title: Outcomes of Critical Limb Ischemia in an Urban, Safety Net Hospital Population with High WIfI Amputation Scores.
abstract: BACKGROUND
  Patients presenting to a public hospital with critical limb ischemia (CLI) typically have advanced disease with significant comorbidities. The purpose of this study was to assess the influence of revascularization on 1-year amputation rate of CLI patients presenting to Los Angeles County USC Medical Center, classified according to the Society for Vascular Surgery Wound, Ischemia and foot Infection (WIfI).
  
  
  METHODS
  A retrospective review of patients who presented to a public hospital with CLI from February 2010 to July 2014 was performed. Patients were classified according to the WIfI system. Only patients with complete data who survived at least 12 months after presentation were included.
  
  
  RESULTS
  Ninety-three patients with 98 affected limbs were included. The mean age was 62.8 years. Eighty-two patients (84%) had hypertension and 71 (72%) had diabetes. Fifty (57.5%) limbs had Trans-Atlantic Inter-Society Consensus (TASC) C or D femoral-popliteal lesions and 82 (98%) had significant infrapopliteal disease. The majority had moderate or high WIfI amputation and revascularization scores. Eighty-four (86%) limbs underwent open, endovascular, or hybrid revascularization. Overall, one year major amputation (OYMA) rate was 26.5%. In limbs with high WIfI amputation score, the OYMA was 34.5%: 21.4% in those who were revascularized and 57% in those who were not. On univariable analysis, factors associated with increased risk of OYMA were nonrevascularization (P = 0.005), hyperlipidemia (P = 0.06), hemodialysis (P = 0.005), gangrene (P = 0.02), ulcer classification (P = 0.05), WIfI amputation score (P = 0.026), and WIfI wound grade (P = 0.04). On multivariable analysis, increasing WIfI amputation score (odds ratio [OR] 1.84, 95% confidence interval [CI] 1.0-3.39) was associated with increased risk of OYMA while revascularization (OR 0.24, 95% CI 0.07-0.80) was associated with decreased risk of OYMA.
  
  
  CONCLUSIONS
  The OYMA rates in this population were consistent with those predicted by the WIfI classification system. In this population, revascularization significantly reduced the risk of amputation. Comorbidities including diabetes mellitus and TASC classification did not moderate the association of WIfI amputation score with risk of 1-year major amputation.
authors.affiliation: Department of Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA.
authors.forename: Robert
authors.initials: R
authors.lastname: Ward
authors.affiliation: Division of Vascular Surgery and Endovascular Therapy, Department of Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA.
authors.forename: Joie
authors.initials: J
authors.lastname: Dunn
authors.affiliation: Division of Cardiovascular Medicine, Department of Medicine, University of Southern California, Los Angeles, CA.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Clavijo
authors.affiliation: Division of Cardiovascular Medicine, Department of Medicine, University of Southern California, Los Angeles, CA.
authors.forename: David
authors.initials: D
authors.lastname: Shavelle
authors.affiliation: Division of Vascular Surgery and Endovascular Therapy, Department of Surgery, Keck School of Medicine, University of Southern California, Los Angeles, CA.
authors.forename: Vincent
authors.initials: V
authors.lastname: Rowe
authors.affiliation: Division of Vascular Surgery, Department of Surgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA. Electronic address: kwoo@mednet.ucla.edu.
authors.forename: Karen
authors.initials: K
authors.lastname: Woo
mesh_terms: D000368:Aged; D000671:Amputation, Surgical; D016009:Chi-Square Distribution; D015897:Comorbidity; D016638:Critical Illness; D057510:Endovascular Procedures / Q000009:adverse effects; D005260:Female; D006786:Hospitals, Urban; D006801:Humans; D007511:Ischemia / Q000175:diagnosis / Q000601:surgery*; D023821:Limb Salvage; D015141:Los Angeles; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D058729:Peripheral Arterial Disease / Q000175:diagnosis / Q000601:surgery / Q000628:therapy*; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D064876:Safety-net Providers; D013997:Time Factors; D016896:Treatment Outcome; D014656:Vascular Surgical Procedures / Q000009:adverse effects