Current antithrombotic treatment in East Asia: Some perspectives on anticoagulation and antiplatelet therapy

Real-world data emulating randomized controlled trials of non-vitamin K antagonist oral anticoagulants in patients with venous thromboembolism

BACKGROUND

Emulating randomized controlled trials (RCTs) by real-world evidence (RWE) studies would benefit future clinical and regulatory decision-making by balancing the limitations of RCT. We aimed to evaluate whether the findings from RWE studies can support regulatory decisions derived from RCTs of non-vitamin K antagonist oral anticoagulants (NOACs) in patients with venous thromboembolism (VTE).

METHODS

Five landmark trials (AMPLIFY, RE-COVER II, Hokusai-VTE, EINSTEIN-DVT, and EINSTEIN-PE) of NOACs were emulated using the South Korean nationwide claims database (January 2012 to August 2020). We applied an active comparator and new-user design to include patients who initiated oral anticoagulants within 28 days from their VTE diagnoses. The prespecified eligibility criteria, exposure (each NOAC, such as apixaban, rivaroxaban, dabigatran, and edoxaban), comparator (conventional therapy, defined as subcutaneous heparin followed by warfarin), and the definition of outcomes from RCTs were emulated as closely as possible in each separate emulation cohort. The primary outcome was identical to each trial, which was defined as recurrent VTE or VTE-related death. The safety outcome was major bleeding. Propensity score matching was conducted to balance 69 covariates between the exposure groups. Effect estimates for outcomes were estimated using the Mantel-Haenszel method and Cox proportional hazards model and subsequently compared with the corresponding RCT estimates.

RESULTS

Compared to trial populations, real-world study populations were older (range: 63-69 years [RWE] vs. 54-59 years [RCT]), with more females (55-60.5% vs. 39-48.3%) and had a higher prevalence of active cancer (4.2-15.4% vs. 2.5-9.5%). The emulated estimates for effectiveness outcomes showed superior effectiveness of NOAC (AMPLIFY: relative risk 0.81, 95% confidence interval 0.70-0.94; RE-COVER II: hazard ratio [HR] 0.60, 0.37-0.96; Hokusai-VTE: 0.49, 0.31-0.78; EINSTEIN-DVT: 0.54, 0.33-0.89; EINSTEIN-PE: 0.50, 0.34-0.74), when contrasted with trials that showed non-inferiority. For safety outcomes, all emulations except for AMPLIFY and EINSTEIN-DVT yielded results consistent with their corresponding RCTs.

CONCLUSIONS

This study revealed the feasibility of complementing RCTs with RWE studies by using claims data in patients with VTE. Future studies to consider the different demographic characteristics between RCT and RWE populations are needed.

Low-dose non-vitamin K antagonist oral anticoagulants in patients with atrial fibrillation

In the last decade, non-vitamin K antagonist oral anticoagulants (NOACs), a new generation of OACs, were introduced to prevent thromboembolism in patients with atrial fibrillation. Although vitamin K-dependent anticoagulants have long been used as OACs, their inherent disadvantage of considerable bleeding complications has limited their use. NOACs demonstrate similar or superior clinical outcomes to those of warfarin. Although strict dose reduction criteria are recommended for NOACs, low-dose NOACs are frequently utilized, especially in Asian patients. Low-dose NOACs have shown clinical outcomes similar to those of warfarin in randomized controlled trials (RCTs) and real-world studies. However, off-label low-dose NOACs have shown inconsistent results compared with standard-dose NOACs and warfarin. Therefore, strict dose reduction criteria for NOACs should be followed until RCTs confirm the issues associated with NOAC underdosing.

