title: Poststroke dementia predicts poor survival in long-term follow-up: influence of prestroke cognitive decline and previous stroke.
abstract: BACKGROUND
  The aim of this study was to investigate the influence of poststroke dementia on long-term survival after acute stroke and also to assess the possible influence of prestroke cognitive decline and previous stroke on this relationship.
  
  
  METHODS
  A total of 451 consecutive patients with acute ischaemic stroke admitted to hospital were included in the study and followed up for 12 years. Dementia was diagnosed 3 months after stroke in 115 patients (25.5%).
  
  
  RESULTS
  In Kaplan-Meier analysis, poststroke dementia predicted poor long-term survival (5.1 years vs 8.8 years in patients who did not have poststroke dementia; p<0.001). Prestroke cognitive decline had a negative influence on survival in patients with poststroke dementia (3.8 years vs 5.8 years; p<0.001); however, previous stroke did not affect survival in these patients (p = 0.676). In stepwise Cox regression proportional hazards analysis adjusted for significant covariates, poststroke dementia (hazard ratio (HR) 1.53; p = 0.003), advanced age (HR 1.07; p<0.001), severity of stroke (HR 1.91; p<0.001), smoking (HR 1.35; p = 0.035), cardiac failure (HR 1.61; p = 0.003) and atrial fibrillation (HR 1.89; p = 0.035) were all independent predictors of poor long-term survival. Poststroke dementia (HR 2.33; p<0.001), advanced age (HR 1.07; p<0.001) and poor Rankin score (HR 2.15; p = 0.001) were associated with death from brain-related causes, including infarction, haemorrhage and dementia.
  
  
  CONCLUSIONS
  Long-term follow-up of our large well-defined poststroke cohort indicated that in patients with acute stroke, dementia is a significant predictor of poor long-term survival and death from brain-associated causes. Prestroke cognitive decline seems to have an additional negative influence on survival, but previous stroke does not seem to affect survival.
authors.affiliation: Department of Neurology, Helsinki University Central Hospital, POB 300, 00029 HUS, Finland. susanna.melkas@hus.fi
authors.forename: S
authors.initials: S
authors.lastname: Melkas
authors.forename: N K J
authors.initials: NK
authors.lastname: Oksala
authors.forename: H
authors.initials: H
authors.lastname: Jokinen
authors.forename: T
authors.initials: T
authors.lastname: Pohjasvaara
authors.forename: R
authors.initials: R
authors.lastname: Vataja
authors.forename: A
authors.initials: A
authors.lastname: Oksala
authors.forename: M
authors.initials: M
authors.lastname: Kaste
authors.forename: P J
authors.initials: PJ
authors.lastname: Karhunen
authors.forename: T
authors.initials: T
authors.lastname: Erkinjuntti
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002423:Cause of Death; D003072:Cognition Disorders / Q000209:etiology* / Q000523:psychology; D015331:Cohort Studies; D003627:Data Interpretation, Statistical; D003704:Dementia / Q000209:etiology*; D005260:Female; D005387:Finland / Q000453:epidemiology; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D015983:Selection Bias; D012737:Sex Factors; D012959:Socioeconomic Factors; D020521:Stroke / Q000150:complications*; D013534:Survival; D016019:Survival Analysis