EPA Correlates Inversely with Ischemic Brain Infarcts in Patients with Atrial Fibrillation

This cross-sectional study examined the association between plasma EPA levels and ischemic brain infarcts detected by MRI in 1,657 patients with atrial fibrillation enrolled in the Swiss-AF registry.

Higher plasma EPA concentration was inversely associated with large noncortical or cortical ischemic brain infarcts — the type most likely to represent thromboembolic events — but not with small vessel disease markers (white matter hyperintensities, lacunar infarcts). The association persisted after adjustment for anticoagulation status and traditional cardiovascular risk factors.

Atrial fibrillation is the leading cause of cardioembolic stroke, and the AF population carries substantial cerebrovascular disease burden even with oral anticoagulation. The finding that EPA — not just DHA or combined omega-3 — inversely correlates with large embolism-type infarcts is mechanistically consistent with EPA’s proposed anti-thrombotic and plaque-stabilizing properties. DHA was not independently associated with infarct burden after adjustment for EPA.

The cross-sectional design cannot establish causality, and the observed EPA association may reflect healthier dietary patterns that confound the omega-3/outcome relationship. This study is observational corroboration of EPA biology in a distinct population (AF rather than CAD) — relevant to the broader EPA hypothesis but not definitive.

We rate the evidence limited. A cross-sectional observational study in AF patients showing inverse association between EPA and brain infarcts — mechanistically interesting but insufficient for clinical recommendations.