Fish Oils: Yes for HF and Secondary Prevention, No for the General Population, Says AHA

Prescription omega-3 polyunsaturated fatty acids (PUFAs), or fish oil supplementation, may be a treatment option in heart failure patients with reduced ejection fraction, according to a new scientific statement from the American Heart Association (AHA).

The updated recommendations continue to state that omega-3 fish oil supplements prescribed by a physician are “reasonable” in the setting of secondary prevention, including patients who have had a myocardial infarction, but are not recommended for reducing clinical outcomes in patients without CHD. At present, there are no randomized controlled trials testing fish oil supplementation for the primary prevention of coronary disease, the AHA document says, so no recommendation can be made at this time.

The new recommendation for heart failure patients is based on data from the GISSI-HF study, a randomized trial that included 6,875 patients. In the 2008 study, in which heart-failure patients received 840 mg of omega-3 fish oil per day, all-cause mortality was reduced by 9% over nearly 4 years of follow-up while total mortality or hospitalizations for cardiovascular causes was reduced by 8%.

Published March 13, 2017, in Circulation, the new science advisory was chaired by David Siscovick, MD (New York Academy of Medicine), and is the first update on fish oil supplementation since 2002. In total, 15 studies were included in the AHA’s review. 

In secondary prevention, the use of fish oil offers an approximate 10% relative reduction in CHD mortality, possibly through a reduction in sudden cardiac death, Siscovick and colleagues point out. The majority of the writing committee members classified fish oil supplements for the prevention of CHD death as a class IIa recommendation (a minority preferred a lower-strength recommendation: class IIb). For heart failure patients, the use of fish oil is a class IIa recommendation.   

Aside from secondary prevention and heart failure, the use of fish oil gains no ground elsewhere. At this time, fish oil is not recommended for the prevention of cardiovascular disease in patients with diabetes, nor is it recommended for individuals at high cardiovascular risk. Fish oil is not indicated for the secondary prevention of atrial fibrillation in patients with the arrhythmia and is not recommended for preventing atrial fibrillation after surgery.

The AHA writing committee makes no recommendations on the use of fish oil supplements for the secondary prevention of stroke, the primary prevention of heart failure, or the primary prevention of atrial fibrillation because its use has not been studied in these settings, authors say.

In the United States, approximately 18.8 million adults reported taking a fish oil dietary supplement in 2012, although the vast majority of these are over-the-counter products. At present, there are five prescription omega-3 PUFA products available in the US.