Early β-Blocker Use and Clinical Outcomes in Acute Myocardial Injury: A Retrospective Cohort Study.

Abstract

Background: Acute myocardial injury is defined by elevated cardiac troponin (cTn) levels with a rising and/or falling pattern, and is associated with increased mortality risk compared to patients without myocardial injury. The role of β-blockers in patients with acute myocardial injury remains unclear.

Methods: This multicenter, retrospective cohort study used data from the Tianjin Health and Medical Data Platform to assess the impact of early β-blocker use on 1-year all-cause mortality and major adverse cardiovascular events (MACE) in acute myocardial injury patients, employing a new user and target trial emulation design. Propensity score matching (PSM) was applied, and Cox regression was used to calculate hazard ratios (HR) and 95% confidence intervals (CI).

Results: After PSM, a total of 25,966 participants were included: 8,667 to the β-blocker group and 17,299 to the non-β-blocker group. A total of 3,487 deaths (13.5%) and 5,795 MACE (22.3%) occurred. Compared with non-users, β-blocker was associated with the reduced risk of all-cause mortality (HR: 0.89, 95% CI: 0.83-0.95) and MACE (HR: 0.90, 95% CI: 0.85-0.95). In the subgroup analysis, β-blockers were associated with a significantly reduced risk of mortality in patients without stroke (HR 0.85, 95% CI: 0.78-0.93), while no significant association was observed in patients with stroke (HR 1.04, 95% CI: 0.93-1.16).

Conclusions: Early use of β-blockers is associated with the reduced risk of 1-year mortality in patients with acute myocardial injury. To more accurately assess the therapeutic effects, prospective trials are necessary, and these data provide key research directions for future trials.