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Effect of Marine Omega-3 Fatty Acid and Vitamin D Supplementation on Incident Atrial Fibrillation: A Randomized Clinical Trial

C. Albert, N. Cook, Julie Pester, M. V. Moorthy, Claire Ridge, J. Danik, B. Gencer, H. Siddiqi et al.

Journal of the American Medical Association (JAMA), 2021

6,296 participants · 114 citations

Abstract

Importance

Atrial fibrillation (AF) is the most common heart rhythm disturbance, continues to increase in incidence, and results in significant morbidity and mortality. The marine omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and vitamin D have been reported to have both benefits and risks with respect to incident AF, but large-scale, long-term randomized trial data are lacking.

Objective

To test the effects of long-term administration of marine omega-3 fatty acids and vitamin D on incident AF.

Design, Setting, and Participants

An ancillary study of a 2 × 2 factorial randomized clinical trial involving 25 119 women and men aged 50 years or older without prior cardiovascular disease, cancer, or AF. Participants were recruited directly by mail between November 2011 and March 2014 from all 50 US states and were followed up until December 31, 2017.

Interventions

Participants were randomized to receive EPA-DHA (460 mg/d of EPA and 380 mg/d of DHA) and vitamin D3 (2000 IU/d) (n = 6272 analyzed); EPA-DHA and placebo (n = 6270 analyzed); vitamin D3 and placebo (n = 6281 analyzed); or 2 placebos (n = 6296 analyzed).

Main Outcomes and Measures

The primary outcome was incident AF confirmed by medical record review.

Results

Among the 25 119 participants who were randomized and included in the analysis (mean age, 66.7 years; 50.8% women), 24 127 (96.1%) completed the trial. Over a median 5.3 years of treatment and follow-up, the primary end point of…

How strong is the evidence?

Evidence Hub reads this as a randomized trial, done in people. Its evidence level is 2 of 5 (High · randomized trial). Randomized trials of a reasonable size are the strongest single-study design. Reported size: 6,296 participants or records.

How the five levels of evidence work. The level is assigned automatically from the abstract and can be wrong, so check the paper.

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