Rivaroxaban or Aspirin for Extended Treatment of Venous Thromboembolism
Background
Although many patients with venous thromboembolism require extended treatment, it is uncertain whether it is better to use full- or lower-intensity anticoagulation therapy or aspirin.
許多靜脈血栓的病人需要後期繼續治療，但是使用全強度或稍低強度抗凝治療還是阿司匹林抗板治療，暫不明確哪種治療更佳。
Methods
In this randomized, double-blind, phase 3 study, we assigned 3396 patients with venous thromboembolism to receive either once-daily rivaroxaban (at doses of 20 mg or 10 mg) or 100 mg of aspirin. All the study patients had completed 6 to 12 months of anticoagulation therapy and were in equipoise regarding the need for continued anticoagulation. Study drugs were administered for up to 12 months. The primary efficacy outcome was symptomatic recurrent fatal or nonfatal venous thromboembolism, and the principal safety outcome was major bleeding.
這是一個隨機、雙盲、三期試驗，納入了3396名靜脈血栓病人，試驗設計：一組使用每日一次的利伐沙班(20mg或10mg/次)，另一組服用100mg阿司匹林。所有的病人在此之前都完成了6-12個月的抗凝治療，然後根據抗凝需要繼續使用。該研究的藥物使用都是長達12個月的。研究的主要結果是出現致命或非致命的血栓栓塞複發症狀，主要的安全結局是大出血。
Results
A total of 3365 patients were included in the intention-to-treat analyses (median treatment duration, 351 days). The primary efficacy outcome occurred in 17 of 1107 patients (1.5%) receiving 20 mg of rivaroxaban and in 13 of 1127 patients (1.2%) receiving 10 mg of rivaroxaban, as compared with 50 of 1131 patients (4.4%) receiving aspirin (hazard ratio for 20 mg of rivaroxaban vs. aspirin, 0.34; 95% confidence interval [CI], 0.20 to 0.59; hazard ratio for 10 mg of rivaroxaban vs. aspirin, 0.26; 95% CI, 0.14 to 0.47; P<0.001 for both comparisons). Rates of major bleeding were 0.5% in the group receiving 20 mg of rivaroxaban, 0.4% in the group receiving 10 mg of rivaroxaban, and 0.3% in the aspirin group; the rates of clinically relevant nonmajor bleeding were 2.7%, 2.0%, and 1.8%, respectively. The incidence of adverse events was similar in all three groups.
共有3365名患者被納入意向治療分析(中位治療時間，351天)。主要療效結果為： 1107例接受20 mg利伐沙班的患者中出現17例(1.5%)，1127例接受10毫克利伐沙班的患者中出現13例(1.2%)，1131例接受阿司匹林的患者中出現50例(4.4%)(危險比：20毫克利伐沙班vs.阿司匹林，0.34;95%可信區間[CI] 0.20-0.59;10毫克利伐沙班vs.阿司匹林，0.26;95% CI 0.14-0.47;兩組P<0.001)。20毫克利伐沙班組大出血率為0.5%，10毫克利伐沙班組為0.4%，阿司匹林組有0.3%;臨床相關的非大出血率分別為2.7%、2%和1.8%。三組患者的不良事件發生率相似。
Conclusions
Among patients with venous thromboembolism in equipoise for continued anticoagulation, the risk of a recurrent event was significantly lower with rivaroxaban at either a treatment dose (20 mg) or a prophylactic dose (10 mg) than with aspirin, without a significant increase in bleeding rates.
繼續抗凝的靜脈血栓栓塞患者中，治療劑量(20毫克)或預防劑量(10毫克)的利伐沙班，其複發風險顯著低於阿司匹林，而並無出血率的顯著增加。
