Fish Oil Supplements May Increase the Risk for Atrial Fibrillation: What Does This Mean?

Omega-3 Fatty Acids and Arrhythmias

The pro- and antiarrhythmic effects of omega-3 polyunsaturated fatty acids (n-3 PUFAs) have been extensively studied in preclinical and human trials. Despite early evidence of an antiarrhythmic role of n-3 PUFA in the prevention of sudden cardiac death and postoperative and persistent atrial fibrillation (AF), subsequent well-designed randomized trials have largely not shown an antiarrhythmic benefit. Two trials that tested moderate and high-dose n-3 PUFA demonstrated a reduction in sudden cardiac death, but these findings have not been widely replicated, and the potential of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) to reduce arrhythmic death in combination, or as monotherapy, remains uncertain. The accumulated clinical evidence does not support supplementation of n-3 PUFA for postoperative AF or secondary prevention of AF. Several large, contemporary, randomized controlled trials of high-dose n-3 PUFA for primary or secondary cardiovascular prevention have demonstrated a small, significant, dose-dependent increased risk of incident AF compared with mineral oil or corn oil comparator. These findings were reproduced with both icosapent ethyl monotherapy and a mixed EPA+DHA formulation. The proarrhythmic mechanism of increased AF in contemporary cohorts exposed to high-dose n-3 PUFA is unknown. EPA and DHA and their metabolites have pleiotropic cardiometabolic and pro- and antiarrhythmic effects, including modification of the lipid raft microenvironment; alteration of cell membrane structure and fluidity; modulation of sodium, potassium, and calcium currents; and regulation of gene transcription, cell proliferation, and inflammation. Further characterization of the complex association between EPA, EPA+DHA, and DHA and AF is needed. Which formulations, dose ranges, and patient subgroups are at highest risk, remain unclear.

Drug-induced atrial fibrillation. A narrative review of a forgotten adverse effect

Atrial fibrillation (AF) is the most common cardiac arrhythmia and is associated with an increased morbidity and mortality. There is clinical evidence that an increasing number of cardiovascular and non-cardiovascular drugs, mainly anticancer drugs, can induce AF either in patients with or without pre-existing cardiac disorders, but drug-induced AF (DIAF) has not received the attention that it might deserve. In many cases DIAF is asymptomatic and paroxysmal and patients recover sinus rhythm spontaneously, but sometimes, DIAF persists, and it is necessary to perform a cardioversion. Furthermore, DIAF is not mentioned in clinical guidelines on the treatment of AF. The risk of DIAF increases in elderly and in patients treated with polypharmacy and with risk factors and comorbidities that commonly coexist with AF. This is the case of cancer patients. Under these circumstances ascribing causality of DIAF to a given drug often represents a clinical challenge. We review the incidence, the pathophysiological mechanisms, risk factors, clinical relevance, and treatment of DIAF. Because of the limited information presently available, further research is needed to obtain a deeper insight into DIAF. Meanwhile, it is important that clinicians are aware of the problem that DIAF represents, recognize which drugs may cause DIAF, and consider the possibility that a drug may be responsible for a new-onset AF episode.

Do omega-3 fatty acids increase risk of atrial fibrillation?

PURPOSE OF THE REVIEW

To summarize the findings from recent observational follow-up studies and randomized trials of plant- and marine omega-3 fatty acids on the risk of atrial fibrillation (AF).

RECENT FINDINGS

Recent randomized cardiovascular outcome trials have indicated that supplements with marine omega-3 fatty acids may be associated with a higher risk of AF, and a meta-analysis has suggested that marine omega-3 fatty acid supplements were associated with a 25% higher relative risk of AF. Also, a recent large observational study reported a modest higher risk of AF in habitual users of marine omega-3 fatty acid supplements. However, recent observational biomarker studies of circulating and adipose tissue content of marine omega-3 fatty acids have in contrast reported a lower risk of AF. Very limited knowledge exists on the role of plant-derived omega-3 fatty acids and AF.

SUMMARY

Marine omega-3 fatty acid supplements may increase the risk of AF, whereas biomarkers reflecting consumption of marine omega-3 fatty acids have been linked to a lower risk of AF. Clinicians should inform patients that marine omega-3 fatty acid supplement may increase AF risk, and this should be taking into account when discussing pros and cons of taking supplements with marine omega-3 fatty acids.

Antiarrhythmic and Hemodynamic Effects of Omega-3 Polyunsaturated Fatty Acids on Cardiovascular Diseases

This review presents the results of previously performed epidemiological, experimental and clinical studies indicating the use of ω-3 PUFA (polyunsaturated fatty acids) contributes to reduce the risk of developing cardiovascular diseases. Experimental studies have shown ω-3 PUFA are exhibiting antiarrhythmic effects, improving endothelial function, showing an anti- inflammatory effect, affecting the rheological properties of blood, reducing triglyceride concentrations, and increasing the stability of atheromatous plaque. Wide-scale clinical trials have established high efficacy of ω-3 PUFA in primary and secondary prevention of coronary heart disease. It is found to reduce the risk of ventricular arrhythmias and sudden cardiac death. Also, reduces overall mortality and hospitalization rates due to cardiovascular causes in patients with chronic heart failure. Clinical efficacy among cardiovascular diseases of the prescription drugs ω-3 PUFA standardized by qualitative and quantitative compositions to be studied further in a comparison to the other medications with similar make-up.