Omega-3 fatty acids protective against sudden cardiac death in ACS

In patients with non–ST‐segment elevation acute coronary syndrome (ACS), elevated levels of plasma long-chain omega-3 polyunsaturated fatty acids (ω3‐PUFAs) appear to contribute to a lower risk of sudden cardiac death, a study has found.

The case-cohort study used data from the MERLIN‐TIMI 36* trial involving patients hospitalized with non–ST‐segment–elevation ACS. A total of 203 patients with cardiovascular death, 325 with myocardial infarction, 271 with ventricular tachycardia, 161 with atrial fibrillation, and a random sample of 1,612 event‐free individuals as controls were included.

Baseline plasma ω3‐PUFA composition (α‐linolenic acid, eicosapentaenoic acid, docosapentaenoic acid, and docosahexaenoic acid) was evaluated using gas chromatography with flame ionization. The analysis was conducted using logistic regression models inverse probability weighting.

Participants with a higher relative proportion of long‐chain ω3‐PUFAs (eicosapentaenoic acid, docosapentaenoic acid, and docosahexaenoic acid) had 18-percent decreased odds of cardiovascular death (adjusted odds ratio [aOR] per 1 SD, 0.82, 95 percent confidence interval [CI], 0.68–0.98). This association was primarily driven by a lower likelihood of sudden cardiac death (aOR per 1 SD, 0.73, 95 percent CI, 0.55–0.97).

Furthermore, long‐chain ω3‐PUFA levels in the top quartile reduced the likelihood of cardiovascular death by half (aOR, 0.49, 95 percent CI, 0.27–0.86) and of sudden cardiac death by more than 60 percent (aOR, 0.37, 95 percent CI, 0.16–0.56).

The relationship between long‐chain ω3‐PUFA and cardiovascular and sudden cardiac death was attenuated for α‐linolenic acid (aOR, 0.92, 95 percent CI, 0.74–1.14 and aOR, 0.91, 95 percent CI, 0.67–1.25, respectively).

There was no significant association between any ω3‐PUFAs and the odds of cardiovascular death unrelated to sudden cardiac death, myocardial infarction, atrial fibrillation, or early post-ACS ventricular tachycardia.

*Metabolic Efficiency With Ranolazine for Less Ischemia in Non–ST‐Elevation‐Acute Coronary Syndrome–Thrombolysis in Myocardial Infarction 36