Are β-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 coronary revascularization. However, the clinical practice guidelines established by the American College of Cardiology and the American Heart Association recommend that beta-blocker therapy be considered for patients who underwent successful revascularization after AMI. Methods: Using data from the Cooperative Cardiovascular Project, we compared the initiation of beta-blocker therapy at discharge in patients aged 65 years or older who underwent coronary artery bypass surgery (CABG) or percutaneous transluminal coronary angioplasty (PTCA) during their hospitalization for AMI with that of patients who did not undergo revascularization. We then 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 therapy, 84 457 patients remained in the study sample. Of these, 8482 patients underwent CABG, and 13 997 patients underwent PTCA. After adjusting for demographic and clinical factors, we found that these patients were less likely 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 confounders, beta-blockers were significantly associated with lower 1-year mortality in patients who underwent CABG (hazard ratio [HR], 0.70; 95% CI, 0.55-0.89) 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 effective in reducing 1-year mortality for elderly patients who have undergone CABG or PTCA as for a nonrevascularized group. Our findings suggest that routine use of beta-blockers should be considered for patients who undergo revascularization after AMI.