Does beta-blocker therapy improve clinical outcomes of acute myocardial infarction after successful primary angioplasty?

Objectives: We sought to determine if beta-blocker therapy improves clinical outcomes of acute myocardial infarction (AMI) after successful primary percutaneous coronary intervention (PCI).Background: We have shown that pre-treatment with beta-blockers has a beneficial effect on short-term clinical outcomes in patients undergoing primary PCI for AMI. It is unknown if beta-blocker therapy after successful primary PCI improves prognosis of AMI.Methods: We analyzed clinical, angiographic, and outcomes data in 2,442 patients who underwent successful primary PCI in the Primary Angioplasty in Acute Myocardial Infarction-2 (PAMI-2), PAMI No Surgery-on-Site (PAMI noSOS), Stent PAMI, and Air PAMI trials. We classified patients into beta group (those who received beta-blockers after successful PCI, n = 1,661) and no-beta group (n = 781). We compared death and major adverse cardiac events (MACE) (death, reinfarction, and ischemia-driven target vessel revascularization) at six months between groups receiving and not receiving beta-blockers.Results: At six months, beta patients were less likely to die (2.2% vs. 6.6%, p < 0.0001) or experience MACE (14 vs. 17%, p = 0.036). In multivariate analysis, beta-blockers were independently associated with lower six-month mortality (odds ratio [OR] 0.43, 95% confidence interval [CI] 0.26 to 0.73, p = 0.0016). Beta-blocker therapy was an independent predictor of lower six-month events in high-risk subgroups: ejection fraction ≤50% (death: OR 0.34, 95% CI 0.19 to 0.60, p = 0.0002) or multi-vessel coronary artery disease (CAD) (death: OR 0.26, 95% CI 0.14 to 0.48, p < 0.0001; MACE: OR 0.57, 95% CI 0.41 to 0.80, p = 0.0011).Conclusions: Treatment with beta-blockers after successful primary PCI is associated with reduced six-month mortality, with the greatest benefit in patients with a low ejection fraction or multi-vessel CAD. [Copyright &y& Elsevier]