Chronic renal dysfunction and anaemia are associated with cognitive impairment in older patients with heart failure

Cognitive impairment, anaemia and chronic kidney disease (CKD) are associated with mortality and disability in chronic heart failure patients. We hypothesized that anaemia and CKD are independent predictors of cognitive impairment in older patients with heart failure.

One hundred and ninety community-living elderly patients aged at least 70 years, treated with optimized therapy for heart failure in stable clinical conditions, were prospectively studied. They underwent clinical and multidimensional assessment. Cognitive status was assessed by the Mini Mental State Examination. Cognitive impairment was defined as the Mini Mental State Examination score adjusted by age and educational level below 24. CKD was defined as the Cockcroft-Gault glomerular filtration rate below 60  ml/min and anaemia as haemoglobin below 12  g/dl.

Cognitive impairment was diagnosed in 38.9% of patients, CKD in 85.7% and anaemia in 42.6%. Age, female sex, BMI, education less than 5 years, depressive symptoms, anaemia, CKD, disability and worse quality of life were significantly associated with cognitive impairment. Cognitive impairment involved primarily global cognitive deficit, memory, mental speed, attention, calculation and language. A significant relationship between haemoglobin levels and cognitive impairment was found, with the range of 15-16.5  g/dl having the lower prevalence of cognitive impairment (19.4%). At multivariate analysis, advanced age, low education level, anaemia and CKD were independently associated with cognitive impairment. Cox analysis showed that cognitive impairment was an independent predictor of hospitalization for worsening heart failure alone and combined with all-cause death.

Cognitive impairment is common in elderly heart failure patients and is independently associated with anaemia and renal dysfunction. Further studies are needed to assess whether optimal treatment of anaemia and CKD may prevent the development of cognitive impairment in heart failure patients.