Background: Cognitive impairment is as high as 70% among adults with heart failure (HF) and its prevalence increases with the duration and severity of HF. However, little is known about the prevalence of cognitive impairment early in the course of HF. This is important, as high cognitive impairment at diagnosis would suggest that earlier screening would be warranted. We examined the prevalence and correlates of cognitive impairment among adults with incident HF.
Methods: We used data from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study, an observational, longitudinal cohort study of 30,239 community-dwelling adults >45 recruited from 2003 to 2007. Blacks and residents of the stroke belt were oversampled. Global cognitive status was assessed annually by telephone with the Six-item Screener (SIS) and the diagnosis of incident HF was validated by physicians using medical records and standard clinical criteria. Participants who were hospitalized for incident HF from 2004 until 2016 with a SIS completed > 1 month but < 18 months before the index hospitalization were included. After determining the prevalence of cognitive impairment among this cohort, we identified which of their baseline characteristics were independently associated with cognitive impairment using multivariable logistic regression. We then compared the prevalence of cognitive impairment among adults with incident HF to the prevalence of cognitive impairment among age, sex, and race matched participants without HF, stratifying by 10-year Framingham Coronary Heart Disease Risk Scores (FRS) (<10%, 10-20%, and > 20%).
Results: Of the 436 participants with incident HF, 14.9% had cognitive impairment. In an age-adjusted model, older age (OR 1.04 [95% CI 1.01 - 1.08], black race (OR 1.88 [95% 1.08-3.28]), < high school education (OR 1.89 [95% 1.02-3.51]), and anticoagulation (OR 3.01 [95% 1.05 - 8.63]) were independently associated with higher odds of cognitive impairment, whereas female sex (OR 0.54 [95% 0.31 - 0.94]) was associated with lower odds of cognitive impairment. The prevalence of cognitive impairment among participants with incident HF was higher than the prevalence of cognitive impairment among controls with low FRS (9.4%) but was less than the prevalence of cognitive impairment among controls with high FRS (21.9%).
Conclusion: The prevalence of cognitive impairment among adults with incident HF was greater than the prevalence of cognitive impairment among matched participants with low CHD risk, but less than the prevalence of cognitive impairment among matched participants with the highest CHD risk. This suggests that the majority of cognitive decline in HF may occur later in the course of the disease. Increased awareness of cognitive impairment among newly diagnosed patients, as well as ways to mitigate cognitive decline in the context of HF management, are warranted.