Bachground: Habitual intake of long-chain omega-3 fatty acids, especially eicosapentaenoic and docosahexaenoic acid (EPA+DHA) from fish, has been associated with a lower risk of fatal coronary heart disease (CHD) in population-based studies. Whether that is also the case for patients with CHD is not yet clear. We studied the associations of dietary and circulating EPA+DHA and alpha-linolenic acid, a plant-derived omega-3 fatty acids, with long-term mortality risk after myocardial infarction.
Methods and results: We analyzed data from 4067 Dutch patients with prior myocardial infarction aged 60 to 80 years (79% men, 86% on statins) enrolled in the Alpha Omega Cohort from 2002 to 2006 (baseline) and followed through 2018. Baseline intake of fish and omega-3 fatty acids were assessed through a validated 203-item food frequency questionnaire and circulating omega-3 fatty acids were assessed in plasma cholesteryl esters. Hazard ratios (HRs) with 95% CIs were obtained from Cox regression analyses. During a median follow-up period of 12 years, 1877 deaths occurred, of which 515 were from CHD and 834 from cardiovascular diseases. Dietary intake of EPA+DHA was significantly inversely associated with only CHD mortality (HR, 0.69 [0.52– 0.90] for >200 versus ≤50 mg/d; HR, 0.92 [0.86– 0.98] per 100 mg/d). Similar results were obtained for fish consumption (HRCHD, 0.74 [0.53–1.03] for >40 versus ≤5 g/d; Ptrend: 0.031). Circulating EPA+DHA was inversely associated with CHD mortality (HR, 0.71 [0.53– 0.94] for >2.52% versus ≤1.29%; 0.85 [0.77– 0.95] per 1-SD) and also with cardiovascular diseases and all-cause mortality. Dietary and circulating alpha-linolenic acid were not significantly associated with mortality end points.
Conclusions: In a cohort of Dutch patients with prior myocardial infarction, higher dietary and circulating EPA+DHA and fish intake were consistently associated with a lower CHD mortality risk.