Off-label reduced-dose apixaban does not reduce hemorrhagic risk in Taiwanese patients with nonvalvular atrial fibrillation: A retrospective, observational study

ABSTRACT

East Asians are reportedly at high risk of anticoagulant-related bleeding; therefore, some physicians prefer to prescribe low-dose direct oral anticoagulants (DOACs). Little is known about the therapeutic effectiveness and safety of off-label reduced-dose apixaban in East Asians with nonvalvular atrial fibrillation (AF). We aimed to investigate the effectiveness and safety of off-label reduced-dose apixaban in Taiwanese patients with nonvalvular AF.This retrospective cohort study enrolled 1073 patients with nonvalvular AF who took apixaban between July 2014 and October 2018 from 4 medical centers in southern Taiwan. The primary outcomes included thromboembolic events (stroke/transient ischemic attack or systemic embolism), major bleeding, and all-cause mortality.Among all patients, 826 (77%) patients were classified as the "per-label adequate-dose" treatment group (i.e., consistent with the Food and Drug Administration label recommendations) while 247 (23%) patients were the "off-label reduced-dose" treatment group. The mean follow-up period was 17.5 ± 13 months. The "off-label reduced-dose" group did not have a lower major bleeding rate than the "per-label adequate-dose" group (4.8% vs 3.8%, adjusted hazard ratio [HR] 1.20, 95% confidence interval [CI] 0.69-2.09), but had a nonsignificantly higher incidence of thromboembolic events (4.23% vs 3.05%, adjusted HR: 1.29, 95% CI: 0.71-2.34).An off-label reduced-dose apixaban treatment strategy may not provide incremental benefits or safety for Taiwanese patients with nonvalvular AF.

Implications and characteristics of high bleeding risk in East Asian patients undergoing percutaneous coronary intervention: Start with what is right rather than what is acceptable

Recent advances in percutaneous coronary intervention (PCI) technology and medication have changed the main focus of PCI from preventing ischemic to preventing bleeding events. Bleeding risk assessment is essential for preventing bleeding. Several types of assessment tools have been established, but they are heterogeneous, making interpretation, generalization, and comparison between trials difficult. In 2019, the Academic Research Consortium (ARC) introduced a new consensus document with 20 criteria to define high bleeding risk (HBR). The applicability of the ARCHBR criteria were subsequently investigated, and 4 studies have already demonstrated wide applicability worldwide, including in Japan. Nevertheless, it hase been suggested that bleeding risk is higher in people from East Asian countries than in people from Western countries. Patients with HBR have a 3-fold higher risk of major bleeding, and in Japan approximately 50% of patients undergoing PCI have HBR. In addition, patients with overlapping factors, such as older age, renal disease, and anemia, are at increased risk of bleeding, and each additional factor further increases the risk. In Japanese patients undergoing PCI, in addition to the ARC-HBR criteria, low body weight, heart failure, and peripheral arterial disease are high-risk subsets for bleeding. The addition of these factors to the ARCHBR criteria increases the prevalence of HBR in Japanese patients to 58% and improves the sensitivity of diagnostic evaluations. The additional factors are clinically important because they are often encountered in everyday practice, and Japan's newly updated guideline has adopted them as criteria for HBR. Studies found a temporal trend over the past 20 years of a gradual and consistent increase of bleeding risk. This finding contrasts with improved outcomes in people at risk of ischemic and thrombotic events. Therefore, further research is needed to eliminate the risk of bleeding while maintaining the efficacy of antithrombotic therapy after PCI.

The East Asian Paradox: An Updated Position Statement on the Challenges to the Current Antithrombotic Strategy in Patients with Cardiovascular Disease

East Asian patients have reduced anti-ischemic benefits and increased bleeding risk during antithrombotic therapies compared with Caucasian patients. As potent P2Y₁₂ receptor inhibitors (e.g., ticagrelor and prasugrel) and direct oral anticoagulants are commonly used in current daily practice, the unique risk-benefit trade-off in East Asians has been a topic of emerging interest. In this article, we propose updated evidence and future directions of antithrombotic treatment in East Asian patients.

Ethnic Differences in Oral Antithrombotic Therapy

Oral antithrombotic therapy (antiplatelet therapy and anticoagulation therapy) is a key element of pharmacotherapy in patients with cardiovascular (CV) disease. Several reports of ethnic differences have suggested that there may be difference therapeutic requirements and response to therapy for antithrombotic therapy. In particular for East Asians, there seems to be a lower incidence of ischemic outcomes and a higher incidence of bleeding outcomes compared to Westerners. The purpose of this review is to describe the ethnicity-related differences in antithrombotic therapy for CV disease and to discuss the need to establish a more effective and targeted antithrombotic treatment strategy in East Asians.

