Heparin is often administered during and after coronary angioplasty to prevent closure of the dilated vessel. However, ischemic or hemorrhagic complications occur in 5 to 10 percent of treated patients. We studied whether these complications could be prevented when the direct thrombin inhibitor bivalirudin (Hirulog) was used in place of heparin. We performed a double-blind, randomized trial in 4098 patients undergoing angioplasty for unstable or postinfarction angina. Patients were assigned to receive either heparin or bivalirudin immediately before angioplasty. The primary end point was death in the hospital, myocardial infarction, abrupt vessel closure, or rapid clinical deterioration of cardiac origin. In the total study group, bivalirudin did not significantly reduce the incidence of the primary end point (11.4 percent, vs. 12.2 percent for heparin) but did result in a lower incidence of bleeding (3.8 percent vs. 9.8 percent, P<0.001). In the prospectively stratified subgroup of 704 patients with postinfarction angina, bivalirudin therapy resulted in a lower incidence of the primary end point (9.1 percent vs. 14.2 percent, P = 0.04) and a lower incidence of bleeding (3.0 percent vs. 11.1 percent, P<0.001), but in a similar cumulative rate of death, myocardial infarction, and repeated revascularization in the six months after angioplasty (20.5 percent vs. 25.1 percent, P = 0.17). Bivalirudin was at least as effective as high-dose heparin in preventing ischemic complications in patients who underwent angioplasty for unstable angina, and it carried a lower risk of bleeding. Bivalirudin, as compared with heparin, reduced the risk of immediate ischemic complications in patients with postinfarction angina, but this difference was no longer apparent after six months. Heparin is often given to patients during coronary angioplasty to inhibit coagulation locally within a segment of the coronary artery and thus prevent closure of the dilated vessel. High doses of heparin are commonly used during coronary angioplasty to overcome the theoretical limitation of localized resistance to heparin,1–3 but the efficacy of heparin in coronary angioplasty is not uniform. Approximately 5 to 10 percent of patients who undergo angioplasty have ischemic or hemorrhagic complications.4–10 Direct-acting thrombin inhibitors, such as hirudin and its analogues, have several theoretical advantages over heparin. Thrombin inhibitors that act directly do not require a.
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