title: Comparative Effectiveness of Prestroke Aspirin on Stroke Severity and Outcome.
abstract: OBJECTIVE
  The effect of prestroke aspirin use on initial severity, hemorrhagic transformation, and functional outcome of ischemic stroke is uncertain.
  
  
  METHODS
  Using a multicenter stroke registry database, patients with acute ischemic stroke of three subtypes (large artery atherosclerosis [LAA], small vessel occlusion [SVO], or cardioembolism [CE]) were identified. NIH stroke scale (NIHSS) and hemorrhagic transformation at presentation and discharge modified Rankin Scale (mRS) were compared between prestroke aspirin users and nonusers.
  
  
  RESULTS
  Among the 10,433 patients, 1,914 (18.3%) reported prestroke aspirin use. On crude analysis, initial NIHSS scores of aspirin users were higher than nonusers (mean difference: 0.35; 95% confidence interval [CI]: 0.04-0.66). However, a multivariable analysis with an application of inverse probability of treatment weighting based on a propensity score of prestroke aspirin, having an interaction effect of prestroke aspirin use and stroke subtype in the model, showed less stroke severity for aspirin users in LAA, but not in SVO and CE than for nonusers; mean difference in NIHSS scores in LAA was -0.97 (95% CI: -1.45 to -0.49). With respect to hemorrhagic transformation and mRS, no significant interaction effects were found. Prestroke aspirin use increased the risk of hemorrhagic transformation (adjusted odd ratio: 1.34; 95% CI: 1.05-1.73), but decreased the odds of the higher discharge mRS (0.86; 0.76-0.96).
  
  
  CONCLUSIONS
  Prestroke aspirin use may reduce initial stroke severity in atherothrombotic stroke and can improve functional outcome at discharge despite an increase of hemorrhagic transformation irrespective of stroke subtype.
authors.affiliation: Departments of Neurology, Eulji, General Hospital, Eulji University, Seoul.
authors.forename: Jong-Moo
authors.initials: JM
authors.lastname: Park
authors.affiliation: Departments of Neurology, Eulji, General Hospital, Eulji University, Seoul.
authors.forename: Kyusik
authors.initials: K
authors.lastname: Kang
authors.affiliation: Ilsan Paik Hospital, Inje University College of Medicine, Goyang.
authors.forename: Yong-Jin
authors.initials: YJ
authors.lastname: Cho
authors.affiliation: Ilsan Paik Hospital, Inje University College of Medicine, Goyang.
authors.forename: Keun-Sik
authors.initials: KS
authors.lastname: Hong
authors.affiliation: Soonchunhyang University Hospital, Seoul.
authors.forename: Kyung Bok
authors.initials: KB
authors.lastname: Lee
authors.affiliation: Seoul Medical Center, Seoul.
authors.forename: Tai Hwan
authors.initials: TH
authors.lastname: Park
authors.affiliation: Eulji University Hospital, Daejeon.
authors.forename: Soo Joo
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: Eulji University Hospital, Daejeon.
authors.forename: Youngchai
authors.initials: Y
authors.lastname: Ko
authors.affiliation: Seoul National University Bundang Hospital, Seongnam.
authors.forename: Moon-Ku
authors.initials: MK
authors.lastname: Han
authors.affiliation: Yeungnam University Hospital, Daegu.
authors.forename: Jun
authors.initials: J
authors.lastname: Lee
authors.affiliation: Dong-A University Hospital, Busan.
authors.forename: Jae-Kwan
authors.initials: JK
authors.lastname: Cha
authors.affiliation: Dong-A University Hospital, Busan.
authors.forename: Dae-Hyun
authors.initials: DH
authors.lastname: Kim
authors.affiliation: Dongguk University Ilsan Hospital, Goyang.
authors.forename: Dong-Eog
authors.initials: DE
authors.lastname: Kim
authors.affiliation: Chonnam National University Hospital, Gwangju.
authors.forename: Joon-Tae
authors.initials: JT
authors.lastname: Kim
authors.affiliation: Jeju National University Hospital, Jeju.
authors.forename: Jay Chol
authors.initials: JC
authors.lastname: Choi
authors.affiliation: Hallym University College of Medicine, Pyeongchon.
authors.forename: Kyung-Ho
authors.initials: KH
authors.lastname: Yu
authors.affiliation: Hallym University College of Medicine, Pyeongchon.
authors.forename: Byung-Chul
authors.initials: BC
authors.lastname: Lee
authors.affiliation: Clinical Research Center, Asan Medical Center, Seoul.
authors.forename: Ji Sung
authors.initials: JS
authors.lastname: Lee
authors.affiliation: Department of Biostatistics, Korea University College of Medicine, Seoul.
authors.forename: Juneyoung
authors.initials: J
authors.lastname: Lee
authors.affiliation: Department of Translational Science and Molecular Medicine, Michigan State University College of Human Medicine, and Mercy Health Hauenstein Neurosciences, Grand Rapids, MI.
authors.forename: Philip B
authors.initials: PB
authors.lastname: Gorelick
authors.affiliation: Seoul National University Bundang Hospital, Seongnam.
authors.forename: Hee-Joon
authors.initials: HJ
authors.lastname: Bae
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001241:Aspirin / Q000009:adverse effects / Q000494:pharmacology*; D002545:Brain Ischemia / Q000453:epidemiology / Q000517:prevention & control* / Q000628:therapy; D005260:Female; D006801:Humans; D020300:Intracranial Hemorrhages / Q000139:chemically induced* / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care / Q000706:statistics & numerical data*; D010975:Platelet Aggregation Inhibitors / Q000009:adverse effects / Q000494:pharmacology*; D012042:Registries / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D012720:Severity of Illness Index; D020521:Stroke / Q000453:epidemiology / Q000517:prevention & control* / Q000628:therapy
chemical_list: D010975:Platelet Aggregation Inhibitors; D001241:Aspirin