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Omega-3 fatty acid supplementation of more than 1 g per day increases the risk of atrial fibrillation
Clinical Question
Do omega-3 fatty acid supplements increase the likelihood of developing atrial fibrillation?
Bottom line
Patients given a high dose of omega-3 fatty acids (1.8 g to 4.0 g per day) have a 50% higher risk of developing AF. Given a 1% baseline risk, adding the omega-3 fatty acid would increase it to 1.5% per year, with a number needed to harm of 200 per year. Of course, the studies that actually found cardiovascular benefit were the studies of the higher doses, such as REDUCE-IT. 1a
Reference
Study design: Meta-analysis (randomized controlled trials)
Funding: Government
Setting: Outpatient (any)
Synopsis
Results of randomized trials of the effects of omega-3 fatty acid supplements have shown varying effects on the incidence of atrial fibrillation (AF). This study carefully searched the literature and found all randomized trials with at least 500 participants and at least 1 year's duration that randomized patients to an omega-3 fatty acid supplement or placebo (olive oil in 4 studies, corn oil in 2 studies, and mineral oil in 1 study). They found 7 studies with a total of 81,210 patients and a median follow-up of approximately 5 years. They allowed varying definitions of "AF event" including a new diagnosis, hospitalization, and worsening AF; 4 of 7 studies (accounting for about half the patients) used "new onset AF." The mean age of participants was 65 years and 39% were women. The authors found an increased risk of an AF event in patients who were randomized to an omega-3 fatty acid supplement (hazard ratio [HR] 1.25; 95% CI 1.07 - 1.46). Findings were moderately heterogeneous between studies (I2 = 55%), but stratification by dose (1 g vs > 1 g) largely made that heterogeneity go away. Patients in the high-dose studies had a higher risk of an AF event (HR 1.49; 1.04 - 2.15) than those in the lower-dose studies (HR 1.11; 1.06 - 1.15).
Reviewer
Mark H. Ebell, MD, MS
Professor
University of Georgia
Athens, GA
Comments
Helpful
Informative
Omega 3
Most of the people I know who were on it have discontinued it and were on lower doses.
OMEGA 3FATTY ACUDS AS ATrigger of AF
Highly enlightening and thought provoking study. Pinch on indiscriminate advocacy of omega 3 FA . The sample of study was large and the term of study reasonably long and bringing out a very valid and alarming information of the probability of provocation of AF. Excellent and unforgettable inference
large doses of omega fatty acids
increases AF by 50% to 1.5% but still has cvs benefit