ISIS-4: Fourth International Study of Infarct Survival Purpose To assess the separate and combined effects on all-cause mortality of adding early captopril, mononitrate and magnesium sulphate to conventional treatment of patients with definite or suspected acute MI Reference Fourth International Study of Infarct Survival Collaborative Group. ISIS-4: A randomized factorial trial assessing early oral captopril, oral mononitrate, and intravenous magnesium sulphate in 58,050 patients with suspected acute myocardial infarction. Lancet 1995; 345: 669–85.

ISIS-4: Fourth International Study of Infarct Survival - TRIAL DESIGN - Design : Multicenter, multinational, randomized, partial double-blind, placebo-controlled, 2 x 2 x 2 factorial study Patients: 58,050 patients hospitalized within 24h of suspected acute MI; patients with cardiogenic shock or persistent severe hypertension excluded Follow up and primary end point: Median 15 months follow up. Primary endpoint all-cause mortality Treatment : All patients received three study treatments, each being randomly assigned to active or placebo within each treatment: Oral captopril 50mg twice daily or placebo, for 28 days (blinded) Oral controlled-release isosorbide mononitrate 60mg twice daily or placebo, for 28 days (blinded) Intravenous magnesium sulfate as 8 mmol bolus over 15 min then 72 mmol over 24 h, or no infusion (open)

ISIS-4: Fourth International Study of Infarct Survival - RESULTS - With captopril, compared with control: —Significant reduction in 5-week mortality (7% odds reduction, 2P = 0.02) —Survival advantage maintained over 12 months: 5.4 fewer deaths/1000 (88.01 vs % survival) —No significant increase in 5-week reinfarction, heart failure or death due to cardiogenic shock —Significant increase in hypotension warranting termination of captopril (10.0 vs. 4%, 52 excess/1000, 2P<0.0001) —Significant increase in in mild/moderate (but not severe) renal dysfunction and dizziness with/without profound hypotension Mononitrate: well tolerated and, compared with control, was associated with a non-significant reduction in 5-week mortality; 12-month follow up indicated no survival advantage Magnesium: non-significant increase in 5-week mortality; no survival advantage on 12-month follow up

ISIS-4: Fourth International Study of Infarct Survival - RESULTS continued - Days after randomization Deaths Mortality in days 0– Placebo (n=29,022) Captopril (n=29,028) ISIS-4 Collaborative Group. Lancet 1995; 345: 669– Mononitrate (n=29,018) Placebo (n=29,032) Magnesium (n=29,011) Control (n=29,039) P=0.02 better NS better NS worse

ISIS-4: Fourth International Study of Infarct Survival - RESULTS continued - 2P Deaths/n Mortality (%) Deaths/n Mortality (%) Deaths/n Mortality (%) Captopril Mononitrate Magnesium 2088/29, /29, /29, /29, /29, /29, NS 7% odds reduction 3% odds reduction 6% odds increase Mortality and odds reduction in days 0–35 PlaceboTreatment Odds ratio and 95% CI Odds reduction or increase ISIS-4 Collaborative Group. Lancet 1995; 345: 669–

ISIS-4: Fourth International Study of Infarct Survival - RESULTS continued - 2P Dizziness With profound hypotension Renal dysfunction Mild Moderate Severe 110 (0.39) 30 (0.11) 170 (0.60) 74 (0.26) 23 (0.08) 13 (0.05) 155 (0.54) 83 (0.29) 316 (1.11) 130 (0.46) 68 (0.24) 26 (0.09) 1.6 (0.6) 1.9 (0.4) 5.1 (0.8) 2.0 (0.5) 1.6 (0.3) 0.5 (0.2) <0.01 <0.001 Other clinical events reported with captopril up to day 35 Placebo n=29,022 No. (%) Captopril n=29,028 No. (%) Excess/1000 (SD) ISIS-4 Collaborative Group. Lancet 1995; 345: 669–85.

ISIS-4: Fourth International Study of Infarct Survival - SUMMARY - In patients with suspected or definite acute MI: Early treatment with captopril reduced all-cause mortality at 35 days and during long-term follow up Mononitrate conferred no survival advantage in the short or long term Magnesium conferred no survival advantage, in contrast with earlier and smaller studies