Comparison of low-intensity warfarin therapy with conventional-intensity warfarin therapy for long-term prevention of recurrent venous thromboembolism
Comparison of low-intensity warfarin therapy with conventional-intensity warfarin therapy for long-term prevention of recurrent venous thromboembolism
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DOI：
10.1056/nejmoa035422
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发表时间：
2003-08-14
影响因子：
158.5
通讯作者：
Gent, M
中科院分区：
文献类型：
--
作者：
Kearon, C;Ginsberg, JS;Gent, M
研究背景华法林在预防复发性静脉血栓栓塞方面非常有效，但也与大量出血风险相关。经过三个月的常规华法林治疗，低剂量的抗凝药物可能会导致更少的出血，仍然可以防止复发性静脉血栓栓塞。其中738例因不明原因静脉血栓栓塞而完成3个月或3个月以上华法林治疗的患者被随机分配继续华法林治疗，目标国际标准化比值（INR）2.0 - 3.0（常规强度）或目标INR 1.5 - 1.9（低强度）。患者平均随访2.4年。在369例接受低强度治疗的患者中，16例复发静脉血栓栓塞（1.9/100人-年），而369例接受常规强度治疗的患者中有6例复发静脉血栓栓塞（0.7/100人-年;风险比为2.8; 95%置信区间为1.1~7.0）。9例接受低强度治疗的患者（1.1例事件/100人年）和8例接受常规强度治疗的患者（0.9例事件/100人年;风险比为1.2; 95%置信区间为0.4 - 3.0）发生了大出血事件。两组间总出血频率无显著差异（危害比，1.3; 95%可信区间，0.8~2.1）。结论常规强度华法林治疗在长期预防复发性静脉血栓栓塞方面比低强度华法林治疗更有效。低强度华法林方案不能降低临床重要出血的风险。
BACKGROUNDWarfarin is very effective in preventing recurrent venous thromboembolism but is also associated with a substantial risk of bleeding. After three months of conventional warfarin therapy, a lower dose of anticoagulant medication may result in less bleeding and still prevent recurrent venous thromboembolism.METHODSWe conducted a randomized, double-blind study, in which 738 patients who had completed three or more months of warfarin therapy for unprovoked venous thromboembolism were randomly assigned to continue warfarin therapy with a target international normalized ratio (INR) of 2.0 to 3.0 (conventional intensity) or a target INR of 1.5 to 1.9 (low intensity). Patients were followed for an average of 2.4 years.RESULTSOf 369 patients assigned to low-intensity therapy, 16 had recurrent venous thromboembolism (1.9 per 100 person-years), as compared with 6 of 369 assigned to conventional-intensity therapy (0.7 per 100 person-years; hazard ratio, 2.8; 95 percent confidence interval, 1.1 to 7.0). A major bleeding episode occurred in nine patients assigned to low-intensity therapy (1.1 events per 100 person-years) and eight patients assigned to conventional-intensity therapy (0.9 event per 100 person-years; hazard ratio, 1.2; 95 percent confidence interval, 0.4 to 3.0). There was no significant difference in the frequency of overall bleeding between the two groups (hazard ratio, 1.3; 95 percent confidence interval, 0.8 to 2.1).CONCLUSIONSConventional-intensity warfarin therapy is more effective than low-intensity warfarin therapy for the long-term prevention of recurrent venous thromboembolism. The low-intensity warfarin regimen does not reduce the risk of clinically important bleeding.