Oral captopril versus placebo among 14,962 patients with suspected acute myocardial infarction: a multicenter, randomized, double-blind, placebo controlled clinical trial. Chinese Cardiac Study (CCS-1) Collaborative Group.

OBJECTIVE

To assess the efficacy of captopril on mortality and morbidity after acute myocardial infarction (AMI).

METHODS

A total of 14,962 patients entering 650 hospitals from 30 provinces and autonomous regions of China up to 36 hours (mean 16.6 +/- 10.2 hours) after the onset of suspected acute myocardial infarction (MI) with no clear contraindications or indications to the study treatments (in particular, no persistent hypotension or hypovolemia due to long-term use of large dose of diuretics) were randomized to use either 4 weeks of oral captopril (6.25 mg initial dose, 12.5 mg 2 hours later, and then 12.5 mg three times daily) or matching placebo.

RESULTS

Captopril was associated with a non-significant reduction in 4-week mortality (9.12% vs 9.74%; P = 0.20); but incidence of heart failure was significantly reduced among captopril group (17.0% vs 18.7%; P = 0.01). The combined end point (death + heart failure) was 1680 (21.5%) in captopril group and 1733 (23.1%) in placebo group (P = 0.02). Anterior wall infarction of captopril treated group was found to have lower mortality (8.6% vs 10.2%, P = 0.02). Captopril treated group with a heart rate (HR) > or = 60/min at entry showed significantly lower mortality than placebo group (9.2% vs 10.7%; P = 0.01). There was a significant excess of hypotension, mostly after the start of treatment, but no evidence of any adverse effect on early mortality.

CONCLUSIONS

The angiotensin converting enzyme inhibitors (CEI) therapy started early in acute MI prevents about 6 deaths per 1000 treated, and about 15 deaths due to heart failure per 1000 in the 1st 4 weeks with greater benefits. In anterior myocardial infarction group it prevents 16 deaths per 1000 with nearly no benefit for the inferior infarction group. Due to the parasympathetic mimic effect, CEI should be used carefully in inferior infarction patients especially when HR is slow or heart block and hypotension are present.