An increased risk for dementia has been reported among patients with atrial fibrillation (AF) associated with diabetes and stroke, according to study findings published in The American Journal of Cardiology.
AF is associated with dementia and cognitive decline, but that the specific mechanisms explaining this link remain unclear. The researchers of the current study sought to identify risk factors for dementia in patients with AF that might shed some light on the pathways underlying cognitive impairment in these individuals.
The current analysis included patients with a diagnosis of nonvalvular AF at any point during the study period. Data from the MarketScan commercial claims and encounters database, along with the Medicare supplemental and Coordination of Benefits Database, obtained between January 1, 2007, and September 30, 2015, were used for the current analysis. Once all relevant inclusion and exclusion criteria were applied to the MarketScan cohort, a total of 621,773 patients with AF without dementia at the time of diagnosis were enrolled in the study. Overall, 41% of the participants were women. The mean patient age at diagnosis of AF was 68±14 years.
The incidence of dementia and presence of predictors at time of AF diagnosis (ie, cardiometabolic conditions, mental/neurologic disorders, other chronic conditions) were based on the International Classification of Diseases, Ninth Revision, Clinical Modification codes in outpatient and inpatient claims. All medication usage was based on outpatient pharmacy claims. A previously established algorithm was used to calculate a frailty score. Multivariable Cox models were utilized to evaluate the association between the predictors of interest and dementia.
During a mean follow-up of 2.0 years, a total of 16,073 cases of dementia were diagnosed. The strongest predictors of dementia included frailty (HR, 1.43; 95% CI, 1.40-1.45, per 1–SD increase in the score), cognitive impairment (HR, 1.50; 95% CI, 1.36-1.65), mood disorders (HR , 1.49; 95% CI, 1.32-1.70), schizophrenia (HR, 1.86; 95% CI, 1.75 to 1.98), and substance abuse (HR, 1.58; 95% CI, 1.39-1.80).
Regarding cardiometabolic disorders, only stroke (HR, 1.17; 95% CI, 1.13-1.22) and diabetes (HR, 1.14; 95% CI, 1.11-1.18) were associated with small increases in risk for dementia after adjustments for frailty, demographics, comorbidities, and medications were made.
Study limitations included the fact that since the data used were derived from private insurance and Medicare claims, the results may not be generalizable to uninsured or underinsured populations in the US or to those on Medicaid. Another drawback was the limited follow-up time involved because of the characteristics of the data source.
“These findings highlight the importance of stroke prevention and diabetes control as potential mechanisms for preventing cognitive impairment and dementia in patients with AF and the potential of recognizing mental health conditions and frailty as possible markers for patients with AF at high risk for developing dementia,” the researchers concluded.
Disclosure: One of the study authors has declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of the author’s disclosures.
Alam AB, Lutsey PL, Chen LY, MacLehose RF, Shao IY, Alonso A. Risk factors for dementia in patients with atrial fibrillation. Am J Cardiol. Published online April 23, 2022. doi:10.1016/j.amjcard.2022.03.029