Abstract and Commentary - Heart Failure and Cognition

Research Abstract and Commentary
Cognitive Deficits in Chronic Heart Failure (authors’ abstract)

BACKGROUND: Patients with heart failure (HF) have been found to have cognitive deficits, but it remains unclear whether these deficits are associated with HF or with aging or comorbid conditions common in HF.
OBJECTIVES: The purpose of this study was (a) to determine the types, the frequency, and the severity of cognitive deficits among patients with chronic HF compared with age- and education-matched healthy participants and participants with major medical conditions other than HF, and (b) to evaluate the relationships between HF severity, age, and comorbidities and cognitive deficits.
METHODS: A sample of 414 participants completed the study (249 HF patients, 63 healthy and 102 medical participants). The HF patients completed measures of HF severity, comorbidity (multiple comorbidity, depressive symptoms), and neuropsychological functioning. Blood pressure and oxygen saturation were assessed at interview; clinical variables were abstracted from records. Participants in the comparison groups completed the same measures as the HF patients except those specific to HF.
RESULTS: Compared with the healthy and medical participants, HF patients had poorer memory, psychomotor speed, and executive function. Significantly more HF patients (24%) had deficits in three or more domains. Higher (worse) HF severity was associated with more cognitive deficits; HF severity interacted with age to explain deficits in executive function. Surprisingly, men with HF had poorer memory, psychomotor speed, and visuospatial recall ability than women. Multiple comorbidity, hypertension, depressive symptoms, and medications were not associated with cognitive deficits in this sample.
DISCUSSION: HF results in losses in memory, psychomotor speed, and executive function in almost one fourth of patients. Patients with more severe HF are at risk for cognitive deficits. Older patients with more severe HF may have more problems in executive function, and men with HF may be at increased risk for cognitive deficits. Studies are urgently needed to identify the mechanisms for the cognitive deficits in HF and to test innovative interventions to prevent cognitive loss and decline.

Pressler, S. J., Subramanian, U., Kareken, D., Perkins, S. M., Gradus-Pizlo, I., Sauvé, M. J., … Shaw, R. M. (2010). Cognitive deficits in chronic heart failure. Nursing Research, 59, 127-39.



Commentary by Dana Rutledge

In this carefully done comparative study, HF patients were compared with healthy (although a bit younger) and medical (current diagnosis of a major chronic disorder other than HF) patients on a battery of cognitive performance measures. HF diagnosis was documented by a test such as echocardiography, nuclear imaging, or cardiac catheterization within a 2-year window; patients had a left ventricular ejection fraction of 40% or less. HF patients came from seven sites in one Midwestern city; healthy and medical participants came from one medical practice, family members of HF participants, and volunteers. Measures selected were valid (measured what they are supposed to measure) and reliable in the populations of interest (accurate, sensitive, replicable). Procedures for testing were carefully laid out.

Study findings support previous work showing that HF patients have poorer performance compared with healthy/medical patients in memory, psychomotor speed, and executive functioning. Deficits found in HF patients show that the systematic damage from HF includes cerebral damage, and lead to cerebral hypoperfusion. Memory deficits were the most common problems identified in HF patients, followed by psychomotor slowing, and decreased executive function (thinking). These deficits are more severe in persons with greater HF severity and executive function was especially problematic in older patients with more severe HF. A unique finding was that deficits were worse in men.

What do these results say to nurses caring for patients with HF? Cognitive deficits occurred in almost 25% of patients!! Can these persons handle new information? When you try to teach them something, can they learn? Can they care for themselves? These are important considerations. All nurses should be evaluating the potential learning capacity or incapacity of these patients to determine what home care needs they have, and what deficits need to be addressed, and potentially managed by others. Home care may be necessary for many of these persons.