Problem Suspected acute MI
Format Double-blinded multi-center RCT
Treatment Oral ISMN (MR) OR oral captopril OR IV magnesium
Control Standard therapy
Population 58050
Inclusion criteria Within 24 h of the onset of symptoms of suspected acute MI
No clear indications for, or contraindications to, any one of the study treatments

The only exception was that patients who were to be given non-study nitrate for just a few days could still be entered. (Such use of non-study nitrates was recorded at randomisation to allow separate analysis of the effects of the 1-month study nitrate regimen among patients who were not, at the time of randomisation, being given non-study nitrates.)
Exclusion criteria Specified not by the protocol but by the responsible physician
Suggested that caution should be taken with hypotension, cardiogenic shock, poor peripheral perfusion, or cases whether the chance of death was either very low or very high.
Follow-up 5 weeks
Primary endpoint 5-week mortality
Secondary endpoint(s) -
Details .
Brief summary: Captopril shows benefit post-MI within 5 weeks, no nitrate/magnesium benefit
PAPER: ISIS-4: a randomised factorial trial assessing early oral captopril, oral mononitrate, and intravenous magnesium sulphate in 58,050 patients with suspected acute myocardial infarction.
Date 18 Mar 1995
Journal Lancet. 1995 Mar 18;345(8951):669-85.
Information Captopril (vs placebo)
-Small but significant reduction in 5 week mortality, maintained for 1 year
-Greatest advantage in high risk patients
No survival benefit for ISMN or magnesium at 5 weeks
ISMN well tolerated