Anticoagulation with bivalirudin for off-pump coronary artery bypass grafting: The results of the EVOLUTION-OFF study

Objectives: Unfractionated heparin has many shortcomings, including indirect and partial inhibition of thrombin, antibody formation, and platelet activation. Bivalirudin, a short- acting direct thrombin inhibitor, avoids these limitations and has superior outcomes during percutaneous revascularization. This trial was performed to evaluate the safety and efficacy of bivalirudin in off- pump coronary artery bypass grafting. Methods: An open- label, multicenter randomized trial compared heparin with protamine reversal to bivalirudin in patients undergoing off- pump coronary artery bypass. The primary objective was safety as demonstrated by similar rates of procedural success defined as freedom from a composite of death, myocardial infarction, stroke, and repeat revascularization. Twenty- one institutions randomized 105 patients to receive bivalirudin and 52 patients to receive heparin. Results: The mean age was 65 years for both groups. The bivalirudin group had more grafts: 3.0 +/- 1 versus 2.5 +/- 1. Procedural success rates at 30 days were identical in bivalirudin- and heparin- treated patients ( 93%). Operative times, total blood loss, reoperations for bleeding, and major adverse events were not significantly different. Strokes were more frequent in the heparin group: 5.5% versus 0; P = .05. Mortality was 2% in each group. Repeat revascularization was required in 3% of bivalirudin- and 2% of the heparin- treated patients. Conclusions: For patients undergoing off- pump coronary artery bypass grafting, bivalirudin was an effective anticoagulant, without excessive bleeding and with a safety profile similar to that of heparin. Further trials are warranted to assess whether anticoagulation with bivalirudin improves clinical outcomes.