Clinical Question

Does beta-blocker treatment after myocardial infarction reduce mortality?

Bottom Line

Although recommended by guidelines and used as a so-called quality indicator of hospital care, the use of beta blockers following myocardial infarction, when combined with optimal acute and chronic treatment, does not provide a further survival benefit. Beta-blocker use reduces subsequent reinfarction and angina symptoms, but these benefits begin to wane within 30 days. Heart failure and cardiogenic shock can occur with treatment, and patients often have trouble continuing treatment. (Level of Evidence = 1a)

Synopsis

These authors assembled randomized trials by searching three databases, including Cochrane CENTRAL, and found 60 trials that enrolled more than 100,000 patients. They separately analyzed studies conducted in the reperfusion era (n = 12), because the large gains in mortality reduction associated with the availability of thrombolytics, stents, and grafts—as well as the routine use of aspirin and statins—may blunt any additional benefit of beta-blocker treatment. Two researchers independently selected studies for inclusion and evaluated them for bias. Although early studies showed a benefit with beta blockers, modern era studies show no additional survival benefit when adding a beta blocker to optimal treatment. Beta blockers reduce reinfarction rates (number needed to treat = 209) and angina symptoms (number needed to treat = 26), but these benefits seemed to be limited to the first 30 days after the initial myocardial infarction. Rates of heart failure and cardiogenic shock are increased (numbers needed to treat to harm = 79 and 90, respectively).

Study design: Meta-analysis (randomized controlled trials)

Funding source: Self-funded or unfunded

Setting: Various (meta-analysis)

Reference: BangaloreSMakaniHRadfordMet alClinical outcomes with ß-blockers for myocardial infarction: a meta-analysis of randomized trials. Am J Med.2014; 127( 10): 939– 953.