Randomized Trial of Aspirin, Sibrafiban, or Both for Secondary Prevention After Acute Coronary Syndromes Second SYMPHONY Investigators Background—The first Sibrafiban Versus Aspirin to Yield Maximum Protection From Ischemic Heart Events Post–Acute Coronary Syndromes

Background—The first Sibrafiban Versus Aspirin to Yield Maximum Protection From Ischemic Heart Events Post–Acute Coronary Syndromes (SYMPHONY) trial showed no benefit of 2 doses of sibrafiban over aspirin for secondary prevention after acute coronary syndromes. In 2nd SYMPHONY, we compared low-dose sibrafiban plus aspirin (LDS1A), high-dose sibrafiban (HDS), and aspirin alone. Methods and Results—When the first SYMPHONY results became known, enrollment in 2nd SYMPHONY was stopped prematurely at 6671 patients who had been treated for a median of 90 days. The primary end point of death, myocardial (re)infarction (MI), or severe recurrent ischemia did not differ significantly between aspirin (9.3%) and LDS1A (9.2%; OR, 0.98; 95% CI, 0.80 to 1.20) or HDS (10.5%; OR, 1.14; 95% CI, 0.9 to 1.39) patients. Secondary end points did not differ significantly between aspirin and LDS1A patients. Death or MI occurred significantly more often with HDS (OR, 1.43; 95% CI, 1.14 to 1.80), as did mortality alone (OR, 1.83; 95% CI, 1.17 to 2.88) and MI (OR, 1.32; 95% CI, 1.03 to 1.69). Major bleeding was significantly more frequent in LDS1A patients (5.7%) versus aspirin alone (4.0%) but not in HDS patients (4.6%). Conclusions—Combining aspirin with LDS did not improve outcomes after acute coronary syndromes and caused more bleeding compared with aspirin alone. There was a trend toward increased mortality in this group and a significant increase in the high-dose arm. (Circulation. 2001;103:1727-1733.)