Indications for ACE inhibitors in the early treatment of acute myocardial infarction: systematic overview of individual data from 100,000 patients in randomized trials. ACE Inhibitor Myocardial Infarction Collaborative Group

Abstract

Background: Several large-scale trials have demonstrated improved survival with ACE-inhibitor therapy started during acute myocardial infarction. A systematic overview was conducted to resolve uncertainties regarding time of initiation, time course of effect, and identification of patients in whom the benefits or the risks may be greater.

Methods and results: This overview aimed to include individual data from all randomized trials involving more than 1000 patients in which ACE-inhibitor treatment was started in the acute phase (0 to 36 hours) of myocardial infarction and continued for a short time (4 to 6 weeks). Data were available for 98,496 patients from 4 eligible trials, and the results were consistent among the trials. Thirty-day mortality was 7.1% among patients allocated to ACE inhibitors and 7.6% among control subjects, corresponding to a 7% (SD, 2%) proportional reduction (95% CI, 2% to 11%; 2P<0.004). This represented avoidance of approximately 5 (SD, 2) deaths per 1000 patients, with most of the benefit observed within the first week. The proportional benefit was similar in patients at different underlying risk. The absolute benefit was particularly large in some high-risk groups (ie, Killip class 2 to 3, heart rate > or = 100 bpm at entry) and in anterior MI. ACE-inhibitor therapy also reduced the incidence of nonfatal cardiac failure (14.6% versus 15.2%, 2P=0.01) but was associated with an excess of persistent hypotension (17.6% versus 9.3%, 2P<0.01) and renal dysfunction (1.3% versus 0.6%, 2P<0.01).

Conclusions: These results support the use of ACE inhibitors early in the treatment of acute MI, either to a wide range of patients or selectively in patients with anterior MI and in those at increased risk of death.