Post-infectious myocardial infarction: New insights for improved screening

Abstract

Acute infection is suspected of involvement in the onset of acute myocardial infarction (MI). We aimed to assess the incidence, pathogenesis and prognosis of post-infectious MI. All consecutive patients hospitalized for an acute MI in coronary care units were prospectively included. Post-infectious MI was defined by a concurrent diagnosis of acute infection at admission. Type 1 MI (acute plaque disruption) or Type 2 MI (imbalance in oxygen supply/demand) were adjudicated according to the universal definition of MI. From the 4573 patients admitted for acute MI, 466 (10%) had a concurrent acute infection (median age 78 (66–85) y, 60% male), of whom 313 (67%) had a respiratory tract infection. Type 2 MI was identified in 72% of post-infectious MI. Compared with other MI, post-infectious MI had a worse in-hospital outcome (11 vs. 6% mortality, p < 0.01), mostly from cardiovascular causes. After adjusting for confounders, acute infections were no more associated with mortality (odds ratio 0.72; 95% confidence interval 0.43–1.20). In the group of post-infectious MI, Type 1 MI and respiratory tract infection were associated with a worse prognosis (respective odds ratio 2.44; 95% confidence interval: 1.12–5.29, and 2.89; 1.19–6.99). In this large MI survey, post-infectious MI was common, accounting for 10% of all MI, and doubled in-hospital mortality. Respiratory tract infection and Type 1 post-infectious MI were associated with a worse prognosis.