Population-based Ethnoracial Disparity in Life's Essential 8 Vascular Health, Cerebral Small Vessel Disease & Cognition

Background: Whether ethnoracial differences in cerebral small vessel disease (cSVD) appear in multimarker burden, particular MRI manifestations, or both, and how they relate to Life's Essential 8 (LE8) cardiovascular health and cognition, remain unclear. Methods: This cross-sectional study included 44,982 participants and an age- and sex-matched subsample of 1,426 with reviewed lacune and cerebral microbleed (CMB) ratings. White, South Asian, Black, Chinese and Mixed participants were compared on 0-2 (white matter hyperintensity [WMH]/enlarged perivascular space [ePVS]) and 0-4 (adding CMB and lacunes) composite scores and each marker. LE8 was related to WMH and composite burden, and cognitive means were compared by group. Models were age-, sex- and center-adjusted with false-discovery-rate correction. Results: Both composite scores differed across groups (0-2: P=0.00010; 0-4: P=0.0011), with greater burden in Black than South Asian (0-4: OR 1.66; 95% CI, 1.21-2.28) and Chinese participants (OR 2.36; 1.51-3.70), whereas Black-White contrasts were not detected. Black participants had higher WMH volume than White participants (=0.209; 0.110-0.308), robust to deprivation adjustment and segmentation method; South Asian participants had fewer ePVS (0.82; 0.72-0.93). No ethnoracial-group differences in lacune or CMB counts were detected after correction. Higher LE8 was associated with lower WMH volume (0.13 per SD; 0.17 to 0.09) and lower two-marker burden (OR 0.89 per SD; 0.87-0.91) without detected ethnoracial moderation. Black participants, who had the least favorable LE8 scores, and South Asian participants had lower global cognition than White participants (z 0.76 and 0.57 versus 0.24) despite differing WMH profiles; the pooled WMH-cognition association was null. Conclusions: Ethnoracial differences in multimarker cSVD burden were evident but marker-dependent: WMH showed the clearest Black-White difference; focal-lesion contrasts were inconclusive. Better cardiovascular health related to lower WMH and aggregate cSVD burden across groups, whereas cognitive differences did not track cSVD burden, supporting prospective prevention and cognition studies.