Abstract WMP76: Carotid Revascularization Slows Hemispheric White Matter Disease Progression

Introduction: Carotid revascularization is known to prevent stroke in patients with high-grade carotid stenosis, but whether carotid revascularization may slow the progression of hemispheric WMD in patients with carotid stenosis to prevent cognitive decline have not been well described. Methods: We conducted a longitudinal study involving patients age ≥40 years with carotid stenosis on ultrasound from 2011-2015 with serial brain MRI scans at least 1 year apart followed for radiographic and clinical outcomes to 2020. Severity of carotid stenosis was defined as moderate 50-69%, high-grade 70-99%, or occluded. Hemispheric WMD volume was quantified from axial T2 FLAIR images. Patients were stratified by revascularization status. Primary outcome was change in WMD volume per year ipsilateral or contralateral to the index carotid. Hemispheric differences in the annual rate of WMD progression (cc/yr) were compared between revascularized vs not revascularized using multivariable linear regression analysis adjusted for variables that differed between revascularization status. Results: Of the 150 patients, moderate stenosis was present in 37.3%, high-grade stenosis in 42.0%, and carotid occlusion in 20.7%. Mean age was 71±10 years, 36.7% were female. Seventy-three (48.7%) had carotid revascularization with a median follow-up of 5.1 years. Baseline WMD volume was 4.86cc ipsilateral and 4.39cc contralateral to the index carotid. Patients who underwent revascularization trended to have slower WMD progression in the hemisphere ipsilateral to the index carotid compared to those not revascularized (0.32cc/yr vs 0.63 cc/yr, p=0.340). The same trend was not observed in the contralateral hemisphere. In adjusted models, carotid revascularization was associated with a 0.33 cc per year decrease in WMD progression between hemispheres compared to those not revascularized (β= -0.33, p=0.070). Conclusions: In this study with a median follow-up of 5 years, we found that carotid revascularization resulted in a 50% reduction in the annual rate of WMD progression. Intervention trials should test whether carotid revascularization slows WMD progression in patients with cognitive impairment to prevent further cerebrovascular events and cognitive decline.