Effects of n-3 polyunsaturated fatty acids on malignant ventricular arrhythmias in patients with chronic heart failure and implantable cardioverter-defibrillators: A substudy of the Gruppo Italiano per lo Studio della Sopravvivenza nell'Insufficienza Cardiaca (GISSI-HF) trial

Am Heart J. 2011 Feb;161(2):338-343.e1. doi: 10.1016/j.ahj.2010.10.032.


Background: The antiarrhythmic effects of n-3 polyunsaturated fatty acids (n-3PUFA) in ischemic heart disease have been demonstrated; however, studies in patients surviving malignant ventricular arrhythmias of different etiologies treated with an implantable cardioverter-defibrillator (ICD) have given conflicting results. The purpose of this study was to assess the antiarrhythmic effect of n-3PUFA versus placebo in 566 patients with heart failure enrolled in the GISSI-HF trial who received an ICD for secondary or primary prevention of ventricular fibrillation (VF) or tachycardia (VT).

Methods: Clinical data and arrhythmic event recordings extracted from the device memory were obtained. We tested the treatment effect by a multivariate Cox model adjusting for all clinical parameters associated with the primary end point defined as time to first appropriate ICD discharge for VT/VF.

Results: In the 566 patients with at least one recorded follow-up visit, 1363 VT and 316 VF episodes were terminated by ICD pacing or shock over a median follow-up of 928 days. The incidence of the primary end point event was 27.3% in the n-3PUFA group and 34.0% in the placebo group (adjusted hazard rate = 0.80, 95% CI 0.59-1.09, P = .152). Patients who received 1, 2 to 3, or >3 ICD discharges were 8.9%, 7.1%, and 11.1% in the n-3PUFA group, compared with slightly higher rates of 11.1%, 10.7%, and 12.1% in the placebo group (overall P = .30). Patients with the highest 3-month increase in plasma n-3PUFA had a somewhat lower incidence of arrhythmic events.

Conclusions: The results of this study, though not statistically significant, support prior evidences of an antiarrhythmic effect of n-3PUFA in patients with ICD, although they leave open the issue of whether this effect leads to a survival benefit.

Trial registration: ClinicalTrials.gov NCT00336336.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Chronic Disease
  • Defibrillators, Implantable*
  • Fatty Acids, Omega-3 / therapeutic use*
  • Female
  • Heart Failure / complications*
  • Humans
  • Male
  • Middle Aged
  • Prospective Studies
  • Tachycardia, Ventricular / drug therapy
  • Tachycardia, Ventricular / etiology*
  • Tachycardia, Ventricular / therapy*
  • Ventricular Fibrillation / drug therapy
  • Ventricular Fibrillation / etiology*
  • Ventricular Fibrillation / therapy*


  • Fatty Acids, Omega-3

Associated data

  • ClinicalTrials.gov/NCT00336336