Double Blind Randomized Control Trial of Postoperative Low Molecular Weight Heparin Bridging Therapy for Patients Who Are at High Risk for Arterial Thromboembolism (PERIOP 2)

Background It remains uncertain if patients with atrial fibrillation or mechanical heart valves requiring interruption of warfarin for procedures benefit from post-procedure anticoagulant bridging therapy. Methods In order to determine the efficacy and safety of postoperative LMWH bridging, we conducted a multicenter randomized double-blind controlled trial of patients with atrial fibrillation or a mechanical heart valve who require interruption of warfarin for a planned procedure. We excluded patients with active bleeding within 30 days, platelet count Results Starting in October 2006 we randomized a total of 1471 patients of whom 1167 had atrial fibrillation (without mechanical heart valves) and 304 had mechanical valves (99 also had atrial fibrillation). Last follow up was completed in May 2016. Baseline characteristics were similar between the LMWH and the placebo groups (see Table 1). Due to a randomization program system error at two centres more atrial fibrillation patients were randomized to dalteparin rather than to placebo. Major thromboembolism occurred in 6/820 (0.71%) dalteparin patients and 7/650 (1.11%) placebo patients. Major post-procedure bleeding occurred in 12 (1.46%) dalteparin patients and 16 (2.46%) placebo patients. Findings were similar in patients with atrial fibrillation alone and in patients with mechanical heart valves (with or without atrial fibrillation) (Table 2). Conclusions In patients with atrial fibrillation and/or mechanical heart valves who had warfarin interrupted for a procedure there was no benefit from post-procedure LMWH bridging. Disclosures Kovacs: Bayer: Research Funding; Daiichi Sankyo Pharma Development: Research Funding. Wells: Janssen: Honoraria; Sanofi: Honoraria; BMS: Honoraria, Research Funding; Bayer: Honoraria. Schulman: Boehringer-Ingelheim: Honoraria, Research Funding; Daiichi-Sankyo: Honoraria; Sanofi: Honoraria; Bayer: Honoraria.