Sorond, Farzaneh A.

Complex bidirectional interactions between the nervous and cardiovascular systems are integrated through the heart–brain axis, a physiological pathway that governs both neural regulation of cardiovascular function and cardiovascular influences on brain health. Emerging evidence indicates that even in the absence of overt disease, subclinical changes in the heart, aortic arch, and extracranial arteries contribute to brain injury and cognitive vulnerability. This review synthesizes current knowledge on how subclinical heart–brain axis dysfunction affects brain structure and function, highlighting the roles of central and autonomic neural pathways as well as hormonal signaling in driving neurological decline. Key biomarkers linked to silent brain injury, cognitive decline, and dementia are discussed, emphasizing their potential for early risk stratification and as targets for preventive interventions. We also outline mechanistic pathways connecting subclinical heart–brain axis dysfunction to adverse brain outcomes, identify major gaps in current evidence, and propose priorities for future research and clinical trials aimed at early detection and risk reduction to preserve brain health.

AbstractIntroductionWe evaluated whether better cardiovascular health at midlife and improvement of cardiovascular health within midlife were associated with dementia risk.MethodsTwo longitudinal population‐based studies were used: Atherosclerosis Risk in Communities (ARIC) (n = 11,460/visits at ages 54 and 60), and Age, Gene/Environment Susceptibility (AGES)‐Reykjavik (n = 3907/visit at age 51). A cardiovascular health score (range 0–12/0–14, depending on diet availability) including six/seven items was calculated at each visit, with weight assigned to each item as poor (0), intermediate (1), or ideal (2). Cardiovascular health was defined as low (score 0–4/0–5), intermediate (5–7/6–9), or high (8–12/10–14). Incident dementia was ascertained through linkage to health records and with neuropsychological examinations.ResultsMidlife high compared to low cardiovascular health (hazard ratios [HRs]: for ARIC: 0.60 [95% confidence interval: 0.52, 0.69]); for AGES‐Reykjavik: 0.83 [0.66, 0.99] and improvement of cardiovascular health score within midlife (HR per one‐point increase: ARIC: 0.94 [0.92, 0.96]) were associated with lower dementia risk.DiscussionBetter cardiovascular health at midlife and improvement of cardiovascular health within midlife are associated with lower dementia risk.Highlights Cardiovascular health and dementia were studied in two large cohort studies. Better cardiovascular health at midlife relates to lower dementia risk. Improvement of cardiovascular health within midlife relates to lower dementia risk. Promotion of cardiovascular health at midlife can help to reduce dementia risk.