The Impact of Omega-3 Fatty Acid Use on the Risk of Atrial Fibrillation in Patients with Cardiovascular Disease

Fish oils containing omega-3 fatty acids (OM3FA) are widely prescribed in the management of dyslipidemia. An asso-ciation between OM3FA and reduced risk of atrial fibrillation (AF) has been proposed. We examined the impact of OM3FA exposure on the risk of developing AF in patients with cardiovascular disease. Data was obtained from elec-tronic medical records of patients seen by our cardiology service between 2005 and 2007. Patients were excluded if AF developed prior to, or on the day of, OM3FA exposure. A total of 11,360 subjects were eligible for analyses. Subjects exposed to OM3FA were at higher risk for AF. Nearly all AF risk factors were significantly more prevalent in the OM3FA exposed group. As expected, those prescribed OM3FA were also more likely to be prescribed statins, ACE in-hibitors, aspirin, and beta blockers. AF occurred in 8.5% (221/2600) of OM3FA exposed subjects and 23.5% (2054/8760) of those not exposed. After controlling for AF risk factors, OM3FA exposed subjects were 74% less likely to develop AF than those not exposed to OM3FA (odds ratio 0.26, 95%CI 0.22-0.30, p < 0.0001). After controlling for risk factors for AF, OM3FA use is significantly associated with a reduced risk for AF in patients with cardiovascular disease. Potential mechanisms which may explain the ability of OM3FAs to reduce AF include its anti-inflammatory and anti-arrhythmic properties. The optimal dose of OM3FA to prevent AF is unknown and warrants prospective as-sessment in a randomized controlled trial of OM3FAs powered to detect significant differences in AF.