Effect of beta-blocker therapy on mortality rates and future myocardial infarction rates in patients with coronary artery disease but no history of myocardial infarction or congestive heart failure

Beta-blocker therapy has been shown to benefit patients who have coronary artery disease and present with acute myocardial infarction (AMI) and/or congestive heart failure (HF). However, whether β-blocker therapy provides a similar benefit in patients who have coronary artery disease but not AMI or HF is unknown. A population of 4,304 patients who did not have HF but did have angiographically confirmed coronary artery disease (≥1 stenosis of ≥70%) without AMI at hospital presentation was evaluated. Baseline demographics, cardiac risk factors, clinical presentation, therapeutic procedures, and discharge medications were recorded. Patients were followed for a mean of 3.0 ± 1.9 years (range 1 month to 6.9 years) for outcomes of all-cause death or AMI. Patients' average age was 65 ± 11 years and 77% were men. Overall, 10% died and 5% had a nonfatal AMI. Discharge β-blocker prescription was associated with an increased event-free AMI survival rate for all-cause death (no β blocker 88.3%, β blocker 94.5%, p <0.001) and death/AMI (no β blocker 83.4%, β blocker 89.2%, p <0.001) but not non-fatal AMI (no β blocker 93.6%, β blocker 94.1%, p = 0.60). After adjustment for 16 covariates, including statin prescription, angiotensin-converting enzyme inhibitor prescription, and type of baseline therapy, the effect of β blockers on the combination end point of death/AMI was eliminated. However, the effect of β blockers on death remained (hazard ratio 0.66, 95% confidence interval 0.47 to 0.93, p = 0.02). Thus, β blockers are clearly indicated for most patients who have HF or AMI, and our results suggest that patients who have coronary artery disease without these conditions have approximately the same protective benefit against death. No effect was observed on longitudinal incidence of AMI or the combination of death/nonfatal MI.