAR) proteins, are reported, but there remains the possibility of the existence of unidentified membrane-deforming proteins that have not been uncovered by sequence homology. To identify new lipid membrane deformation proteins, we applied liposome-based microscopic screening, using unbiased-darkfield microscopy. Using this method, we identified phospholipase Cß1 (PLCß1) as a new candidate. PLCß1 is well characterized as an enzyme catalyzing the hydrolysis of phosphatidylinositol-4,5-bisphosphate (PIP2). In addition to lipase activity, our results indicate that PLCß1 possessed the ability of membrane tubulation. Lipase domains and inositol phospholipids binding the pleckstrin homology (PH) domain of PLCß1 were not involved, but the C-terminal sequence was responsible for this tubulation activity. Computational modeling revealed that the C terminus displays the structural homology to the BAR domains, which is well known as a membrane sensing/sculpting domain. Overexpression of PLCß1 caused plasma membrane tubulation, whereas knockdown of the protein reduced the number of caveolae and induced the evagination of caveolin-rich membrane domains. Taken together, our results suggest a new function of PLCß1: plasma membrane remodeling, and in particular, caveolae formation.

Aspirin for Stroke Prevention in Elderly Patients With Vascular Risk Factors: Japanese Primary Prevention Project.

BACKGROUND AND PURPOSE: The effect of aspirin in primary prevention of stroke is controversial among clinical trials conducted in Western countries, and no data are available for Asian populations with a high risk of intracranial hemorrhage. The objective of this study was to evaluate the effect of aspirin on the risk of stroke and intracranial hemorrhage in the Japanese Primary Prevention Project (JPPP). METHODS: A total of 14 464 patients (age, 60-85 years) with hypertension, dyslipidemia, and diabetes mellitus participated and were randomized into 2 treatment groups: 100 mg of aspirin or no aspirin. The median follow-up period was 5.02 years. RESULTS: The cumulative rate of fatal or nonfatal stroke was similar for the aspirin (2.068%; 95% confidence interval [CI], 1.750-2.443) and no aspirin (2.299%; 95% CI, 1.963-2.692) groups at 5 years; the estimated hazard ratio was 0.927 (95% CI, 0.741-1.160; P=0.509). Aspirin nonsignificantly reduced the risk of ischemic stroke or transient ischemic attack (hazard ratio, 0.783; 95% CI, 0.606-1.012; P=0.061) and nonsignificantly increased the risk of intracranial hemorrhage (hazard ratio, 1.463; 95% CI; 0.956-2.237; P=0.078). A Cox regression adjusted by the risk factors for all stroke, which were age >70 years, smoking, and diabetes mellitus, supported the above result. CONCLUSIONS: Aspirin did not show any net benefit for the primary prevention of stroke in elderly Japanese patients with risk factors for stroke, whereas age >70 years, smoking, and diabetes mellitus were risk factors for stroke regardless of aspirin treatment. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00225849.

Effects of CYP2C19 allelic variants on inhibition of platelet aggregation and major adverse cardiovascular events in Japanese patients with acute coronary syndrome: The PRASFIT-ACS study.

BACKGROUND: We examined the effects of cytochrome P450 2C19 (CYP2C19) polymorphisms on the efficacy and safety of prasugrel and clopidogrel in a post hoc analysis of the PRASugrel compared with clopidogrel For Japanese patIenTs with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) (PRASFIT-ACS) study. METHODS: Japanese ACS patients undergoing PCI were randomized (double-blind) to receive prasugrel (loading/maintenance dose: 20/3.75mg) or clopidogrel (300/75mg) plus aspirin for 24-48 weeks. Pharmacogenomic analyses were conducted in 773/1363 patients. P2Y12 reaction units (PRU) were determined using the VerifyNow(®) P2Y12 assay (Accumetrics, San Diego, CA, USA). CYP2C19 genotypes were classified as extensive metabolizers (EM), intermediate metabolizers (IM), and poor metabolizers (PM). RESULTS: Overall, 39.2% and 60.8% of patients in the prasugrel group and 35.2% and 64.8% of patients in the clopidogrel group were classified as EM and IM+PM, respectively. Among EM patients, PRU was significantly lower in the prasugrel group than in the clopidogrel group at 2-4 and 5-12h after the loading dose, but was similar in both groups from week 4 onwards. Among IM+PM patients, PRU was significantly lower in the prasugrel group than in the clopidogrel group throughout the study. Among EM patients, the incidence of major adverse cardiovascular events (MACE) at 24 weeks was 11.8% in the prasugrel group and 11.9% in the clopidogrel group [hazard ratio (HR): 0.99, 95% confidence interval (CI): 0.50-1.96]. Among IM+PM patients, the incidence of MACE was 9.3% in the prasugrel group and 12.5% in the clopidogrel group (HR: 0.78, 95% CI: 0.45-1.35). The incidences of major, minor, and clinically relevant bleeding were similar between the two groups for each genotype. CONCLUSIONS: Prasugrel showed more consistent antiplatelet effects than clopidogrel in Japanese ACS patients irrespective of the CYP2C19 phenotype.

Efficacy and safety of rituximab in Japanese patients with relapsed chronic immune thrombocytopenia refractory to conventional therapy.

Primary immune thrombocytopenia (ITP) is an autoimmune disease mediated by the production of autoantibody against platelets. Rituximab, an anti-CD20 antibody, is reported to be useful for treatment of ITP. In Japan, however, robust evidence on this treatment has not been accumulated. Hence, we conducted this open-label phase III clinical trial to confirm the efficacy and safety of rituximab, administered at 375 mg/m² once per week at weekly intervals for 4 consecutive weeks in Japanese patients with chronic ITP, who had relapsed and were refractory to conventional therapy. The primary endpoint was defined as the percentage of patients with a platelet count above 50 × 109/L at week 24 after the first dose of rituximab, which was 30.8% of 26 patients (95% confidence interval 14.3-51.8%). Although the lower confidence limit of primary endpoint failed to meet the pre-specified threshold of 20%, the clinical efficacy of rituximab is substantial in consideration of the 2% response rate in the placebo arm in other clinical studies in patients with chronic ITP. We conclude that rituximab is clinically useful and safe in the treatment of Japanese patients with chronic ITP, achieving the goal of maintaining platelet count and reducing risk of bleeding while minimizing treatment-related toxicity.