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

Background: The association between atrial fibrillation (AF) and 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 of cardiovascular disease (CVD) but without diabetes or a history of stroke. Participants with baseline pre-existing clinical dementia, prescribed dementia medications, or missing AF or cognition data were excluded. AF was identified using centrally read electrocardiograms. 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 endpoint of MCI/PDI. Results: A total of 8539 participants (mean age: 67.9 years; 35.1% female) were included in the analysis. Of these, 264 had AF at baseline or during follow-up. Over a median follow-up period of 5 years, 318 PD, 625 MCI, and 849 composite PD or MCI events 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 endpoint of MCI/PDI [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 significantly change these associations. Conclusions: AF is associated with an increased risk of dementia and cognitive impairment in patients with hypertension but not diabetes or stroke. Further research is needed to determine whether AF management strategies can mitigate cognitive decline.