Effect of angiotensin converting enzyme inhibition on sudden cardiac death in patients following acute myocardial infarction - A meta-analysis of randomized clinical trials

OBJECTIVES Estimate the effect of angiotensin converting enzyme (ACE) inhibitors on the risk of sudden cardiac death (SCD) following myocardial infarction (MI). BACKGROUND Trials in post-MI patients have shown that ACE inhibitor therapy reduces mortality. However, the effect on SCD as a mechanism has not been clarified. METHODS Trials of ACE inhibitor therapy following MI reported between January, 1978 and August, 1997 were identified. Studies were included if they met the following criteria: 1) randomized comparison of ACE inhibitor to placebo within 14 days of MI; 2) study duration/blinded follow-up of greater than or equal to 6 weeks; 3) the number of deaths and modes of death were reported or could be obtained from the investigators. RESULTS We identified 374 candidate articles, of which 15 met the inclusion criteria. The 15 trials included 15,104 patients, 2,356 of whom died. Most (87%) fatalities were cardiovascular and 900 were SCDs. A significant reduction in SCD risk or a trend towards this was observed in all of the larger (N > 500) trials. Overall, ACE inhibitor therapy resulted in significant reductions in risk of death (random efforts odds ratio [OR] = 0.83; 95% confidence interval [CI] 0.71-0.97), cardiovascular death (OR = 0.82; 95% CI 0.69-0.97) and SCD (OR = 0.80; 95% CI 0.70-0.92). CONCLUSIONS This analysis is consistent with prior reports showing that ACE inhibitors decrease the risk of death following a recent MI by reducing cardiovascular mortality. Moreover, this analysis suggests that a reduction in SCD risk with ACE inhibitors is an important component of this survival benefit. (C) 1999 by the American College of Cardiology .