Prediction of gastrointestinal bleeding events in patients with acute coronary syndrome undergoing percutaneous coronary intervention: An observational cohort study (STROBE compliant)

Bleeding complications of acute coronary syndromes (ACS) after percutaneous coronary intervention (PCI) are strongly associated with adverse patient outcomes, and gastrointestinal bleeding (GIB) is the most common major bleeding event, especially in the early post-PCI period. Current guidelines recommend routinely conducting bleeding risk assessments. The existing tools are mainly used to evaluate the overall bleeding risk and guide the adjustment of antithrombotic strategies after 1 year. However, there are no specific tools for GIB risk assessment.Between January 2015 and June 2015, 4943 ACS patients underwent PCI were consecutively enrolled in the derivation cohort. GIB, cardiovascular, and cerebrovascular events were recorded within 1 year of follow-up. A validation cohort including 1000 patients who met the same inclusion and exclusion criteria was also established by propensity-score matching baseline characteristics. Multivariable cox proportional-hazards regression model was used to derive a risk-scoring system, and predictive variables were selected. A risk score nomogram based on the risk prediction model was created to estimate the 1-year risk of GIB.In this study, we found that the usage of clopidogrel (hazard ratio, HR: 2.52, 95% confidence intervals, CI: 1.573-4.021) and glycoprotein IIb/IIIa receptor inhibitors (HR: 1.863, 95% CI: 1.226-2.829), history of peptic ulcers (HR: 3.601, 95% CI: 1.226-2.829) or tumor (HR: 4.884, 95% CI: 1.226-2.829), and cardiac insufficiency (HR: 11.513, 95% CI: 7.282-18.202), renal insufficiency (HR: 2.010, 95% CI: 1.350-2.993), and prolonged activated partial thromboplastin time (HR: 4.639, 95% CI: 2.146-10.032) were independent risk factors for GIB 1 year after PCI. Based on these 7 factors, a nomogram and scoring system was established. The area under curve of risk score was 0.824 in the deviation cohort and 0.810 in the verification cohort. In both cohorts, the GIB score was significantly better than that of 3 classical bleeding scores (all P < .05).This score could well predict the risk of GIB within 1 year after PCI and could be used to guide antithrombotic strategies.

Comparison between ticagrelor versus clopidogrel in long term outcomes of Taiwanese diabetic subjects with acute coronary syndrome undergoing successful revascularization: From TSOC ACS-DM registry

Although previous clinical trials demonstrated that ticagrelor could reduce cardiovascular events and mortality versus clopidogrel in patients with acute coronary syndrome (ACS), the real-world evidence of its clinical impacts on East Asian Diabetic population has rarely been investigated.Between November 2013 and June 2015, 1534 patients were recruited into the Acute Coronary Syndrome-Diabetes Mellitus Registry of the Taiwan Society of Cardiology (TSOC ACS-DM registry). After propensity score matching, a total of 730 patients undergoing successful revascularization and discharged on ticagrelor (N = 365) or clopidogrel (N = 365) were analyzed. The primary and secondary endpoints were all-cause mortality and re-hospitalization, respectively. The all-cause death associated with ticagrelor vs clopidogrel was 3.6% vs 7.4% (adjusted hazard ratio (HR) 0.34 [0.15-0.80]; P = .0138) at 24 months. The re-hospitalization rate at 24 months was 38.9% vs 39.2% (P = .3258).For diabetic patients with ACS, ticagrelor provided better survival benefit than clopidogrel without an increase of re-hospitalization in 24 months after successful percutaneous coronary intervention. This study in real-world circumstance provided valuable complementary data to externally validate platelet inhibition and patient outcomes (PLATO) finding especially in Asian diabetic population.

Efficacy and safety of standard and low dose ticagrelor versus clopidogrel in east AsianPatients with chronic total occlusion undergoing percutaneous coronary intervention: a single center retrospective study

BACKGROUND

Patients with coronary chronic total occlusion (CTO) require effective antiplatelet therapy after percutaneous coronary intervention (PCI). Ticagrelor has more pronounced platelet inhibition than clopidogrel. However, the most appropriate dose of ticagrelor in East Asian populations remains unclear.

