Dietary supplementation with n-3 polyunsaturated fatty acids and vitamin E after myocardial infarction: results of the GISSI-Prevenzione trial

Summary

GISSI-Prevenzione enrolled 11,324 Italian adults who had survived a recent myocardial infarction, randomizing them to one of four arms: n-3 polyunsaturated fatty acid supplementation (1 g/day of EPA + DHA ethyl esters), vitamin E supplementation, both, or neither. After 3.5 years of follow-up, the n-3 PUFA arm showed a statistically significant reduction in the combined primary endpoint of death, nonfatal myocardial infarction, and stroke compared with control. The benefit appeared early — within the first months — and was driven primarily by reductions in cardiovascular mortality and sudden cardiac death rather than by reductions in nonfatal infarction. Vitamin E supplementation did not significantly affect outcomes. The trial is one of the foundational pieces of evidence supporting omega-3 supplementation in secondary cardiovascular prevention and was influential in shaping European Society of Cardiology and American Heart Association recommendations on fish and omega-3 intake.