title: Early reperfusion rates with IV tPA are determined by CTA clot characteristics.
abstract: OBJECTIVE
  An ability to predict early reperfusion with IV tPA in patients with acute ischemic stroke and intracranial clots can help clinicians decide if additional intra-arterial therapy is needed or not. We explored the association between novel clot characteristics on baseline CTA and early reperfusion with IV tPA in patients with acute ischemic stroke by using classification and regression tree analysis.
  
  
  METHODS
  Data are from patients with acute ischemic stroke and proximal anterior circulation occlusions from the Calgary CTA data base (2003-2012) and the Keimyung Stroke Registry (2005-2009). Patients receiving IV tPA followed by intra-arterial therapy were included. Clot location, length, residual flow within the clot, ratio of contrast Hounsfield units pre- and postclot, and the M1 segment origin to the proximal clot interface distance were assessed on baseline CTA. Early reperfusion (TICI 2a and above) with IV tPA was assessed on the first angiogram.
  
  
  RESULTS
  Two hundred twenty-eight patients (50.4% men; median age, 69 years; median baseline NIHSS score, 17) fulfilled the inclusion criteria. Median symptom onset to IV tPA time was 120 minutes (interquartile range = 70 minutes); median IV tPA to first angiography time was 70.5 minutes (interquartile range = 62 minutes). Patients with residual flow within the clot were 5 times more likely to reperfuse than those without it. Patients with residual flow and a shorter clot length (≤15 mm) were most likely to reperfuse (70.6%). Patients with clots in the M1 MCA without residual flow reperfused more if clots were distal and had a clot interface ratio in Hounsfield units of <2 (36.8%). Patients with proximal M1 clots without residual flow reperfused 8% of the time. Carotid-T/-L occlusions rarely reperfused (1.7%). Interrater reliability for these clot characteristics was good.
  
  
  CONCLUSIONS
  Our study shows that clot characteristics on CTA help physicians estimate a range of early reperfusion rates with IV tPA.
authors: From the Departments of Clinical Neurosciences (S.M.M., T.T.S., A.T., M.A., E.Q., M.E., M.G., A.M.D., B.K.M.).
authors: S M
authors: SM
authors: Mishra
authors: Radiology (J.D., M.A., M.E., M.G., A.M.D., B.K.M.).
authors: J
authors: J
authors: Dykeman
authors: From the Departments of Clinical Neurosciences (S.M.M., T.T.S., A.T., M.A., E.Q., M.E., M.G., A.M.D., B.K.M.) Community Health Sciences (T.T.S., B.K.M.), University of Calgary, Calgary, Alberta, Canada Hotchkiss Brain Institute (T.T.S., M.G., A.M.D., B.K.M.), Calgary, Alberta, Canada.
authors: T T
authors: TT
authors: Sajobi
authors: From the Departments of Clinical Neurosciences (S.M.M., T.T.S., A.T., M.A., E.Q., M.E., M.G., A.M.D., B.K.M.).
authors: A
authors: A
authors: Trivedi
authors: From the Departments of Clinical Neurosciences (S.M.M., T.T.S., A.T., M.A., E.Q., M.E., M.G., A.M.D., B.K.M.) Radiology (J.D., M.A., M.E., M.G., A.M.D., B.K.M.) Faculty of Medicine (M.A.), King Abdulaziz University, Jeddah, Saudi Arabia Seaman Family MR Center (M.A., E.Q., M.E., M.G., A.M.D., B.K.M.), Calgary, Alberta, Canada.
authors: M
authors: M
authors: Almekhlafi
authors: Department of Neurology (S.I.S.), Dongsan Medical Center, Keimyung University, Daegu, South Korea.
authors: S I
authors: SI
authors: Sohn
authors: Department of Neurology (S.B.), University of Manitoba, Winnipeg, Manitoba, Canada.
authors: S
authors: S
authors: Bal
authors: From the Departments of Clinical Neurosciences (S.M.M., T.T.S., A.T., M.A., E.Q., M.E., M.G., A.M.D., B.K.M.) Seaman Family MR Center (M.A., E.Q., M.E., M.G., A.M.D., B.K.M.), Calgary, Alberta, Canada.
authors: E
authors: E
authors: Qazi
authors: Department of Neurology (A.C.), Hospital Clinico Universitario, University of Valladolid, Valladolid, Spain.
authors: A
authors: A
authors: Calleja
authors: From the Departments of Clinical Neurosciences (S.M.M., T.T.S., A.T., M.A., E.Q., M.E., M.G., A.M.D., B.K.M.) Radiology (J.D., M.A., M.E., M.G., A.M.D., B.K.M.) Seaman Family MR Center (M.A., E.Q., M.E., M.G., A.M.D., B.K.M.), Calgary, Alberta, Canada.
authors: M
authors: M
authors: Eesa
authors: From the Departments of Clinical Neurosciences (S.M.M., T.T.S., A.T., M.A., E.Q., M.E., M.G., A.M.D., B.K.M.) Radiology (J.D., M.A., M.E., M.G., A.M.D., B.K.M.) Seaman Family MR Center (M.A., E.Q., M.E., M.G., A.M.D., B.K.M.), Calgary, Alberta, Canada Hotchkiss Brain Institute (T.T.S., M.G., A.M.D., B.K.M.), Calgary, Alberta, Canada.
authors: M
authors: M
authors: Goyal
authors: From the Departments of Clinical Neurosciences (S.M.M., T.T.S., A.T., M.A., E.Q., M.E., M.G., A.M.D., B.K.M.) Radiology (J.D., M.A., M.E., M.G., A.M.D., B.K.M.) Seaman Family MR Center (M.A., E.Q., M.E., M.G., A.M.D., B.K.M.), Calgary, Alberta, Canada Hotchkiss Brain Institute (T.T.S., M.G., A.M.D., B.K.M.), Calgary, Alberta, Canada.
authors: A M
authors: AM
authors: Demchuk
authors: From the Departments of Clinical Neurosciences (S.M.M., T.T.S., A.T., M.A., E.Q., M.E., M.G., A.M.D., B.K.M.) Radiology (J.D., M.A., M.E., M.G., A.M.D., B.K.M.) Community Health Sciences (T.T.S., B.K.M.), University of Calgary, Calgary, Alberta, Canada Seaman Family MR Center (M.A., E.Q., M.E., M.G., A.M.D., B.K.M.), Calgary, Alberta, Canada Hotchkiss Brain Institute (T.T.S., M.G., A.M.D., B.K.M.), Calgary, Alberta, Canada. docbijoymenon@gmail.com.
authors: B K
authors: BK
authors: Menon
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000000981:diagnostic imaging / Q000188:drug therapy; D002533:Cerebral Angiography; D005260:Female; D005343:Fibrinolytic Agents / Q000008:administration & dosage*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D020767:Intracranial Thrombosis / Q000000981:diagnostic imaging* / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D015424:Reperfusion / Q000379:methods*; D015203:Reproducibility of Results; D015912:Thrombolytic Therapy; D013997:Time Factors; D010959:Tissue Plasminogen Activator / Q000008:administration & dosage*
chemical_list: D005343:Fibrinolytic Agents; D010959:Tissue Plasminogen Activator