Effect of carvedilol on outcome after myocardial infarction in patients with left-ventricular dysfunction: the CAPRICORN randomised trial

Background The beneficial effects of beta -blockers on longterm outcome aft er acute myocardial infarction were shown before the introduction of thromb olysis and angiotensin-converting-enzyme (ACE) inhibitors. Generally, the p atients recruited to these trials were at low risk: few had heart failure, and none had measurements of left-ventricular function taken. We investigat ed the long-term efficacy of carvedilol on morbidity and mortality in patie nts with left-ventricular dysfunction after acute myocardial infarction tre ated according to current evidence-based practice. Methods In a multicentre, randomised, placebo-controlled trial, 1959 patien ts with a proven acute myocardial infarction and a left-ventricular ejectio n fraction of less than or equal to 40% were randomly assigned 6.25 mg carv edilol (n = 975) or placebo (n = 984). Study medication was progressively i ncreased to a maximum of 25 mg twice daily during the next 4-6 weeks, and p atients were followed up until the requisite number of primary endpoints ha d occurred. The primary endpoint was all-cause mortality or hospital admiss ion for cardiovascular problems. Analysis was by intention to treat. Findings Although there was no difference between the carvedilol and placeb o groups in the number of patients with the primary endpoint (340 [35%] vs 367 [37%], hazard ratio 0.92 [95% CI 0.80-1.07]), all-cause mortality alone was lower in the carvedilol group than in the placebo group (116 [12%] vs 151 [15%], 0.77 [0.60-0.98], p = 0.03). Cardiovascular mortality, non-fatal myocardial infarctions, and all-cause mortality or non-fatal myocardial in farction were also lower on carvedilol than on placebo. Interpretation In patients treated long-term after an acute myocardial infa rction complicated by left-ventricular systolic dysfunction, carvedilol red uced the frequency of all-cause and cardiovascular mortality, and recurrent , non-fatal myocardial infarctions. These beneficial effects are additional to those of evidence-based treatments for acute myocardial infarction incl uding ACE inhibitors.