title: Perfusion computed tomography in patients with stroke thrombolysis.
abstract: See Saver (doi:10.1093/awx020) for a scientific commentary on this article.Stroke shortens an individual's disability-free life. We aimed to assess the relative prognostic influence of pre- and post-treatment perfusion computed tomography imaging variables (e.g. ischaemic core and penumbral volumes) compared to standard clinical predictors (such as onset-to-treatment time) on long-term stroke disability in patients undergoing thrombolysis. We used data from a prospectively collected international, multicentre, observational registry of acute ischaemic stroke patients who had perfusion computed tomography and computed tomography angiography before treatment with intravenous alteplase. Baseline perfusion computed tomography and follow-up magnetic resonance imaging were analysed to derive the baseline penumbra volume, baseline ischaemic core volume, and penumbra salvaged from infarction. The primary outcome measure was the effect of imaging and clinical variables on Disability-Adjusted Life Year. Clinical variables were age, sex, National Institutes of Health Stroke Scale score, and onset-to-treatment time. Age, sex, country, and 3-month modified Rankin Scale were extracted from the registry to calculate disability-adjusted life-year due to stroke, such that 1 year of disability-adjusted life-year equates to 1 year of healthy life lost due to stroke. There were 772 patients receiving alteplase therapy. The number of disability-adjusted life-year days lost per 1 ml of baseline ischaemic core volume was 17.5 (95% confidence interval, 13.2-21.9 days, P < 0.001). For every millilitre of penumbra salvaged, 7.2 days of disability-adjusted life-year days were saved (β = -7.2, 95% confidence interval, -10.4 to -4.1 days, P < 0.001). Each minute of earlier onset-to-treatment time resulted in a saving of 4.4 disability-free days after stroke (1.3-7.5 days, P = 0.006). However, after adjustment for imaging variables, onset-to-treatment time was not significantly associated with savings in disability-adjusted life-year days. Pretreatment perfusion computed tomography can (independently of clinical variables) predict significant gains, or loss, of disability-free life in patients undergoing reperfusion therapy for stroke. The effect of earlier treatment on disability-free life appears explained by salvage of penumbra, particularly when the ischaemic core is not too large.
authors.affiliation: Departments of Neurology, John Hunter Hospital, University of Newcastle, Lookout Road, New Lambton Heights, NSW 2305, Australia.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kawano
authors.affiliation: Departments of Neurology, John Hunter Hospital, University of Newcastle, Lookout Road, New Lambton Heights, NSW 2305, Australia.
authors.forename: Andrew
authors.initials: A
authors.lastname: Bivard
authors.affiliation: Departments of Neurology, John Hunter Hospital, University of Newcastle, Lookout Road, New Lambton Heights, NSW 2305, Australia.
authors.forename: Longting
authors.initials: L
authors.lastname: Lin
authors.affiliation: Department of Neurology, Monash Medical Centre, Monash University, 246 Clayton Road Clayton, VIC, 3168, Australia.
authors.forename: Henry
authors.initials: H
authors.lastname: Ma
authors.affiliation: Department of Neurology, Huashan Hospital, Fudan University, 12 Wulumuqi Zhong Road, Shanghai 200040, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Cheng
authors.affiliation: Department of Medical Imaging, Sunnybrook Health Sciences Centre, University of Toronto, 2075 Bayview Avenue, Toronto, ON M4N 3M5, Canada.
authors.forename: Richard
authors.initials: R
authors.lastname: Aviv
authors.affiliation: Department of Neurology, Gosford Hospital, Holden Street, Gosford, NSW, 2250, Australia.
authors.forename: Billy
authors.initials: B
authors.lastname: O'Brien
authors.affiliation: Division of Neurology, Department of Medicine, University of Alberta, 13-103 Clinical Sciences Building, 11350-83 Avenue, Edmonton, Alberta, T6G 2R3, Canada.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Butcher
authors.affiliation: Department of Neurology, the Second Affiliated Hospital of Zhejiang University, No.88 Jiefang Road, Hangzhou, 310009, China.
authors.forename: Min
authors.initials: M
authors.lastname: Lou
authors.affiliation: Department of Neurology, Baotou Central Hospital, Inner Mongolia, Baotou, 014040, China.
authors.forename: Jingfen
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Neurology, The Queen Elizabeth Hospital, 28 Woodville Road Woodville South, SA, 5011, Australia.
authors.forename: Jim
authors.initials: J
authors.lastname: Jannes
authors.affiliation: Department of Neurology, Huashan Hospital, Fudan University, 12 Wulumuqi Zhong Road, Shanghai 200040, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Dong
authors.affiliation: Departments of Neurology, John Hunter Hospital, University of Newcastle, Lookout Road, New Lambton Heights, NSW 2305, Australia.
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Levi
authors.affiliation: Departments of Neurology, John Hunter Hospital, University of Newcastle, Lookout Road, New Lambton Heights, NSW 2305, Australia.
authors.forename: Mark W
authors.initials: MW
authors.lastname: Parsons
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002560:Cerebrovascular Circulation; D006233:Persons with Disabilities; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D055420:Perfusion Imaging; D020127:Recovery of Function; D012189:Retrospective Studies; D012720:Severity of Illness Index; D020521:Stroke / Q000150:complications / Q000000981:diagnostic imaging* / Q000628:therapy*; D015912:Thrombolytic Therapy / Q000379:methods*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
keywords: acute stroke; disability; perfusion CT; thrombolysis