Abstract 1122‐000198: Failure of Tenecteplase in Maintaining Collateral Circulation in Large Vessel Occlusion Strokes.

Abstract

Introduction : Acute administration of alteplase with collateral patency has been systematically evaluated in acute ischemic stroke (AIS) patients. Large studies evaluating alteplase demonstrate a significant association of successful recanalization (TICI score) and good clinical outcome (mRS) with ASITN/SIR collateral grade greater than 2. However there is paucity of data looking at the association between IV tenecteplase (TNK) and acute collateralization. Our objective was to investigate early TNK use association for the degree of collateralization in subjects with AIS secondary to large vessel occlusion (LVO). Methods : Collateralization was assessed on digital subtraction angiography using the American Society of Intervention and Therapeutic Neuroradiology/Society of Interventional Radiology (ASTIN/SIR) scale. Grades were defined by the following: 0 no collaterals to ischemic region; 1 slow collaterals peripherally; 2 rapid collaterals peripherally; 3 slow collaterals within ischemic region; 4 complete retrograde perfusion to ischemic region. Subjects with LVO undergoing mechanical thrombectomy status post TNK as part of the pilot early clinical use of TNK within 4.5 hours of last known well were assigned a grade. Mean ASITN/SIR collateral grade was determined. Spearman’s rho was used to measure association of collateral grade with thrombolysis in cerebral infarction (TICI) score. Patients with TNK‐associated recanalization at time of cerebral angiogram were excluded from study. Social Science Statistics was used for data analysis. Results : From October 2020 to April 2021, 16 subjects (6 females; age, 63.25 95% CI [54.9207, 71.5793]) received TNK and underwent mechanical thrombectomy. From those subjects, 25 % (n = 4) had IV TNK‐associated recanalization with normalization of collateral blood flow and were excluded. Of the rest (n = 12, 75%) had a mean ASITN/SIR collateral grade of 1.08 (95% CI [0.5762, 1.5838]). Association between collateral grade and final TICI score was not statistically significant (rs = ‐0.33576, p = 0.28598) suggesting inability of TNK to result in/maintain a robust collateral flow. Conclusions : Poor correlation of collateral grade and final TICI score may have implications of faster progression in patients with ischemic stroke receiving TNK in the setting of LVO if immediate recanalization is not achieved. Larger prospective studies are needed to evaluate the effect of TNK on collateralization when compared to Alteplase.