Association of β-blocker use at discharge and prognosis of oldest old with acute myocardial infarction: a prospective cohort study

To examine the effect of β-blockers on long-term cardiovascular mortality (CVM) in the oldest old (≥ 80 years) with acute myocardial infarction (AMI). β-blocker use at discharge had no significant association with long-term CVM in oldest old with AMI, which were further demonstrated by propensity score matching, inverse probability treatment weighting, and subgroup analyses. This study first suggested β-blockers use in oldest old with AMI could not reduce post-discharge CVM, which need to be further verified by randomized controlled trials. It is uncertain whether β-blockers are beneficial for long-term prognosis in older patients following acute myocardial infarction (AMI). Thus, this study sought to examine the effect of β-blockers on long-term cardiovascular mortality (CVM) in the oldest old (≥ 80 years) with AMI. In this prospective, consecutive, non-randomized study, a total of 1156 patients with AMI admitted within 24 h after onset of symptoms were enrolled from January 2012 to February 2020. Univariate and multivariate Cox regression analyses were performed to examine the impact of β-blocker use on prognosis. Furthermore, one-to-one propensity score matching (PSM) and inverse probability treatment weighting (IPTW) analyses were used to control for systemic differences between groups. The primary outcome was long-term CVM. Among the enrolled subjects, 972 (85.9