Abstract

Background
High intake of marine n-3 polyunsaturated fatty acids (PUFA) has been associated with reduced risk of cardiovascular events; however, this has not been confirmed in patients with a recent acute myocardial infarction (AMI). Elderly patients are at particularly increased cardiovascular risk after MI, but few trials address this group specifically. Omega-3 fatty acids hold the potential to reduce cardiovascular events with limited adverse effects in this vulnerable group. The hypothesis was that daily addition of 1.8g n-3 PUFA to standard of care secondary prophylaxis in elderly patients who have survived an AMI would reduce the risk of subsequent cardiovascular events during 2 years follow-up.

Methods
The OMega-3 fatty acids in Elderly with Myocardial Infarction (OMEMI) trial is an investigator-initiated, multi-center, randomized clinical trial adding 1.8 g n-3 PUFA (930 mg EPA and 660 mg DHA) versus placebo (corn oil) daily to standard of care in 70-82 years old patients with recent (2-8 weeks) AMI. The primary endpoint was a composite of non-fatal AMI, unscheduled revascularization, stroke, all-cause death, heart failure hospitalization after two years. The secondary outcome was new atrial fibrillation. The safety outcome was major bleeding. Serum fatty acids were measured as biomarkers of adherence.

Results
In total, 1,027 patients were randomized. Follow-up data were available for 1,014 patients who were included in the intention-to-treat analysis. Mean ± SD age was 75±3.6 years, 294 (29%) were female and mean triglycerides were 111.4±61.9 mg/dL. The primary endpoint occurred in 108 (21.4%) patients on n-3 PUFA vs 102 (20.0%) on placebo (HR 1.08 [95%CI 0.82-1.41], p=0.60). The secondary endpoint occurred in 28 (7.2%) patients on n-3 PUFA vs 15 (4.0%) on placebo (1.84 [0.98 -3.45], p=0.06). Median changes in EPA and DHA were +87% and +16% for n-3 PUFA vs -13% and -8% for placebo. Major bleeding occurred in 54 (10.7%) and 56 (11.0%) in the n-3 PUFA and placebo groups, respectively (p=0.87). Similar results were found in per-protocol analysis (n=893).

Conclusions
We could not detect reduction in clinical events in our elderly patients with a recent AMI, treated with 1.8 g n-3 PUFAs daily for 2 years.