Hypotension and cognitive impairment

BACKGROUND: Arterial hypotension has been associated with increased risk of dementia in some large prospective studies; and cognitive impairment is common among elderly with left ventricular function. The authors assessed whether arterial hypotension might be associated with cognitive impairment among older subjects with heart failure. METHODS: This study involved all 13,635 patients (of whom 1,583 had heart failure) without cerebrovascular disease or AD, admitted to 81 Italian academic hospitals in 1995 and 1997. The association between blood pressure and cognitive impairment (as indicated by a Hodkinson Mental Test score < 7) according to the presence of heart failure was assessed by univariate analyses, including linear discriminant analysis. This association was also verified by multivariate analyses after stratifying for diagnosis of heart failure. RESULTS: Cognitive impairment was found in 26% of patients with heart failure and in 19% of remaining subjects (Fisher exact p < 0.0001). Blood pressure levels did not differ according to diagnosis of heart failure, but discriminant analysis indicated that systolic blood pressure levels below 130 mm Hg predicted cognitive impairment only among participants with heart failure. Among such participants, systolic blood pressure was associated with cognitive impairment in multiple logistic regression modeling (for 10 mm Hg intervals, OR = 0.78; 95% CI = 0.71 to 0.86). Again, this association was not found among participants without heart failure. CONCLUSIONS: Systolic hypotension is selectively associated with cognitive impairment in older patients with heart failure. As early treatment of cardiac low-output states can reverse cognitive dysfunction, the routine management of heart failure should include systematic assessment of cognitive performance.