n-3 polyunsaturated fatty acids and atrial fibrillation in patients with chronic heart failure: the GISSI-HF trial

Aims In the last few years, n-3 polyunsaturated acids (PUFAs) have been extensively studied for the prevention of AF, mostly in patients without heart failure (HF) or LV dysfunction. This post-hoc analysis of the GISSI-HF trial assessed the effect of n-3 PUFAs on AF in patients with chronic HF without AF at study entry over a median follow-up of 3.9 years. Methods and results In the GISSI-HF trial, 6975 patients with chronic HF were randomized to 1 g daily of n-3 PUFAs or placebo on top of recommended therapy for HF. Of these, 1140 (16.3%) had AF at baseline ECG and were excluded from the present analysis. AF during the trial was defined as the presence of AF on the ECGs done at each visit during the trial or AF as a cause of worsening HF or hospital admission or as an event during hospitalization. Dietary fish consumption and the circulating levels of n-3 PUFAs (the latter in a subset of 1203 patients) were also available. Among the 5835 patients without AF at study entry, 444 randomized to n-3 PUFAs (15.2%) and 408 to placebo (14.0%) developed AF (unadjusted hazard 1.10, P = 0.19). Lower circulating n-3 PUFA levels were independently associated with higher AF prevalence at study entry, but not with its new occurrence. Conclusions Despite an inverse relationship between plasma n-3 PUFA levels and prevalent AF, this study found no evidence that 1 g daily n-3 PUFA supplementation in patients with chronic HF reduces incident AF.