Effect of preinfarction angina pectoris on outcome in patients with acute myocardial infarction treated with primary angioplasty (results from the Myocardial Infarction Registry [MIR])

Preinfarction angina is associated with better clinical outcome in patients with acute myocardial infarction (AMI) who receive intravenous thrombolysi s. This has not been proved in patients with AMI treated with primary angio plasty. We analyzed the data of the prospective multicenter Myocardial Infa rction Registry (MIR). Of 14,440 patients with AMI, 774 with a prehospital delay of less than or equal to 12 hours were treated with primary angioplas ty. Five hundred thirty-two patients (68.7%) had preinfarction angina. Pati ents with preinfarction angina were slightly older than patients without (6 3 vs 62 years, p = 0.042), prehospital delay was 1 hour longer (180 vs 120 minutes, p = 0.001), and arterial hypertension was more prevalent (47.6% vs 32.2%, odds ratio [OR] 1.91, 95% confidence intervals [CI] 1.39 to 2.62). There was no significant difference in hospital mortality (5.6% vs 3.3%, OR 1.75, 95% CI 0.79 to 3.87), reinfarction, stroke, or the combined end poin t of death, reinfarction, or stroke between the 2 groups. Logistic regressi on analysis showed no association of preinfarction angina with the occurren ce of either death (OR 2.21, 95% CI 0.91 to 6.08) or the combined end point s (OR 1.10, 95% CI 0.55 to 2.31). There was also no significant difference in mortality (6% vs 5.1%, OR 1.19, 95% CI 0.56 to 2.52), reinfarction, stro ke, postinfarction angina, or the combined end points between patients with preinfarction angina within 48 hours compared with patients with preinfarc tion angina between 49 hours and 4 weeks before the AMI. Thus, the MIR data showed no protective effects of preinfarction angina in patients with AMI treated with primary angioplasty. (C) 2001 by Excerpta Medica, Inc.