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.