Omega-3 in Antiarrhythmic Therapy

Bruno Trimarco

Omega-3 (n-3 polyunsaturated fatty acids) has demonstrated its ability to reduce global mortality, obtaining an indication for the prevention of sudden death in patients with myocardial infarction of the anterior wall. These observations have led to the design of several clinical studies aimed at demonstrating the potential antiarrhythmic effect of omega-3. These studies have given contradictory results, probably due to differences in the populations and doses used. Observations supporting the use of omega-3 as antiarrhythmic agents come from a study in patients with post-ischaemic dilatative cardiomyopathy and carriers of implantable cardioverter defibrillators (ICDs), without cardiovascular events in the last 12 months. In this population a combination of nutraceuticals containing omega-3 (Ritmonutra®) has been able to reduce the number of ventricular and supraventricular arrhythmias without modification of the left ventricle function. Specifically, a 46% reduction of premature ventricular contractions (BEV), 54.2% of premature supraventricular contractions (BESV), 48% of BESV run and 33% of sustained or non-ventricular tachycardia were observed (all significant, p < 0.0001).In a following study, the antiarrhythmc effect of Ritmonutra® was evaluated by Holter ECG for 24 hours in patients with essential hypertension, without ischaemia, preserved left ventricular function and positive anamnesis for arrhythmia. The results showed that omega-3 treatment produced a significant reduction of ventricular and supraventricular arrhythmias compared with placebo, without modification of heart rate, intra-cardiac conduction and contractility.A recent meta-analysis of studies conducted on omega-3 and possible reduction of cardiovascular events concluded that no significant beneficial effects are related to omega-3 treatment on reducing death for all cardiovascular events. Do these conclusions exclude omega-3 as an anti-arrhythmic?We currently have no antiarrhythmic therapies showing a clear reduction of mortality, with the exception of amiodarone and β-blockers (β-adrenoceptor antagonists). This consideration is even more important for treatment of arrhythmias in healthy subjects, when the first goal is the relief of symptoms and improvement in quality of life. Keeping these last points in mind, the answer to the previous question is a loud 'NO', also taking into account the fact that omega-3, in contrast to the other antiarrhythmics, do not negatively affect myocardial contractility.