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.