Abstract TP21: Consequences of Atrial Fibrillation Burden on Deep Cerebral Hemodynamic Related Structural Brain Damage

Abstract

Background: Recent data using ultrahigh-resolution brain MRI suggests that atrial fibrillation (AF) has adverse effects on wall shear stress and blood flow in lenticulostriate arteries (LSA). The structural consequences of such pathophysiological alterations and whether they contribute to cognitive impairment in AF are not known. We hypothesized that the AF burden is associated with the severity of MRI markers of ischemic and hemorrhagic injury related to LSA disease. Methods: We analyzed data from 560 patients with AF and no clinical history of stroke or neurodegenerative disease, who received brain MRIs at a tertiary referral center. Neuroimaging data were collected by a stroke neurologist who was blinded to the clinical data. The presence of paroxysmal/persistent vs permanent AF was the main measure of AF burden. The imaging outcome variables were counts of deep lacunes, deep cerebral microbleeds (dCMB), and presence of a peri-basal ganglia white matter hyperintensity pattern (peri-BG WMH). Results: The mean age of the 560 AF patients was 73 + 11 and 212 (38%) patients were female. Mean CHA 2 DS 2 -VASc was 3.4 + 1.5 and 86 (15.4%) had permanent atrial fibrillation. Deep lacunes were found in 26.6%, dCMBs in 6.3% and a peri-BG WMH pattern in 2.7% of patients. In univariate analyses, the presence of permanent AF was associated with higher mean deep lacune counts (0.84 vs 0.51, p=0.026), higher mean dCMB counts (0.25 vs 0.1, p=0.018), and peri-BG WMH pattern (7.1% vs 1.9%, p=0.016) when compared to paroxysmal/persistent AF. In separate multivariable analyses, permanent AF type remained an independent predictor of dCMBs (p=0.019) and peri-BG WMH pattern (p=0.028) after controlling for age, sex, and vascular risk factors. Permanent AF also showed a tendency for independent association with deep lacunes (p=0.06) in a similar model. Discussion: Our results show that AF burden independently correlates with parenchymal MRI markers of LSA disease in patients without history of stroke. Such deep brain damage might contribute to AF-induced cognitive changes. The effects of better rhythm control on visible brain damage and cognitive changes should be studied in randomized trials.