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, 0.66-1.26) 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.
Trial Registration clinicaltrials.gov Identifier: NCT00110838
Sudden cardiac death is one of the most common and often the first manifestation of coronary heart disease. It is responsible for approximately 50% of all mortality from cardiovascular disease in the Western world.1 The majority of sudden deaths are directly caused by acute ventricular arrhythmia.2 Epidemiological studies indicate that intake of very-long-chain n-3 polyunsaturated fatty acids (omega-3 PUFAs) as present in fish or fish oil is associated with a reduction in cardiovascular mortality.3-7 These observational studies showed a strong relationship between omega-3 PUFAs and sudden death, but not between omega-3 PUFAs and nonfatal heart disease.5,8,9 This is confirmed by the outcome of some clinical trials; in the Diet and Reinfarction Trial (DART),10 consumption of fish or fish oil reduced fatal heart disease by more than 30%, and the open-label Gruppo Italiano per lo Studio della Sopravvivenza nell’Infarto miocardico (GISSI) trial4 found a 45% reduction in sudden death in patients consuming omega-3 PUFAs.
Animal and in vitro studies also suggest an effect of omega-3 PUFAs through reduced propensity for arrhythmia.11-18 Infusion of omega-3 PUFAs also prevented inducible sustained ventricular tachycardia (VT) in some patients.19 In contrast, Burr et al did not show a protective effect of intake of fish or fish oil on cardiac death in a trial of 3114 patients with stable angina.20 Furthermore, 2 recent trials on fish oil and ventricular arrhythmia in patients with implantable cardioverter-defibrillators (ICDs) yielded inconclusive results.21,22 Thus, the potential of omega-3 PUFAs for reducing risk of life-threatening arrhythmia in patients with ICDs is unclear.
We report the effect of omega-3 PUFAs from fish on the incidence of recurrent ventricular arrhythmia and all-cause mortality in a large double-blind, randomized trial of patients with ICDs.
Corresponding Author: Ingeborg A. Brouwer, PhD, Wageningen Centre for Food Sciences, Human Nutrition, Bomenweg 2, 6703 HD Wageningen, the Netherlands (firstname.lastname@example.org).
Author Contributions: Dr Brouwer had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Brouwer, Zock, Camm, Böcker, Hauer, Wever, Ronden, Katan, Schouten.
Acquisition of data: Brouwer, Zock, Böcker, Hauer, Wever, Dullemeijer, Ronden, Lubinski, Buschler, Schouten.
Analysis and interpretation of data: Brouwer, Zock, Camm, Dullemeijer, Katan, Lubinski, Schouten.
Drafting of the manuscript: Brouwer, Zock, Camm, Hauer, Schouten.
Critical revision of the manuscript for important intellectual content: Brouwer, Zock, Camm, Böcker, Hauer, Wever, Dullemeijer, Ronden, Katan, Lubinski, Buschler.
Statistical analysis: Brouwer, Zock, Dullemeijer, Schouten.
Obtained funding: Brouwer, Zock, Katan, Schouten.
Administrative, technical, or material support: Brouwer, Böcker, Hauer, Dullemeijer, Ronden, Buschler.
Study supervision: Brouwer, Zock, Camm, Böcker, Hauer, Katan, Schouten.
Financial Disclosures: None reported.
Funding/Support: Funding for this study was provided by Wageningen Centre for Food Sciences, a non-profit alliance of major Dutch food industries, TNO Nutrition and Food Research, Maastricht University and Wageningen University and Research Centre, the Netherlands, with financial support by the Dutch government. An additional grant was received from the European Union (SEAFOODplus integrated project: No. 506359).
Role of the Sponsor: The SOFA trial was designed by the members of the executive and steering committees and then approved by the member organizations of the funder, Wageningen Centre for Food Sciences (WCFS). No industry members of WCFS were involved in the conduct of the study; in the collection, management, analysis, and intrepretation of the data; or in the preparation, review, and approval of the manuscript. Dr Peter Zock left Wageningen University on February 1, 2005, to join Unilever, which is a member organization of the trial's funder WCFS. Since February 2005 he has contributed to writing the manuscript. However, this was not in his capacity as a Unilever employee, and Dr Zock's contributions to the manuscript since February 2005 were neither submitted to, nor seen, revised, or approved by his employer, Unilever.
