Asian Race Disparities in LVO Stroke Severity, Revascularization, and Outcomes

Introduction: The expanding ischemic Stroke Belt now affects 850,000 Americans annually; although the exact proportion of Large Vessel Occlusions (LVO) is unknown, LVOs often result in particularly adverse outcomes, and endovascular thrombectomy (EVT) enhances these outcomes. Amidst COVID-19's disproportionate effects on minorities, this study explores the genetic and environmental factors behind observed ethnic group based variations in LVO severity at presentation to a large CSC, and the early post-EVT outcomes, aiming to refine care, direct stroke policy, and innovate.

Methods: We conducted a retrospective analysis of two AIS patient databases at Stanford (2015-2022), classifying data by race/ethnicity, LVO confirmation, EVT status, and TICI score. We focused on EVT rates, initial and discharge NIHSS scores. Language-concordant NIHSS assessments were used. Given the absence of mRS90 data, we utilized One-Way-ANOVA or Kruskal-Wallis tests with post-hoc analyses of NIHSS for statistical evaluation.

Results: 714 Anterior LVO patients who presented to Stanford between January 2015 and March 2022 were analyzed. Caucasians (443; 61%), Asians (113; 15.8%), Hispanics (105; 14.7%), and Blacks (53; 7.4%) were represented in even gender distributions. Asian patients had higher initial median and mean NIHSS scores upon admission compared to other groups (e.g., A: 17, C: 14, p=.004), potentially indicating greater average stroke severity via a larger proportion of “severe” strokes in Asian patients vs. a large number of low NIHSS confirmed LVO in Caucasians. Notably, Black and Hispanic patient NIHSS averages were closer to their Caucasian counterparts, (B: 13.5, H: 14.6, p=.004). Despite overall improvements in NIHSS scores by discharge, Asian identifying patients consistently scored higher. Subgroup analysis by imaging, selection for EVT, laterality, and TICI score showed this disparity in Asian patient stroke severity persisted, particularly for left-sided lesions on arrival (A: 18, C: 15, p=.01) without significant differences in a particular group’s EVT selection rates, predilection to a side, or success.

Conclusion : We found significant differences in NIHSS at presentation and discharge for Asian patients in this cohort study. The COVID pandemic did not exacerbate these disparities.