Effect of Fish Oil on Ventricular Tachyarrhythmia and Death in Patients With Implantable Cardioverter Defibrillators: The Study on Omega-3 Fatty Acids and Ventricular Arrhythmia (SOFA) Randomized Trial

Context Very-long-chain n-3 polyunsaturated fatty acids (omega-3 PUFAs) from fish are thought to reduce risk of sudden death, possibly by reducing susceptibility to cardiac arrhythmia. Objective To study the effect of supplemental fish oil vs placebo on ventricular tachyarrhythmia or death. Design, Setting, and Patients The Study on Omega-3 Fatty acids and ventricular Arrhythmia ( SOFA) was a randomized, parallel, placebo-controlled, double-blind trial conducted at 26 cardiology clinics across Europe. A total of 546 patients with implantable cardioverter-defibrillators ( ICDs) and prior documented malignant ventricular tachycardia ( VT) or ventricular fibrillation ( VF) were enrolled between October 2001 and August 2004. Patients were randomly assigned to receive 2 g/d of fish oil ( n= 273) or placebo ( n= 273) for a median period of 356 days ( range, 14-379 days). Main Outcome Measure Appropriate ICD intervention for VT or VF, or all-cause death. Results The primary end point occurred in 81 ( 30%) patients taking fish oil vs 90 ( 33%) patients taking placebo ( hazard ratio [ HR], 0.86;95% confidence interval [ CI], 0.64-1.16; P=. 33). In prespecified subgroup analyses, the HR was 0.91 ( 95% CI, 0.661.26) for fish oil vs placebo in the 411 patients who had experienced VT in the year before the study, and 0.76 ( 95% CI, 0.52-1.11) for 332 patients with prior myocardial infarctions. Conclusion Our findings do not indicate evidence of a strong protective effect of intake of omega-3 PUFAs from fish oil against ventricular arrhythmia in patients with ICDs