The SOFA Study Group:Executive Committee/Data analyses: I. A. Brouwer, C. Dullemeijer; Steering Committee: E. G. Schouten (chair), A.J. Camm (co-chair), P. L. Zock, D. Böcker, R. N. W. Hauer, E. F. D. Wever, J. E. Ronden; Investigators: A. Zienciuk, A. Lubinski (Medical University of Gdansk, Gdansk, Poland), J. Vogt, H. Buschler (Herz-und Diabeteszentrum Bad Oeynhausen, Bad Oeynhausen, Germany), J. Köbe, D. Böcker (Universitätsklinikum Münster, Münster, Germany), Z. Kornacewicz-Jach, R. Rzeuski (Pomeranian Academy of Medicine, Szczecin, Poland), A.R. Ramdat Misier (Isala Clinics, Zwolle, the Netherlands), E. F. D. Wever (St. Antonius Hospital, Nieuwegein, the Netherlands), H. Szwed, A. Przybylski (Instytut Kardiologii, Warzawa, Poland), R. N. W. Hauer (UMC Utrecht, Utrecht, the Netherlands), M. Sepsi, B. Semrad (FN Brno Interni Kardiologicka Klinika, Brno, the Czech Republic), A. Meijer (Catharina Hospital, Eindhoven, the Netherlands), L. J. Jordaens (Erasmus Medical Centre Rotterdam, Rotterdam, the Netherlands), A. J. Camm, I. Savelieva (St George's Hospital, London, England), R. Tavernier (University Hospital Gent, Gent, Belgium), H. R. Figulla, C. Kalmbach (Klinikum der Friedrich-Schiller-Universität, Jena, Germany), A. A. M. Wilde (Academic Medical Centre, Amsterdam, the Netherlands), M. Trusz-Gluza, A. Filipecki (I Klinika Kardiologii, Katowice, Poland), W. Haverkamp (Medizinische Klinik m. S. Kardiologie, Berlin, Germany), M. Zabel (Klinikum Benjamin Franklin Berlin, Berlin, Germany), J. M. Morgan (Southampton General Hospital, Southampton, England), H. Pitschner (Kerckhoff-Klinik GmbH, Bad Nauheim, Germany), M. J. Griffith (Queen Elizabeth Hospital, Birmingham, England), A. Podczeck, K. Steinbach (Wilhelminenspital Wien, Vienna, Austria), M. Block (Stiftsklinik Augustinum, Munchen, Germany), P. Kulakowski (Grochowski Hospital, Warszawa, Poland), J. Kautzner (Institute of Clinical and Experimental Medicine, Prague, the Czech Republic), M. Fromer (CHUV, University Hospital Lausanne, Lausanne, Switzerland).
Core Laboratory: D. A. M. J. Theuns (Cardialysis, Rotterdam, the Netherlands).
Endpoint Adjudication Committee Members: I. Savelieva, C. Wolpert (University Hospital Mannheim, Mannheim, Germany), A. A. M. Wilde, J. O. Schwab (Universitätsklinikum Bonn, Bonn, Germany), M. Fromer, M. J. Griffith, L. J. Jordaens (Erasmus University Rotterdam, Rotterdam, the Netherlands).
Data and Safety Monitoring Board Members: E. Boersma (Erasmus Medical Centre Rotterdam, Rotterdam, the Netherlands), P. J. Schwartz (University of Pavia, Pavia, Italy), K. Swedberg (Göteborg University, Göteberg, Sweden).
Acknowledgment: The data analyses were checked by E. Boersma, MSc, PhD, statistician at the Erasmus Medical Centre Rotterdam, Department of Cardiology, the Netherlands. Dr Boersma received compensation for his work as the chair of the data and safety monitoring board, but did not receive any compensation for checking the data analyses. We thank all the research nurses, co-investigators, research assistants at Wageningen University, the personnel of the Core Laboratory in Rotterdam and the Laboratory of the Division of Human Nutrition in Wageningen for their valuable contributions to the study.
Huikuri HV, Castellanos A, Myerburg RJ. Sudden death due to cardiac arrhythmias. N Engl J Med
. 2001;345:1473-148211794197Google ScholarCrossref
Hu FB, Willett WC. Optimal diets for prevention of coronary heart disease. JAMA
. 2002;288:2569-257812444864Google ScholarCrossref
Gruppo Italiano per lo Studio della Sopravvivenza nell’Infarto miocardico. Dietary supplementation with n-3 polyunsaturated fatty acids and vitamin E after myocardial infarction: results of the GISSI-Prevenzione trial. Lancet
. 1999;354:447-45510465168Google ScholarCrossref
Albert CM, Hennekens CH, O’Donnell CJ.
et al. Fish consumption and risk of sudden cardiac death. JAMA
. 1998;279:23-289424039Google ScholarCrossref
Siscovick DS, Raghunathan TE, King I.
et al. Dietary intake and cell membrane levels of long-chain n-3 polyunsaturated fatty acids and the risk of primary cardiac arrest. JAMA
. 1995;274:1363-13677563561Google ScholarCrossref
Kromhout D, Bosschieter EB, de-Lezenne-Coulander C. The inverse relation between fish consumption and 20-year mortality from coronary heart disease. N Engl J Med
. 1985;312:1205-12093990713Google ScholarCrossref
Albert CM, Campos H, Stampfer MJ.
