Comparison of Safety and Efficacy of Unfractionated Heparin Versus Bivalirudin in Patients Undergoing Percutaneous Coronary Intervention

Background Anti-platelet and anti-coagulant adjunctive therapies are associated with a clinically significant increased risk of major bleeding. We retrospectively assessed in-hospital major adverse clinical events (MACE) and major bleeding in patients undergoing percutaneous coronary intervention (PCI) who received either unfractionated heparin (UFH) or bivalirudin. Method Consecutive patients undergoing PCI for acute coronary syndrome (ACS) at Fremantle Hospital from August 2008 to December 2013 were identified. Patients received dual antiplatelet therapy (DAPT), with either UFH (50-100IU/kg) or bivalirudin (bolus 0.75 mg/kg and infusion 1.75 mg/kg/hr). Adjunctive glycoprotein IIb/IIIa (GPIIbIIIa) antagonist use was at the operator's discretion. In-hospital events were identified from case notes and PCI database review. Results Of 3371 patients identified, 1740 received UFH and 1631 received bivalirudin. The two groups were similar with respect to age, 62.5 SD 12.1 yrs vs. 62.8 SD 12.2 yrs, (p = 0.575) female gender, 24% vs. 26% (p = 0.10), current smokers, 66% vs. 70% (p = 0.53), diabetes, 25% vs. 26% (p = 0.62) and the use of DAPT (p = ns). Presentation with ST-segment-elevation myocardial infarction (STEMI) was significantly higher in the UFH group (28% vs. 19%, p<0.001). The use of transfemoral arterial access was similar (93% UFH vs. 92% bivalirudin) (p = 0.41). More patients received GPIIb/IIIa antagonist in the UFH group (30% vs. 3%; p < 0.001). There was no difference in predischarge acute stent thrombosis (< 24 hours) occurring in 1.0% with UFH vs. 0.5% with bivalirudin (p = 0.20). The equipoise on the outcomes of stent thrombosis persisted after multivariate adjustment for difference in rates of STEMI. In-hospital BARC Type 1-3 major bleeding occurred in 3.7% in the UFH group vs. 2.9% in the bivalirudin group (p = 0.20). Conclusion Unfractionated heparin compared with bivalirudin was not associated with a higher incidence of inhospital MACE or major bleeding in a cohort with overall high rates of transfemoral access, despite significantly higher use of GPIIb/IIIa antagonists in the UFH group.