Fish oil and postoperative atrial fibrillation: the Omega-3 Fatty Acids for Prevention of Post-operative Atrial Fibrillation (OPERA) randomized trial.
Level 2 - randomized trial
Multicenter double-blind randomized placebo-controlled trial
PubMed 23128104 · doi:10.1001/jama.2012.28733
What was done
The OPERA double-blind, placebo-controlled randomized trial enrolled 1,516 cardiac surgery patients across 28 centers in the United States, Italy, and Argentina (2010–2012). Participants were randomized to receive perioperative fish oil (≥840 mg n-3-PUFAs/g ethyl esters) or placebo. Dosing included a preoperative loading regimen (10 g over 3–5 days or 8 g over 2 days) followed by 2 g/day postoperatively until discharge or postoperative day 10. The primary endpoint was postoperative atrial fibrillation/flutter (AF) lasting longer than 30 seconds. Secondary endpoints included sustained/symptomatic AF, AF episode frequency, hospital utilization, and adverse events.
What was found
The primary endpoint occurred in 30.0% (227/758) of the n-3-PUFA group compared to 30.7% (233/758) of the placebo group (OR 0.96, 95% CI 0.77–1.20; P = .74). Secondary endpoints did not differ significantly, including sustained, symptomatic, or treated AF (29.6% vs 30.5%; P = .70) and number of AF episodes per patient (1 episode: 20.7% vs 20.6%; 2 episodes: 6.5% vs 7.8%; ≥3 episodes: 2.8% vs 2.4%; P = .73). Fish oil supplementation was well tolerated, with no increased risk of bleeding or serious adverse events.
Why it matters
This large trial refutes earlier small studies suggesting benefit and demonstrates that perioperative fish oil supplementation is ineffective for preventing postoperative atrial fibrillation in cardiac surgery.
Limits
The brief preoperative loading period (2 to 5 days) may not have allowed sufficient time for maximal myocardial incorporation of fatty acids before surgery. The study excluded patients with baseline arrhythmias or ongoing fish oil use, and follow-up was restricted to hospital stay or 10 days postoperatively.
Cited by
- supports In the OPERA clinical trial, pre-loading cardiac surgery patients with omega-3 fatty acids prior to open-heart surgery did not reduce postoperative atrial fibrillation.