Trial Details:

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

Inclusion Criteria: 

  • 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:

  • Cardiogenic shock
  • Profound hypotension
  • 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.

Original Publication:

Lancet. 1995 Mar 18;345(8951):669-85.