Effect of combined beta-blocker and angiotensin-converting enzyme inhibitor treatment on 1-year survival after acute myocardial infarction:: findings of the PRIAMHO-II registry

Introduction and objectives. Clinical trials have shown that combining beta-blockers and angiotensin-converting enzyme (ACE) inhibitors has an additive effect in reducing mortality in patients with left ventricular dysfunction following acute myocardial infarction. Whether this additive effect also occurs in unselected post-myocardial infarction patients is unknown. Methods. In total, 5397 patients who were discharged from hospital after suffering an acute myocardial infarction were followed for 1 year. The primary endpoint was all-cause mortality. The effects of the medications on 1-year survival were analyzed using a Cox regression model, which included propensity scores for beta-blocker and ACE inhibitor use to take account of any potential imbalance in drug prescription rates. Results. At hospital discharge, 55.9% of patients were receiving beta-blockers and 45.1%, ACE inhibitors. The 1 year mortality rate was 5.5%. Overall, combination of the two medications significantly reduced the 1-year mortality rate (hazard ratio [HR]=0.51; 95% confidence interval [IC], 0.32-0.82); P < 005) to a greater extent than ACE inhibitors alone (HR=0.78; 95% Cl, 0.54-1.12; P=.2) or betablockers alone (HR=0.67; 95% Cl, 0.43-1.05; P=.08). The same trend was also observed in low-risk patients without acute heart failure who had an ejection fraction 40%. Conclusions. In unselected post-myocardial infarction patients, combined prescription of beta-blockers and ACE inhibitors had an additive effect on the 1-year survival rate.