The Heart-Brain Connection: Heart Failure, Atrial Fibrillation, Coronary Heart Disease, and Dementia

A scientific statement from the American Heart Association (AHA) indicates that heart failure (HF), atrial fibrillation (AF), and coronary heart disease (CHD), the 3 most common types of cardiovascular diseases (CVDs), are linked with cognitive impairment and increased risk of dementia. The statement discusses the underlying causal mechanisms that link each of these CVDs to impaired cognition.¹

The statement emphasizes the crucial role of heart health in preserving brain health, cognitive function, and reducing progression to dementia. Image Credit: © Studio Romantic - stock.adobe.com

According to the AHA, approximately 80% of all brain disease can be linked back to CVD and cognitive issues affect over 70% of stroke survivors, emphasizing the significant relationship between these 2 disease states. Over the years, research has shown that a longitudinal worsening of CVD is associated with cognitive impairment and decline, and that good health can reduce risks of stroke, heart disease, memory loss and difficulty with thinking and learning. Although once believed to be 2 independent organs, evidence shows that the brain and heart are interdependent and linked through shared risk factors and genetic variants.^2-4

“Stroke and cognitive decline, both major determinants of brain health, are chronic and disabling conditions that have a dramatic impact at the individual and societal level,” said statement writing group Chair Fernando D. Testai, MD, PhD, FAHA, professor of neurology and rehabilitation and vascular neurology fellowship director at the University of Illinois College of Medicine, stroke medical director at the University of Illinois Hospital in Chicago. “Managing heart health from an early age is important to prevent cardiovascular disease and cardiac events, protect brain health and reduce the risk of cognitive decline in later life.”¹

HF has been linked to cognitive decline and previous studies have found that an estimated 50% of individuals with HF are affected, which tends to be higher for patients with more severe conditions. HF affects the brain in multiple ways including reduced blood flow resulting in mini-strokes or silent brain injuries, or chronic inflammation and neurohormonal activation that can contribute to brain damage. Studies have also found that structural brain changes commonly observed in patients with HF contributes to reduced cognitive function.¹

The cognitive health of patients with AF are also impacted. AF has multiple shared risk factors with dementia including high blood pressure, type 2 diabetes (T2D), HF, smoking, vascular disease, and aging, which can all lead to structural brain changes. Aspects of AF such as compromised blood flow can lead to strokes, microhemorrhages, inflammation, or blood clots that all contribute to decreased brain function and thereby cognitive decline. However, proper management of AF has been shown to reduce cognitive decline risk.¹

Similar to AF, CHD shares risk factors including T2D and high blood pressure, which cause inflammation that affects the blood-brain area. The reduced blood flow to the brain leads to cognitive decline and dementia. Other studies have also identified a potential link between Alzheimer disease, blood vessel damage, and brain degeneration.¹

The statement emphasizes the crucial role of heart health in preserving brain health, cognitive function, and reducing progression to dementia. Through lifestyle modifications and medical intervention, patients with CVDs can mitigate risk and preserve thinking and memory to maintain independence as they age.

“Although new medications with the potential to treat Alzheimer's disease are being developed, the medical community is well aware that prevention is better than a cure. More research is needed to confirm and outline how cardiovascular care can improve brain health,” said Testai. “In addition, more research is needed to understand the ways gender, race and ethnicity may influence the connection between the brain and the heart.”¹

REFERENCES

1. Heart failure, atrial fibrillation & coronary heart disease linked to cognitive impairment. American Heart Association. October 10, 2024. Accessed October 15, 2024. https://newsroom.heart.org/news/heart-failure-atrial-fibrillation-coronary-heart-disease-linked-to-cognitive-impairment?preview=8c99&preview_mode=True

2. Brain health. American Heart Association. Accessed October 15, 2024. https://www.stroke.org/en/healthy-living/brain-health

3. Risk factors for heart disease linked to dementia. National Institutes of Health. August 15, 2017. Accessed October 15, 2024. https://www.nih.gov/news-events/nih-research-matters/risk-factors-heart-disease-linked-dementia

4. Farnsworth von Cederwald B, Josefsson M, Wåhlin A, et al. Association of cardiovascular risk trajectory with cognitive decline and incident dementia. Neurology. April 20, 2022. Accessed October 15, 2024. doi:10.1212/WNL.000000000020025