Association of Atrial Fibrillation with Incident Probable Dementia and Cognitive Impairment in the Systolic Blood Pressure Intervention Trial (SPRINT)

Background: The association of atrial fibrillation (AF) with dementia and cognitive decline in individuals with hypertension is not well established. Methods: The Systolic Blood Pressure Intervention Trial (SPRINT) enrolled participants with hypertension at high risk for cardiovascular disease (CVD) but without diabetes or a history of stroke. Participants with baseline pre-existing clinical dementia, prescribed dementia medications, or with missing AF or cognition data were excluded. AF was identified through electrocardiograms read centrally. Mild cognitive impairment (MCI), and probable dementia (PD) were determined during follow-up by an adjudication committee. Multivariable Cox proportional hazards regression models were employed to assess the association of time-dependent AF with MCI, PD, and a composite of both, separately. Results: A total of 8,539 participants (mean age: 67.9 years; 35.1% female) were included in the analysis. Out of those, 264 had AF at baseline or during follow-up. Over a median follow-up period of 5 years, 318 PD, 625 MCI, and 849 a composite of either PD or MCI occurred. In models adjusted for treatment assignment, baseline sociodemographics, CVD risk factors, and potential confounders, time-dependent AF was associated with incident PD, MCI, and a composite of both [HR (95% CI): 1.84 (1.09, 3.13), 1.59 (1.01, 2.53) and 1.63 (1.12, 2.38), respectively]. Further adjustment for incident stroke did not materially change these associations. Conclusion: AF is associated with an increased risk of dementia and cognitive impairment in patients with hypertension but no diabetes or stroke. Further research is needed to determine whether AF management strategies can mitigate cognitive decline.