CT Angiography in an Acute Stroke Protocol: Correlation between Occlusion Site and Outcome of Intravenous Thrombolysis

Abstract

Thrombolysis with intravenous rt-PA is the current therapy for acute ischemic stroke. Unlike other outcome factors, relatively little is known about the prognostic value of the occlusion site on treatment outcome. We compared the effectiveness and safety of intravenous thrombolysis in patients with different levels of occlusion identified by CT angiography (CTA) in anterior circulation stroke, and analyzed the influence of the occlusion site on treatment outcome in relation to other outcome factors.

We selected 71 patients from a stroke database collected between June 2007 and December 2011 at our hospital. All of the studied patients had anterior circulation stroke with intracranial occlusion detected by CTA and were treated with intravenous rt-PA. They were divided into two groups according to the site of occlusion along the middle cerebral artery course: proximal (carotid “T”, complete M1 and mild M1 occlusions) and distal (M2/M3 occlusions). Treatment effectiveness was assessed by modified Rankin Scale (mRS) at three months, considering a positive outcome a mRS value ≤ 2. Treatment safety was assessed by evaluating the rate of hemorrhagic complications seen on unenhanced CT at 24 hours. Binary logistic regression was performed to evaluate the interaction between occlusion site and other variables such as sex, age, ASPECT score on admission and baseline NIHSS value in determining treatment outcome.

The degree of effectiveness and safety differed when considering patients with proximal and distal occlusions. The percentage of successfully treated cases was 28.6% in the first group compared to 72% in the second, and the rate of hemorrhagic complications was 28.6% and 6% respectively. After adjustment for sex, age, ASPECT score on admission and baseline NIHSS value, occlusion site was the only variable significantly influencing treatment safety and, together with baseline NIHSS value, the only valid predictor of treatment effectiveness.

We demonstrated a correlation between the site of arterial occlusion and outcome of intravenous thrombolysis. By helping the choice of the best therapeutic strategy depending on the identified occlusion site, CTA could be usefully added to the examinations included in the Stroke Protocol for the baseline evaluation of patients with suspected acute stroke.

Keywords

head and neck CT-angiography stroke thrombolysis occlusion site

Get full access to this article

View all access options for this article.

References

Mori

Yoneda

Tabuchi

. Intravenous recombinant tissue plasminogen activator in acute carotid artery territory stroke. Neurology 1992; 42: 976–982.

Haley

Jr Brott

Sheppard

. Pilot randomized trial of tissue plasminogen activator in acute ischemic stroke. The TPA Bridging Study Group. Stroke. 1993; 24: 1000–1004.

The National Institute of Neurological Disorders and Stroke rtPA Stroke Study Group. Tissue Plasminogen Activator for acute ichemic stroke. N Engl J Med. 1995; 333: 1581–1587.

Hacke

Kaste

Fieschi

. The European Cooperative Acute Stroke Study (ECASS) Intravenous thrombolysis with recombinant tissue plasminogen activator for acute hemispheric stroke. JAMA. 1995; 274 (13): 1017–1025.

The NINDS t-PA Stroke Study Group. Intracerebral hemorrhage after intravenous t-PA therapy for ischemic stroke. Stroke. 1997; 28 (11): 2109–2118.

Brott

Haley

Jr Levy

. Urgent therapy for stroke. I. Pilot study of tissue plasminogen activator administered within 90 minutes. Stroke. 1992; 23: 632–40.

Haley

Jr Levy

Brott

. Urgent therapy for stroke. II. Pilot study of tissue plasminogen activator administered 91–180 minutes from onset. Stroke. 1992; 23: 641–645.

Marler

Tilley

. Early stroke treatment associated with better outcome: the NINDS rt-PA stroke study. Neurology. 2000; 55 (11): 1649–1655.

Hacke

Donnan

Fieschi

. ATLANTIS Trials Investigators; ECASS Trials Investigators; NINDS rt-PA Study Group Investigators. Association of outcome with early stroke treatment: pooled analysis of ATLANTIS, ECASS, and NINDS rt-PA stroke trials. Lancet. 2004; 363 (9411): 768–774.

10.

The NINDS t-PA Stroke Study Group. Generalized efficacy of t-PA for acute stroke: subgroup analysis of the NINDS t-PA Stroke Trial. Stroke. 1997; 28: 2119–2125.

11.

Kasim

Brizzi

Petersson

. Combined clinical and radiological prognostic model in acute ischemic stroke. Acta Neurol Belg. 2010; 110 (3): 239–245.

12.

Saňák

Herzig

Zapletalová

. Predictors of good clinical outcome in acute stroke patients treated with intravenous thrombolysis. Acta Neurol Scand. 2011; 123 (5): 339–344.

13.

von Kummer

Allen

Holle

. Acute stroke: usefulness of early CT findings before thrombolytic therapy. Radiology. 1997; 205 (2): 327–333.

14.

Trouillas

Nighoghossian

Derex

. Thrombolysis with intravenous rtPA in a series of 100 cases of acute carotid territory stroke: determination of etiological, topographic, and radiological outcome factors. Stroke. 1998; 29 (12): 2529–2540.

15.

