Sustained beneficial effect of β-blockers on clinical outcomes after discontinuation in patients with ST elevation myocardial infarction

Abstract

Our previous study demonstrated that beneficial effect of β-blockers on clinical outcomes in patients with ST elevation myocardial infarction (STEMI). In clinical practice, β-blocker treatment is occasionally discontinued due to their side effect. The purpose of this study is to assess the impact of discontinuation of β-blockers on long-term clinical outcomes in patients with STEMI. We analyzed the data and clinical outcomes of 901 patients (716 males, 58 ± 13-year-old) STEMI patients who underwent successful primary percutaneous coronary intervention. At discharge of index STEMI, 598 patients were treated with β-blockers (491 males, 56 ± 12-year-old). After more than 1-month β-blocker treatment, β-blockers were stopped in 188 patients for any reason. We classified patients into continuation of β-blockers (410 patients, 56 ± 12-year-old) and discontinuation of β-blockers groups (188 patients, 57 ± 11-year-old) according to discontinuation of β-blockers. Occurrence of major adverse cardiovascular events (MACEs; death, recurrent MI and target vessel revascularization) during up to 10 years of follow-up was evaluated. Mean follow-up month was 56 ± 28 month. In 132 patients (22%), MACEs were occurred. The MACE-free survival rates in the 2 groups were not statistically different (log-rank P = .461). Adjusted hazard ratio (HR) of discontinuation of β-blockers for MACEs was 1.006 (95% confidence interval (CI) 0.701-1.445, P = .973; all cause of death, HR = 0.942, 95% CI = 0.547-1.622, P = .828; recurrent MI, HR = 0.476, 95% CI = 0.179-1.262, P = .136; target vessel revascularization, HR = 1.417, 95% CI = 0.865-2.321, P = .166). The MACE-free survival and survival rates of the non β-blockers treatment group was significantly worse than the discontinuation of β-blockers group (log-rank P = .003 and < 0.001, respectively). This study demonstrated that discontinuation of β-blockers was not associated with adverse cardiovascular outcomes after STEMI. The beneficial effect of β-blockers on clinical outcomes may persist in patients with initial β-blockers treatment at index STEMI.