Abstract W MP18: Baseline-24h CT ASPECTS Mismatch. A Predictor Variable of Successful Trhrombectomy

Abstract

BACKGROUND: In acute thromboembolic stroke, mechanical recanalization with retrieval stents may result in immediate flow restoration. A selection criteria to treatment is a small volume of infarct in baseline CT scan, usually it is identified as an infarct <1/3 MCA or mild early ischemic changes (ASPECTS>7). We assess whether evaluation of basal and 24h CT using Alberta Stroke Program Early Computed Tomography Score (ASPECTS) have predictive value for functional independence after stroke on noncontrast CT (NCCT). METHODS: We performed an retrospective analysis of 257 consecutive patients treated with thrombectomy (Solitaire, Trevo) , from April of 2010 to June of 2013, that met inclusion criteria for intervention. Vessel patency pre and post procedural were measured by TIMI and TICI score.Successful recanalization (TICI 2b-3), functional and clinical good outcome (mRankin 0-2) and mortality at day 90 and symptomatic hemorrhage were prospectively assessed. We evaluated baseline NCCT, mean final infarct extension measuring by 24h-ASPECTS and change in ASPECTS from baseline to 24h CT. RESULTS: A total of 168 patients with ischemic stroke of the MCA territory (M1 segment or terminal internal carotid occlusion) were included in this study. We calculated ASPECTS mismatch as 24H NCCT ASPECTS/Baseline NCCT ASPECTS*100. Low percentage represents a reduced infarct and an higher efficacy of the neurointerventionism (TICI 2b-3, p:0.001) . Basal and 24h ASPECTS were dichotomized at >=8 vs <8 according with ROC analysis. Higher scores >=8 in NCCT ASPECTS implied a higher probability of an independent functional outcome at 90 days (mRankin 0-2) when compared to <8 ASPECTS group (OR 1.47, 95% CI 1.21-1.83) and likewise in 24h NCCT (OR 1.65, 95% CI 1.35-2.1). The mismatch between basal ASPECTS in NCCT and 24h ASPECTS demonstrated important predictive value (OR 0.54, 95% CI 0.42-0.68) of clinical prognosis (cut-off value <20%, Sensivity 81%, Specificity 72%; AUC 0,74; p:0001), mainly in the group of 24h ASPECTS <8. CONCLUSIONS: The baseline and 24h NCCT ASPECTS were a strong predictor of functional outcome. Moreover lower mismatch between basal and 24h ASPECTS was also reliable as predictive value in good functional outcome.