E-057 Clot perviousness but not density is associated with first-pass recanalization of aspiration thrombectomy in the compass trial

Background Imaging clot characteristics such as clot density and perviousness (the latter is defined as a difference in regional clot density values between computed tomography angiography (CTA) and non-contrast CT [NCCT]), can be used as an imaging marker characterizing red blood cell and fibrin composition of the clot serving. We aimed to examine whether clot density and perviousness were associated with angiographic outcomes of aspiration and stent retriever thrombectomy in the COMPASS Trial: a Direct Aspiration First Pass Technique trial. Methods Clot density (Hounsfield units, HU) and perviousness were measured by two operators who were blind to all the final angiographic and clinical outcomes except for the knowledge of stroke laterality. NCCT and CTA images were co-registered to accurately localize clot on both imaging modalities. The values were then matched with angiographic and clinical outcome data of the first pass for each randomization arm. Univariate and multivariate analysis was carried out to assess the association of clot density and perviousness using SPSS version 25. Results Of the original 270 patients included in the COMPASS trial, 165 were eligible for the post-hoc analysis (81 patients in the aspiration first and 84 in the stent retriever first groups). There was no difference between the groups in regards to gender distribution, age, laterality and side of large vessel occlusion, smoking status of patients, and comorbidities. There was also no difference between the aspiration and stent retriever first randomization groups in regards to baseline clot Hounsfield units (HU) on NCCT (49.9 ±8.2 vs. 47.8 ±8.7, P=0.11), and perviousness (26.84 ±21.8 vs. 22.8 ±19.9, P=0.20). For the aspiration first group, there was a difference in mean perviousness values among patients who achieved TICI 2c-3 vs. TICI 2b vs. TICI 0–2a (33.1 ±26, 35.9 ±25.1, and 19.0 ±14.2, respectively; P=0.016). There was no difference between clot HU density on NCCT among these 3 groups (48.8 ±8.5, 50.1 ±7.2, and 51.0 ±8.4, P=0.56). In the stent retriever first group, there was no difference in perviousness or HU density of clot in patients with TICI 2c/3, TICI 2b or TICI 0–2a after first pass (perviousness 21.6 ±17.0, 22.4 ±18.04 and 22.6 ±22.9, P=0.97; HU on NCCT 48.7 ±9.1, 49.7 ±6.5 and 46.7 ±9.0, P=0.47).In multivariate analysis using a model that included use of intravenous tPA, balloon guide catheter use, onset to groin puncture and age, perviousness of more than 10 was the only independent factor predictive of successful recanalization (defined as TICI 2b-3) after first pass in the aspiration first group with odds ratio of 3.4 (95% CI 1.0 -12.0). We did not find any significant predictors of successful reperfusion (TICI 2b-3) after first pass in the stent retriever first group. Conclusions Clot perviousness values are associated with first pass angiographic success in patients treated with the aspiration first approach for thrombectomy. Additional research is needed to determine if clot perviousness may be used to identify patients who are more likely to have successful recanalization with aspiration when deciding between aspiration versus stent retriever first approaches. Disclosures M. Mokin: 1; C; NIH R21NS109575. 2; C; Medtronic, Canon medical, Cerenovus. 4; C; Serenity medical, Synchron, VICIS, Endostream. M. Waqas: None. J. Fifi: 1; C; Stryker, Penumbra, Microvention. 4; C; Cerebrotech, The Stroke Project. R. De Leacy: 1; C; Penumbra. 6; C; Cerenovus, Siemens. D. Fiorella: 1; C; Penumbra, Cerenovus, Stryker. 6; C; Genentech, Shape Memory Medical. E. Gu: None. E. Levy: 6; C; Penumbra, NextGen Biologics, Rapid Medical, Cognition Medical, Three Rivers Medical, Stryker, MedX, Endostream Medical. K. Snyder: 6; C; Penumbra, Canon Medical Systems, Medtronic, Jacobs Institute; and other from Neurovascular Diagnostics. R. Hanel: 6; C; Penumbra, Endostream, Cerebrotech, Synchron, InNeuroCo, Medtronic, Microvention, Stryker, Cerenovus; Elum, Three Rivers. A. Aghaebrahim: None. K. Woodward: 6; C; Penumbra. H. Hixson: 6; C; Penumbra. M. Chaudry: 6; C; Penumbra, Pulsar Vascular, Medtronic, Microvention, Codman, Blockade. A. Spiotta: 6; C; Penumbra, Pulsar Vascular, Stryker, Microvention. A. Rai: 6; C; Penumbra, Microvention, Stryker. D. Frei: 6; C; Penumbra, Cerenovus, Stryker, Genentech, Shape Memory Medical, Siemens. J. Delgado Almandoz: 6; C; Penumbra, Medtronic. M. Kelly: 6; C; Penumbra, Medtronic, Endostream. A. Arthur: 6; C; Penumbra. B. Baxter: 6; C; Penumbra, Medtronic, Stryker, Viz, and 880 Medical. J. English: 6; C; Penumbra, Medtronic, Stryker, Route 92 Medical. I. Linfante: 6; C; Penumbra, Medtronic, Stryker, Microvention, InNeuroCo, andThree Rivers. K. Fargen: 6; C; Penumbra and Cerebrotech. A. Turk III: 6; C; Penumbra, Pulsar Vascular, Codman, Microvention, Medtronic, Blockade. A. Siddiqui: 6; C; Amnis Therapeutics, Serenity Medical, Silk Road Medical, Rebound Therapeutics, Penumbra Medtronic, Three Rivers Medical, Microvention, Imperative Care, Cerenovus, Endostream Medical, StimMed, Claret M. J. Mocco: 6; C; Penumbra, Cerebrotech, Rebound Therapeutics, TSP, Lazarus Effect, Medina, Pulsar Vascular, Blockade.