N-3 polyunsaturated fatty acids for cardiovascular risk

Abstract

Purpose of review 

Use of omega-3 fatty acid (OM3FA) supplements to reduce risk of cardiovascular events has been investigated, largely without evidence of meaningful benefit, over the last 4 decades.

Recent findings 

The first contemporary clinical trial to show benefit of OM3FA use was the REDUCE-IT trial (2018), showing a remarkable 25% relative risk reduction in the intervention group that received icosapent ethyl 4 g daily compared to a mineral oil placebo group. The STRENGTH trial (2020), which was similar in design to the REDUCE-IT trial but compared 4 g daily dose of combined OM3FA with a corn oil placebo, was terminated early due to futility.

Summary 

This article provides a review of the data surrounding these trials and discusses the differing results of the two trials. There are key differences in the design of the two trials, the most notable is the use of mineral oil in the REDUCE-IT trial, which was potentially a nonneutral comparator. Additionally, both trials showed an increase in the incidence of atrial fibrillation. With the unclear benefit of OM3FA supplementation and possibility of harm, the current data suggest that the risk of routine use of OM3FA outweighs the possibility of reduction in risk of cardiovascular events.