Predictors of Moderate-to-Severe Pericardial Effusion, Cardiac Tamponade, and Electromechanical Dissociation in Patients With ST-Elevation Myocardial Infarction

Occurrence of moderate-to-severe pericardial effusion (PE; ≥10 mm), cardiac tamponade (CT), and sudden electromechanical dissociation (EMD) was investigated in 4,361 patients with ST-elevation myocardial infarction from 1993 to 2011 in 3 different periods: 1993 to 2000 (n: 1,488); 2001 to 2008 (n: 1,844); and 2009 to 2011 (n: 1,014). Their predictors, including the use of no reperfusion therapy (n: 1,186), thrombolysis (n: 1,607), or primary percutaneous coronary intervention (PPCI, n: 1,562), were also evaluated. Incidence of PE (8.7%, 6.8%, and 5.0%), CT (5.0%, 2.9%, and 1.9%), and EMD (3.7%, 1.7%, and 1.0%), declined over the 3 periods as did mortality (12.0% 8.2%, and 5.9%) with different rates of thrombolytic therapy (52%, 37%, and 14%) and PPCI (7%, 38%, and 76%; all p <0.001). In patients treated without reperfusion therapy, thrombolysis, and PPCI, incidence of PE (12.0%, 5.7%, and 4.3%), CT (6.0%, 3.0%, and 2.2%), and EMD (4.1%, 2.2%, and 0.8%) was different as was mortality (14.4%, 8.3%, and 5.9%; all p <0.001). Independent predictors of PE were lateral infarction (odds ratio [OR] 4.09, 95% confidence interval [CI] 2.57 to 6.49), increasing age (OR 1.05, 95% CI 1.04 to 1.07), number of electrocardiographic leads involved (OR 1.34, 95% CI 1.23 to 1.45), and admission delay (OR 1.01, 95% CI 1.01 to 1.02). Increasing ejection fraction (OR 0.97, 95% CI 0.96 to 0.98), thrombolysis (OR 0.53, 95% CI 0.37 to 0.75), and PPCI (OR 0.35, 95% CI 0.25 to 0.50), however, were protectors (all p <0.001). Lateral infarction, age, number of leads involved, ejection fraction, thrombolytic therapy, and PPCI were also predictors/protectors of CT and EMD. In conclusion, PE, CT, and EMD rates in patients with ST-elevation myocardial infarction have objectively fallen in the last 2 decades, and their predictors are lateral site, increasing age, number of leads involved, and lack of reperfusion therapy. Late hospital admission is also a relevant predictor of PE.