Association of Plasma Omega-3 Levels With Incident Heart Failure and Related Mortalities

Objective: To investigate the association between plasma omega-3 levels and incident heart failure (HF) and to examine their relationship with total and cardiovascular (CV) mortality among patients with preexisting HF.

Patients and methods: The UK Biobank is an ongoing prospective cohort study of individuals recruited in the United Kingdom between April 1, 2007, and December 31. 2010. We used Cox proportional hazards models to predict incident HF in those without baseline HF and total and CV mortality in those with baseline HF, all as a function of baseline plasma omega-3 levels.

Results: In participants without HF at baseline (n=271,794), a generally linear inverse association was observed between omega-3 levels and incident HF during a median follow-up of 13.7 years. The risk was 21% lower in the highest quintile of omega-3 compared with the lowest quintile (hazard ratio, 0.79; 95% CI, 0.74 to 0.84; P<.001) in multivariable models. In parallel models in participants with prevalent HF (n=1239), risk for all-cause and CV mortality were both reduced by approximately 50% comparing top to bottom omega-3 quintiles (hazard ratio, 0.53; 95% CI, 0.33 to 0.86; and hazard ratio, 0.50; 95% CI, 0.31 to 0.79, respectively; both P<.01).

Conclusion: Higher plasma levels of marine omega-3 fatty acids were associated with a lower incidence of HF. Furthermore, among patients with preexisting HF, higher omega-3 levels were associated with lower risks of all-cause mortality and CV mortality. These findings suggest that increasing plasma omega-3 levels, whether by diet or supplementation, could reduce both risk for development of HF and death in those with prevalent HF.