Abstract 3: Collaterals, Not Clots! CT Angiography Predictors of Recanalization, Reperfusion and Clinical Outcomes After Thrombectomy in Pooled Analyses of TREVO EU and TREVO2
Background: CTA is often used to define clot location prior to endovascular therapy yet systematic evaluation may reveal many details about underlying pathophysiology. We tested a battery of CTA measures to identify optimal predictors of response to thrombectomy.
Methods: CTA datasets of anterior circulation strokes in TREVO EU and TREVO2 with available source images were reconstructed into 3D-curved and 2D-orthogonal maximum-intensity projections by the core lab. Occlusion site, clot length and volume, clot burden score (CBS) and regional leptomeningeal collateral score (rLMC) were scored on CTA. Hyperdense vessels, Hounsfield Unit (HU) indices and location of hyperdensity relative to CTA occlusion site were noted on noncontrast CT.
Results: 111 cases (mean age 68.0 ± 13.8 years; 58.6% women; median baseline NIHSS 18 (8-28)) were analyzed. CTA occlusions were 68.5% M1, 22.5% M2, and 9.0% ICA. CTA clot volumes were mean 49.3 ± 36.3 mm3 with mean CBS 6.7 ± 1.8 and mean rLMC 15.3 ± 4.2. Noncontrast hyperdensity was noted at M1 in 44.1%, M2 in 27.0%, and ICA 8.1%, with ipsilateral:contralateral HU indices of mean 1.3 ± 0.2. Noncontrast CT hyperdensity relative to CTA opacification revealed hyperdensity proximal to occlusions in 2.7%, just past occlusion in 55.0%, and distal to clot end in 6.2%. Only better collaterals on rLMC predicted AOL 2-3 recanalization (OR 1.26, p=0.058) in multivariate analyses and distal hyperdensity (OR 0.11, p=0.037) predicted worse recanalization. Similarly, only rLMC predicted TICI 2b-3 reperfusion (OR 1.27, p=0.004) and distal hyperdensity (OR 0.12, p=0.071) predicted worse reperfusion. Clots (CBS) and collaterals (rLMC) were moderately correlated with each other (0.44 Spearman) in multivariate models of good clinical outcome (mRS 0-2) at day 90, yet clots were significant only when removing collaterals.
Conclusions: Collaterals, not clots, are the best CTA predictors of outcomes after thrombectomy. Worse outcomes with hyperdensity distal to clots on CTA likely reflect stasis due to poor retrograde collaterals.
Author Disclosures: D.S. Liebeskind: Research Grant; Significant; NIH/NINDS K24NS072272. Consultant/Advisory Board; Modest; Stryker, Covidien. N. Sanossian: Consultant/Advisory Board; Modest; Stryker. F. Scalzo: None. B. Xiang: Consultant/Advisory Board; Modest; Stryker. M.S. Johnson: None. R. Gupta: Consultant/Advisory Board; Modest; Covidien, Rapid Medical, Stryker. T.G. Jovin: Ownership Interest; Modest; Silk Road Medical. Consultant/Advisory Board; Modest; Stryker, Covidien. G.W. Albers: None. H.L. Lutsep: Consultant/Advisory Board; Modest; Stryker Neurovascular, Co-Axia. W.S. Smith: Consultant/Advisory Board; Modest; Stryker. M. Killer-Oberpfalzer: None. J.M. Macho: Consultant/Advisory Board; Modest; Stryker, Covidien. O. Jansen: None. N. Wahlgren: None. R.G. Nogueira: Consultant/Advisory Board; Modest; Stryker, Covidien, Reverse Medical.
- © 2014 by American Heart Association, Inc.