et al. Blood levels of long-chain n-3 fatty acids and the risk of sudden death. N Engl J Med
. 2002;346:1113-111811948270Google ScholarCrossref
Ascherio A, Rimm EB, Stampfer MJ, Giovannucci EL, Willett WC. Dietary intake of marine n-3 fatty acids, fish intake, and the risk of coronary disease among men. N Engl J Med
. 1995;332:977-9827885425Google ScholarCrossref
Burr ML, Fehily AM, Gilbert JF.
et al. Effects of changes in fat, fish, and fibre intakes on death and myocardial reinfarction: Diet and Reinfarction Trial (DART). Lancet
. 1989;2:757-7612571009Google ScholarCrossref
Billman GE, Hallaq H, Leaf A. Prevention of ischemia-induced ventricular fibrillation by omega 3 fatty acids. Proc Natl Acad Sci U S A
. 1994;91:4427-44308183925Google ScholarCrossref
Billman GE, Kang JX, Leaf A. Prevention of sudden cardiac death by dietary pure omega-3 polyunsaturated fatty acids in dogs. Circulation
. 1999;99:2452-245710318669Google ScholarCrossref
Leaf A, Kang JX. Prevention of cardiac sudden death by N-3 fatty acids: a review of the evidence. J Intern Med
. 1996;240:5-128708597Google ScholarCrossref
McLennan PL, Abeywardena MY, Charnock JS. Dietary fish oil prevents ventricular fibrillation following coronary artery occlusion and reperfusion. Am Heart J
. 1988;116:709-7173414486Google ScholarCrossref
Billman GE, Kang JX, Leaf A. Prevention of ischemia-induced cardiac sudden death by n-3 polyunsaturated fatty acids in dogs. Lipids
. 1997;32:1161-11689397401Google ScholarCrossref
McLennan PL. Relative effects of dietary saturated, monounsaturated, and polyunsaturated fatty acids on cardiac arrhythmias in rats. Am J Clin Nutr
. 1993;57:207-2128424390Google Scholar
McLennan PL, Bridle TM, Abeywardena MY, Charnock JS. Comparative efficacy of n-3 and n-6 polyunsaturated fatty acids in modulating ventricular fibrillation threshold in marmoset monkeys. Am J Clin Nutr
. 1993;58:666-6698237873Google Scholar
Leaf A, Kang JX, Xiao YF, Billman GE. n-3 fatty acids in the prevention of cardiac arrhythmias. Lipids
Schrepf R, Limmert T, Claus WP, Theisen K, Sellmayer A. Immediate effects of n-3 fatty acid infusion on the induction of sustained ventricular tachycardia. Lancet
. 2004;363:1441-144215121409Google ScholarCrossref
Burr ML, Ashfield WP, Dunstan FDJ.
et al. Lack of benefit of dietary advice to men with angina: results of a controlled trial. Eur J Clin Nutr
. 2003;57:193-20012571649Google ScholarCrossref
Raitt MH, Connor WE, Morris C.
et al. Fish oil supplementation and risk of ventricular tachycardia and ventricular fibrillation in patients with implantable defibrillators: a randomized controlled trial. JAMA
. 2005;293:2884-289115956633Google ScholarCrossref
Leaf A, Albert CM, Josephson M.
et al. Prevention of fatal arrhythmias in high-risk subjects by fish oil n-3 fatty acid intake. Circulation
. 2005;112:2762-276816267249Google ScholarCrossref
Brouwer IA, Zock PL, Wever EF.
et al. Rationale and design of a randomised controlled clinical trial on supplemental intake of n-3 fatty acids and incidence of cardiac arrhythmia: SOFA. Eur J Clin Nutr
. 2003;57:1323-133014506496Google ScholarCrossref
Zock PL, Mensink RP, Harryvan J, de-Vries JH, Katan MB. Fatty acids in serum cholesteryl esters as quantitative biomarkers of dietary intake in humans. Am J Epidemiol
. 1997;145:1114-11229199541Google ScholarCrossref
Pacifico A, Hohnloser SH, Williams JH.
et al. Prevention of implantable-defibrillator shocks by treatment with sotalol. N Engl J Med
. 1999;340:1855-186210369848Google ScholarCrossref
Katan MB, Deslypere JP, van-Birgelen AP, Penders M, Zegwaard M. Kinetics of the incorporation of dietary fatty acids into serum cholesteryl esters, erythrocyte membranes, and adipose tissue: an 18-month controlled study. J Lipid Res
. 1997;38:2012-20229374124Google Scholar
Siscovick DS, Raghunathan T, King I.
et al. Dietary intake of long-chain n-3 polyunsaturated fatty acids and the risk of primary cardiac arrest. Am J Clin Nutr
. 2000;71:208S-212S10617973Google Scholar
Leaf A, Kang JX, Xiao YF, Billman GE. Clinical prevention of sudden cardiac death by n-3 polyunsaturated fatty acids and mechanism of prevention of arrhythmias by n-3 fish oils. Circulation
. 2003;107:2646-265212782616Google ScholarCrossref
McLennan PL. Myocardial membrane fatty acids and the antiarrhythmic actions of dietary fish oil in animal models. Lipids