Low-Dose Aspirin for Prevention of Stroke in Low-Risk Patients With Atrial Fibrillation

Abstract

on behalf of the Japan Atrial Fibrillation Stroke Trial (JAST) GroupBackground and Purpose-Although the efficacy of anticoagulant therapy for primary prevention of stroke in patients with nonvalvular atrial fibrillation (NVAF) has been established, efficacy of antiplatelet therapy for low-risk patients is disputable in Japanese patients because of the frequent hemorrhagic complications. We examined the efficacy and safety of aspirin therapy in Japanese patients with NVAF in a prospective randomized multicenter trial. Methods-Patients with NVAF were randomized to an aspirin group (aspirin at 150 to 200 mg per day) or a control group without antiplatelet or anticoagulant therapy. Primary end points included cardiovascular death, symptomatic brain infarction, or transient ischemic attack. Results-A total of 426 patients were randomized to aspirin group and 445 to no treatment. The trial was stopped earlier because there were 27 primary end point events (3.1% per year; 95% CI, 2.1% to 4.6% per year) in the aspirin group versus 23 (2.4% per year; 95% CI, 1.5% to 3.5% per year) in the control group, suggesting a low possibility of superiority of the aspirin treatment for prevention of the primary end point. In addition, treatment with aspirin caused a marginally increased risk of major bleeding (7

Comparison Between CHADS₂ and CHA₂DS₂-VASc Score for Risk Stratification of Ischemic Stroke in Japanese Patients With Non-Valvular Paroxysmal Atrial Fibrillation Not Receiving Anticoagulant Therapy

“…16,17) The annual incidence in Japan thus appears to be similar to that in Europe and the United States. The CHADS 2 score in particular is an independent predictor not only for ischemic stroke but also for conversion to chronic AF in patients with paroxysmal AF during antiarrhythmic drug therapy.…”

“…20) According to the guidelines for pharmacotherapy of AF published by JCS in 2008, 21) only anticoagulant therapy (warfarin) as an antithrombotic regimen is recommended for patients with non-valvular AF. Based on the results of a largescale controlled study in Japan, Europe, and the United States, 17,22) antiplatelet therapy recommended in the previous JCS guidelines was deleted. Furthermore, warfarin therapy for prevention of ischemic stroke/systemic thromboembolism in patients with non-valvular AF is expected to be about more than 60% in Europe and the United States, 23) and Japan, 24) although its effi cacy is infl uenced by the quality of anticoagulant control that it provides (management of PT-INR).…”

Antiplatelet Therapy of Atrial Fibrillation: Focus on the Elderly

“…Пользу от применения АСК не удалось выявить ни в одной возрастной груп-пе (<65 лет, 65-74 лет, ≥75 лет, ≥80 лет). Из-за тен-денции к повышенному риску развития ишемическо-го инсульта, транзиторной ишемической атаки и сер-дечно-сосудистой смерти при применении АСК по сравнению с отсутствием лечения было досрочно пре-рвано РКИ с участием японских пациентов с низким рис-ком развития инсульта [16].…”

Stroke Prevention in Atrial Fibrillation: Pharmacologic Update

“…These studies were associated with relative risk reductions of stroke ranging from 11-44% and metaanalysis estimated overall risk reduction was 22; 95 CI, 2-39% (Hart et al, 2007;Petersen et al, 1989;AHA, 1991;Benavente and Hart, 1997;EAFT, 1993;Benavente et al, 2000). Two other studies (LASAF and JAST) compared no treatment to aspirin at doses of either 125mg daily or every other day for LASAF and 150g daily for JAST (Posada and Barriales, 1999;Sato et al, 2006). Relative risks of 10 and 17% were observed in JAST and the arm of LASAF that dosed aspirin daily, respectively.…”