Petitti D B, Strom B L, Melmon K L
Am J Med. 1986 Aug;81(2):255-9. doi: 10.1016/0002-9343(86)90260-3.
To determine the association of duration of warfarin anticoagulant therapy after hospitalization for venous thromboembolism with the probability of recurrent thromboembolism and with the risks of hemorrhage, medical records of 2,422 patients hospitalized in 1970 through 1980 with pulmonary embolism, thrombophlebitis, or both were reviewed. Multivariate life-table analyses were performed for 370 patients who had positive results of venography or pulmonary angiography, or who had lung scanning evidence of a "high probability" of pulmonary embolism and no history of the disease. For these patients, warfarin therapy for more than six weeks was not associated with a lower risk of recurrent thromboembolism when compared with warfarin therapy for one through six weeks (risk of recurrence for seven to 26 weeks of treatment 0.8; 95 percent confidence limits 0.3 and 2.5; risk of recurrence for more than 26 weeks of treatment 1.1; 95 percent confidence limits 0.4 and 3.1). The longer the warfarin therapy, the higher the risk of medically important complications from therapy. From one week through five years, the probability of major hemorrhage increased almost linearly: 10 percent for 12 weeks, 18 percent at one year, 26 percent at two years, and 41 percent at five years. This study suggests that intensive, long-term warfarin anticoagulation, in patients with a first episode of venous thromboembolism and no predisposing condition, is associated with more toxicity than efficacy and should be abandoned.
为确定静脉血栓栓塞症住院后华法林抗凝治疗的持续时间与复发性血栓栓塞的可能性以及出血风险之间的关联，我们回顾了1970年至1980年间因肺栓塞、血栓性静脉炎或两者皆有而住院的2422例患者的病历。对370例静脉造影或肺血管造影结果呈阳性，或肺部扫描有“高度可能”肺栓塞证据且无该病病史的患者进行了多变量生命表分析。对于这些患者，与1至6周的华法林治疗相比，超过6周的华法林治疗与复发性血栓栓塞风险降低无关（治疗7至26周的复发风险为0.8；95%置信区间为0.3和2.5；治疗超过26周的复发风险为1.1；95%置信区间为0.4和3.1）。华法林治疗时间越长，治疗引起的具有医学重要性并发症的风险越高。从1周到5年，严重出血的可能性几乎呈线性增加：12周时为10%，1年时为18%，2年时为26%，5年时为41%。这项研究表明，对于首次发生静脉血栓栓塞且无易感因素的患者，强化、长期的华法林抗凝治疗与其说是有效，不如说是毒性更大，应该放弃。
