title: Undetermined stroke with an embolic pattern--a common phenotype with high early recurrence risk.
abstract: BACKGROUND
  Undetermined strokes with an embolic pattern (USEP) represent a common phenotype. We assessed their frequency and compared USEP with cardioembolic stroke with a known source and non-cardioembolic stroke etiology.
  
  
  METHODS
  Study patients were 540 consecutive ischemic stroke patients admitted to Helsinki University Hospital with primary end-point of recurrent stroke in a 21-month follow-up. Cox regression adjusting for CHA2DS2-VASc and anticoagulation estimated the risk of USEP on recurrent stroke.
  
  
  RESULTS
  A total of 229 (42.4%) patients had a non-cardioembolic stroke etiology, 184 (34.1%) had a cardioembolic stroke with a known source, and 127 (23.5%) were classified as USEP. USEP patients had less diabetes and prior TIA, with more severe symptoms than the non-cardioembolic stroke cases. They were younger, had fewer comorbidities, and less severe symptoms than the cardioembolic stroke patients. Cumulative risk of recurrent stroke was 10.0% (95% CI 4.1%-15.9%) for USEP, 5.0% (1.1%-8.9%) for cardioembolic strokes, and 5.0% (3.0%-7.0%) for non- cardioembolic strokes (P = 0.089). USEP associated with a higher risk of recurrent stroke compared to non-cardioembolic strokes (hazard ratio 2.36, 95% CI 1.02-5.47; P = 0.046) and cardioembolic stroke with a known source (1.83, 1.07-3.14; P = 0.028).
  
  
  CONCLUSIONS
  Despite their younger age and more favorable risk factor profile compared with other phenotypes, USEP exhibited a high risk of stroke recurrence.
authors.affiliation: a Neurology, Helsinki University Hospital and University of Helsinki , Finland.
authors.forename: Jukka
authors.initials: J
authors.lastname: Putaala
authors.forename: Tuomo
authors.initials: T
authors.lastname: Nieminen
authors.forename: Elena
authors.initials: E
authors.lastname: Haapaniemi
authors.forename: Atte
authors.initials: A
authors.lastname: Meretoja
authors.forename: Kirsi
authors.initials: K
authors.lastname: Rantanen
authors.forename: Noora
authors.initials: N
authors.lastname: Heikkinen
authors.forename: Janne
authors.initials: J
authors.lastname: Kinnunen
authors.forename: Daniel
authors.initials: D
authors.lastname: Strbian
authors.forename: Satu
authors.initials: S
authors.lastname: Mustanoja
authors.forename: Sami
authors.initials: S
authors.lastname: Curtze
authors.forename: Sami
authors.initials: S
authors.lastname: Pakarinen
authors.forename: Mika
authors.initials: M
authors.lastname: Lehto
authors.forename: Turgut
authors.initials: T
authors.lastname: Tatlisumak
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006331:Heart Diseases / Q000150:complications* / Q000453:epidemiology; D006801:Humans; D020766:Intracranial Embolism / Q000209:etiology* / Q000473:pathology; D002546:Ischemic Attack, Transient / Q000453:epidemiology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D012189:Retrospective Studies; D020521:Stroke / Q000209:etiology* / Q000473:pathology; D013548:Sweden / Q000453:epidemiology; D014057:Tomography, X-Ray Computed
keywords: Atrial fibrillation; mortality; recurrence; stroke