Abstract 16764: Changes in Triglyceride Levels During Omega-3 Fatty Acid Supplementation, and Incident Cardiovascular Events: Secondary Analysis From the OMEMI Trial

Abstract

Background: Elevated triglyceride levels are associated with increased cardiovascular risk. Omega-3 polyunsaturated fatty acids (n-3PUFA) are known to reduce triglyceride levels, but whether changes in triglycerides mediate any cardiovascular effects of n-3PUFA, remains unclear. Methods: In the randomized controlled OMEMI trial, 1014 elderly (70-82 years) patients with a recent acute myocardial infarction (AMI) were treated with 1.8 g/day of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) or placebo (corn oil) for two years, and followed for the primary outcome of MACE (AMI, coronary revascularization, stroke, heart failure hospitalization or all-cause death). Relative changes in triglycerides from baseline to 3 months (n=920, 91%), were associated with incident MACE (N=175) using landmark Cox regression models. Results: The median (Q1-Q3) baseline triglyceride concentration was 97 (74-135) mg/dL, and higher levels were associated with higher BMI, diabetes and heart failure, in multivariable models. After 3 months of treatment, triglycerides decreased by median -10% and 0% in the n-3PUFA and placebo groups, respectively, followed by relatively stable levels at 12 and 24 months ( Figure ). Greater triglyceride reductions at 3-months were associated with a lower risk of MACE in the n-3PUFA group (HR 1.98 [95%CI 1.23-3.17] per doubling, p=0.004; Figure ), and this persisted after adjusting for baseline triglycerides, age, sex, BMI and comorbidities (HR 2.34 [1.37-3.98], p=0.002). Changes in triglycerides did not associate with MACE in the placebo group (HR 1.13 [0.63-2.02], p=0.68). Conclusion: Treatment with 1.8 g/day of EPA/DHA modestly reduced triglyceride levels and greater on-treatment triglyceride-reductions were associated with a lower risk of MACE. Although the overall OMEMI-trial was neutral, these findings suggest that n-3PUFA-related triglyceride changes may play a role with respect to cardiovascular outcomes.