Predictive Factors of Pericardial Effusion After a First Acute Myocardial Infarction and Successful Reperfusion.

The aim of the study was to identify the determinants of pericardial effusion (PE) after a first myocardial infarction (MI). Cardiac magnetic resonance enables early analysis of multiple post-MI parameters; 193 patients with a first ST-elevation MI admitted to the Angers University Hospital (France) were enrolled prospectively. Cardiac magnetic resonance was performed at baseline (median of 5 days [4 to 7]) and repeated at a 3-month follow-up to investigate left ventricular (LV) volumes, LV ejection fraction, infarct size, microvascular obstruction (MVO), systolic wall stress (SWS), and PE presence and extent. A 1-year follow-up was also performed. Overall, 113 patients (58.5%) showed a PE with a median size of 31.6 ± 24.0 ml in the event that a PE was present. Patients with PE typically presented larger initial infarct sizes and LV volumes, and higher SWS, with more depressed LV ejection fraction and more frequent MVO and pleural effusions. Patients with PE exhibited higher rates of heart failure during hospitalization. At follow-up, there was no relevant PE, with no pericardiocentesis required. The multivariate analysis revealed SWS (odds ratio [OR] 1.092 [95% CI 1.007 to 1.184], p = 0.042), infarct size (OR 1.048 [95% CI 1.014 to 1.083], p = 0.003), and MVO extent (OR 1.274 [95% CI 1.028 to 1.579], p = 0.018) to be independent predictors for PE presence and volume. One patient died of LV free wall rupture during initial hospitalization, with only "small" PE found. In conclusion, infarct size, MVO, and SWS were independently related to PE presence and volume. Post-MI PE was found in 58.5% of cases, being regressive at follow-up. Among these patients with early reperfusion and optimal medical therapy, PE volume did not seem to be related to future clinical events.