Objective To determine the efficacy and safety of dalteparin postoperative bridging treatment versus placebo for patients with atrial fibrillation or mechanical heart valves when warfarin is temporarily interrupted for a planned procedure. Design Prospective, double blind, randomised controlled trial. Setting 10 thrombosis research sites in Canada and India between February 2007 and March 2016. Participants 1471 patients aged 18 years or older with atrial fibrillation or mechanical heart valves who required temporary interruption of warfarin for a procedure. Intervention Random assignment to dalteparin (n=821; one patient withdrew consent immediately after randomisation) or placebo (n=650) after the procedure. Main outcome measures Major thromboembolism (stroke, transient ischaemic attack, proximal deep vein thrombosis, pulmonary embolism, myocardial infarction, peripheral embolism, or vascular death) and major bleeding according to the International Society on Thrombosis and Haemostasis criteria within 90 days of the procedure. Results The rate of major thromboembolism within 90 days was 1.2% (eight events in 650 patients) for placebo and 1.0% (eight events in 820 patients) for dalteparin (P=0.64, risk difference −0.3%, 95% confidence interval −1.3 to 0.8). The rate of major bleeding was 2.0% (13 events in 650 patients) for placebo and 1.3% (11 events in 820 patients) for dalteparin (P=0.32, risk difference −0.7, 95% confidence interval −2.0 to 0.7). The results were consistent for the atrial fibrillation and mechanical heart valves groups. Conclusions In patients with atrial fibrillation or mechanical heart valves who had warfarin interrupted for a procedure, no significant benefit was found for postoperative dalteparin bridging to prevent major thromboembolism. Trial registration Clinicaltrials.gov [NCT00432796][1]. [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT00432796&atom=%2Fbmj%2F373%2Fbmj.n1205.atom

中文翻译：

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动脉血栓栓塞高危患者术后低分子肝素桥接治疗（PERIOP2）：双盲随机对照试验

目的 确定当华法林因计划手术暂时中断时，达肝素术后桥接治疗与安慰剂对房颤或机械心脏瓣膜患者的疗效和安全性。设计前瞻性、双盲、随机对照试验。2007 年 2 月至 2016 年 3 月期间，在加拿大和印度设立了 10 个血栓形成研究中心。参与者 1471 名 18 岁或以上的房颤或机械心脏瓣膜患者，他们需要暂时中断华法林进行手术。干预 手术后随机分配至达肝素（n=821；一名患者在随机化后立即撤回同意）或安慰剂（n=650）。主要结局指标 严重血栓栓塞（中风、短暂性脑缺血发作、近端深静脉血栓形成、肺栓塞、心肌梗塞、外周栓塞或血管死亡）和根据国际血栓形成和止血学会标准在手术后 90 天内发生大出血。结果 安慰剂组 90 天内主要血栓栓塞的发生率为 1.2%（650 名患者中有 8 次事件），达肝素组为 1.0%（820 名患者中有 8 次事件）（P=0.64，风险差 -0.3%，95% 置信区间 -1.3到 0.8）。安慰剂组的大出血率为 2.0%（650 名患者中有 13 次事件），达肝素组为 1.3%（820 名患者中有 11 次事件）（P=0.32，风险差 -0.7，95% 置信区间 -2.0 至 0.7）。心房颤动组和机械心脏瓣膜组的结果一致。结论 对于因手术中断华法林的房颤或机械心脏瓣膜患者，未发现术后达肝素桥接预防严重血栓栓塞的显着益处。试验注册 Clinicaltrials.gov [NCT00432796][1]。[1]：/lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT00432796&atom=%2Fbmj%2F373%2Fbmj.n1205.atom