Triggering receptor expressed on myeloid cells 2 (TREM2) is a transmembrane protein expressed on myeloid cells, including macrophages and microglia, and is involved in modulating inflammation and lipid metabolism. Elevated plasma levels of soluble TREM2 (sTREM2) have been associated with heart failure (HF) and neurodegenerative diseases, such as Alzheimer's disease (AD). This post hoc analysis explored the association of plasma sTREM2 with cognition and mortality in the Cognition.Matters-HF cohort of 148 patients with chronic HF. Plasma sTREM2 levels were measured using a bead-based immunoassay, and the cohort was split into high and low sTREM2 groups based on a median concentration of 16.6 ng/mL. Higher sTREM2 levels were associated with worse cognitive performance, particularly in working memory (