Incidence of dementia and subsequent outcomes in patients with heart failure

Background — Dementia and heart failure (HF) frequently coexist; however, the relationship between these conditions is not fully explored.

Objectives — The objectives of the study were to: 1) compare dementia incidence in newly-diagnosed patients with HF or matched non-HF controls; and 2) examine risk factors for and outcomes after dementia diagnosis in HF patients.

Methods — In community-dwelling residents (aged 40-80 years), we compared incident dementia in those with new-onset HF vs age/sex, and cardiovascular risk factor/disease-matched non-HF controls. In those with HF, we examined time-varying dementia onset as the exposure with outcomes of mortality and hospitalization. We also compared physician visits after vs before dementia diagnosis.

Results — Among 211,548 outpatients with HF (median 68 [60-75] years, 41.2% female), time-dependent HRs for dementia were 1.42 (95% CI: 1.38-1.47) at 5 years and 1.31 (95% CI: 1.27-1.35) at 10 years compared to non-HF controls. Prior stroke or transient ischemia attack (HR: 1.41; 95% CI: 1.33-1.50) and hospital frailty risk score >10 vs <5 (HR: 1.93; 95% CI: 1.77-2.09) were important predictors of dementia (both P < 0.001). Incident dementia was associated with higher multivariable-adjusted hazards of all-cause mortality (HR: 2.44; 95% CI: 2.40-2.49) and all-cause hospitalization (HR: 1.63; 95% CI: 1.58-1.69) in outpatients with HF (all P < 0.001). Rates of outpatient physician visits with primary care, internal medicine, cardiologists (post/pre-rate ratio range 1.08-1.19), and geriatricians (post/prerate ratio 10.70; all P < 0.001) were higher after (versus before) dementia onset.

Conclusions — Incident HF was associated with higher risk of incident dementia. Dementia onset was associated with higher rates of outpatient physician visits and increased risk of adverse outcomes.