Abstract 10072: Red Blood Cell Fatty Acid Levels Improve Grace Score Prediction of 2-Yr Mortality in Patients with Myocardial Infarction
Background: Blood omega-3 and omega-6 fatty acid (FA) levels, which reflect the intake of these essential nutrients, have been associated with reduced risk for total mortality in patients with stable coronary heart disease (CHD), but their relationship with mortality in patients admitted with myocardial infarction (MI) are unknown.
Objective: To determine the association between red blood cell (RBC) FA levels measured at admission and 2-year mortality, independent of the GRACE risk score, a validated MI risk stratification tool.
Design: Admission RBC FA levels were measured in patients enrolled in a prospective, 24-center MI registry (TRIUMPH). Two-year mortality was modeled with Cox proportional hazards regression to assess the extent to which the inclusion of FA levels would improve 2-year mortality predictions with the GRACE score.
Results: RBC FA data were available from 1,144 patients who did not report taking fish oil supplements after discharge and for whom mortality follow-up data were available. The GRACE score was significantly associated with 2-year mortality (c-statistic = 0.747). Two RBC FAs combined [eicosapentaenoic acid (EPA n-3) and docosapentaenoic (DPA n-6)] added independent prognostic discrimination to the GRACE prediction: the c-statistic increased to 0.768 (p<0.05); the net reclassification index improved by 31% (95% CI, 15%,48%); and the relative incremental discrimination index improved by 19.8% (7.5% to 35.7%). An EPA level of <0.25% (found in 3.7% of the cohort) compared to a level of greater than or equal to 0.8% (28.5% of the cohort) was associated with an increased mortality risk (HR 3.71, 1.81 to 7.61; p<0.001; Figure).
Conclusion: RBC EPA and DPA n-6 levels improved the prediction of 2-yr mortality over the GRACE score in MI patients. Measurement of RBC EPA and DPA n-6 at admission for an MI may help identify patients at increased risk of death, and future studies should evaluate whether EPA supplementation can improve post MI outcomes.
- © 2011 by American Heart Association, Inc.