Context: ST-segment elevation myocardial infarction (STEMI) treatment has improved outcomes and shortened hospital stay. Recently, 30-day readmission rates have been proposed as a metric for care of patients with STEMI. However, international rates and predictors of 30-day readmission after STEMI have not been studied.

Objective: To determine international variation in and predictors of 30-day readmission rates after STEMI and country-level care patterns.

Design, setting, and patients: Post hoc analysis of the Assessment of Pexelizumab in Acute Myocardial Infarction trial that enrolled 5745 patients with STEMI at 296 sites in the United States, Canada, Australia, New Zealand, and 13 European countries from July 13, 2004, to May 11, 2006. Multivariable logistic regression analysis was used to identify independent predictors of all-cause and nonelective 30-day postdischarge readmission.

Main outcome measures: Predictors of 30-day postdischarge all-cause and nonelective readmissions.

Results: Of 5571 patients with STEMI who survived to hospital discharge, 631 (11.3%) were readmitted within 30 days. Thirty-day readmission rates were higher for the United States than other countries (14.5% vs 9.9%; P < .001). Median length of stay was shortest for US patients (3 days; interquartile range, 2-4 days) and longest for Germany (8 days; interquartile range, 6-11 days). In multivariable regression, the predictors of 30-day readmission included multivessel disease (odds ratio [OR], 1.97; 95% CI, 1.65-2.35) and US location (OR, 1.68; 95% CI, 1.37-2.07). Excluding elective readmission for revascularization, US enrollment was still an independent predictor of readmission (OR, 1.53; 95% CI, 1.20-1.96). After adjustment of the models for country-level median length of stay, US location was no longer an independent predictor of 30-day all-cause or nonelective readmission. Location in the United States was not a predictor of in-hospital death (OR, 0.88; 95% CI, 0.60-1.30) or 30-day postadmission death (OR, 1.0; 95% CI, 0.72-1.39).

Conclusions: In this multinational study, there was variation across countries in 30-day readmission rates after STEMI, with readmission rates higher in the United States than in other countries. However, this difference was greatly attenuated after adjustment for length of stay.