Background: Many cardiovascular risk factors are shown to increase the risk of dementia and Alzheimer's disease (AD), but the impact of heart disease on later development of dementia is still unclear.
Objective: The aim of the study was to investigate the long-term risk of dementia and Alzheimer's disease (AD) related to midlife and late-life atrial fibrillation (AF), heart failure (HF), and coronary artery disease (CAD) in a population-based study with a follow-up of over 25 years.
Methods: Cardiovascular Risk Factors, Aging and Dementia (CAIDE) study includes 2000 participants who were randomly selected from four separate, population-based samples originally studied in midlife (1972, 1977, 1982, or 1987). Re-examinations were carried out in 1998 and 2005-2008. Altogether 1,510 (75.5%) persons participated in at least one re-examination, and 127 (8.4%) persons were diagnosed with dementia (of which 102 had AD).
Results: AF in late-life was an independent risk factor for dementia (HR 2.61, 95% CI 1.05-6.47; p = 0.039) and AD (HR 2.54, 95% CI 1.04-6.16; p = 0.040) in the fully adjusted analyses. The association was even stronger among the apolipoprotein E (APOE) ε4 non-carriers. Late-life HF, but not CAD, tended to increase the risks as well. Heart diseases diagnosed at midlife did not increase the risk of later dementia and AD.
Conclusion: Late-life heart diseases increase the subsequent risk of dementia and AD. Prevention and effective treatment of heart diseases may be important also from the perspective of brain health and cognitive functioning.
Keywords: Alzheimer disease; atrial fibrillation; cohort studies; coronary artery disease; dementia; heart failure; risk factors.