High-risk patients with acute coronary syndromes treated with early revascularization and enoxaparin or unfractionated heparin during hospitalization have similar outcomes at one year, including remaining at substantial risk for adverse cardiovascular events, according to an article in the November 23 issue of the Journal of the American Medical Association.

Patients with non?ST-segment elevation acute coronary syndromes make up a spectrum of risk for adverse cardiac events, according to background information in the article. In the Superior Yield of the New Strategy of Enoxaparin, Revascularization, and Glycoprotein IIb/IIIa Inhibitors (SYNERGY) trial, patients at high risk for recurrent ischemic cardiac events were randomly assigned to receive low-molecular-weight heparin (enoxaparin) or unfractionated heparin.

The primary results at 30 days showed that enoxaparin was at least as effective as unfractionated heparin in reducing death or nonfatal myocardial infarction. The current study examines the results at six months and one year.

“We believe this to be valuable, given the high-risk clinical characteristics of the patient population in SYNERGY and the need to understand the long-term outcomes in patients managed with an early aggressive invasive treatment strategy,” the researchers wrote.

Kenneth W. Mahaffey, MD, and his American colleagues analyzed follow-up data at six months and one year from the SYNERGY trial, which included 9,978 patients who were randomized from August 2001 through December 2003 in 487 hospitals in 12 countries.

At six months, 541 patients (5.4 percent) had died, and 739 (7.4 percent) had died at one year. The researchers found that death or nonfatal myocardial infarction at six months occurred in 872 patients receiving enoxaparin (17.6 percent) vs. 884 receiving unfractionated heparin (17.8 percent). Rehospitalization within 180 days occurred in 858 patients receiving enoxaparin (17.9 percent) and 911 receiving unfractionated heparin (19.0 percent). One-year all-cause death rates were similar in the two treatment groups.

“The SYNERGY trial studied a high-risk cohort of patients with non-ST-segment elevation acute coronary syndrome. The 30-day, 6-month, and 1-year data show that this cohort of patients remains at substantial risk for recurrent cardiovascular events and coronary revascularization procedures: Nearly 20 percent of patients died or experienced reinfarction by six months. Overall, the rates of death and nonfatal MI were similar at 6 months between treatment groups. The reduction in death or nonfatal MI at 30 days seen in the subgroup of patients treated with consistent therapy during the initial study drug assignment was sustained through 6 months, but mortality at 1 year was similar. Despite aggressive revascularization strategies and high use of evidence-based therapies, patients with high-risk ACS features remain at risk for continued adverse cardiac morbidity and mortality,” the authors concluded.