ALPHA OMEGA: Few post-MI patients benefit from low-dose n-3 fatty acids

1 September 2010

MedWire News: The overall rate of cardiovascular events in post-myocardial infarction (MI) patients is not reduced by low doses of dietary n-3 fatty acids, although some subgroups may benefit, the ALPHA OMEGA study results show.

“We found that cardiovascular mortality rate in the study population was only half that expected, probably because of their excellent treatment. This may also be why the rate of MACE during follow-up was no lower in the fatty acid groups than in the placebo group,” lead author Daan Kormhout (Wageningen University, The Netherlands) told delegates at the European Society of Cardiology 2010 Congress in Stockholm, Sweden.

Kormhout and team randomly assigned over 4837 patients aged 60–80 years, who had suffered MI approximately 4 years previously, to receive 400 mg eicosapentaenoic acid plus docosahexaenoic acid (EPA+DHA) alongside an alpha linolenic (ALA) placebo, 2 g alpha linolenic acid (ALA) alongside an EPA+DHA placebo, 400 mg EPA+DHA plus 2 g ALA, or ALA placebo plus EPA+DHA placebo per day. The supplements were delivered by enriched margarine eaten on 20 g of bread per day, approximating to 3–4 slices.

The patients were followed-up for 40 months, during which time 671 patients (13.9%) suffered a MACE.

However, neither EPA-DHA nor ALA treatment significantly reduced the risk for MACE, including cardiac interventions, or secondary outcomes comprising the incidence of cardiovascular diseases, fatal cardiovascular diseases, fatal coronary heart disease, ventricular-arrhythmia-related events, and death from any cause, with hazard ratios of 1.01 and 0.91 respectively.

The results did show, however, a borderline significant 26% reduction in the risk for MACE among a prespecified subgroup of women (p=0.07). Also, an exploratory analysis in 1014 diabetes patients indicated that EPA+DHA was linked to a significant reduction in coronary heart disease mortality (hazard ratio [HR]=0.51; p=0.04) and that EPA+DHA and ALA were associated with a reduction in ventricular-arrhythmia-related events (HR=0.51; p=0.09, and HR=0.39; p=0.02, respectively).

Kormhout pointed out that the paients were already “very well treated”. Indeed, in addition to receiving n-3 fatty acids, 98% of patients were also receiving antithrombotic agents, 90% were on hypertensive drugs, and 86% were taking lipid-lowering therapy.

He said that this might explain their finding of low MACE risk reduction with low-dose n-3 fatty acid supplementation.

The findings have also been published advance online by the New England Journal of Medicine.

MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a trading division of Springer Healthcare Limited. © Springer Healthcare Ltd; 2010

N Engl J Med 2010; Advance online publication