Abstract WP2: Natural History of Large Vessel Occlusion Patients Presenting With Minor Stroke Symptoms

Abstract

Background: Acute ischemic stroke is a leading cause of mortality and disability in the US, with 50% of patients with minor stroke symptoms (MSS). Large vessel occlusion (LVO) is found in 10% of MSS cases and predicts poor neurological outcomes. However, treatment strategies for MSS-LVO lack consensus, and a deeper understanding of the natural history of MSS-LVO is needed. Methods: We screened all patients presenting to a large stroke network, from May 2017 to August 2023, for intracranial anterior circulation LVO and MSS (NIHSS %lt 6). Descriptive statistics were applied to demographic, clinical, radiographic, and neurological outcomes data, including early neurological deterioration (END) (NIHSS gain 3+). Results: Ninety patients participated in the study, averaging 64.5 years old, with 58.8% male, 48.8% white, 22.2% black, and 16.2% Hispanic. Comorbidities included diabetes (23%), hypertension (67.7%), atrial fibrillation (22%), hyperlipidemia (53%), and smoking (40%). Patients arrived with mean 7 hours (SE 1.6) from LKW, and a mean NIHSS 3.95 (SE 0.40). The majority of patients had baseline mRS of 0-2 (92.6%). Occlusion sites included M1 (38.9%), M2 (40%), and ICA terminus (2.2%). The mean ASPECTS score was 9.4 (SE 0.13). Immediate thrombolytic treatment was delivered to 34% of patients. Out of 90 patients, 31 (34%) suffered END, with mean NIHSS at END of 9.17 (SE 0.85), necessitating rescue endovascular thrombectomy (EVT). Collateral vessel failure caused 87.1% of END cases, clot migration 9.7%, and additional strokes 3.2%. Of the 31 EVT cases, 29 (93%) achieved TICI 2b-3, averaging 3.1 (SE 0.35) passes. ICH occurred in 5 patients; 2 had undergone EVT, although none were symptomatic. At 24 hours and 5 days from presentation, the mean NIHSS were 3.15 and 2.86 respectively, worse in END patients (6.16 vs 1.55, p=0.00, and 6.28 vs 1.14, p=0.00). After 30 days, only 66% of END patients had mRS of 0-2 compared to 84% of non-END patients (p=0.02). Similarly, at 90 days, only 65% of END patients, versus 86% of non-END patients, had mRS of 0-2 (p=0.02). Conclusion: The study details the natural history of MSS-LVO, showing a prominent incidence of EVT-requiring END due to collateral failure. Future research should identify high-risk END patients for tailored treatment.