Heart Failure-Induced Brain Injury

Abstract

Heart failure (HF) is a systemic illness with grave implications for bodily functions. The brain, among other vital organs, often suffers insults as a result of HF, and both anatomic and functional brain abnormalities were found in the HF population. This injury was demonstrated across a wide range of clinical conditions and cardiac functions and was shown to affect patients' outcomes. Although reduced cardiac output and high burden of cardiovascular risk factors are the prevailing explanations for these findings, there are data showing the involvement of neurohormonal, nutritional, and inflammatory mechanisms in this complex process. Here, the authors review the suggested pathophysiology behind brain injury in HF, describe its effect on patients' outcomes, offer a diagnostic approach, and discuss possible therapeutic options.

Heart and brain interaction in patients with heart failure: overview and proposal for a taxonomy. A position paper from the Study Group on Heart and Brain Interaction of the Heart Failure Association

“…The heart and the brain are linked by multiple feedback signals that account for mutual interaction, aggravation and progression of disease processes. Indirect and direct interactions between both organs led to the concept of a ‘cardio‐cerebral syndrome’ in HF …”

Compromised Cerebrovascular Regulation and Cerebral Oxygenation in Pulmonary Arterial Hypertension

“…Exercise‐induced cerebral hypoxia might lead to a shift toward nonoxidative metabolization of lactate and glucose, in a similar manner as short‐term altitude exposure in healthy individuals, increasing central fatigue and contributing to early exercise termination. Prevalent mental disturbance has been associated with HF, including multiple brain anatomical and cognitive changes . Different investigators considered that impaired CBF might be one contributing factor .…”

“…Other determinants include cardiac output (CO), arterial blood gas, and autonomic nervous system and neurovascular coupling for meeting local cerebral metabolic demand . Contemporary evidence demonstrates that CBF is reduced in patients with mild to severe heart failure (HF), leading to cognitive dysfunction, brain anatomical changes, and exercise intolerance . Potential mechanisms involved in CBF reduction remain unclear, but might be related to low CO, lowered cerebrovascular reactivity to CO 2 , and an abnormal regulation of the cerebral pressure‐flow relationship at rest or during posture change .…”

Integrating assessment of cognitive status in elderly cardiovascular care

“…The confluence of factors which leads to cognitive impairment in patients with HF was termed by Havakuk et al, the “cardiocerebral syndrome,” defined as “a state of cognitive impairment of undefined cause in HF patients, beyond the one anticipated in age‐matched controls, typically accompanied by anatomic brain changes.” Magnetic resonance imaging (MRI) in this population typically shows white matter hyperintensities, particularly periventricular, and gray matter atrophy, particularly involving the hippocampus and frontal cortex. Laboratory studies typically show high levels of neurohormones and inflammatory markers (IL‐6, TNF‐alpha, cortisol, epinephrine).…”

“…Laboratory studies typically show high levels of neurohormones and inflammatory markers (IL‐6, TNF‐alpha, cortisol, epinephrine). Other medical and neurological conditions that can cause cognitive dysfunction are simultaneously ruled out …”