title: Perfusion computed tomography to assist decision making for stroke thrombolysis.
abstract: The use of perfusion imaging to guide selection of patients for stroke thrombolysis remains controversial because of lack of supportive phase three clinical trial evidence. We aimed to measure the outcomes for patients treated with intravenous recombinant tissue plasminogen activator (rtPA) at a comprehensive stroke care facility where perfusion computed tomography was routinely used for thrombolysis eligibility decision assistance. Our overall hypothesis was that patients with 'target' mismatch on perfusion computed tomography would have improved outcomes with rtPA. This was a prospective cohort study of consecutive ischaemic stroke patients who fulfilled standard clinical/non-contrast computed tomography eligibility criteria for treatment with intravenous rtPA, but for whom perfusion computed tomography was used to guide the final treatment decision. The 'real-time' perfusion computed tomography assessments were qualitative; a large perfusion computed tomography ischaemic core, or lack of significant perfusion lesion-core mismatch were considered relative exclusion criteria for thrombolysis. Specific volumetric perfusion computed tomography criteria were not used for the treatment decision. The primary analysis compared 3-month modified Rankin Scale in treated versus untreated patients after 'off-line' (post-treatment) quantitative volumetric perfusion computed tomography eligibility assessment based on presence or absence of 'target' perfusion lesion-core mismatch (mismatch ratio >1.8 and volume >15 ml, core <70 ml). In a second analysis, we compared outcomes of the perfusion computed tomography-selected rtPA-treated patients to an Australian historical cohort of non-contrast computed tomography-selected rtPA-treated patients. Of 635 patients with acute ischaemic stroke eligible for rtPA by standard criteria, thrombolysis was given to 366 patients, with 269 excluded based on visual real-time perfusion computed tomography assessment. After off-line quantitative perfusion computed tomography classification: 253 treated patients and 83 untreated patients had 'target' mismatch, 56 treated and 31 untreated patients had a large ischaemic core, and 57 treated and 155 untreated patients had no target mismatch. In the primary analysis, only in the target mismatch subgroup did rtPA-treated patients have significantly better outcomes (odds ratio for 3-month, modified Rankin Scale 0-2 = 13.8, P < 0.001). With respect to the perfusion computed tomography selected rtPA-treated patients (n = 366) versus the clinical/non-contrast computed tomography selected rtPA-treated patients (n = 396), the perfusion computed tomography selected group had higher adjusted odds of excellent outcome (modified Rankin Scale 0-1 odds ratio 1.59, P = 0.009) and lower mortality (odds ratio 0.56, P = 0.021). Although based on observational data sets, our analyses provide support for the hypothesis that perfusion computed tomography improves the identification of patients likely to respond to thrombolysis, and also those in whom natural history may be difficult to modify with treatment.
authors: 1 Department of Neurology, John Hunter Hospital, University of Newcastle, New South Wales, Australia Andrew.bivard@newcastle.edu.au.
authors: Andrew
authors: A
authors: Bivard
authors: 1 Department of Neurology, John Hunter Hospital, University of Newcastle, New South Wales, Australia.
authors: Christopher
authors: C
authors: Levi
authors: 1 Department of Neurology, John Hunter Hospital, University of Newcastle, New South Wales, Australia.
authors: Venkatesh
authors: V
authors: Krishnamurthy
authors: 1 Department of Neurology, John Hunter Hospital, University of Newcastle, New South Wales, Australia.
authors: Patrick
authors: P
authors: McElduff
authors: 1 Department of Neurology, John Hunter Hospital, University of Newcastle, New South Wales, Australia.
authors: Ferdi
authors: F
authors: Miteff
authors: 1 Department of Neurology, John Hunter Hospital, University of Newcastle, New South Wales, Australia.
authors: Neil J
authors: NJ
authors: Spratt
authors: 2 Department of Radiology, John Hunter Hospital, University of Newcastle New South Wales, Australia.
authors: Grant
authors: G
authors: Bateman
authors: 3 Melbourne Brain Centre, Florey Neuroscience Institute, University of Melbourne, Parkville, Victoria, Australia.
authors: Geoffrey
authors: G
authors: Donnan
authors: 3 Melbourne Brain Centre, Florey Neuroscience Institute, University of Melbourne, Parkville, Victoria, Australia.
authors: Stephen
authors: S
authors: Davis
authors: 1 Department of Neurology, John Hunter Hospital, University of Newcastle, New South Wales, Australia.
authors: Mark
authors: M
authors: Parsons
mesh_terms: D061605:Administration, Intravenous; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005260:Female; D005343:Fibrinolytic Agents / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D020521:Stroke / Q000188:drug therapy*; D015912:Thrombolytic Therapy / Q000379:methods*; D010959:Tissue Plasminogen Activator / Q000008:administration & dosage*; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D005343:Fibrinolytic Agents; D010959:Tissue Plasminogen Activator
keywords: acute stroke; infarct; perfusion CT; time to treatment