Rationale and design of a randomised controlled clinical trial on supplemental intake of n-3 fatty acids and incidence of cardiac arrhythmia: SOFA.
BACKGROUND
Evidence from earlier studies indicates that intake of very long-chain n-3 polyunsaturated fatty acids (n-3 PUFA, also named omega-3 fatty acids) as present in fish oil reduces the risk of sudden death. Sudden death forms a major part of mortality from cardiovascular disease and is in most cases a direct consequence of cardiac arrhythmia. n-3 PUFA may exert their protective effect through reducing the susceptibility for cardiac arrhythmia.


OBJECTIVE
To investigate the effect of n-3 PUFA on the incidence of recurrent ventricular arrhythmia. This paper presents the rationale, design and methods of the Study on Omega-3 Fatty acids and ventricular Arrhythmia (SOFA) and discusses problems encountered in conducting a multicentre clinical trial on food.


METHODS
A randomised, parallel, placebo-controlled, double blind intervention study, which obeys the guidelines for Good Clinical Practice.


METHODS
Multiple cardiology centres in Europe.


METHODS
A total of 500 patients with an implantable cardioverter defibrillator (ICD). An ICD detects, treats and stores cardiac arrhythmic events in its memory chip.


METHODS
Patients receive either 2 g/day of fish oil, containing approximately 450 mg eicosapentaenoic acid and 350 mg docosahexaenoic acid, or placebo for 12 months.


METHODS
Spontaneous ventricular tachyarrhythmias as recorded by the ICD or all-cause mortality.


CONCLUSIONS
SOFA is designed to answer the question whether intake of n-3 PUFA from fish-a regular food ingredient-can reduce the incidence of life-threatening cardiac arrhythmia. If this proves to be true, increasing the intake of n-3 PUFA could be an easy, effective and safe measure to prevent fatal arrhythmia in the general population.
D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage; D001145:Arrhythmias, Cardiac / Q000453:epidemiology / Q000517:prevention & control*; D016757:Death, Sudden, Cardiac / Q000517:prevention & control; D017147:Defibrillators, Implantable; D004311:Double-Blind Method; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage*; D005395:Fish Oils; D006801:Humans; D015994:Incidence; D015337:Multicenter Studies as Topic / Q000379:methods; D010349:Patient Compliance; D010865:Pilot Projects; D011786:Quality Control; D016032:Randomized Controlled Trials as Topic / Q000379:methods* / Q000592:standards; D012107:Research Design; D018401:Sample Size
D000889:Anti-Arrhythmia Agents; D015525:Fatty Acids, Omega-3; D005395:Fish Oils