- Question
- Does early treatment with oral captopril, oral mononitrate or intravenous magnesium sulphate reduce mortality in patients with suspected acute myocardial infarction?
- Design
- Randomised 2 x 2 x 2 factorial trial, with matching placebo for captopril and mononitrate and an open control for magnesium. It enrolled 58050 patients in 1086 hospitals, within 24 h (median 8 h) of symptom onset.
- Population
- Patients with suspected acute myocardial infarction and no clear contraindication to the study treatments (in particular, no cardiogenic shock or persistent severe hypotension).
- Intervention
- Oral captopril for 1 month (6.25 mg initial dose, titrated up to 50 mg twice daily); oral controlled-release mononitrate for 1 month (30 mg initially, up to 60 mg once daily); intravenous magnesium sulphate for 24 h (8 mmol initial bolus followed by 72 mmol).
- Control
- Matching placebo for captopril and for mononitrate; open control (no infusion) for magnesium sulphate.
- Primary outcome
- 5-week mortality, assessed in the randomised comparison of about 29000 active versus 29000 control patients for each drug.
- Results
- Captopril reduced 5-week mortality: 2088 deaths (7.19%) versus 2231 (7.69%) with placebo, a 7% proportional reduction (2p = 0.02), about 4.9 fewer deaths per 1000 patients treated. Mononitrate showed no significant reduction: 2129 deaths (7.34%) versus 2190 (7.54%). There were no significant interactions between the three treatments.
- Safety
- Captopril increased hypotension requiring treatment termination by 52 per 1000, cardiogenic shock by 5 per 1000 and renal dysfunction by 5 per 1000, with no excess of deaths on days 0-1. Mononitrate only increased hypotension, by 15 per 1000, with somewhat fewer deaths on days 0-1.
- Conclusion
- Early oral captopril modestly reduced 5-week mortality after suspected myocardial infarction, whereas oral mononitrate showed no mortality benefit.
- Why it matters
- It supported early use of ACE inhibitors after acute myocardial infarction, with greater absolute benefit in higher-risk patients, and showed that routine oral nitrates do not improve survival.
Card generated automatically with AI from the abstract of the original publication and the trial registry; every figure was checked against those sources. It may contain errors: verify the data at the source before using it for clinical decisions.
Generated on October 10, 2026