title: Tissue at risk in acute stroke patients treated beyond 8 h after symptom onset.
abstract: BACKGROUND
  The decision on thrombolytics administration is usually based on a generalized, rigid time-based rule rather than an individualized evaluation of the "tissue at risk of infarction" which is the target of the recanalization therapies. The goals of our article are to assess whether there is tissue at risk of infarction in a group of acute stroke patients treated beyond 8 h after symptom onset and to investigate the baseline imaging and clinical features that predict the fate of this tissue at risk.
  
  
  METHODS
  We retrospectively reviewed a series of patients with acute ischemic stroke treated with endovascular recanalization therapies beyond 8 h after symptom onset. The tissue at risk was calculated as the difference between the infarct volumes on baseline and follow-up imaging (infarct growth). We analyzed the epidemiological distribution of infarct growth, and we performed a multivariate regression analysis to identify the baseline variables that predict infarct growth.
  
  
  RESULTS
  Our study group included 75 patients (65 ± 13.8 years, baseline National Institutes of Health Stroke Scale 14 ± 4.9, time to treatment 15.2 ± 8.7 h). The mean infarct growth was 78.6 ± 95.0 cc (p < 0.001), and, overall, the infarct growth was greater when the baseline volume of infarct tissue was small (p < 0.001) and in the case of a unsuccessful arterial recanalization (p = 0.001).
  
  
  CONCLUSIONS
  There is potentially salvageable ischemic tissue at risk in acute stroke patients treated beyond 8 h after symptom onset.
authors.affiliation: Department of Radiology, Neuroradiology Division, University of Virginia, 1215 Lee Street-New Hospital, 1st Floor, Room 1011, PO Box 800170, Charlottesville, VA 22908, USA.
authors.forename: C
authors.initials: C
authors.lastname: Leiva-Salinas
authors.forename: A
authors.initials: A
authors.lastname: Aghaebrahim
authors.forename: G
authors.initials: G
authors.lastname: Zhu
authors.forename: J T
authors.initials: JT
authors.lastname: Patrie
authors.forename: W
authors.initials: W
authors.lastname: Xin
authors.forename: B C
authors.initials: BC
authors.lastname: Lau
authors.forename: T
authors.initials: T
authors.lastname: Jovin
authors.forename: M
authors.initials: M
authors.lastname: Wintermark
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002533:Cerebral Angiography / Q000706:statistics & numerical data*; D057510:Endovascular Procedures / Q000401:mortality*; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D058958:Organs at Risk / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery; D011379:Prognosis; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D020521:Stroke / Q000175:diagnosis* / Q000401:mortality / Q000628:therapy*; D015996:Survival Rate; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology
chemical_list: D005343:Fibrinolytic Agents
references.citation: Stroke. 2003 Nov;34(11):2729-35
references.pmid: 14576370
references.citation: Stroke. 2009 Dec;40(12):3834-40
references.pmid: 19834014
references.citation: Stroke. 2006 May;37(5):1227-31
references.pmid: 16574922
references.citation: JAMA. 1999 Dec 1;282(21):2003-11
references.pmid: 10591382
references.citation: Ann Neurol. 2000 Aug;48(2):228-35
references.pmid: 10939574
references.citation: Lancet. 2010 May 15;375(9727):1695-703
references.pmid: 20472172
references.citation: N Engl J Med. 2008 Sep 25;359(13):1317-29
references.pmid: 18815396
references.citation: Stroke. 2010 Sep;41(9):1996-2000
references.pmid: 20651271
references.citation: Stroke. 2011 Aug;42(8):2206-11
references.pmid: 21778444
references.citation: Neurology. 2009 Sep 29;73(13):1066-72
references.pmid: 19786699
references.citation: Stroke. 2003 Oct;34(10):2426-33
references.pmid: 14500935
references.citation: Ann Neurol. 2006 Nov;60(5):508-17
references.pmid: 17066483
references.citation: Neuroradiology. 2011 Oct;53(10):763-71
references.pmid: 21789602
references.citation: Neurology. 2007 Jan 2;68(1):39-44
references.pmid: 17200490
references.citation: Stroke. 2011 Jan;42(1):44-7
references.pmid: 21106958
references.citation: Stroke. 2007 Mar;38(3):967-73
references.pmid: 17272772
references.citation: Stroke. 2005 Jan;36(1):66-73
references.pmid: 15569863
references.citation: Lancet. 2010 May 15;375(9727):1667-8
references.pmid: 20472152
references.citation: Radiology. 2009 Mar;250(3):878-86
references.pmid: 19164120
references.citation: Arch Neurol. 2006 May;63(5):661-4
references.pmid: 16682535
references.citation: Neurology. 1998 Dec;51(6):1617-21
references.pmid: 9855512