Abstract W P18: Evaluating Clot Burden and the Vascular Basis of Pial Collaterals with a Bimodal Angiographic Score
Treatment decision for endovascular recanalization in acute ischemic stroke is based on validated outcome predictors such as age, initial infarct size, collaterals and clot burden. The CTA-based Clot Burden Score (CBS) only considers occlusions of the A1-segment of the anterior cerebral artery (ACA), but patency of the ipsilateral A2-segment is mandatory for collateral formation in a typical middle cerebral artery (MCA) occlusion. Secondly, CTA often cannot differentiate between an extra- or intra-cranial internal carotid artery (ICA) occlusion due to non-contrasting of the whole ICA in both. Thirdly, a 4-vessel angiogram, necessary to grasp the vascular basis of all pial collaterals, is often not done during acute recanalization therapy for reasons of time. To bypass these inadequacies, we propose a combined CTA/DSA score (ALITA) to assess pre-therapeutic thrombus load. We hypothesized a good outcome prediction of this score. We evaluated the ALITA score in a retrospective study including consecutive patients of the years 2010-12, who received endovascular therapy for acute stroke in the ICA-territory. Final outcome was measured with the modified Rankin Scale score (mRS) at 90 days. Reperfusion (mTICI), collaterals (CT-CS), clot burden (CBS), and the ALITA score were independently assessed. ALITA evaluates patency of the ACA and MCA in CTA and of the ICA in DSA. Data-driven ordinal regression analysis modeled outcome prediction of all scores. Of 99 patients 60% had a good reperfusion (mTICI 2b/3) and 29% had a good outcome (mRS 0-2), mortality was 23%. Age and reperfusion were independent predictors of good outcome (p<.001). CT-CS (p<.01), CBS (p<.01) and ALITA (p<.05) were significant predictors, but showed interaction regarding outcome. In the considered model CBS was a stronger predictor than ALITA. Although ALITA assesses all vessels of the anterior circulation contributing to collaterals the score was statistically different from CT-CS. This is consistent with results that describe pial collaterals as genetically determined. In conclusion, the combined CTA/DSA clot burden score better depicts the vascular basis of pial collaterals and predicts outcome in acute stroke patients.
Author Disclosures: J. Gerber: None. M. Kuhn: None. M. Petrova: None. V. Puetz: None. R. von Kummer: None.
- © 2015 by American Heart Association, Inc.