title: MRI profile and response to endovascular reperfusion after stroke (DEFUSE 2): a prospective cohort study.
abstract: BACKGROUND
  Whether endovascular stroke treatment improves clinical outcomes is unclear because of the paucity of data from randomised placebo-controlled trials. We aimed to establish whether MRI can be used to identify patients who are most likely to benefit from endovascular reperfusion.
  
  
  METHODS
  In this prospective cohort study we consecutively enrolled patients scheduled to have endovascular treatment within 12 h of onset of stroke at eight centres in the USA and one in Austria. Aided by an automated image analysis computer program, investigators interpreted a baseline MRI scan taken before treatment to establish whether the patient had an MRI profile (target mismatch) that suggested salvageable tissue was present. Reperfusion was assessed on an early follow-up MRI scan (within 12 h of the revascularisation procedure) and defined as a more than 50% reduction in the volume of the lesion from baseline on perfusion-weighted MRI. The primary outcome was favourable clinical response, defined as an improvement of 8 or more on the National Institutes of Health Stroke Scale between baseline and day 30 or a score of 0-1 at day 30. The secondary clinical endpoint was good functional outcome, defined as a modified Rankin scale score of 2 or less at day 90. Analyses were adjusted for imbalances in baseline predictors of outcome. Investigators assessing outcomes were masked to baseline data.
  
  
  RESULTS
  138 patients were enrolled. 110 patients had catheter angiography and of these 104 had an MRI profile and 99 could be assessed for reperfusion. 46 of 78 (59%) patients with target mismatch and 12 of 21 (57%) patients without target mismatch had reperfusion after endovascular treatment. The adjusted odds ratio (OR) for favourable clinical response associated with reperfusion was 8·8 (95% CI 2·7-29·0) in the target mismatch group and 0·2 (0·0-1·6) in the no target mismatch group (p=0·003 for difference between ORs). Reperfusion was associated with increased good functional outcome at 90 days (OR 4·0, 95% CI 1·3-12·2) in the target mismatch group, but not in the no target mismatch group (1·9, 0·2-18·7).
  
  
  CONCLUSIONS
  Target mismatch patients who had early reperfusion after endovascular stroke treatment had more favourable clinical outcomes. No association between reperfusion and favourable outcomes was present in patients without target mismatch. Our data suggest that a randomised controlled trial of endovascular treatment for patients with the target mismatch profile is warranted.
  
  
  BACKGROUND
  National Institute for Neurological Disorders and Stroke.
authors.affiliation: Stanford Stroke Center, Stanford University School of Medicine, Stanford, CA, USA.
authors.forename: Maarten G
authors.initials: MG
authors.lastname: Lansberg
authors.forename: Matus
authors.initials: M
authors.lastname: Straka
authors.forename: Stephanie
authors.initials: S
authors.lastname: Kemp
authors.forename: Michael
authors.initials: M
authors.lastname: Mlynash
authors.forename: Lawrence R
authors.initials: LR
authors.lastname: Wechsler
authors.forename: Tudor G
authors.initials: TG
authors.lastname: Jovin
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Wilder
authors.forename: Helmi L
authors.initials: HL
authors.lastname: Lutsep
authors.forename: Todd J
authors.initials: TJ
authors.lastname: Czartoski
authors.forename: Richard A
authors.initials: RA
authors.lastname: Bernstein
authors.forename: Cherylee W J
authors.initials: CW
authors.lastname: Chang
authors.forename: Steven
authors.initials: S
authors.lastname: Warach
authors.forename: Franz
authors.initials: F
authors.lastname: Fazekas
authors.forename: Manabu
authors.initials: M
authors.lastname: Inoue
authors.forename: Aaryani
authors.initials: A
authors.lastname: Tipirneni
authors.forename: Scott A
authors.initials: SA
authors.lastname: Hamilton
authors.forename: Greg
authors.initials: G
authors.lastname: Zaharchuk
authors.forename: Michael P
authors.initials: MP
authors.lastname: Marks
authors.forename: Roland
authors.initials: R
authors.lastname: Bammer
authors.forename: Gregory W
authors.initials: GW
authors.lastname: Albers
mesh_terms: D000368:Aged; D038524:Diffusion Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D057510:Endovascular Procedures / Q000295:instrumentation / Q000379:methods*; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000295:instrumentation / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D015424:Reperfusion / Q000379:methods*; D012720:Severity of Illness Index; D020521:Stroke / Q000175:diagnosis / Q000628:therapy*; D013997:Time Factors; D016896:Treatment Outcome