Background: Cardiac tamponade is a life-threatening complication of acute myocardial infarction (MI). Data on the incidence, risk factors, and outcome of tamponade in patients with acute MI in the fibrinolytic era are limited.
Methods: Data from a combined clinical trials database of ST-segment elevation MI were used to evaluate the incidence of cardiac tamponade, baseline characteristics, and outcomes in patients with and without tamponade. Univariable and multivariable analyses assessed the relationship between patient characteristics and tamponade development, and the influence of tamponade on mortality.
Results: Of 102,060 patients, 865 (0.85%) developed isolated cardiac tamponade during initial hospitalization. Patients with tamponade were older (median 71.9 vs 61.6 years, P < .001), were more likely to be female (54.0% vs 25.1%, P < .001), were more likely to have an anterior MI (61.9% vs 41.5%, P < .001), and had a longer time from symptom onset to reperfusion (median 3.5 vs 2.8 hours, P < .001) than those without tamponade. Multivariable analyses identified increasing age, anterior MI location, female sex, and increased time from symptom onset to treatment as significant independent predictors of tamponade. Patients with tamponade had an increased death rate at 30 days (hazard ratio 7.9, 95% CI 4.7-13.5).
Conclusion: Cardiac tamponade occurs in < 1% of patients with fibrinolytic-treated acute MI and is associated with increased 30-day mortality. Time from symptom onset to treatment strongly predicted the development of tamponade, underscoring the need for continued efforts to increase speed to treatment in acute MI.