Bijoy Menon MBBS, MD, Abstract Co-Author: Nothing to Disclose

Sharon Yeatts PhD, Abstract Co-Author: Consultant, F. Hoffmann-La Roche Ltd

Sachin Mishra, Abstract Co-Author: Nothing to Disclose

Emmad Qazi, Presenter: Nothing to Disclose

Anurag Trivedi, Abstract Co-Author: Nothing to Disclose

Vivek Nambiar, Abstract Co-Author: Nothing to Disclose

Volker Puetz MD, Abstract Co-Author: Nothing to Disclose

Michael D. Hill MD, Abstract Co-Author: Nothing to Disclose

Lydia Foster, Abstract Co-Author: Nothing to Disclose

Liqiong Fan, Abstract Co-Author: Nothing to Disclose

Pooja Khatri, Abstract Co-Author: Support, Penumbra, Inc Support, F. Hoffmann-La Roche Ltd

Ruediger Von Kummer MD, Abstract Co-Author: Research Consultant, H. Lundbeck A/S Research Consultant, SYNARC Inc Speakers Bureau, Boehringer Ingelheim GmbH Speakers Bureau, Penumbra, Inc Research Consultant, Penumbra, Inc Research Consultant, Covidien AG

David S. Liebeskind, Abstract Co-Author: Consultant, Stryker Corporation Consultant, Covidien AG

Thomas A. Tomsick MD, Abstract Co-Author: Nothing to Disclose

Mayank Goyal MD, FRCPC, Abstract Co-Author: Shareholder, Calgary Scientific, Inc Research Grant, Covidien AG Consultant, Covidien AG Shareholder, NoNO Inc Investigator, Covidien AG

Joseph P. Broderick MD, Abstract Co-Author: Support, F. Hoffmann-La Roche Ltd Support, Merck & Co, Inc Research funded, F. Hoffmann-La Roche Ltd Travel support, Boehringer Ingelheim GmbH

Andrew Demchuk MD, Abstract Co-Author: Nothing to Disclose

In IMS-III trial patients, we evaluate if clot characteristics on baseline non-contrast CT (NCCT) or CT-angio (CTA) determine recanalization with IV-tPA using classification and regression tree analysis (CART). 

IMS-III protocol is published. Two readers assessed clot characteristics on NCCT [hyperdense(HD) sign location, length, ratio of maximal Hounsfield Unit (HU) HDS/contralateral MCA (rHU)] and CTA [Clot burden score, length, residual flow through clot, ratio of contrast HU at proximal/distal clot interface (cirHU)] by consensus. Very early arterial weighted CTAs were excluded; appropriate imputation techniques used whenever distal clot interface was not measured. Early recanalization with IV-tPA was assessed on first angio (only in the endovascular arm) while 24-hour recanalization with IV-tPA was assessed on follow-up CTA (only in the IV-tPA alone arm). 

Of 263 patients with anterior circulation clots on baseline CTA, after excluding patients with missing data, 64 in the IV-tPA and 175 in the endovascular arm were analyzed. CART models for early and 24-hr recanalization with IV-tPA are shown in Figures 1 and 2 respectively. 

Clot characteristics on NCCT and CTA can help physicians estimate a range of early and late recanalization rates with IV-tPA.

Clot characteristics on both NCCT and CTA can help determine the effecay of tPA and should be considered when deciding to treat patients with tPA over endovascular. 

Menon, B, Yeatts, S, Mishra, S, Qazi, E, Trivedi, A, Nambiar, V, Puetz, V, Hill, M, Foster, L, Fan, L, Khatri, P, Von Kummer, R, Liebeskind, D, Tomsick, T, Goyal, M, Broderick, J, Demchuk, A, Clot Characteristics on Baseline Imaging Predicts Recanalization with IV tPA in the IMS III Trial.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14016904.html