While the benefits of beta-blockade following myocardial infarction (MI) are well known, these benefits have been extrapolated to all patients with coronary artery disease (CAD), and even to high risk patients without coronary artery disease. However, beta-blockers also have a number of side effects and their tolerability is not ideal. Therefore, the objective of this study was to evaluate the differential association of beta-blocker use on long-term cardiovascular outcomes in patients with known prior MI, in patients with CAD without MI, and in patients with only risk factors for CAD.
This was a longitudinal, observational study of patients in the Reduction of Atherothrombosis for Continued Health (REACH) registry; patients were followed up until April 2009. The main primary outcome was a composite of cardiovascular death, nonfatal MI, or nonfatal stroke. The secondary outcome was the primary outcome plus hospitalisation for atherothrombotic events or a revascularisation procedure.
Of 44,708 patients, 21,860 were included in the propensity score-matched analysis. Median follow-up was 44 months. Event rates were not significantly different in patients with beta-blocker use compared with those without beta-blocker use for any of the outcomes tested, even in patients who had previously had an MI. In the cohort with only risk factors for CAD, but no known history of the disease, event rates were higher for the primary outcome amongst patients taking beta-blockers (14.22% vs. 12.11%; P=.02), and also for the secondary outcome (22.01% vs. 20.17%; P=.04). In patients with known coronary disease, but who had never suffered an MI, no significant difference in the primary outcome measure was seen between patients taking – compared to those not taking – beta-blockers, and indeed the rates of the secondary endpoint were higher. A benefit from taking beta-blockers was seen in patients who had suffered an MI within the last year (OR 0.77).
In this study beta-blockade did not appear to benefit patients with no history of MI, and even patients who had suffered an MI more than a year previously.
- Bangalore S, Steg PHG, Deedwania P, et al. Beta blocker use and clinical outcomes in stable outpatients with and without coronary artery disease. JAMA 2012; 308:1340-1349.