NEW YORK (Reuters Health) – Bivalirudin offers a number of advantages over other antithrombin agents in treating patients with acute coronary syndromes, according to members of the Thrombolysis in Myocardial Infarction (TIMI) 8 study group. Advantages include a stable anticoagulant effect with infrequent need to adjust the dose, a reasonably wide therapeutic window, and decreased risk of bleeding compared with low molecular weight heparin.
Bivalirudin has been approved by the US Food and Drug Administration for use in patients undergoing percutaneous coronary interventions. It is a 20-amino acid peptide that is a highly potent, direct thrombin inhibitor.
According to Dr. Elliott M. Antman, of the Brigham and Women's Hospital in Boston, and associates, 133 patients were enrolled in TIMI 8 in 1994 with a diagnosis of unstable angina or non-ST-elevation MI.
Sixty-five patients were randomly assigned to treatment with unfractionated heparin titrated to an activated partial thromboplastin time (aPTT) of 55 to 85 seconds. The remaining 68 were assigned to bivalirudin with titration to the same endpoint. The agents were administered for a median of 77 and 72 hours, respectively. The results appear in the American Heart Journal for February.
Patients achieved significantly better results with bivalirudin than heparin (p = 0.03), based on a post hoc, secondary end point consisting of death, nonfatal MI, or major hemorrhage. By 14 days, nine patients in the heparin group and one in the bivalirudin group had had one of these events. By day 30, the numbers were 11 and 3, respectively.
Dr. Harvey D. White, of Green Lane Hospital in Auckland, New Zealand, remarks in an editorial that the uncoupling of ischemic and bleeding complications associated with bivalirudin is not seen with other existing anticoagulants. He attributes this advantage to bivalirudin's ability to bind reversibly to both fibrin-bound and free circulating thrombin, and to its short half-life.
"Bivalirudin may well become the foundation anticoagulant for use in patients with acute coronary syndromes," he concludes.