AIMS: Up to 50% of patients with heart failure (HF) may suffer from severe 
cognitive impairment (SCI), but longitudinal studies are sparse, and effects of 
changes in HF severity on cognitive function are unknown. Therefore, we assessed 
the prevalence of SCI in HF patients, its relationship with HF severity, its 
effects on morbidity and mortality, and the relationship between changes in HF 
severity and cognitive function.
METHODS AND RESULTS: We included 611 patients from the Trial of Intensified 
versus standard Medical therapy in Elderly patients with Congestive Heart 
Failure (TIME-CHF) and assessed cognitive function [Hodkinson Abbreviated Mental 
Test (AMT)] in relation to severity of HF (NYHA class, NT-proBNP) at baseline 
and 18 months (n = 382) and effects on hospitalization-free survival and 
mortality. SCI (i.e. AMT score ≤ 7) was present in 9.2% of patients at baseline, 
but only 20% of them had a diagnosis of dementia. Prevalence of SCI remained 
stable during follow-up. SCI was present at baseline more often in NYHA IV 
patients compared with NYHA II [odds ratio 2.94; 95% confidence interval (CI) 
1.15-7.51, P = 0.025], but it was not related to NT-proBNP levels. SCI was 
related to higher mortality (hazard ratio 1.53, 95% CI 1.02-2.30, P = 0.04), but 
not hospitalization-free survival. Changes in HF severity were not significantly 
related to changes in cognitive function.
CONCLUSION: SCI is a frequent, but often unrecognized finding in HF patients, 
but the influence of HF severity and its changes on cognitive function were less 
than hypothesized. Trial registration ISRCTN43596477.