Abstract P174: Omega-3 Index: An Independent Predictor of 1 Year All-Cause Mortality in Myocardial Infarction (MI) Patients

Abstract

Introduction: The omega-3 index, which reflects the red cell membrane content of eicosapentaenoic acid plus docosahexaenoic acid, has been recently suggested as a modifiable cardiovascular risk factor. Case control studies showed that lower omega-3 fatty acid levels are associated with a higher risk of sudden cardiac death, acute coronary syndrome and myocardial infarction (MI). A cut-off point of 4% has been suggested as the point below which the risk increases. However, the prognostic value of the omega-3 index in the setting of acute MI is unknown. Methods: Baseline omega-3 index levels were measured in patients enrolled in a prospective, 24-center MI registry (TRIUMPH). One-year mortality data were collected. Cox proportional hazards regression models of 1-year mortality were developed to determine the association of an omega-3 index level <4% with mortality, independent of other clinically important demographic and clinical factors (Figure). Results: Among 1424 MI patients who had their baseline omega-3 index levels measured, the mean (SD) age was 59.1(12.4), 45.2% (644) had an admission diagnosis of ST-elevation MI, and 27% (387) had an omega-3 index level <4%. Overall 1-year mortality was 5.6% (80/ 1424). In the fully-adjusted model, an omega-3 index of <4% was independently associated with mortality at 1 year (hazard ratio = 2.0 [95% CI (1.2, 3.3)]; Figure) Conclusion: Lower omega-3 fatty acid levels were independently associated with all-cause mortality in this MI cohort. Since omega-3 levels are modifiable, use of the omega-3 index to direct secondary preventive measures, including fish oil supplementation, may prove beneficial in the post-MI population.