β -Blocker in Post-Myocardial Infarct Survivors with Preserved Left Ventricular Systolic Function CHUNG-WAH SIU, M.B.B.S.,*,† VINCENT PONG, M.B.B.S.,* MAN-HONG JIM, M.D.,* WEN-SHENG YUE, M.D.,* HEE-HWA HO, M.B.B.S.,* SHEUNG-WAI LI, M.B.B.S.,‡ CHU-PAK LAU, M.D.,*,† and HUNG-FAT TSE, M.D., PH.D.*,† From the *Cardiology Division, Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong, China; †Research Center of Heart, Brain, Hormone and Healthy Aging, The University of Hong Kong, Hong Kong, China; and ‡Department of Medicine, Tung Wah Hospital, Hong Kong, China 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) β -blocker, myocardial infarction, survival Introduction The current American Heart Association and American College of Cardiology (AHA/ACC) guidelines for management of patients with ST- elevation myocardial infarction (MI) recommend initiating β -blocker in all post-MI patients with- out contraindications and continuing the therapy indefinitely (Class I, level of evidence A). 1,2 It has been demonstrated in several large randomized control trials in prefibrinolytic era involving co- horts of relatively unselected post-MI patients that β -blockade therapy improves survival by 25–39% Disclosure: None of the author has a real or perceived conflict of interest or a disclosure of any personal or financial support. Address for reprints: Hung-Fat Tse, M.D., Ph.D., Cardiology Di- vision, Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong Kong, China. Fax: 852-2818-6304; e-mail: hftse@hkucc.hku.hk Received June 30, 2009; revised November 29, 2009; accepted December 20, 2009. doi: 10.1111/j.1540-8159.2010.02694.x through a reduction in cardiac mortality, sudden cardiac death, and reinfarction. 3–6 Survival bene- fit of long-term β -blockade therapy is mainly ob- served among patients at high risk including those with impaired left ventricular (LV) function, ven- tricular tachyarrhythmia, and recurrent/persistent ischemia. 3,7 In contrast, clinical data concerning the long-term β -blockade therapy in post-MI pa- tients at low risk such as those with good LV function and negative stress test are limited, 8 thereby it remains unclear whether low-risk sub- jects could be benefited from the therapy. More im- portantly, these data were obtained from clinical trials predating the incorporation of angiotensin- converting enzyme (ACE) inhibitors and revas- cularization therapy into the standard post-MI management algorithm, which could potentially undermine the benefits of long-term β -blockade. Therefore, the purpose of this study was to de- termine the effects of β -blockade therapy on the clinical outcomes in a cohort of post-MI patients with preserved LV function, ACE inhibition, but no ischemia. C 2010, The Authors. Journal compilation C 2010 Wiley Periodicals, Inc. PACE, Vol. 33 June 2010 675