Cognitive impairment and medication adherence in outpatients with heart failure. 
The study objectives were (a) to describe the prevalence and severity of cognitive impairment (CI) in an outpatient veteran population with heart failure (HF), (b) to describe the cognitive domains affected in those subjects found to have CI, (c) to examine clinical and demographic variables that may be associated with CI, and (d) to determine the relationship between CI and medication adherence (MA).  We hypothesized that CI is a prevalent condition in veterans with HF and is associated with poorer MA.  Adherence to therapy is essential for successful outcomes.  CI may affect adherence; little is known about CI in veterans with HF or the effect of CI on MA.  We enrolled 251 veteran outpatients with HF.  Subjects were screened for CI; adherence was determined by pill counts.  Subjects with CI underwent further neuropsychologic testing.  Unrecognized CI was found in 58% of subjects.  Verbal learning, immediate memory, and delayed verbal memory were most impaired.  CI was significantly associated with poorer MA.  Variables associated with CI included age, African-American race, depression, use of alcohol, and nonparticipation in pill count.  Unrecognized CI was prevalent and associated with poorer MA.  We propose routine screening for CI in patients with HF.