Outcomes of patients in clinical trials with ST-segment elevation myocardial infarction among countries with different gross national incomes

Aims To evaluate whether there is an association between 30- day mortality in patients with ST-segment elevation myocardial infarction (STEMI) included in clinical trials and country gross national income (GNI). Methods and results A retrospective analysis of the databases of five randomized trials including 50 310 patients with STEMI (COBALT 7169, GIK-2 2931, HERO-2 17 089, ASSENT-2 17 005, and ASSENT-3 6116 patients) from 53 countries was performed. Countries were divided into three groups according to their GNI based on the World Bank data: low (less than US$ 2900), medium (between US$ 2900 and 9000), and high GNI (more than US$ 9000 per capita). Baseline characteristics, in-hospital management variables, and 30-day outcomes were evaluated. A previously defined logistic regression model was used to adjust for differences in baseline characteristics and to predict mortality. The observed mortality was higher than the predicted mortality in the low (12.1 vs. 11.8%) and in the medium income groups (9.4 vs. 7.9%), whereas it was lower in the high income group (4.9 vs. 5.6%). Conclusion An inverse relationship between mortality and GNI was observed in STEMI clinical trials. Most of the variability in mortality can be explained by differences in baseline characteristics; however, after adjustment, lower income countries have higher mortality than the expected.