Coexisting Frailty, Cognitive Impairment, and Heart Failure: Implications for Clinical Care

Cognitive Impairment in Heart Failure

Epidemiology

Cognitive impairment occurs frequently in patients with heart failure, and the presence of cognitive impairment in persons with heart failure has been shown to heighten risk for adverse clinical outcomes, disability, poor quality of life, and mortality [26,27]. Heart failure negatively influences cognitive functioning in most domains [28–32]. The most common domains adversely affected by heart failure and aging are memory and executive function. Deficits in these domains can substantially diminish patient ability to carry out essential self-care behaviors [30,32].

The most common form of cognitive impairment seen in patients with heart failure is mild cognitive impairment (MCI), which is a measurable deficit with memory or another core cognitive domain. Up to 60% of persons with heart failure have been reported to have MCI. Patients with MCI have cognitive deficits that are more pronounced than those seen in normal aging, but lack other symptoms of dementia, such as impaired judgment or reasoning. MCI often will not impede patients’ ability to carry out the activities of daily living (ADLs) independently, but patients may have difficulty in performing some instrumental activities of daily living (IADLs), such as remembering medications, scheduling provider appointments. Dementia, a decline in cognitive ability severe enough to hinder an individual’s ability to perform ADLs or IADLs or engage in social activities or occupational responsibilities, occurs in approximately 25% of persons with heart failure [33].

Persons with heart failure have a fourfold greater likelihood of developing CI than persons without heart failure. Several cohort studies have shown that persons with heart failure had lower performance on cognitive tests than individuals without heart failure [34,35] and were 50% more likely to progress to dementia.

Assessment Tools

Although a comprehensive neurocognitive battery would aid in detecting cognitive impairment in heart failure, few clinical practice settings have the resources to perform such a detailed and time-consuming measurement. Most studies in heart failure have relied on global screening questionnaires such as the Mini-Mental State Examination (MMSE) [36] to assess cognitive functioning in persons with heart failure and in other cardiovascular disorders. Global cognitive measures, however, often lack sensitivity for detecting subtle cognitive deficits such as seen in MCI [28–30]. Screening that measures executive function may be the most beneficial for busy clinical settings, since declines in this domain are well established as contributing to poor outcomes in persons with heart failure.

The Montreal Cognitive Assessment (MoCA) is a rapid screening test designed to detect MCI. It assesses different cognitive domains, including attention, memory, language, and executive function [37]. The MoCA lends itself to use in clinical setting because it is brief, requires little training to administer, and is easy to score. This instrument has been used successfully to assess MCI in persons with heart failure and may be more sensitive than the MMSE in identifying clinically relevant cognitive dysfunction. In 2013 study, Cameron et al [38] administered the MMSE and MoCA to 93 hospitalized heart failure patients and found that the MoCA classified 41% of patients as cognitively impaired that were not classified using the MMSE. For persons with a vascular cognitive deficit, the MMSE has been portrayed as an inadequate screening test due to lack of sensitivity for visuospatial and executive function deficits. Because the MoCA was designed to be more sensitive to such deficits, it may be a superior screening method for persons with heart failure. Although previous studies support the use of the MoCA in persons with heart failure, more research is needed in larger, more diverse heart failure samples with a wide range of cognitive deficits.