Abstract 2706: Neurocognitive Deficits Associated with Advanced Heart Failure
The measures of general cognition which have previously been used to demonstrate cognitive impairment in patients with congestive heart failure (CHF) provide only broad indications of what cognitive function(s) in particular are impaired. The objectives of this study are:
quantify the severity of neurocognitive impairment;
use specific neurocognitive subtests to identify what functions are impaired;
use fMRI to identify brain regions putatively involved in neurocognitive impairments of patients with advanced CHF.
Hypoperfusion associated with CHF has been thought to be the primary cause of neuropathology in this population. We tested the hypothesis, suggested by our own preliminary data, that Verbal Fluency is impaired relative to Picture Naming and pathology of frontal lobe function is involved. Veterans with NYHA class III or IV CHF from our Advanced Heart Failure Clinic were given several cognitive tests, including the Addenbrooke Cognitive Exam (ACE). The ACE is a validated indicator of dementia comprised of four indices: Verbal Fluency, Language (Naming), Orientation, and Immediate Memory. Follow-up fMRI while performing Verbal Fluency and Picture Naming tasks was conducted to localize abnormalities of brain activation. Results showed that 64.5% of the group (n = 31, age = 62.3 (11.4) years) met the ACE cut-off score criterion of probable dementia (Total Score less than or equal to 88). Significantly lower scores on Verbal Fluency (p = .01), Language (p = .02), and Immediate Memory (p = .00), but not Orientation, were found in the probable dementia subgroup compared to the cognitively intact subgroup. After partialling out dementia status, ACE Total Score significantly correlated (r(31) = .31, p = .05) with cardiac output (measured with bioimpedance plethysmograhy). The fMRI procedure was administered on 7 patients. Activation patterns revealed absence of frontal activation (Brodmann Area 46) on Verbal Fluency relative to Picture Naming. In conclusion, many advanced heart failure patients appear to be undergoing a dementing process, and neurocognitive and neuroimaging results are consistent in suggesting impairment of explicit word generation and retrieval, but not semantic knowledge, with associated frontal lobe dysfunction.