WEDNESDAY, Aug. 12, 2026 (HealthDay News) -- Subclinical cardiac dysfunction relates to greater neurodegeneration cross-sectionally and longitudinally among APOE ε4 carriers, according to a study published online July 24 in Alzheimer's & Dementia.Elizabeth E. Moore, M.D., from Mass General Brigham in Boston, and colleagues examined cardiac output in relation to longitudinal gray matter volumes among 756 middle-aged and older adults during an 11-year period. Cross-sectional and longitudinal analyses were conducted, adjusting for demographic factors.The researchers found that in APOE ε4-positive participants only, lower cardiac output related to smaller brain volumes. Baseline cardiac output interacted with APOE ε4 status in longitudinal models. In APOE ε4 carriers only, lower baseline cardiac output related to a greater increase in inferior lateral ventricle volume over time."Our findings suggest that even subtle reductions in cardiac function may have important implications for brain health, particularly among individuals at increased genetic risk for Alzheimer's disease," Moore said in a statement. "This study highlights that a precision medicine approach that accounts for genetic information is an important direction for specifically tailoring prevention and screening efforts for Alzheimer's disease."Several authors disclosed ties to the diagnostics and pharmaceutical industries.Abstract/Full Text.Sign up for our weekly HealthDay newsletter