METHOD

We compared ticagrelor (180 mg loading dose, 90 mg twice daily thereafter and 120 mg loading dose, 60 mg twice daily thereafter) and clopidogrel (300 mg loading dose, 75 mg daily thereafter) for prevention of cardiovascular events in 525patients with CTO undergoing PCI.

RESULTS

The rate of in-hospital major adverse cardiac and cerebral events (MACCE) was not different between the groups. At 1-year follow-up, target vessel revascularization (TVR) in both ticagrelor groups were significantly lower than that in the clopidogrel group (p = 0.047); TVR was significantly decreased in 60 mg ticagrelor compared to standard dose clopidogrel (p = 0.046). At 1-year follow-up, overall MACCE in both ticagrelor groups were significantly lower than that in the clopidogrel group (p = 0.023). Kaplan-Meier analysis showed MACCE-free survival was significantly higher in both ticagrelor groups than in the clopidogrel group (p = 0.024). During hospitalization, minor bleeding was significant increased in the 90 mg ticagrelor group (p = 0.021). At 1-year follow-up, risk of major and minor bleeding were significantly increased in the 90 mg ticagrelor group.

CONCLUSION

In East Asian patients with CTO undergoing PCI, 60 mg ticagrelor was as effective as 90 mg, at the same time significantly reduced risk of bleeding.

Ablation Versus Medical Therapy for Atrial Fibrillation in the Elderly: A Propensity Score-Matched Comparison

Background

Whether ablation therapy reduces the risk of death and embolic events in elderly patients with atrial fibrillation (AF) remains unclear.

Material/Methods

AF patients ≥65 years old receiving either catheter ablation or non-ablation therapy at 2 tertiary and 2 non-tertiary hospitals in Beijing from November 2009 to December 2012 were enrolled. Patients were followed up every 6 months for information on treatment and clinical event occurrence. A propensity score matching algorithm produced comparable 2 groups of patients treated with ablation or non-ablation. Rates of a composite of all-cause death, non-fatal stroke, and peripheral embolism were the primary outcomes. Each composite component and major bleeding were the secondary outcomes.

Results

There were 596 ablated patients and 1144 patients with non-ablation therapy enrolled. Propensity score algorithm matched 347 comparable pairs of patients. Patient characteristics variables were well balanced. During 523.5 and 497.5 patient-years follow-up, respectively, ablation therapy was associated with a significant lower risk of experiencing the primary composite outcome (hazard ratio [HR]=0.40; 95% confidence interval [CI]: 0.19–0.85), all-cause death (HR=0.13 95% CI: 0.04–0.43), and major bleeding (HR=0.23; 95% CI: 0.12–0.67), without apparent heterogeneity by age, sex, and AF type, and for risk score subgroups.

Conclusions

In this propensity-matched elderly sample, ablation therapy was associated with lower risk of composite outcome consisting of all-cause death, non-fatal stroke, and peripheral embolism, and therefore might be an alternative to conservative therapy.

Guideline-Adherent Treatment for Stroke and Death in Atrial Fibrillation Patients From UK and Japanese AF Registries

BACKGROUND

Guideline-adherent antithrombotic treatment (ATT) reduces the risk of stroke and death in patients with atrial fibrillation (AF). However, the effect of ATT adherence among different ethnicities remains uncertain. We compared the prognosis of AF patients in Japan and the UK according to guideline adherence status.Methods and Results:We compared the clinical characteristics and outcomes of AF patients from the Fushimi AF registry (Japan; n=4,239) and the Darlington AF registry (UK; n=2,259). ATT adherence was assessed against the Japanese Circulation Society Guidelines and UK National Institute for Health and Care Excellence guidelines. The rates of guideline-adherent ATT were 58.6% and 50.8% in the Fushimi and Darlington registries, respectively. There was no significant difference in 1-year stroke rates between Fushimi and Darlington (2.6% vs. 3.0%, P=0.342). On multivariate logistic regression analysis, non-guideline adherent-ATT was significantly associated with an increased risk of stroke (odds ratio [OR]: 1.69, 95% confidence interval [CI]: 1.21-2.34, P=0.002 for undertreatment, OR: 2.13, 95% CI: 1.19-3.80, P=0.010 for overtreatment). No significant interaction for ATT and the 2 populations was found in the incidence of stroke, all-cause death, and the composite outcome.

