Analysis was performed for the acute myocardial infarction and postmyocardial infarction cohorts separately after stratifying trails based on the reperfusion-era status. For the primary outcome, the difference between the 2 strata between the 2 strata. If the test for interaction for the primary outcome was significant, all other outcome were interpreted separately for the 2 strata. In addition, further analysis was performed categorizing trails by early initial intravenous dose vs no initial intravenous beta-blockers dose to test for the effect of intravenous beta-blockers on outcomes. Finally, a series of landmark analysis (at 30 days post myocardial infarction, between 30-day and 1-year and > 1-year landmark time points) were performed to evaluate the duration of benefit of beta-blockers. Patients who died were censored at the beginning of each landmark analysis, that is, for the 30-days to 1-year analysis, patients who died within 30 days were excluded.