Aims: Given controversy over anticoagulation regimens for percutaneous coronary intervention (PCI), we performed an updated meta-analysis of randomized controlled trials (RCTs) to compare bivalirudin versus heparin. Methods and results: Medline/Pubmed and Cochrane CENTRAL were searched for all RCTs comparing bivalirudin with provisional glycoprotein IIb/IIIa inhibitor (GPI) use versus heparin with provisional or routine GPI use for PCI. Pooled estimates of 30 day outcomes, presented as risk ratios (RR) [95% confidence intervals], were generated with random-effect models. Our analysis included 14 studies with 30,446 patients that were randomized to bivalirudin with provisional GPI use (n = 14,869) versus heparin with provisional (n = 6451) or routine GPI use (n = 9126). There was no significant difference between anticoagulation with bivalirudin compared with heparin for death (RR 0.95 [0.78-1.14]) or myocardial infarction (RR 1.10 [0.97-1.25]). Early stent thrombosis was significantly greater with bivalirudin compared with heparin (RR 1.61 [1.18-2.20], p = 0.003), especially in patients undergoing primary PCI (2.15 [1.15-4.03], p = 0.02). However, bivalirudin reduced the risk of major bleeding (RR 0.59 [0.51-0.70], p < 0.0001) and TIMI major bleeding (RR 0.59 [0.48-0.72], p < 0.0001) compared with heparin. Meta-regression analysis demonstrated that bleeding risk with use of heparin significantly increases with increasing GPI use (p = 0.02). Conclusion: Meta-analysis of 14 RCTs with 30,446 patients demonstrated that bivalirudin is associated with higher risk of stent thrombosis but lower risk of major bleeding compared with heparin. (C) 2014 Published by Elsevier Inc.