title: Asymptomatic hemorrhagic transformation after acute ischemic stroke: is it clinically innocuous?
abstract: BACKGROUND
  Whether asymptomatic hemorrhagic transformation (HT) is clinically innocuous, that is, unassociated with clinically detectable neurologic deterioration, remains an open question. To explore this, we examined whether asymptomatic HT affects long-term poor outcome and risk of stroke recurrence.
  
  
  METHODS
  We consecutively and prospectively enrolled patients with acute ischemic stroke who were admitted to our hospital. Based on clinical and imaging data, patients were diagnosed as having asymptomatic HT, symptomatic HT, or not HT, and the 3 groups were compared in terms of basic clinical characteristics, poor outcome, and stroke recurrence. We constructed Kaplan-Meier survival curves and compared groups by means of log rank tests for significant difference.
  
  
  RESULTS
  Of the 1789 patients enrolled, 143 (8.0%) presented with asymptomatic HT, 25 (1.4%) presented with symptomatic HT. These patients with were more likely to be female, to have experienced atrial fibrillation, and to have higher National Institute of Health Stroke Scale score on stroke than were patients without HT. After adjusting for other confounding factors, the risk of poor outcome was significantly higher among those with asymptomatic HT and symptomatic HT than among those without HT. Moreover, patients with asymptomatic HT and symptomatic HT showed a significantly lower cumulative 1-year survival rate than did those without HT (P < .001). The patients showed similar rates of cumulative stroke recurrence at 1 year (P = .673).
  
  
  CONCLUSIONS
  Asymptomatic HT and symptomatic HT after acute ischemic stroke worsened long-term clinical outcomes, although it did not affect risk of stroke recurrence. These findings suggest that asymptomatic HT should not be considered clinically innocuous.
authors.affiliation: Stroke Clinical Research Unit, Department of Neurology, West China Hospital, Sichuan University, Chengdu, P. R. China.
authors.forename: Chunyan
authors.initials: C
authors.lastname: Lei
authors.affiliation: Stroke Clinical Research Unit, Department of Neurology, West China Hospital, Sichuan University, Chengdu, P. R. China; State Key Laboratory of Human Disease Biotherapy and Ministry of Education, Department of Neurology, West China Hospital, Sichuan University, Chengdu, P. R. China. Electronic address: dragonwbtxf@hotmail.com.
authors.forename: Bo
authors.initials: B
authors.lastname: Wu
authors.affiliation: Stroke Clinical Research Unit, Department of Neurology, West China Hospital, Sichuan University, Chengdu, P. R. China; State Key Laboratory of Human Disease Biotherapy and Ministry of Education, Department of Neurology, West China Hospital, Sichuan University, Chengdu, P. R. China.
authors.forename: Ming
authors.initials: M
authors.lastname: Liu
authors.affiliation: Stroke Clinical Research Unit, Department of Neurology, West China Hospital, Sichuan University, Chengdu, P. R. China.
authors.forename: Yanchao
authors.initials: Y
authors.lastname: Chen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000150:complications* / Q000503:physiopathology; D002543:Cerebral Hemorrhage / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D012307:Risk Factors; D012737:Sex Factors; D020521:Stroke / Q000150:complications* / Q000503:physiopathology; D013997:Time Factors
keywords: Ischemic stroke; asymptomatic hemorrhagic transformation; poor outcome; recurrence