title: The impact of prolonged lower limb ischemia on amputation, mortality, and functional status: the FRIENDS registry.
abstract: BACKGROUND
  Peripheral artery disease (PAD) is a major cause of cardiovascular ischemic events and amputation. Knowledge gaps exist in defining and measuring key factors that predict these events. The objective of this study was to assess whether duration of limb ischemia would serve as a major predictor of limb and patient survival.
  
  
  METHODS
  The FReedom from Ischemic Events: New Dimensions for Survival (FRIENDS) registry enrolled consecutive patients with limb-threatening peripheral artery disease at a single tertiary care hospital. Demographic information, key clinical care time segments, functional status and use of revascularization, and pharmacotherapy data were collected at baseline, and vascular ischemic events, cardiovascular mortality, and all-cause mortality were recorded at 30 days and 1 year.
  
  
  RESULTS
  A total of 200 patients with median (interquartile range) age of 76 years (65-84 years) were enrolled in the registry. Median duration of limb ischemia was 0.75 days for acute limb ischemia (ALI) and 61 days for chronic critical limb ischemia (CLI). Duration of limb ischemia of <12, 12 to 24, and >24 hours in patients with ALI was associated with much higher rates of first amputation (P = .0002) and worse amputation-free survival (P = .037). No such associations were observed in patients with CLI.
  
  
  CONCLUSIONS
  For individuals with ischemic symptoms <14 days, prolonged limb ischemia is associated with higher 30-day and 1-year amputation, systemic ischemic event rates, and worse amputation-free survival. No such associations are evident for individuals with chronic CLI. These data imply that prompt diagnosis and revascularization might improve outcomes for patients with ALI.
authors.affiliation: Vascular Medicine Program, Cardiovascular Division and Lillehei Heart Institute, University of Minnesota Medical School, Minneapolis, MN.
authors.forename: Sue
authors.initials: S
authors.lastname: Duval
authors.affiliation: Kantonsspital Aarau AG, Division of Angiology, Aarau, Switzerland.
authors.forename: Hong H
authors.initials: HH
authors.lastname: Keo
authors.affiliation: Vascular Medicine Program, Cardiovascular Division and Lillehei Heart Institute, University of Minnesota Medical School, Minneapolis, MN.
authors.forename: Niki C
authors.initials: NC
authors.lastname: Oldenburg
authors.affiliation: Swiss Cardiovascular Center, Division of Angiology, University Hospital and University of Bern, Bern, Switzerland.
authors.forename: Iris
authors.initials: I
authors.lastname: Baumgartner
authors.affiliation: Massachusetts General Hospital, Boston, MA.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Jaff
authors.affiliation: Center for Health Promotion, Health Promotion and Chronic Disease Division, Minnesota Department of Health, Saint Paul, MN.
authors.forename: James M
authors.initials: JM
authors.lastname: Peacock
authors.affiliation: Appleton Medical Center, Appleton, WI.
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Tretinyak
authors.affiliation: Cedars-Sinai Heart Institute, Los Angeles, CA.
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Henry
authors.affiliation: Division of Epidemiology and Community Health, University of Minnesota School of Public Health, Minneapolis, MN.
authors.forename: Russell V
authors.initials: RV
authors.lastname: Luepker
authors.affiliation: Vascular Medicine Program, Cardiovascular Division and Lillehei Heart Institute, University of Minnesota Medical School, Minneapolis, MN.
authors.forename: Alan T
authors.initials: AT
authors.lastname: Hirsch
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000671:Amputation, Surgical / Q000401:mortality*; D002423:Cause of Death / Q000639:trends; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007511:Ischemia / Q000401:mortality / Q000601:surgery*; D035002:Lower Extremity / Q000098:blood supply*; D008297:Male; D011379:Prognosis; D012042:Registries; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends; D014481:United States / Q000453:epidemiology