Impact of Beta Blockers on Left Ventricular Reverse Remodeling Following Primary Coronary Intervention for ST-elevation Myocardial Infarction

Background.Benefits of beta-adrenergic receptor blockers (BB) following ST-elevation myocardial infarction (STEMI) are based on data before primary percutaneous coronary intervention (PCI) became the therapeutic first choice. This study examined the relationship between BB dose and magnitude of left ventricular ejection fraction (LVEF) improvement in STEMI following primary PCI.Methods and Findings.A total of 235 STEMI patients following primary PCI who underwent echocardiography during the acute phase and over 6 months from onset were studied retrospectively. Serial LVEFs were assessed for three groups: no BB (n=33), carvedilol (n=163), and bisoprolol (n=42). Left ventricular reverse remodeling (RR) was defined as LVEF improvement ≥10%. All patients received fixed doses of BB and renin-angiotensin system inhibitor during observation. The median interval between echocardiographs was 526 days. The mean LVEF change was +2.6% (acute: 53.9±9.9%, chronic: 56.4±10.6%). Carvedilol and bisoprolol groups showed LVEF improvement, but none was seen in the no BB group (+3.7±6.5%, +3.8±6.9%, -4.2±5.0%, P<0.0001, respectively). The LVEF improvement effect was BB dose dependent. Therapy with BBs had a high rate of RR (no BB 0%, carvedilol 19.4%, bisoprolol 16.7%, P=0.0225, respectively). Multivariate analysis showed the following predictors of RR: baseline LVEF <50% and regular dose of BB, ≥10 mg of carvedilol or ≥1.25 mg of bisoprolol (Odds ratio 2.35, 95% Confidence Interval [CI] 1.12-5.02, P=0.0242; Odds ratio 4.45, 95% CI 2.06-10.27, P=0.0001).Conclusions.Immediate BB administration following primary PCI for STEMI provided a dose-dependent LVEF improvement. A LVEF <50% and regular dose of BB are predictors of RR.