Post-operative atrial fibrillation/flutter (AF) is one of the most common complications of cardiac surgery and significantly increases morbidity and healthcare utilization. A few small trials have evaluated whether long-chain n-3-polyunsaturated fatty acids (PUFA) reduce post-op AF, with mixed results.
To determine whether peri-operative n-3-PUFA supplementation reduces post-op AF.
Randomized, double-blind, placebo-controlled, multinational, clinical trial.
A total of 1,516 patients scheduled for cardiac surgery across 28 centers in the US, Italy, and Argentina, enrolled between Aug 2010 and Jun 2012. Inclusion criteria were broad; the main exclusions were regular use of fish oil or absence of sinus rhythm at enrollment. Forty-eight percent of screened patients and 94% of eligible patients were enrolled.
Patients were randomized to receive fish oil (1 g capsules containing ≥840 mg n-3-PUFA as ethyl esters) or placebo, with pre-operative loading of 10g over 3-5 days (or 8g over 2 days) followed post-operatively by 2g/d until hospital discharge or post-op day10, whichever first.
Main Outcome Measures
The primary endpoint was occurrence of post-op AF >30 sec. We also evaluated post-op AF lasting >1hr, resulting in symptoms, or treated with cardioversion; other secondary post-op AF endpoints; other tachyarrhythmias; hospital utilization; and major adverse cardiovascular events, 30-day mortality, bleeding, and other adverse events. All endpoints and analyses plans were prespecified.
At enrollment, mean±SD age was 64±13 years, 72.2% were male, and 51.8% had planned valvular surgery. The primary endpoint occurred in 233 (30.7%) and 227 (30.0%) patients assigned to placebo and n-3-PUFA, respectively (OR=0.96, 95%CI=0.77-1.20; P=0.74). None of the secondary endpoints were significantly different, including post-op AF that was sustained, symptomatic, or treated (n=231 [30.5%] vs. n=224 [29.6%], P=0.70) or number of post-op AF episodes per patient (1 episode: n=220 [29.0%] vs. n=217 [28.6%]; 2 episodes: n=156 [20.6%] vs. n=157 [20.7%]; 3+ episodes: n=18 [2.4%] vs. n=21 [2.8%]; P=0.73). n-3-PUFA was generally well-tolerated, with no evidence for increased risk of bleeding or serious adverse events.
In this large multinational trial among patients undergoing cardiac surgery, peri-operative supplementation with n-3-PUFA, compared to placebo, did not reduce the risk of post-operative AF.