Clinical outcomes with beta-blocker use in patients with prior history of myocardial infarction
Jackevicius CA, Krumholz HM, Ross JS, Koh M, Chong A, Austin PC, Stukel TA, Azizi P, Ko DT. Can J Cardiol. 2020; Feb 4 [Epub ahead of print]. DOI: https://doi.org/10.1016/j.cjca.2020.01.024
Background — It is uncertain whether BB are beneficial in contemporary, stable patients with prior MI. Therefore, we sought to examine the effectiveness of BB use in this population.
Methods — We conducted a cohort study using administrative databases of patients ≥65 years, alive on 4/1/2012 (index date) with a hospital discharge diagnosis of MI within the prior 3 years. The primary outcome was time to death or hospitalization for MI/ angina 1-year post-index date, with inverse probability of treatment weighting.
Results — We included 33,811 patients with prior MI, of whom 21,440 (63.4%) were dispensed a BB. The median age was 78 years, and 56% were male. There was no difference in the 1-year hazard of death/hospitalization for MI/angina [14.8% vs 14.7%; HR 1.00 (95%CI 0.94-1.07); p=0.90] in those receiving versus not receiving BB. Similarly, there was no difference in the individual endpoints within the composite, nor in 3-year outcomes. Subgroup analysis by age, sex, MI timing, MI type, heart failure, and atrial fibrillation found no benefit. Patients with a history of revascularization treated with BB had a lower rate of the composite outcome compared with those without such history (p=0.006 for interaction], at 1-year but not at 3-years.
Conclusions — In this large, contemporary population-based observational study of older stable patients with prior MI, BB were not associated with a reduction in major cardiovascular events or mortality in those with prior MI within 3 years. This study supports the need to conduct contemporary clinical trials evaluating the use of BBs post-MI.