Effects Of Omega-3Fatty Acids On Cardiovascular Death: A Meta-Analysis Of Randomized Controlled Trails

OBJECTIVES:This meta-analysis was designed to evaluate the effects of omega-3fatty acids on cardiovascular death in patients with cardiovascular disease (CVD) or at high risk of CVD.BACKGROUND:Omega-3fatty acids have emerged as potential anti-arrhythmic agents recently. However, the benefits of omega-3fatty acids on the reduction of cardiovascular death are not consistent.METHODS:MEDLINE, EMBASE and Cochrane Controlled Trials Register were searched, and randomized controlled trials (RCTs) evaluating the effects of omega-3fatty acids on CVD were collected. The follow-up duration was at least6months, and the endpoints were all cause mortality, cardiac death and sudden cardiac death (SCD). Effects of each treatment were expressed as odds ratio (OR) with95%confidence interval (CI). Heterogeneity was assessed by the O statistic, the p value (result of a statistical test based on the Q statistics), and the I2statistic, and meta regressions were performed to introduce the heterogeneity of studies.RESULTS:After the selection of studies,20RCTs involving58418patients with CVD or at high risk of CVD were identified.1Of these studies, all20reported all cause mortality as an endpoint,17reported cardiac death and11reported SCD. Overall, omega-3fatty acids significantly reduced the risk of cardiac death (OR,0.80;95%CI,0.67-0.94), but had no significantly preventive effects on all cause mortality (OR,0.90;95%CI,0.81-1.01) or SCD (OR,0.86;95%CI,0.65-1.13). There were substantial heterogeneities between studies. In the meta-regression, the effects of omega-3fatty acids on all cause mortality and cardiac death decreased with the mean follow-up duration prolonged, and enhanced with the dose increased. The effects of omega-3fatty acids on endpoints were not affected by the coadministration of rennin-angiotensin blocker, β-blocker, statins or antiplatelet treatment.CONCLUSIONS:Omega-3fatty acids reveal statistically significant effects on the prevention of cardiac death, but not on all cause mortality or SCD in patients with CVD or at high risk of CVD. The effects of omega-3fatty acids decrease with the mean follow-up duration prolonged, enhance with the dose increased, and are not affected by the coadministration of rennin-angiotensin blocker, β-blocker, statins or antiplatelet treatment.