Patients with acute coronary syndromes such as unstable angina who were undergoing an invasive treatment and received one of three anticoagulant regimens did not have significant differences in the rates of ischemia or death after one year, according to a study in the Dec. 5 issue of JAMA.
"Early angiography followed by interventional or surgical revascularization when appropriate has been shown to result in reduced rates of death, myocardial infarction (MI), refractory ischemia, and rehospitalization in patients with acute coronary syndromes (ACS; unstable angina or non-ST-segment elevation MI [a certain pattern on an electrocardiogram following a heart attack]). Because both MI and hemorrhagic complications have been associated with early and late mortality in patients with ACS and in those undergoing percutaneous coronary intervention (PCI), the optimal [added] pharmacological regimen to support the invasive approach in ACS would ideally suppress adverse ischemic and thrombotic events while minimizing iatrogenic [induced by treatment] bleeding," the authors write.
In the Acute Catheterization and Urgent Intervention Triage Strategy (ACUITY) trial, randomization of moderate-risk and high-risk patients with ACS undergoing early invasive management to monotherapy with the direct thrombin (blood-clotting enzyme) inhibitor bivalirudin compared with a heparin-based regimen plus glycoprotein (GP) IIb/IIIa inhibitors resulted in noninferior 30-day rates of adverse ischemic events with reduced rates of major bleeding. The long-term effect of bivalirudin monotherapy and a selective GP IIb/IIIa inhibitor strategy on composite ischemia and death are unknown.
Gregg W. Stone, M.D., of Columbia University Medical Center and the Cardiovascular Research Foundation, New York, and colleagues examined the 1-year clinical outcomes of patients enrolled in the ACUITY trial. The randomized, open-label trial was conducted at 450 academic and community-based institutions in 17 countries. A total of 13,819 patients with moderate- and high-risk ACS undergoing invasive treatment were enrolled between August 2003 and December 2005. Patients were assigned to heparin plus GP IIb/IIIa inhibitors (n = 4,603), bivalirudin plus GP IIb/IIIa inhibitors (n = 4,604), or bivalirudin monotherapy (n = 4,612). Of these patients, 4,605 were assigned to routine upstream (prior to angiography) GP IIb/IIIa use and 4,602 were deferred to selective GP IIb/IIIa use.
Compared with the control group of heparin plus GP IIb/IIIa inhibitors in which the 1-year estimated rate of composite ischemia was 15.4 percent, composite ischemia occurred in 16.0 percent of patients assigned to bivalirudin plus GP IIb/IIIa inhibitors and in 16.2 percent of patients assigned to bivalirudin monotherapy. Death at 1 year occurred in an estimated 3.9 percent of patients assigned to heparin plus GP IIb/IIIa inhibitors, 3.9 percent assigned to bivalirudin plus GP IIb/IIIa inhibitors, and 3.8 percent assigned to bivalirudin monotherapy. There were no significant differences in the rates of the individual components of death, MI, or unplanned revascularization for ischemia between the three groups.
"At 1 year, no statistically significant difference in rates of composite ischemia or mortality among patients with moderate- and high-risk ACS undergoing invasive treatment with the 3 therapies was found," the authors conclude. "There was no statistically significant difference in the rates of composite ischemia between patients receiving routine upstream administration of GP IIb/IIIa inhibitors vs. deferring their use for patients undergoing PCI."