['Intake of long-chain n-3 polyunsaturated fatty acids (n-3 PUFA), including docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), is associated with a lower risk of atherosclerotic cardiovascular events, particularly acute myocardial infarction (AMI). However, limited data are available regarding the association between serum n-3 PUFA levels and heart failure (HF) events in survivors of AMI.', 'We evaluated whether serum DHA and EPA levels were associated with HF-free survival and HF hospitalization rates after AMI. A total of 712 patients were divided into 3 groups according to their tertile serum levels of DHA and EPA (Low, Middle, and High). Propensity-score-stratified Cox regression analysis revealed that DHA- and EPA-Low groups presented statistically significant worse HF-free survival (hazard ratio (HR) 1.68, 95% confidence interval (CI) 1.03-2.72, P=0.0358, and HR 1.69, 95% CI 1.05-2.72, P=0.0280, respectively), with the EPA-Low group having a higher risk of HF hospitalization (HR 2.40, 95% CI 1.21-4.75, P=0.0097) than the DHA-Low group (HR 1.72, 95% CI 0.86-3.45, P=0.1224). The relationship between a low DHA or EPA level and decreased HF-free survival was almost common to all subgroups; however, the effect of low serum EPA on HF hospitalization was prominent in male patients, and those with low levels of high-density lipoprotein cholesterol or without statin therapy.'] Are low levels of serum n-3 polyunsaturated fatty acids associated with worse heart failure-free survival in patients after acute myocardial infarction?