Abstract 101: Predictors of Early Neurological Deterioration in Minor Strokes With Large Vessel Occlusion Treated With Intravenous Thrombolysis. A French Multicentric Observational Study (MINOR-STROKE)

Abstract

Introduction: Whether thrombectomy added on intravenous thrombolysis (IVT), as compared to IVT alone, is beneficial in minor strokes with large vessel occlusion (LVO) is unknown. To identify predictors of early neurological deterioration (END) following IVT alone may help to select the best candidates for additional thrombectomy. Methods: MINOR-STROKE was a multicentric retrospective registry collecting data of IVT-treated minor strokes (NIHSS≤5) with LVO (internal carotid artery [ICA], M1, M2 or basilar artery; with central reading) treated with or without additional thrombectomy in 45 French stroke units. The patients initially intended for IVT alone, including those who eventually received thrombectomy due to END, were included in the present analysis. END was defined as a ≥4 points on NIHSS within 24hrs following admission. Thrombus length was measured centrally either on T2*-MRI, CT (hyperdense middle cerebral artery) or CT-angiography. Results: Overall, 799 patients were included: mean age 69 years, median NIHSS 3, occlusion located in ICA±M1/M2, proximal M1, distal M1, M2, or basilar artery in 20%, 7%, 19%, 50% and 4% of patients, respectively. Thrombus was visible in 78% of patients (median length 9mm, IQR 6-12mm). END occurred in 15% of patients and was associated with poor 3-month functional outcome (mRS>2: 55% vs. 12% of patients with and without END, respectively). Only 15% of ENDs were due to intracranial haemorrhage. In multivariable analysis, a more proximal occlusion site (M2 [reference], distal M1: OR 2.1 [IC95% 1.1-4.1], proximal M1: OR 3.8 [1.6-9.1], ICA±M1/M2: OR 5.0 [2.6-9.6], basilar artery: OR 4.9 [1.1-4.1]; P <0.001) and a longer thrombus (<6mm [reference], [6-9mm[: OR 1.3 [IC95% 0.6-2.9], [9-12mm[: OR 1.8 [0.8-3.9] and ≥12mm: OR 2.7 [1.3-5.6]; P =0.036) were independently associated with END. END occurred in 33%, 19%, 14%, 7% and 27% of patients with ICA±M1/M2, M1 proximal, M1 distal, M2 and basilar artery, respectively, and in 8%, 10%, 14% et 23% of patients with thrombus length of <6, [6-9[, [9-12[ and ≥12mm, respectively. Conclusion: Our study suggests that thrombus location and length are strong predictors of END in minor strokes with LVO. This may help to select the best candidates for additional endovascular therapy.