CONCLUSIONS

Approximately half of the AF patients received optimal ATT according to guideline recommendations, which was associated with a lower risk of stroke. Furthermore, there was no interaction for the 2 populations and the influence of ATT adherence.

Safety and effectiveness of apixaban in Japanese patients with nonvalvular atrial fibrillation in clinical practice: A regulatory postmarketing surveillance, the STANDARD study

BACKGROUND

Apixaban, a non-vitamin K oral anticoagulant (NOAC), was approved in Japan in 2012 for the prevention of thromboembolic events in patients with nonvalvular atrial fibrillation (NVAF). However, the safety and effectiveness of apixaban in clinical practice have not yet been elucidated thoroughly among Japanese NVAF patients.

METHODS

A postmarketing surveillance study was conducted to determine the safety and effectiveness of apixaban. Patients were followed-up for 104 weeks. Outcome events included adverse drug reactions (ADRs), hemorrhages, and thromboembolic events (ischemic stroke, systemic embolism [SE], and transient ischemic attack [TIA]).

RESULTS

Among 6306 NVAF patients in the safety analysis set (age, 74.5 ± 10.1 years; women, 41.1%; and CHADS 2 score, 2.0 ± 1.4), 3600 patients (57.1%) received the standard dose (5 mg twice daily) and 2694 (42.7%) received a reduced dose (2.5 mg twice daily) of apixaban. ADRs occurred in 604 patients (9.58%), with the most common being epistaxis (0.86%), subcutaneous hemorrhage (0.67%), and hematuria (0.57%). Incidence rate of any hemorrhages and major hemorrhage was 5.52% per year and 2.36% per year, respectively. Incidence rate of ischemic stroke/SE/TIA was 1.00% per year among 6286 patients in the effectiveness analysis set. Among three subgroups (3106 apixaban initiators, 2038 patients switched from warfarin, and 1118 patients switched from other NOACs), incidence rates of major hemorrhage (P = 0.221 for trend) and ischemic stroke/SE/TIA (P = 0.686 for trend) were comparable.

CONCLUSIONS

No new safety signals of apixaban were identified in Japanese NVAF patients. Safety and effectiveness of apixaban were consistent with those in the ARISTOTLE study.

2018 update of expert consensus statement on antiplatelet therapy in East Asian patients with ACS or undergoing PCI

East Asians are the most populous race in the world and their health status is an important global issue. Compared with Caucasian populations, East Asian patients have a different benefit/risk ratio when using antithrombotic treatment. Despite this observation, treatment strategies in East Asian patients are mostly based on the American and European guidelines. Despite a lower platelet inhibitory response to clopidogrel, East Asian patients show a similar or even a lower rate of ischemic event occurrence and higher bleeding risk compared with Caucasian patients. For potent P2Y₁₂ inhibitors (ticagrelor and prasugrel), East Asian patients have shown less favorable net clinical benefits compared with Caucasian patients, which may be related to differences in pharmacokinetic/pharmacodynamic profiles and therapeutic zone of antiplatelet effect. This updated consensus mainly focuses on state-of-the-art and current controversies in the East Asian population. In addition, when East Asian patients are administered potent P2Y₁₂ receptor inhibitors, the strategies and ongoing trials to overcome the related hurdles are discussed.

The effect of tranexamic acid in unilateral and bilateral total knee arthroplasty in the South Asian population: A retrospective cohort study

INTRODUCTION

Together with evidence of higher bleeding tendencies, the vulnerability of the South-Asian population to anemia secondary to a higher prevalence of hemoglobinopathies and micronutrient deficiencies merits further exploration of the effects of tranexamic acid on this population. Additionally, limited access to self-care facilities and certain sociocultural beliefs and practices may not be conducive to a speedy recovery from surgical complications. The aim of this study is to investigate the effects of intraoperative administration of tranexamic acid during total knee arthroplasty when considering the South-Asian population.

