Abstract WMP88: Endovascular Therapy For Large Vessel Occlusion Stroke With Low NIH Stroke Scale: A Population-Level Assessment

Abstract

Introduction: There is increasing interest in endovascular therapy (EVT) for patients with large vessel occlusion (LVO) acute ischemic stroke (AIS) presenting with low NIH Stroke Scale. Here, we assess the prevalence of LVO with low NIHSS and real-world trends in utilization of EVT in this population. Methods: We performed a cross-sectional study using the Texas Public Use Data File, which captures all inpatient admissions in the state from non-federal hospitals (10/01/2016-06/30/2020). AIS cases were defined as hospitalizations to acute care hospitals with a primary diagnosis of AIS using ICD-10-CM codes I63.x and NIHSS was determined using ICD-10-CM codes R29.700- R29.742. Low NIHSS was defined as <6 and high NIHSS as ≥ 6. LVO was determined by ICD-10-CM codes and EVT was determined by ICD-10 procedure codes. Comprehensive stroke center (CSC) designation was determined by Texas Department of Health Services published listings. Results: Among 61,524 AIS cases, patients with low NIHSS accounted for 63% and were more likely to be younger, male and white than those with high NIHSS. LVO was twice as prevalent among high NIHSS AIS (52% vs 24% p<0.001) but 44% of LVOs presented with low NIHSS. EVT rates were much lower in low NIHSS LVOs compared to high NIHSS LVOs (4% vs 27%, p<0.001). EVT rates in LVOs increased during the study period (0.4% per quarter, 95% CI 0.3-0.6%, p<0.001), as well in low NIHSS LVOs (0.2% per quarter, 95% CI 0.1-0.3%, p=0.001). These findings, however, were only seen in CSC-certified hospitals, for both high NIHSS LVOs (1.0% per quarter, 95% CI 0.7-1.3%, p<0.001) and low NIHSS LVOs (0.3% per quarter, 95% CI 0.06-0.4%, p=0.010) but not seen in non-CSC hospitals. Conclusions: In this large state-level cohort, nearly one-quarter of low NIHSS patients were found to have LVO, and increasing trends in EVT use were observed in this group. The effectiveness and safety of EVT in low NIHSS LVOs need to be further evaluated in real world clinical settings.