Effect of supplemented intake of omega-3 fatty acids on arrhythmias in patients with ICD: fish oil therapy may reduce ventricular arrhythmia

Purpose: The aim of this study was to evaluate the effects of fish oils, including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), on ventricular tachyarrhythmic episodes (VTEs) in implantable cardioverter defibrillator (ICD) recipients with ischemic cardiomyopathy. Methods: One hundred five ICD recipients with ischemic cardiomyopathy received 3.6 g of EPA and DHA and placebo for 6 months, each at a random order, with a 4-month washout period between treatments. Eighty-seven patients completed the 16-month study protocol. The primary end point was any VTE (including sustained and non-sustained ventricular tachycardias at a rate of >150 bpm) as recorded by the ICDs. Secondary end points included device therapy (anti-tachycardia pacing (ATP) or shocks). Results: During treatment with fish oils, there was a significant increase in EPA and DHA concentrations in red blood cells (RBCs) and subcutaneous fat tissue. Among 87 patients who completed the study protocol, the mean number of VTEs was significantly lower during treatment with fish oil (1.7) vs. placebo (5.6; p = 0.035). Appropriate device therapy for VTE occurred in 18 (21%) patients. Fish oil therapy was associated with a trend toward fewer VTEs terminated with ATP (2.8 ± 13.7 vs. 0.5 ± 2.1, respectively; p = 0.077). VTE terminated by ICD shocks, however, was rare, and rates were similar between both groups (0.11 ± 0.6 vs. 0.10 ± 0.4, p = not significant, respectively). Conclusions: Our data suggest that fish oil therapy may be associated with a reduction in the frequency of VTE in ICD recipients with ischemic cardiomyopathy.