AUSTIN, TEXAS. Atrial fibrillation is a common sequel to coronary artery bypass grafting (CABG). In 2005 a team of Italian researchers reported that supplementation with 2 grams/day of fish oil (EPA + DHA) for 5 days prior to CABG reduced the incidence of postoperative AF from 33.3% (control group) to 15.2% (fish oil group). Now a team of researchers from St. David's Medical Center in Austin, TX, Northeastern College of Medicine in Canton, OH, IKEM in the Czech Republic, and McMaster University in Hamilton, Canada reports that fish oil supplementation before and after a pulmonary vein isolation (PVI) procedure reduces the risk of AF recurrence.

Their retrospective study included 1500 afibbers who underwent a pulmonary vein antrum isolation (PVAI) procedure at St. David's between 2004 and 2007. Two hundred and eighty-five patients (19%) had supplemented with a minimum of 655 mg of fish oil (in capsules) for at least a month prior to their PVAI and continued to do so during the entire follow-up period. It was possible to closely match 129 of these patients (70% paroxysmal and 30% persistent or permanent) with 129 patients (control group) from the remaining 1215 patients who had not taken fish oil. The two groups were matched for type of afib, age, gender, left atrial size, ejection fraction and the presence of type 2 diabetes, hypertension, coronary artery disease and stroke. The two groups, fish oil group and control group, were scheduled for follow-up (including 48-hr Holter monitoring) 3, 6, 9 and 12 months after the procedure and were equipped with a cardiac event monitor during the first 5 months following their PVAI.

During the blanking period (8 weeks following the procedure) 27% of patients in the fish oil group and 44% in the control group experienced afib recurrence; in other words, fish oil supplementation reduced the risk of early recurrence by 39%. Procedural failure (afib recurring more than 8 weeks from the PVAI) was 23% in the fish oil group and 32% in the control group, or a risk reduction of 28%. The research team also noted that the fish oil group had a significantly lower pre-procedure level of C-reactive protein (CRP) than did the control group (2.1 mg/L vs. 3.0 mg/L). CRP, an important marker of inflammation, measured 48 hours after the procedure was also lower in the fish oil group (14.3 mg/L vs. 18.0 mg/L). Complication rates were similar in the two study groups.

The research team concludes that patients treated with long-chain omega-3 polyunsaturated fatty acids (fish oils) prior to and following a PVAI experienced a lower incidence of early recurrence and procedural failure compared to untreated patients.

Shaheen, PD, et al. Omega-3 polyunsaturated fatty acid supplementation reduced atrial fibrillation recurrence after pulmonary vein antrum isolation. Indian Pacing and Electrophysiology Journal, Vol. 9, No. 6, November 1, 2009, pp. 292-98

Editor's comment: The findings of this study are clearly of major importance to afibbers contemplating a catheter ablation. It is odd indeed that the study was published in a relatively obscure journal such as the Indian Pacing and Electrophysiology Journal, especially in light of the fact that the participants were all treated at St. David's Medical Center in Austin, Texas. Certainly, if a completely safe drug had been found to reduce afib recurrence by almost 30%, it would have been trumpeted in major mainstream medical journals and achieved headline status in the general news media.