Cognitive impairment and heart failure: systematic review and meta-analysis

Background Cognitive impairment and dementia are associated with a range of cardiovascular conditions, including hypertension, coronary artery disease, and atrial fibrillation. We aimed to describe the association with heart failure, summarizing published data to give estimates of prevalence, incidence, and relative risk of cognitive impairment/dementia in heart failure. Methods We searched multidisciplinary databases including MEDLINE (OVID), EMBASE (OVID), CINAHL (EBSCO), PsychINFO (EBSCO), Web of Science (Thomson Reuters), and CENTRAL (Cochrane Library) from inception until May 31, 2015. All relevant studies looking at cognitive impairment/dementia in heart failure were included. Studies were selected by 2 independent reviewers using prespecified inclusion/exclusion criteria. Where data allowed, we performed meta-analysis and pooled results using random effects models. Results From 18,000 titles, 37 studies were eligible (n = 8411 participants). Data from 4 prospective cohorts (n = 2513 participants) suggest greater cognitive decline in heart failure compared with non-heart failure over the longer term. These data were not suitable for meta-analysis. In case control studies describing those with and without heart failure (n = 4 papers, 1414 participants) the odds ratio for cognitive impairment in the heart failure population was 1.67 (95% confidence interval 1.15–2.42). Prevalence of cognitive impairment in heart failure cohorts (n = 26 studies, 4176 participants) was 43% (95% confidence interval 30–55). Conclusions This review suggests a substantial proportion of patients with heart failure have concomitant cognitive problems. This has implications for planning treatment and services. These data do not allow us to comment on causation, and further work is needed to describe the underlying pathophysiology.