β-Blocker in Post-Myocardial Infarct Survivors with Preserved Left Ventricular Systolic Function

Background: Long‐term β‐blockade therapy is beneficial in post‐myocardial infarct (MI) patients with left ventricular (LV) dysfunction; nevertheless, its benefit in post‐MI patients with preserved LV function remains unclear. The objective of this study is to investigate the effects of long‐term β‐blockade therapy on the clinical outcomes in post‐MI patients with preserved LV function. Hypothesis: The beneficial effects of long‐term β‐blockade therapy in post‐MI patients with impaired LV function may extend to those with preserved LV function. Methods: Of 617 consecutive post‐MI patients referred for cardiac rehabilitation program, 208 patients (age: 62.7 ± 0.8 years; male: 76%) with preserved LV function (ejection fraction ≥ 50%), negative exercise stress test, and on angiotensin‐converting enzyme inhibition were studied. Results: Baseline characteristics were comparable between patients on β‐blocker (n = 154) and not on β‐blocker (n = 54). After a mean follow‐up of 58.5 ± 2.7 months, 14 patients not on β‐blocker (26%) and 14 patients on β‐blocker (9%) died with hazard ratio (HR) of 2.5 (95% confidence interval [CI]: 1.25–6.42, P = 0.01). Likewise, patients not on β‐blocker had a higher incidence of cardiac death (HR: 3.0, 95% CI: 1.07–12.10, P = 0.04), and non‐sudden cardiac death (HR: 10.1, 95% CI: 1.82–89.65, P = 0.01), but not sudden cardiac death compared with patients on β‐blocker (HR: 1.6, 95% CI: 0.34–7.61, P = 0.54). A Cox regression analysis revealed that only advanced age (≥75 years; HR: 2.55, 95% CI: 1.18–5.49, P = 0.02) and the absence of β‐blocker (HR: 2.41, 95% CI: 1.14–5.09, P = 0.02) were independent predictors for mortality. Conclusion: β‐blocker use was associated with a decrease in overall mortality and cardiac death in post‐MI patients with preserved LV function. (PACE 2010; 33:675–680)