A large randomized controlled trial comparing high-dose omega-3 with placebo corn oil did not find any primary prevention benefit in patients at risk for atrial fibrillation (AF). There was no significant difference in the composite outcome of major adverse cardiovascular events.

Findings from the STRENGTH trial (NCT02104817) were presented by Prof. A. Michael Lincoff (Cleveland Clinic, USA) during a Late-Breaking Science session [1]. The results were simultaneously published in the JAMA [2]. In STRENGTH, 13,078 patients at risk for AF received daily supplementation with 4 g omega-3 fatty acids or corn oil as placebo, in addition to usual background therapies, including statins.

The primary endpoint was a composite of cardiovascular death, non-fatal heart attack, non-fatal stroke, coronary artery revascularization, and hospitalization for unstable angina. The trial was stopped early since there was no significant difference between groups in the primary outcome (HR 0.99). There were no differences between the groups regarding safety outcomes.

Prof. Lincoff said, “The STRENGTH trial showed a 67% increase in AF in the omega-3 treatment group, indicating that there is some uncertainty whether there is net benefit or harm with administration of any omega-3 fatty acid formulation. Given that 2 large clinical trials have now demonstrated a greater incident rate of AF with high dose omega-3 fatty acid administration, this observation requires further study.”

  1. Lincoff AM, et al. STRENGTH Trial: Cardiovascular Outcomes With Omega-3 Carboxylic Acids (Epanova) in Patients With High Vascular Risk and Atherogenic Dyslipidemia LBS.08, Virtual AHA Scientific Sessions 2020, 13-17 Nov.
  2. Nicholls SJ, et al. Effect of High-Dose Omega-3 Fatty Acids vs Corn Oil on Major Adverse Cardiovascular Events in Patients at High Cardiovascular Risk: The STRENGTH Randomized Clinical Trial. JAMA. 2020 Nov 15. doi:10.1001/jama.2020.22258.