CLINICAL QUESTION

Should beta blockers be continued long term or discontinued after acute myocardial infarction (MI)?

BOTTOM LINE

The single-blinded study showed that continued use of beta blockers after acute MI reduced hospitalizations, but there was no change in cardiovascular death, acute MI, or stroke. There were no differences reported in quality of life between groups. (Level of Evidence = 1b)

SYNOPSIS

Beta blockers are often used for life following an acute MI, but is that still appropriate in the modern era of percutaneous coronary interventions and other advances? The French investigators identified 3,698 patients at 49 sites with acute MI in the past 6 months who were taking a beta blocker. Those with heart failure or an ejection fraction of less than 40%, a recent cardiovascular event, or another indication for beta blockers were excluded. Participants were randomized to discontinue the beta blocker or continue taking the same medication at the same dose (which had been prescribed by their physician). At baseline, the average age was 62 years, 67% had an ST-elevation MI, 95% had a history of revascularization, and the median time from acute MI to randomization was 2.9 years. The groups were balanced, and the analysis was by intention to treat. This was a noninferiority study with a prespecified margin of 3%. The primary endpoint was a composite of nonfatal stroke, nonfatal MI, cardiovascular death, or hospitalization for cardiovascular events and was judged as not noninferior for interruption compared with continued therapy (risk difference = 2.8%, favoring continued therapy; 95% CI, < 0.1%–5.5%). Regarding individual outcomes, the benefit came from fewer cardiovascular hospitalizations, with no difference in cardiovascular death, acute MI, or stroke. There was also no difference in quality of life between groups.