Periprocedural bridging using unfractionated heparin (UFH) or low molecular weight heparin (LMWH) in patients receiving chronic oral anticoagulation (OAC) is often utilized with the view to reduce the risk of thromboembolic (TE) events. Optimal perioperative anticoagulant methods have not been established. Methods: Systematic review and meta-analysis of published English-language studies from 2001 to 2010 examining bleeding and TE events in patients receiving bridging therapy during temporary OAC interruption for elective procedures. Results: A search of MEDLINE, EMBASE and Cochrane Collaboration databases yielded 32 studies on 6760 bridged patients. Studies were reviewed by 2 independent data collectors (k=0.869). Study quality was generally poor with risk of bias. Thirty-one studies were observational with 1 randomized controlled trial. Low TE risk and/or non-OAC patient groups were used for comparison in 12 observational studies. Major (22/32, 68.8%) and non-major (27/32, 84.4%) procedures were represented. TE events occurred in 67 of 6760 bridged (0.87%; 95% CI 0.40%–1.35%) and 29 of 4897 non-bridged (0.77%; 95% CI 0.24%–1.30%) patients. Using a random effects model, there was no difference in the risk of TE events in bridged versus non-bridged patients (OR 1.02, 95% CI 0.53–1.95). Bridged patients had a significantly increased risk of overall bleeding (OR 5.47, 95% CI 3.89–7.70) and major bleeding (OR 3.43, 95% CI 1.13–10.4) compared to non-bridged patients. There was no difference in TE events (OR 2.44, 95% CI 0.34–17.4) or overall bleeding (OR 2.40 95% CI 0.72–8.05) in patients receiving full versus intermediate/low dose LMWH. Summary: Patients receiving heparin bridging during OAC interruption appear to be at increased risk of bleeding and similar risk of TE events compared to non-bridged patients. Studies of high methodologic quality are needed to develop an optimal anticoagulation strategy and inform clinical decision-making.
Lim: Leo Pharma: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bayer: Consultancy; Pfizer: Honoraria. Kaatz:Boehringer-Ingelheim: Consultancy, Research Funding, Speakers Bureau; Bristol Myer Squibb: Consultancy, Research Funding; Bayer: Research Funding; National Institute of Health: Research Funding; Canadian Institute of Health Research: Research Funding; Pfizer: Consultancy; Johnson and Johnson: Consultancy; Ortho-McNeil: Consultancy; GlaxoSmithKline: Speakers Bureau; AC Forum: Membership on an entity's Board of Directors or advisory committees; National Certification Board of Anticoagulation Providers: Membership on an entity's Board of Directors or advisory committees; National Blood Clot Alliance: Membership on an entity's Board of Directors or advisory committees.