Abstract TP116: Racial Difference in Intracranial Atherosclerotic Plaque Features by High-resolution Vessel Wall MRI

Abstract

Introduction: Intracranial atherosclerotic stenosis (ICAS), the most common cause of stroke worldwide, is more prevalent in non-white populations including Asian, African-American and Hispanic individuals. We studied the racial difference (white vs non-white) in the plaque features of stroke patients with ICAS using vessel wall MRI (VWMRI). Methods: We retrospectively included stroke patients with etiology being intracranial atherosclerosis who received VWMRI. VWMRI was read by experienced neuroradiologists blinded to other clinic information. Culprit plaque was defined as a plaque in a relevant vessel responsible for the downstream ischemic lesion. In addition to plaque number and degree of the stenosis, other plaques features were analyzed, including degree of plaque enhancement(minimal, moderate and strong), plaque calcification and eccentricity. The association between race, cardiovascular risk factors and plaque features was tested in multivariable models. Results: In 64 stroke patients (mean age 55.6±13.4 y, 62.5% male, 43.8% non-whites), the median number of plaque was 3 (range 0-11). Compared with whites, non-whites have a higher number of plaques (median, 4 vs 3, p=0.029). Smoking was associated with presence of extensive plaque (defined as ≥3 plaques) and remained significant after adjustment for other risks factors (non-white race, hypertension, age≥55 and HbA1C≥6.5; adjusted OR 6.9, 95% CI 1.27-37.66). For culprit plaques, presence of ≥50% stenosis, strong plaque enhancement, eccentric pattern and calcification did not differ by race. LDL >100 mg/dl, history of hyperlipidemia and eGFR<60 mL/min/1.73 m 2 were each associated with presence of strong plaque enhancement, eccentric pattern and calcification respectively (OR 1.5, 95% CI 1.5-19.6; OR 9.9, 95% CI 1.1-85.6; OR 24, 95% CI 2.3-247.4; respectively). Conclusion: A higher number of intracranial atherosclerotic plaques was revealed by VWMRI in non-white stroke patients with stroke etiology being intracranial atherosclerosis, while the features of their culprit plaque were similar compared with white patients. History of smoking was significantly associated with presence of ≥3 plaques. Studies with larger sample size are needed to validate the above findings.