METHODOLOGY

Medical record files of 355 patients who underwent total knee arthroplasty (2007-2015) were reviewed to collect data regarding patient characteristics, surgical variables and post-operative complications. Unilateral and Bilateral total knee arthroplasty were studied separately. Analysis was done using t-test, Mann-Whitney U test, chi-square and Fisher's exact square where appropriate. The threshold for significance was p < 0.05.

RESULTS

The study showed that for unilateral surgery, tranexamic acid caused a significant reduction in estimated blood loss (p-value=0.011), total operative time, calculated blood loss, and hemoglobin change (p-value<0.001) whereas in bilateral surgery, tranexamic acid only caused a significant reduction in calculated blood loss (p-value < 0.001) and hemoglobin change (p-value=0.001). Interestingly, in those who received tranexamic acid vs. those who did not, there was a significant increase in length of hospital stay (p<0.001) and special care unit admissions (p-value=0.033) in unilateral and bilateral surgery respectively.

CONCLUSIONS

Although tranexamic acid effectively reduces intraoperative blood loss, it does not have an effect on the need for post-operative blood transfusions. The increased length of stay and special care unit admissions associated with tranexamic acid use should be explored further to reveal the complete safety profile of tranexamic acid administration in the South-Asian population during total knee arthroplasty.

Total knee Arthroplasty: risk factors for allogeneic blood transfusions in the South Asian population

BACKGROUND

Total knee arthroplasty (TKA) is the recommended treatment for end-stage knee osteoarthritis. Considering the various risks associated with intra and postoperative blood transfusions, better understanding is required with respect to the risk factors contributing to a greater possibility of blood transfusion during or after surgery. Although literature highlights several such factors, our study is among the first to identify these risk factors in the South Asian population which differs from other populations in several ways.

METHODS

The study consists of a review of 658 patients undergoing TKA from 2005 to 2015. Data was obtained from patient medical records and was analysed using logistic regression analysis. The relationship between each predictor and the outcome variable was calculated as an Odds ratio (OR), the threshold of significance for which was p = 0.25 and p = 0.05 for univariate and multivariable analysis respectively.

RESULTS

The mean age of the patient population was 63 years (78% female), 25% of whom received one or more blood transfusions. Multivariable analysis revealed 5 significant independent predictors for increased risk of blood transfusions including bilateral knee surgery (OR:5.51), preoperative anemia (OR:4.15), higher ASA (American Society of Anaesthesiologists) status (3-4) (OR:1.92), female sex (OR:3.44) and BMI (Body mass index) ≤30 (OR:1.79) while increasing co-morbidities and age (>60) were found to be insignificant.

CONCLUSIONS

The factors identified for the South Asian population are largely similar to those for other populations. Identification of high risk patients will permit the application of an international multipronged approach which not only targets the modifiable risk factors but also the decision making process and blood management protocols in order to minimize the transfusion associated risks for a patient undergoing a TKA.

Rationale and design of the Chinese Atrial Fibrillation Registry Study

Background

Robust data on the contemporary management of atrial fibrillation (AF) patients in China are limited. Importantly current practice in AF management has changing dramatically in recent years. Data from a large registry study will enable us to evaluate the uptake and outcomes with different therapies in a large Chinese AF population.

Methods/Design

The Chinese Atrial Fibrillation Registry study (CAFR) aims to enroll 20,000 consecutive atrial fibrillation (AF) patients from 32 tertiary and non-tertiary hospitals in Beijing, China, and follow up these patients every 6 months until 2020. Key data collected includes basic sociodemographic information, symptoms and signs, medical history, results of physical examination and laboratory test, details of treatments and personal insurance status. For patients who consent, 5 ml of blood sample will be stored at −80 °C for future analyses of biomarkers. At each 6 month follow up visit, data relating to clinical outcomes will be collected. Data from a randomly selected 10 % of patients will be internally validated with their raw source data. Ischemic stroke events will be adjudicated by an independent endpoint committee.

