Continuation vs Withdrawal of Beta-Blockers and Outcomes After Myocardial Infarction With Preserved Left Ventricular Function.

Background: The role of routine beta-blocker (BB) use after uncomplicated acute myocardial infarction (AMI) treated with contemporary therapies is not well established.

Objectives: The authors conducted a retrospective cohort study using linked registry and administrative data to evaluate whether early BB discontinuation (a prescription ending within 180 days of discharge) is associated with clinical outcomes.

Methods: We included patients who survived at least 180 days after AMI from 2008 to 2017 with new BB prescription and left ventricular ejection fraction ≥50%. The primary outcome was a composite of recurrent AMI, myocardial revascularization, or all-cause mortality within 5 years. Secondary outcomes were each of the components of the composite. Cox proportional hazard models were used to evaluate the association between early BB discontinuation and outcomes.

Results: Among the 4,768 included patients, 1,155 (24.2%) discontinued BB within 180 days of AMI discharge. During a median follow-up time of 57 months, 964 patients (20.2%) experienced the primary outcome. Early BB discontinuation was not associated with an increased risk of the primary outcome (adjusted HR: 1.09; 95% CI: 0.94-1.26), or with all-cause mortality (HR: 1.04; 95% CI: 0.86-1.26). However, early BB discontinuation was associated with an increased risk for recurrent AMI and a higher rate of repeat revascularization.

Conclusions: In patients with preserved left ventricular ejection fraction after AMI, discontinuation of BB within 180 days was not associated with a significantly increased risk of a composite outcome of death, recurrent AMI, or revascularization but was associated with increased risk of recurrent AMI and need for repeat revascularization.