Abstract DP234: The Effects of Atrial Fibrillation Burden on the Severity of Hypertensive Cerebral Small Vessel Disease and Its Effect on Cognitive Impairment

Background: Atrial fibrillation (AF) has been associated with clinical stroke, cognitive decline, and decreased brain perfusion. The effect of AF on cerebral small vessel disease (cSVD) is unknown. Hypothesis: We hypothesized that AF burden is associated with hypertensive cSVD, but not lobar cSVD, given that the lenticulostriate arteries involved in hypertensive cSVD are anatomically more vulnerable to AF-related perfusion fluctuations due to their length, narrow caliber, and perpendicular branching. Methods: We conducted a retrospective analysis of 706 consecutive patients with AF who underwent brain MRI with appropriate sequences between 2015 and 2022. We excluded patients with prior stroke, transient ischemic attack, or neurodegenerative disorders. Hypertensive cSVD was assessed using the Staals SVD score (0-4), while lobar cSVD was assessed using imaging markers from the Boston criteria as a surrogate for cerebral amyloid angiopathy (CAA)-related lesion burden (0-4, Table 1). AF burden was categorized based on the AF pattern (Table 2). Multivariable ordinal regression models were constructed with relevant covariates, based on univariate ordinal regression analysis for each score. Multivariable binary logistic regression was used to assess the association of cSVD patterns and AF burden category with the presence of mild cognitive impairment (MCI) or dementia. Results: The study included 706 patients with a mean age of 72 ± 11 years; 263 (37.3%) were female; 129 (18.3%) had higher burden AF; the median HTN-cSVD score was 0 (IQR: 0-1), and CAA score was 1 (IQR: 0-1); 105 (14.9%) had MCI or dementia. In multivariable ordinal regression analysis, higher AF burden was independently associated with HTN-cSVD score (p = 0.002), but not with CAA score (p = 0.564). In a separate multivariable model, HTN-cSVD score (p = 0.007), higher AF burden (p < 0.001), and age (p < 0.001) were independently associated with MCI or dementia. Conclusions: In this study, we demonstrate that higher AF burden is associated with hypertensive cSVD, but not with CAA-related brain lesion load. Furthermore, both AF burden and a composite score reflecting hypertensive cSVD burden are independently associated with cognitive impairment. These findings support the importance of approaches aimed at reducing both AF burden and hypertensive cSVD to prevent dementia among AF patients.