Effects of early angiotensin-converting enzyme inhibition in patients with non-ST-elevation acute myocardial infarction.

BACKGROUND: No data are available on the clinical efficacy of the early administration (<24 hours from onset of chest pain) of angiotensin-converting enzyme inhibitors in non-thrombolysed patients with non-ST-elevation myocardial infarction (NSTEMI). We have addressed this issue in a subgroup of NSTEMI patients enrolled in the SMILE trial. METHODS: Of the overall population of 1556 patients, 526 (33.8%) had an anterior wall NSTEMI, defined as an ST elevation <1 mm or an ST depression in at least two contiguous precordial leads with or without new abnormal Q waves. No patient of the SMILE Study received thrombolytic therapy or was reperfused. Patients were randomized, double-blind, to zofenopril (n = 253) or placebo (n = 273) for 6 weeks. The primary end point was the effect of treatment on the 6-week combined occurrence of death and severe congestive heart failure (CHF). Secondary end points included the evaluation of the 6-week rate of severe CHF as well as the 1-year mortality rate. RESULTS: After 6 weeks of treatment, zofenopril significantly reduced both the incidence of the primary end point (risk reduction 65%, 95% CI 20-80, 2P = .003) and the 6-week incidence of severe CHF (84%, 95% CI 33-97, 2P = .006) in NSTEMI patients. One-year mortality was also significantly reduced by zofenopril treatment (43%, 95% CI 14-57, 2P = .036). CONCLUSIONS: Results of this post hoc analysis of the SMILE Study strongly suggest the benefit of the early administration of zofenopril even in patients with an anterior wall NSTEMI.