Fish Oil Offers Cardioprotection in Post-op Atrial Fibrillation

Up to 50% of patients who undergo bypass and heart valve surgeries develop postoperative atrial fibrillation (POAF), the result of which involves more postoperative complications, including stroke, longer hospital stays, and an increase in treatment costs.

Previous research has suggested that n-3 polyunsaturated fatty acids (PUFAs) may play a protective role in cardiovascular disease (CVD), and some clinical trials have even observed improved patient mortality. The fish oil n-3 PUFAs known as eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids appear to be the most promising anti-inflammatory, vasodilating, anti-arrhythmic, and antioxidant agents.

Although clinical findings concerning PUFA’s possible cardioprotective effects have been mixed, researchers at East Carolina University’s Brody School of Medicine narrowed their work published online March 5, 2014, in Antioxidants & Redox Signaling to one clinical indication for n-3 PUFAs: reducing the incidence of POAF after cardiac surgery.

The goal of their randomized, open-label, single-blinded study was to determine whether administering n-3 PUFA therapy in the form of EPA/DHA 3.4 g/day for 2-3 weeks before cardiac surgery could alter antioxidant/anti-inflammatory gene expression in human atrial myocardium. The authors also hoped to identify possible mechanisms of action. To do so, they enrolled 12 patients scheduled for non-emergent cardiac surgery in a treatment arm and 12 patients in an untreated, standard-of-care arm.

The researchers found fish oil triggered increased production of key anti-inflammatory and antioxidant enzymes, which could help protect patients from post-surgery complications, including POAF. Blood and myocardial tissue EPA and DHA levels were significantly higher in n-3 PUFA-treated patients compared to standard-of-care control patients.

Although the study was small, the authors said their findings were significant because they identified peroxisome proliferator-activated receptor γ (PPARγ), a molecular target for hypolipidemic fibrates and the antidiabetics, thiazolidinediones. They also found higher levels of fatty acid metabolic gene expression, mitochondrial fatty acid oxidation, and antioxidant capacity in human atrial myocardium following fish oil administration. Most importantly of all, the study established a dose and duration of therapy to produce positive changes.