Abstract 12773: Dose-dependence of Beta-blocker Therapy on Subsequent Mortality in One Year Survivors After Myocardial Infarction
Background: Beta-blocker (BB) therapy after acute myocardial infarction (MI) improves survival. The benefits of long term treatment remain debated.
Methods: Of 7058 patients enrolled in the OBTAIN prospective multi-center registry of patients with acute MI, follow-up BB dosing information was available in 2822 patients who survived ≥1 year. BB dose was indexed to the target BB dose used in RCTs (when available), reported as %; only BBs studied in RCTs were included in this analysis. Dosage groups were No BB (n=302), ≤12.5% (n=557), 12.6-25% (n=848), 26-50% (n=687), and >50% (n=428) of target dose respectively. Vital status was obtained by chart review, Social Security Death Index, or direct contact. Adjustment for baseline differences among groups was achieved by propensity score analysis (predicted 1-year BB dose as control variable).
Results: In the 5 groups, mean age was 62-64 years, with significant differences in gender, clinical, and MI characteristics. Mean ejection fractions were 47-50%. The figure shows Kaplan-Meier survival curves (unadjusted, p=0.06). Propensity score analysis showed an independent effect of BB dose on mortality (p=0.047). Compared to No BB, only the 12.6-25% dose group had a significant mortality reduction (HR 0.46, 95% CI 0.25-0.86, p=0.014).
Conclusions: At one year after MI, continued BB therapy may be associated with lower mortality, but there appears to be a dose-dependence to this effect. Further studies are needed to optimize BB dosing strategies for long-term treatment after MI.
Author Disclosures: J. Goldberger: None.
- © 2015 by American Heart Association, Inc.