Omega-3 Fatty Acids and Arrhythmias

Area of Science:

• Cardiology
• Pharmacology
• Biochemistry

Background:

• Omega-3 polyunsaturated fatty acids (n-3 PUFAs) have been investigated for both pro- and antiarrhythmic effects.
• Early studies suggested n-3 PUFAs could prevent sudden cardiac death and atrial fibrillation (AF).
• However, recent large randomized trials have yielded conflicting results regarding their antiarrhythmic benefits.

Purpose of the Study:

• To evaluate the complex and often contradictory effects of n-3 PUFAs on cardiac arrhythmias, particularly AF.
• To assess the current clinical evidence regarding the efficacy and safety of n-3 PUFA supplementation for cardiovascular prevention and AF management.
• To investigate the potential proarrhythmic effects of specific n-3 PUFA formulations and doses.

Main Methods:

• Review of preclinical studies and human clinical trials, including randomized controlled trials (RCTs).
• Analysis of data from large contemporary RCTs investigating moderate and high doses of n-3 PUFAs (including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)) for cardiovascular prevention.
• Examination of findings related to incident AF in participants receiving n-3 PUFA compared to control groups.

Main Results:

• Accumulated evidence does not support n-3 PUFA supplementation for postoperative AF or secondary AF prevention.
• Several large RCTs demonstrated a small, significant, dose-dependent increase in incident AF with high-dose n-3 PUFA (icosapent ethyl or EPA+DHA) compared to placebo.
• These proarrhythmic findings were observed with both monotherapy and mixed formulations, but the underlying mechanisms remain unknown.

Conclusions:

• The clinical utility of n-3 PUFAs for preventing cardiac arrhythmias, especially AF, is uncertain and potentially controversial.
• High-dose n-3 PUFA supplementation, including specific formulations like icosapent ethyl, may increase the risk of developing AF.
• Further research is needed to elucidate the complex pro- and antiarrhythmic mechanisms of EPA, DHA, and their metabolites, and to identify patient subgroups at higher risk.