McMaster University, Hamilton, Ontario, Canada.
J Thromb Haemost. 2012 Apr;10(4):507-11. doi: 10.1111/j.1538-7836.2012.04629.x.
Four observations support that anticoagulant therapy for venous thromboembolism (VTE) has an 'active treatment' phase that is limited to about 3 months. First, <3 months of treatment is associated with a higher risk of recurrent VTE than treatment for 3 months or longer, suggesting that <3 months is inadequate therapy. Second, treatment for 3 months is associated with the same risk of recurrent VTE as treatment for 6 months or longer, suggesting that 3 months is adequate therapy. Third, the increase in recurrent VTE with too short a course of treatment is predominantly at the site of the initial thrombosis, suggesting reactivation of initial thrombosis. Fourth, the increase in recurrent VTE with too short a course of treatment occurs immediately after treatment is stopped and is short lived, again suggesting reactivation of initial thrombosis. Once the initial thrombosis has been adequately treated (i.e. the first phase of treatment), further anticoagulation serves as 'secondary prevention' of new, unrelated, episodes of thrombosis (i.e. the second phase of treatment). For most patients, therefore, anticoagulant therapy for VTE should be stopped at 3 months when the acute episode has completed treatment, or should be continued indefinitely as 'secondary prevention' if the risk of recurrence remains unacceptably high having completed 'active treatment'.
有四项观察结果支持抗凝治疗静脉血栓栓塞症 (VTE) 具有“主动治疗”阶段，该阶段的时间限制约为 3 个月。首先，与治疗 3 个月或更长时间相比，<3 个月的治疗与更高的复发性 VTE 风险相关，这表明<3 个月的治疗不够充分。其次，治疗 3 个月与治疗 6 个月或更长时间的复发性 VTE风险相同，这表明 3 个月的治疗是充分的。第三，治疗时间过短导致复发性 VTE增加主要发生在初始血栓形成部位，这表明初始血栓形成的再激活。第四，治疗时间过短导致复发性 VTE增加的情况在治疗停止后立即发生，且持续时间短暂，再次表明初始血栓形成的再激活。一旦初始血栓形成得到充分治疗（即治疗的第一阶段），进一步的抗凝治疗可作为新的、无关的血栓形成事件的“二级预防”（即治疗的第二阶段）。因此，对于大多数患者而言，当急性发作完成治疗时，VTE 的抗凝治疗应在 3 个月时停止，或者如果在完成“主动治疗”后复发风险仍然高得无法接受，则应无限期地继续作为“二级预防”。
