Omega-3 Fatty Acid Supplements and Risk of Atrial Fibrillation and ‘Micro-Atrial Fibrillation’: A Secondary Analysis from the OMEMI Trial

• Published in: Clinical nutrition (Edinburgh, Scotland) Scotland), 2023-09, Vol.42 (9), p.1657-1660
• Main Authors: Myhre, Peder L., Berge, Trygve, Kalstad, Are A., Tveit, Sjur H., Laake, Kristian, Schmidt, Erik B., Solheim, Svein, Arnesen, Harald, Seljeflot, Ingebjørg, Tveit, Arnljot
• Format: Article
• Language: English
• Subjects: atrial fibrillation; docosahexaenoic acid; eicosapentaenoic acid; Omega-3 PUFA
• ISSN: 0261-5614; 1532-1983
• DOI: 10.1016/j.clnu.2023.07.002

Recent randomized clinical trials have raised concerns regarding potential off target adverse effects from supplementation of n-3 polyunsaturated fatty acids (PUFA) on atrial fibrillation (AF) risk. We aimed to assess risk and potential mediators of AF and ‘micro-AF’ from n-3 PUFA in post-myocardial infarction (MI) patients. In the OMEMI trial, 70-82 y.o. patients with a recent MI were randomized to 1.8g/day of eicosapentaenoic-/docosahexaenoic acid (EPA/DHA) or placebo (corn oil) for two years. New-onset AF and ‘micro-AF’ was recorded by clinical detection and by screening with Zenicor thumb-ECG (adjudicated by blinded investigators). Serum EPA and DHA were measured at baseline and study end. At baseline, 759 of 1014 (75%) patients had no AF history. These patients were aged 75±4 years and 71% were male. During follow-up, 43 patients developed new-onset AF (39 clinically-detected and 4 by thumb-ECG screening). In addition, 27 patients had episodes of micro-AF, yielding a total of 70 patients with new-onset AF or ‘micro-AF’. In the n-3 PUFA group 46 (11.9%) had AF/’micro-AF’ (28 AF, 18 ‘micro-AF’) and in the placebo group 24 (6.5%) had AF/micro-AF (15 AF, 9 micro-AF); HR 1.90 (95%CI 1.16-3.11), P=0.011. Changes in serum EPA (but not DHA) mediated the effect from n-3 PUFA on AF risk, explaining 65% of the association. Supplementation of n-3 PUFA post MI increases the risk of ‘micro-AF’ and AF, and increases in EPA seems to be an important mediator of the treatment effect from n-3 PUFA on the risk of AF. Short Communication. OMEMI Study; ClinicalTrails.gov identifier: NCT0184194.