Cognitive deficits in chronic heart failure.

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.

Research in patients with heart failure: challenges in recruitment.

BACKGROUND: Published studies of patients with heart failure may not include details about the challenges in the recruitment process. OBJECTIVES: To describe the recruitment process during the first 18 months of a study being conducted to evaluate cognitive deficits in patients with chronic heart failure. METHODS: Details of the recruitment process are described for 2 clinic sites. RESULTS: A total of 4,027 echocardiograms were screened at site 1 to evaluate eligibility. Of the 161 patients eligible, 61 (38%) were invited to participate, and 29 of the 61 (48%) completed the study. At site 2, four hundred thirty-seven medical records of patients were screened, resulting in 163 eligible patients (37%). The staff invited 70 of the 163 patients (43%) to participate, and 52 of the 70 (74%) completed the study. The refusal rate was 23% at site 1 and 21% at site 2. CONCLUSIONS: Successful recruitment in studies involving patients with heart failure often requires screening of a large group of patients.

A conceptual model of cognitive deficits in chronic heart failure.

PURPOSE: To describe a conceptual model to guide studies of cognitive deficits among patients with heart failure. ORGANIZING FRAMEWORK: The conceptual framework of cognitive deficits in chronic heart failure is based on theoretical and empirical literature about (a) the pathophysiology of heart failure, (b) the pathophysiology of cognitive deficits, and (c) health-related quality of life. Other variables that may cause or contribute to cognitive deficits include age, the relative contributions of multiple comorbid conditions, hypertension, and depressive symptoms. Covariates that might influence cognitive deficits (medications, gender, and education) are also included in the model. The most prominent cognitive deficits are believed to occur in domains of attention, working memory, memory, learning, executive function, and psychomotor speed. The main outcome variable is health-related quality of life, which is believed to be influenced by circulatory insufficiency and cognitive deficits. CONCLUSIONS: The conceptual model described in this paper is a framework for testing cognitive deficits that occur in heart failure. After validation through empirical testing, the model may be useful in developing interventions for patients with heart failure whose care is complicated by cognitive deficits.