Effects of Omega-3 Fatty Acid for Sudden Cardiac Death Prevention in Patients with Cardiovascular Disease: A Contemporary Meta-Analysis of Randomized, Controlled Trials

Purpose Experimental and epidemiological studies suggest that omega-3 fatty acids have an antiarrhythmic effect. However, evidence from randomized controlled trials (RCTs) for prevention of sudden cardiac death (SCD) remains controversial. This study sought to evaluate the efficacy of omega-3 fatty acids for secondary prevention of SCD in patients with cardiovascular disease (CVD) in the era of guidelines-based therapy. Methods We conducted a PubMed/EMBASE/CENTRAL search for RCTs evaluating omega-3 fatty acids for CVD secondary prevention with at least 6 months follow-up and with data on SCD. Primary outcome was SCD. Secondary outcomes were cardiovascular mortality and all-cause mortality. Results Ten randomized controlled trials were identified evaluating a total of 33,429 patients with CVD. In patients with guidelines-adjusted therapy, omega-3 fatty acids did not reduce the risk ratio (RR) of SCD (RR:0.96; 95% CI: 0.84-1.10). In patients with non- guidelines-adjusted therapy, omega-3 fatty acids reduced the RR of SCD (RR: 0.64; 95% CI: 0.51-0.80). Overall, RR for cardiac death and all-cause mortality were 0.81 (95% CI: 0.69-0.95) and 0.89 (95% CI: 0.79-1.01), respectively. Conclusions In the era of guidelines-adjusted treatment for CVD secondary prevention, omega-3 fatty acids do not appear to reduce SCD.