Prescrire Int. 2013 May;22(138):129-33.
In patients with deep venous thrombosis or pulmonary embolism, initial treatment with low-molecular-weight heparin (LMWH) is primarily aimed at preventing thrombus extension. After this initial phase, the goal of treatment is to prevent recurrences, which can be fatal. Is it better to continue treatment of deep venous thrombosis or pulmonary embolism with LMWH or switch to an oral anticoagulant? What is the optimal duration of treatment? To answer these questions, we conducted a review of the literature using the standard Prescrire methodology. In non-cancer patients, two meta-analyses of trials in which treatment was not double blinded showed that severe bleeding was slightly less frequent with LMWH than with a vitamin K antagonist, but no data on mortality or the recurrence rate were provided. In cancer patients, LMWH prevented more recurrences than vitamin K antagonists; LMWH did not reduce overall mortality and did not increase the risk of serious bleeding compared to vitamin K antagonists. Treatment with LMWH requires daily injections and renal monitoring.Treatment with warfarin, the standard vitamin K antagonist, requires regular INR monitoring. There is no evidence that rivaroxaban or dabigatran has a better harm-benefit balance than warfarin for long-term treatment. After a first episode of proximal deep venous thrombosis or pulmonary embolism associated with an identified reversible trigger, several meta-analyses support a 3-month course of anticoagulation. Prolonged anticoagulant therapy is generally considered when there is no identified trigger or in case of a recurrence. Two double-blind randomised placebo-controlled trials failed to establish whether or not aspirin-based antiplatelet therapy given after discontinuation of anticoagulant therapy has a favourable harm-benefit balance. Various clinical practice guidelines published since 2006 recommend first-line treatment with a vitamin K antagonist for at least 3 months in patients without cancer, and continuation of LMWH therapy in patients with cancer. Overall, LMWH and warfarin have similar harm-benefit balances. In practice, it is best to choose between these drugs on a case-by-case basis, taking into account patient preferences, monitoring constraints, difficulty controlling the INR, the risk of bleeding and interactions, and the cost of treatment.
在患有深静脉血栓形成或肺栓塞的患者中，初始使用低分子量肝素（LMWH）治疗主要旨在预防血栓扩展。在这个初始阶段之后，治疗目标是预防复发，因为复发可能是致命的。继续使用LMWH治疗深静脉血栓形成或肺栓塞还是改用口服抗凝剂更好？最佳治疗持续时间是多久？为了回答这些问题，我们使用标准的Prescrire方法对文献进行了综述。在非癌症患者中，两项非双盲治疗试验的荟萃分析表明，LMWH导致的严重出血发生率略低于维生素K拮抗剂，但未提供死亡率或复发率的数据。在癌症患者中，LMWH比维生素K拮抗剂预防了更多的复发；与维生素K拮抗剂相比，LMWH没有降低总体死亡率，也没有增加严重出血的风险。使用LMWH治疗需要每日注射并进行肾脏监测。使用标准维生素K拮抗剂华法林治疗需要定期监测国际标准化比值（INR）。没有证据表明利伐沙班或达比加群在长期治疗中比华法林具有更好的利弊平衡。在首次发生与确定的可逆触发因素相关的近端深静脉血栓形成或肺栓塞后，多项荟萃分析支持3个月的抗凝疗程。当没有确定的触发因素或复发时，通常考虑延长抗凝治疗。两项双盲随机安慰剂对照试验未能确定抗凝治疗停药后给予的基于阿司匹林的抗血小板治疗是否具有良好的利弊平衡。自2006年以来发布的各种临床实践指南建议，非癌症患者一线使用维生素K拮抗剂治疗至少3个月，癌症患者继续使用LMWH治疗。总体而言，LMWH和华法林具有相似的利弊平衡。在实践中，最好根据具体情况在这些药物之间进行选择，同时考虑患者的偏好、监测限制、控制INR的难度、出血风险和相互作用以及治疗成本。