Discussion

CAFR will be one of the largest registries of Asian AF patients (and the largest in Chinese AF patients), as well as providing the longest follow up. This study would provide a valuable opportunity for ‘real world’ clinical epidemiology with insights into the uptake (and outcomes) of contemporary AF management.

Trial registration

Chinese Clinical Trial Registry ChiCTR-OCH-13003729. Registered 22 October 2013.

Electronic supplementary material

The online version of this article (doi:10.1186/s12872-016-0308-1) contains supplementary material, which is available to authorized users.

Endovascular versus Non-Interventional Therapy for Cervicocranial Artery Dissection in East Asian and Non-East Asian Patients: a Systematic Review and Meta-analysis

Endovascular methods have been increasingly applied in treating cervicocranial artery dissection (CCAD). Anti-thrombotic therapy, which is used in non-interventional care of CCAD patients, has differential effects in East Asian patients. Therefore, we aimed to compare the clinical outcomes of endovascular versus non-interventional therapy for CCAD in East Asians and non-East Asians. A search was performed for studies comparing endovascular and non-interventional approaches to CCAD patients. Rates of recovery, disability, and mortality were used to assess these approaches in East Asian and non-East Asian patients. Subgroup analyses were conducted for CCAD patients with ruptured dissections. Eleven East Asian studies and five non-East Asian studies were included. The subgroup analyses for CCAD patients with ruptured dissections on mortality (East Asian odds ratio [OR] [95% confidence interval [CI]]: 0.24 [0.08-0.71], P = 0.01; I² = 34%) and good recovery (East Asian OR [95% CI]: 3.79 [1.14-12.60], P = 0.03; I² = 54%) revealed that endovascular therapy is significantly superior to non-interventional therapy for East Asians. No differences in treatment effect upon mortality, disability, or good recovery outcomes were found for the CCAD populations-at-large nor for non-East Asian CCAD patients with ruptured dissections. Endovascular therapy appears to be superior to non-interventional therapy for East Asian CCAD patients with ruptured dissections.

CYP2C19 Poor Metabolizer Is Associated With Clinical Outcome of Clopidogrel Therapy in Acute Myocardial Infarction But Not Stable Angina

Background—

More intensive platelet suppression is required in patients with acute myocardial infarction (AMI) than in those with stable angina because of differential platelet activation between AMI and stable angina. In this context, CYP2C19 genotype leading to reduced active metabolite formation may profoundly affect the clinical outcome of clopidogrel therapy in patients with AMI compared with those with stable angina.

Methods and Results—

Effects of CYP2C19 genotypes on the clinical outcome of clopidogrel therapy were evaluated in 2188 patients (532 patients with AMI and 1656 patients with stable angina) undergoing percutaneous coronary intervention. The primary clinical outcome was a composite of major adverse cardiac and cerebrovascular events defined as death from any cause, nonfatal myocardial infarction, or stroke during 1 year of clopidogrel therapy. Compared with extensive metabolizer, the CYP2C19 poor metabolizer was significantly associated with higher risk of major adverse cardiac and cerebrovascular events in patients with AMI (hazard ratio, 2.88; 95% confidence interval, 1.27–6.53; P =0.011). However, this finding was not seen in patients with stable angina. A significant interaction between CYP2C19 genotypes and disease subsets of AMI and stable angina was identified with respect to major adverse cardiac and cerebrovascular events (adjusted interaction P =0.045). The patients with AMI showed lower percent inhibition of P2Y12 compared with patients with stable angina in CYP2C19 poor metabolizer or CYP2C19 intermediate metabolizer genotype groups but not in CYP2C19 extensive metabolizer genotype group.

Conclusions—

CYP2C19 poor metabolizer is associated with poor clinical outcome of clopidogrel therapy in Asian patients with AMI but not in those with stable angina possibly because of differential requirement of platelet suppression in patients with AMI and stable angina.

Clinical Trial Registration Information—

URL: clinicaltrials.gov . Identifier: NCTO1239914.