Aims: The aim of this study was to identify a subset of patients at high risk of bleeding or myocardial infarction from a percutaneous coronary intervention and to investigate whether such high-risk subsets derive preferential benefit from heparin or bivalirudin.
Methods and results: This study included 4570 patients with coronary artery disease enrolled in the Intracoronary Stenting and Antithrombotic Regimen: Rapid Early Action for Coronary Treatment trial and randomized to receive bivalirudin or heparin. Primary outcomes were in-hospital incidence of major bleeding and 30-day incidence of myocardial infarction. Major bleeding, myocardial infarction, and bleeding plus myocardial infarction occurred in 140, 204, and 34 patients, respectively. Older age, female sex, lower body weight, low cholesterol, multi-lesion intervention, complex lesions, and heparin therapy were independent correlates of increased risk of bleeding. Multi-lesion intervention, unstable angina, and lower body weight correlated independently with increased risks of myocardial infarction. Compared with heparin, bivalirudin was associated with a reduction in major bleeding (3.1 vs. 4.6%, P = 0.008), but mostly in low-risk patients. A reduction in the bleeding risk inversely correlated with an increase in the risk of myocardial infarction with bivalirudin (R = -0.61).
Conclusion: Bivalirudin and unfractionated heparin have a differential effect on risk of bleeding and myocardial infarction across various subsets of patients.