A Study of Cardiovascular Events in Diabetes - ASCEND Omega-3

Contribution To Literature:

The ASCEND Omega-3 trial showed that dietary supplementation with omega-3 fatty acids did not prevent major adverse cardiovascular events. 


The goal of the trial was to evaluate n-3 (omega-3) fatty acids compared with placebo among diabetics with no known cardiovascular disease (CVD).

Study Design

  • Randomized
  • Parallel
  • Factorial

Patients with diabetes and no known CVD were randomized to omega-3 fatty acid 840 mg daily (n = 7,740) versus placebo (n = 7,740).

  • Total number of enrollees: 15,480
  • Duration of follow-up: mean 7.4 years
  • Mean patient age: 63 years
  • Percentage female: 37%

Inclusion criteria:

  • Diabetic patients ≥40 years of age without known CVD

Exclusion criteria:

  • Contraindication to omega-3

Principal Findings:

The primary efficacy outcome, major adverse cardiovascular events (vascular death, myocardial infarction, or stroke/transient ischemic attack), occurred in 8.9% of the omega-3 group compared with 9.2% of the placebo group (p = 0.55).

There was no treatment interaction according to different categories of baseline risk.

Secondary outcomes:

  • Major adverse cardiovascular event or revascularization: 11.4% with omega-3 vs. 11.5% with placebo (p = not significant [NS])
  • All-cause mortality: 9.7% with omega-3 vs. 10.2% with placebo (p = NS)
  • Nonfatal myocardial infarction: 2.4% with omega-3 vs. 2.6% with placebo (p = NS)
  • Atrial fibrillation: 7.7% with omega-3 vs. 7.6% with placebo (p = NS)
  • Ventricular arrhythmia: 1.0% with omega-3 vs. 0.7% with placebo (p < 0.05)
  • Any arrhythmia: 10.4% with omega-3 vs. 9.9% with placebo (p = NS)


Among diabetic patients with no known CVD, omega-3 fatty acid supplementation was not beneficial. Omega-3 fatty acids failed to reduce the incidence of major adverse cardiovascular events compared with placebo. Omega-3 fatty acid also failed to reduce the incidence of major adverse cardiovascular events or revascularization, atrial fibrillation, or ventricular arrhythmia compared with placebo. Routine dietary supplementation of omega-3 fatty acids is not recommended.


Presented by Dr. Sarah Parish at the European Society of Cardiology Congress, Paris, France, August 31, 2019.

The ASCEND Study Collaborative Group. Effects of n−3 Fatty Acid Supplements in Diabetes Mellitus. N Engl J Med 2018;379:1540-50.

Presented by Dr. Louise Bowman at the European Society of Cardiology Congress, Munich, Germany, August 26, 2018.

Keywords: ESC Congress, ESC 19, ESC18, Diabetes Mellitus, Dietary Supplements, Fatty Acids, Omega-3, Ischemic Attack, Transient, Metabolic Syndrome, Myocardial Infarction, Myocardial Revascularization, Primary Prevention, Stroke, Vascular Diseases

< Back to Listings