Effect of supplemented intake of omega-3 fatty acids
on arrhythmias in patients with ICD: fish oil therapy may reduce
Received: 1 May 2017 /Accepted: 20 June 2017 /Published online: 29 June 2017
Springer Science+Business Media, LLC 2017
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 car-
diomyopathy 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-tachycar-
dia 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 as-
sociated 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
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.
Keywords Fish oils
Omega-3 polyunsaturated fatty acids
Eicosapentaenoic acid (EPA)
Ventricular tachycardia (VT)
Numerous epidemiological studies, case-control studies, and
clinical randomized trials have demonstrated the effects of fish
oil or omega-3 polyunsaturated fatty acids (PUFAs)
(docosahexaenoic acid (DHA) and eicosapentaenoic acid
(EPA)) on major cardiovascular events [1–5], particularly
those related to sudden cardiac death as well as all-cause mor-
tality in patients with prior myocardial infarction . Possible
mechanisms have been proposed including improvement in
endothelial  and vascular functions  and their hypolipid-
emic properties [9–11]. Anti-inflammatory effects [12–14],
decrease in blood pressure , anti-aggregant effects [16,
17], and possible plaque-stabilizing effects  were also
suggested. However, the most established mechanism is relat-
ed to their anti-arrhythmic effects [19–21].
However, despite numerous experimental and animal mod-
el studies published over the years, supporting the beneficial
electrophysiological cardiac effects of PUFAs [22–25], results
are still conflicting [26–28].
As implantable cardioverter defibrillators (ICDs) offer the
opportunity to monitor arrhythmic events, we sought to fur-
ther investigate whether omega-3 PUFAs exert an effect on
Dalit Weisman and Roy Beinart contributed equally to the manuscript.
* Aharon Erez
Leviev Heart Center, Sheba Medical Center, Tel-Hashomer,
52621 Ramat Gan, Israel
Department of Epidemiology and Preventive Medicine, Tel-Aviv
University, Tel-Aviv, Israel
Sackler Faculty of Medicine, Tel Aviv University, Tel-Aviv, Israel
J Interv Card Electrophysiol (2017) 49:255–261