Effects of DHA/EPA Supplementation in Patients with Chronic Heart Failure
GISSI-HF Investigators, Lancet. 372 :1223-1230, 2008.
GISSI-HF Coordinating Centre, ANMCO Research Centre, Florence, Italy
Results from the GISSI-prevenzione trial indicated a lower mortality rate in patients taking omega-3 supplementation as DHA/EPA (combined) after myocardial infarction as compared to those in the control group. These results were associated primarily with the prevention of sudden death and provided clinical support for the possible anti-arrhythmic activity of omega-3 fatty acids in addition to other effects. The present study from the GISSI investigators was conducted since no previous large-scale trials have been reported to evaluate the potential beneficial effects of supplementation with omega-3 fatty acids in a large population of patients with heart failure.
In this study, 7046 eligible patients with documented chronic heart failure were randomized using a double-blind, placebo-controlled trial whereby half the patients (3529) were assigned to omega-3 supplementation and the other half (3517) were assigned to a placebo (control group). The omega-3 supplementation provided 850-882 mg per day as DHA+EPA (with a DHA:EPA ratio of 1.2:1). After 4 years of follow-up, the total mortality from any cause was 29% in the placebo (control) group and 27% in the group receiving omega-3 supplementation (relatively lower by 6% in the omega-3 group). Also, there was a modest difference in the rate of all-cause death or hospital admission for cardiac causes between the two groups (of borderline statistical significance): 59% for those on placebo as compared to 57% in those receiving DHA/EPA supplementation. The authors concluded that omega-3 supplementation can provide a small beneficial advantage in terms of mortality and admission to hospital for cardiovascular reasons in patients with chronic heart failure when receiving the usual medical care. They also reported that adverse reactions leading to discontinuation of omega-3 supplementation were generally of minor clinical relevance (mostly gastrointestinal disorders).
Dr. Holub's Comments:
It should be pointed out that the supplementation was given in addition to conventional treatments of recognized efficacy for chronic heart failure including beta-blockers, diuretic drugs, digitalis, angiotensin-converting enzyme inhibitors for blood pressure, and other appropriate medications. The results also indicated a divergence in the primary end points between the two groups (treated vs. control) after approximately 2 years of intervention. It remains to be studied whether a higher dose of omega-3 fatty acid supplementation and/or differing ratios of DHA:EPA may be of preferential/better impact in patients with chronic heart failure.