Del Zoppo

Poeck

Pessin

. Recombinant tissue plasminogen activator in acute thrombotic and embolic stroke. Ann Neurol. 1992; 32: 78–86.

16.

Linfante

Llinas

Selim

. Clinical and vascular outcome in internal carotid artery versus middle cerebral artery occlusions after intravenous tissue plasminogen activator. Stroke. 2002; 33 (8): 2066–2071.

17.

Derex

Nighoghossian

Hermier

. Influence of pretreatment MRI parameters on clinical outcome, recanalization and infarct size in 49 stroke patients treated by intravenous tissue plasminogen activator. J Neurol Sci. 2004; 225 (1–2): 3–9.

18.

Derex

Hermier

Adeleine

. Influence of the site of arterial occlusion on multiple baseline hemodynamic MRI parameters and post-thrombolytic recanalization in acute stroke. Neuroradiology. 2004; 46 (11): 883–887.

19.

De Silva

Brekenfeld

Ebinger

. Echoplanar Imaging Thrombolytic Evaluation Trial (EPITHET) Investigators. The benefits of intravenous thrombolysis relate to the site of baseline arterial occlusion in the Echoplanar Imaging Thrombolytic Evaluation Trial (EPITHET). Stroke. 2010; 41 (2): 295–299.

20.

Sims

Rordorf

Smith

. Arterial occlusion revealed by CT Angiography predicts NIH Stroke Score and acute outcomes after IV tPA treatment. Am J Neuroradiol. 2005; 26: 246–251.

21.

Saqqur

Uchino

Demchuk

. CLOT-BUST Investigators. Site of arterial occlusion identified by transcranial Doppler predicts the response to intravenous thrombolysis for stroke. Stroke. 2007; 38 (3): 948–954.

22.

Tan

Demchuk

Hopyan

. CT angiography clot burden score and collateral score: correlation with clinical and radiologic outcomes in acute middle cerebral artery infarct. Am J Neuroradiol. 2009; 30 (3): 525–531.

23.

Puetz

Dzialowski

Hill

. Calgary CTA Study Group. Intracranial thrombus extent predicts clinical outcome, final infarct size and hemorrhagic transformation in ischemic stroke: the clot burden score. Int J Stroke. 2008; 3 (4): 230–236.

24.

The European Stroke Organization (ESO) Executive Committee and the ESO Writing Committee. Guidelines for Management of Ischaemic Stroke and Transient Ischaemic Attack. 2008. http://www.eso-stroke.org.

25.

Barber

Demchuk

Zhang

. Validity and reliability of a quantitative computed tomography score in predicting outcome of hyperacute stroke before thrombolytic therapy. Lancet. 2000; 355: 1670–1674.

26.

Van Swieten

Koudstaal

Visser

. Interobserver agreement for the assessment of handicap in stroke patients. Stroke. 1988; 19: 604–607.

27.

De Haan

Limburg

Bossuyt

. The clinical meaning of Rankin “Handicap” grades after stroke. Stroke. 1995; 26: 2027–2030.

28.

Wahlgren

Ahmed

Dávalos

. SITS-MOST investigators. Thrombolysis with alteplase for acute ischaemic stroke in the Safe Implementation of Thrombolysis in Stroke-Monitoring Study (SITS-MOST): an observational study. Lancet. 2007; 369 (9558): 275–282.

29.

Pessin

Del Zoppo

Estol

. Thrombolytic agents in the treatment of stroke. Clin Neuropharmacol. 1990; 13 (4): 271–289.

30.

Wolpert

Bruckmann

Greenlee

. Neuroradiologic evaluation of patients with acute stroke treated with recombinant tissue plasminogen activator. The rt-PA Acute Stroke Study Group. Am J Neuroradiol. 1993; 14 (1): 3–13.

31.

Fiorelli

Bastianello

von Kummer

. Hemorrhagic transformation within 36 hours of a cerebral infarct: relationships with early clinical deterioration and 3-month outcome in the European Cooperative Acute Stroke Study I (ECASS I) cohort. Stroke. 1999; 30 (11): 2280–2284.

32.

Berger

Fiorelli

Steiner

. Hemorrhagic transformation of ischemic brain tissue: asymptomatic or symptomatic? Stroke. 2001; 32 (6): 1330–1335.

33.

Trouillas

von Kummer

. Classification and pathogenesis of cerebral hemorrhages after thrombolysis in ischemic stroke. Stroke. 2006; 37 (2): 556–561.

34.

Overgaard

. Thrombolytic therapy in experimental embolic stroke. Cerebrovasc Brain Metab Rev. 1994; 6 (3): 257–286.

35.

Barbara

Rossi

Procaccianti

. Quantitative determination in the CT diagnosis of ischaemic and heamorragic stroke. The Neuroradiology Journal. 2007; 20 (Suppl 1): 110.

36.

Simonetti

Barbara

Procaccianti

. Is MR really essential in the diagnosis of acute carotid and vertebral dissections? The Neuroradiology Journal 2007; 20 (Suppl 1): 127–128.

37.

Barbara

Stafa

Procaccianti

. CT-Angiography and thrombolysis in acute ischemic stroke. Correlations between occlusion's level and nihss improvement. Our experience based on 127 patients. The Neuroradiology Journal 2009; 22: 771.