N-3 Fatty Acids and Cardiovascular Events After Myocardial Infarction - Alpha Omega

Description:

The goal of the trial was to evaluate treatment with supplemental omega-3 fatty acids (N-3) among patients with prior myocardial infarction (MI). Fatty acids in fish are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), whereas fatty acids in plants are alpha-linolenic acid (ALA).

Hypothesis:

Omega-3 fatty acids will be more effective at reducing major adverse cardiovascular events.

Study Design

  • Parallel
  • Blinded
  • Randomized
  • Placebo Controlled

Patient Populations:

  • MI within the last 4 years

    Number of enrollees: 4,837
    Duration of follow-up: maximum of 40 months
    Age range: mean 69 years
    Percentage female: 22%

Primary Endpoints:

  • MACE

Secondary Endpoints:

  • Cardiovascular mortality
  • All-cause mortality
  • Ventricular arrhythmia-related events (sudden death, cardiac arrest, or implantable cardioverter-defibrillator placement)

Drug/Procedures Used:

Patients who had suffered an MI within the last 4 years were randomized to one of four margarines for dietary consumption: 1) EPA-DHA 400 mg daily + ALA placebo (n = 1,192), 2) EPA-DHA placebo + ALA 2 g daily (n = 1,197), 3) EPA-DHA 400 mg daily + ALA 2 g daily (n = 1,212), or 4) EPA-DHA placebo + ALA placebo (n = 1,236).

Concomitant Medications:

At baseline in the EPA-DHA + ALA group, the use of lipid-lowering drugs was 87%.

Principal Findings:

Overall 4,837 patients were randomized. In the EPA-DHA + ALA group, the mean age was 69 years, 22% were women, 20% were diabetic, systolic blood pressure was 141 mm Hg, and body mass index was 28 kg/m2. Compliance with study medication was verified by measurement of serum fatty acids.

The primary outcome, major adverse cardiovascular events (MACE), was similar between the EPA-DHA group and placebo group (hazard ratio [HR] 1.01, p = 0.93) and between the ALA group and placebo group (HR 0.91, p = 0.20). Among women in the ALA group, there was a nonsignificant reduction in the primary outcome (HR 0.73, p = 0.07) and among diabetics in the ALA group, there was a significant reduction in ventricular arrhythmia-related adverse events (HR 0.39, p = 0.002).

Interpretation:

Among patients with prior MI, dietary supplementation of omega-3 fatty acids was not beneficial since this therapy did not reduce MACE. Subgroup analysis revealed a nonsignificant reduction in MACE among women treated with ALA, and a significant reduction in ventricular arrhythmia-related adverse events among diabetics treated with ALA. Both of these subgroups should be interpreted with caution until further analysis can be performed.

These findings do not refute earlier studies that documented the cardiovascular benefits of fish consumption, but illustrate the importance of eating whole foods rather than dietary supplements.

References:

Kromhout D, Giltay EJ, Geleijnse JM, et al.; on behalf of the Alpha Omega Trial Group. n–3 fatty acids and cardiovascular events after myocardial infarction. N Engl J Med 2010; Aug 29:[Epub ahead of print].

Presented by Dr. Daan Kromhout at the European Society of Cardiology Congress, Stockholm, Sweden, August 2010.

Clinical Topics: Arrhythmias and Clinical EP, Dyslipidemia, Prevention, SCD/Ventricular Arrhythmias, Lipid Metabolism, Nonstatins, Diet

Keywords: alpha-Linolenic Acid, Myocardial Infarction, Margarine, Ventricular Fibrillation, Coronary Disease, Blood Pressure, Eicosapentaenoic Acid, Body Mass Index, Secondary Prevention, Docosahexaenoic Acids, Dietary Supplements, Diabetes Mellitus


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