Pericarditis in acute myocardial infarction: Characterization and clinical significance

Abstract

To determine the significance of pericarditis following acute myocardial infarction, the hospital course and 12-month follow-up were analyzed in 703 patients enrolled in the Multicenter investigation of the Limitation of infarct Size (MILIS). Pericarditis, defined by the detection of a pericardial rub, occurred in 20% of the patients (n = 141) and was more likely to follow Q wave than non-Q wave infarction (25% vs 9%, p < 0.001). Patients with pericarditis experienced more serious myocardial damage compared to those without pericarditis, as evidenced by a larger infarct size (25 ± 1 vs 17 ± 1 MB-CK gm-Eq/m 2, p < 0.001), a lower admission left ventricular ejection fraction (42 ± 1% vs 48 ± 1%, p < 0.001), and a higher incidence of congestive heart failure (47% vs 26%, p < 0.001) and atrial tachyarrhythmias (16% vs 10%, p < 0.05). When patients were classified by the presence of Q or non-Q wave infarction, these differences persisted although statistical significance was not always achieved due to smaller sample size. Mortality at 12-month follow-up for patients with pericarditis was 18% compared with 12% for patients without pericarditis ( p = 0.055). This mortality difference could be accounted for in part by the lower ventricular ejection fraction in patients with pericarditis ( p = 0.20 after adjustment).