Acronym: International Study of Infarct Survival
Purpose: To evaluate adding long-acting nitrates (isosorbide mononitrate) versus captopril versus intravenous magnesium versus standard therapy during acute myocardial infarction.
Format: Double blind, multi-center, randomized control trial
Treatment Group: Either isosorbide mononitrate (Imdur) or captopril (Capoten) or IV magnesium sulfate
Control Group: Standard therapy without any of the above
Number of Patients: 58,050
Suspected acute myocardial infarction within 24 hours of symptom onset
No definite indication or contraindication to the study drugs
Exclusion Criteria: No specific protocol - up to the physician's judgment. Study authors suggested that caution be advised in patients with the following:
Decreased peripheral perfusion
Cases where the mortality risk suspected was either very low or very high
Follow-up: 5 weeks
Primary Endpoint: All-cause mortality
Secondary Endpoint: None defined
Randomized acute MI patients to either isosorbide mononitrate, captopril or IV magnesium versus standard therapy. Captopril showed a reduction in mortality at 5 weeks with the largest advantage in high risk individuals. There was no mortality benefit for isosorbide mononitrate or IV magnesium.
Lancet. 1995 Mar 18;345(8951):669-85.