Are beta-blockers effective in elderly patients who undergo coronary revascularization after acute myocardial infarction?

Background: Although randomized clinical trials have demonstrated that beta -blocker therapy is effective in reducing mortality after acute myocardial infarction (AMI), many of these studies excluded patients who undergo coron ary revascularization. However, the clinical practice guidelines establishe d by the American College of Cardiology and the American Heart Association recommend that beta-blocker therapy be considered for patients who underwen t successful revascularization after AMI. Methods: Using data from the Cooperative Cardiovascular Project, we compare d the initiation of beta-blocker therapy at discharge in patients aged 65 y ears or older who underwent coronary artery bypass surgery (CABG) or percut aneous transluminal coronary angioplasty (PTCA) during their hospitalizatio n for AMI with that of patients who did not undergo revascularization. We t hen examined whether beta-blocker therapy was associated with lower 1-year mortality between revascularized and nonrevascularized groups. Results: After excluding patients with contraindications to beta-blocker th erapy, 84 457 patients remained in the study sample. Of these, 8482 patient s underwent CABG, and 13 997 patients underwent PTCA. After adjusting for d emographic and clinical factors, we found that these patients were less lik ely to initiate beta-blocker therapy after CABG (odds ratio [OR], 0.44; 95% confidence interval [CI], 0.41-0.47) or PTCA (OR, 0.89; 95% CI, 0.85-0.93) relative to the nonrevascularized group. After adjusting for potential con founders, beta-blockers were significantly associated with lower 1-year mor tality in patients who underwent CABG (hazard ratio [HR], 0.70; 95% CI, 0.5 5-0.89) or P-TCA (HR, 0.86; 95% CI, 0.74-1.00), similar to that of the non revascularized group (HR, 0.83; 95% CI, 0.80-0.87). Conclusions: Therapy after AMI with beta-blockers appears to be as effectiv e in reducing 1-year mortality for elderly patients who have undergone CABG or PTCA as for a nonrevascularized group. Our findings suggest that routin e use of beta-blockers should be considered for patients who undergo revasc ularization after AMI.