Cognitive deficits in patients with heart failure: a review of the literature

Chronic heart failure (HF) and cognitive impairments (CI) are common problems in the elderly. Both are associated with increased mortality and disability, decreased quality of life, and increased health care costs. While these conditions may occur by chance in the same individual, there is increasing evidence that HF is independently associated with CI. The purpose of this article is to review and critique the literature addressing the prevalence, type, and severity of CI in HF patients, the clinical factors associated with CI, and the potential pathophysiology underlying the development of CI, and to recommend priority areas for future research.

Memory and attention deficits are the most frequently occurring CI in this patient population, followed by slowed motor response times and difficulties in problem solving. Prevalence rates range from 30% to 80% depending upon the age of the patients and the characteristics of the sample being studied. Most patients have mild impairments, although as many as one fourth may have moderate to severe CI. The relationship between left ventricular ejection fraction and cognition is inconsistent and may be nonlinear. The pathophysiology underlying the development of CI in HF patients may be related to both cerebral infarction and cerebral hypoperfusion either alone or in combination.

The current literature is limited by studies with sometimes small or nonrepresentative samples, few matched control studies, and lack of longitudinal data that could indicate the conditions that favor the development of CI over time. Future research needs to focus on (1) determining the types, frequency, and severity of impairments in cognitive functioning among a representative sample of HF patients, (2) explicating the pathological mechanisms and the clinical factors that underlie the development of cognitive deficits, and (3) identifying the ways CI influences quality of life. Interventions can then be developed to prevent or delay the occurrence of CI or to minimize their effect on patient self-management and quality of life.