title: Incidence, case-fatality rate, and prognosis of ischaemic stroke subtypes in a predominantly Hispanic-Mestizo population in Iquique, Chile (PISCIS project): a community-based incidence study.
abstract: BACKGROUND
  Incidence of ischaemic stroke subtypes, classified by cause, seems to vary between communities. We aimed to prospectively ascertain the incidence of first-ever ischaemic stroke in a predominantly Hispanic-Mestizo population in the northern desertic region of Chile.
  
  
  METHODS
  Between July, 2000, and June, 2002, all patients with possible stroke or transient ischaemic attacks were identified from multiple overlapping sources and were rapidly assessed by two field neurologists. All identified patients were diagnosed by at least two stroke neurologists according to Trial of Org 10172 in Acute Stroke Treatment (TOAST) definitions and were followed up at 6 months. Annual incidence rates were age adjusted to WHO, European, and US populations by the direct method to allow comparisons.
  
  
  RESULTS
  A total of 239 ischaemic strokes were identified, of which 185 (77%) were first-ever cases. 151 (82%) patients were hospitalised, of whom only 70 (38%) were assessed within 6 h of symptom onset. The mean age of patients was 66.4 years (SD 14.9) and 56% were men. The crude annual incidence rates (per 100 000) according to stroke subtype were: cardioembolic, 9.3; large-artery disease, 2.0; small-vessel disease, 15.8; other determined cause, 0.2; and undetermined cause, 17.4. Hypertension was the most common cardiovascular risk factor in all subtypes and atrial fibrillation was the most common cause of cardioembolic stroke. Case fatality at 30 days was highest in cardioembolic strokes (28%) and lowest in small-vessel disease (0%). Dependency or death at 6 months was also highest in cardioembolic strokes (62%) and lowest in small-vessel disease (21%).
  
  
  CONCLUSIONS
  Incidence and prognosis of small vessel and cardioembolic infarction was similar to that in other populations and incidence of large-artery atherothrombotic infarction was lower than in most previous reports. Hypertension and atrial fibrillation were the most common risk factor and cause, respectively, of ischemic stroke in this population. These findings should help the national stroke programme in the prevention of cardioembolic stroke, increase access to specialists and acute brain imaging and vascular studies, and improve stroke care.
authors.affiliation: Neurology Service, Department of Medicine, Clínica Alemana de Santiago-Universidad del Desarrollo, Department of Neurological Sciences, School of Medicine, Universidad de Chile, Santiago, Chile. pablolavados@yahoo.com
authors.forename: Pablo M
authors.initials: PM
authors.lastname: Lavados
authors.forename: Claudio
authors.initials: C
authors.lastname: Sacks
authors.forename: Liliana
authors.initials: L
authors.lastname: Prina
authors.forename: Arturo
authors.initials: A
authors.lastname: Escobar
authors.forename: Claudia
authors.initials: C
authors.lastname: Tossi
authors.forename: Fernando
authors.initials: F
authors.lastname: Araya
authors.forename: Walter
authors.initials: W
authors.lastname: Feuerhake
authors.forename: Marcelo
authors.initials: M
authors.lastname: Gálvez
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Salinas
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Alvarez
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D002677:Chile / Q000453:epidemiology / Q000208:ethnology; D004196:Disease Outbreaks; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D011287:Prejudice; D011379:Prognosis; D012111:Residence Characteristics; D012189:Retrospective Studies; D012307:Risk Factors; D020521:Stroke / Q000145:classification / Q000453:epidemiology / Q000208:ethnology; D013997:Time Factors