title: Outcomes and characteristics of patients undergoing percutaneous angioplasty followed by below-knee or above-knee amputation for peripheral artery disease.
abstract: OBJECTIVE
  Little is known about long-term outcomes among patients who receive percutaneous angioplasty (PTA) for peripheral artery disease (PAD) then undergo below-knee or above-knee amputations. We sought to determine clinical outcomes associated with below-knee or above-knee amputation, along with possible explanatory factors and treatment strategies.
  
  
  METHODS
  Using data from Taiwan's National Health Insurance Research Database from 1997 to 2010, 7,568 adult patients were divided into three groups: lower extremity preserved (LE), below-knee amputation (BK) and above-knee amputation (AK). We assessed outcomes including major adverse cardiovascular events (MACE) and associated risk factors.
  
  
  RESULTS
  Overall MACE was significantly higher in the AK group compared to the LE and BK groups, over a mean follow-up of 2.45 years (hazard ratio [HR]: 1.81; 95% confidence interval [CI]: 1.50-2.18 for AK vs. LE; HR: 1.67; 95% CI: 1.36-2.06 for AK vs. BK). However MACE were similar for the BK and LE groups (HR: 1.08; 95% CI: 0.98-1.20). Overall mortality was highest in the AK group (HR: 1.65, 95% CI: 1.34-2.04 for AK vs. BK). As for patient characteristics, atrial fibrillation was more prevalent in the AK group than in the BK group (17% vs. 7%). Independent risk factors associated with death after above- or below-knee amputation included advanced age, heart failure, dialysis, male gender and high patient volume.
  
  
  CONCLUSIONS
  The MACE rate was highest in the AK group, whereas the LE and BK groups were similar in this regard. Furthermore, overall mortality increased with larger area of amputation.
authors.affiliation: Heart Failure Center, Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital, Keelung, Taiwan; College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Chun-Tai
authors.initials: CT
authors.lastname: Mao
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital, Taipei, Taiwan; College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Ming-Lung
authors.initials: ML
authors.lastname: Tsai
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital, Taipei, Taiwan; College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Chao-Yung
authors.initials: CY
authors.lastname: Wang
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital, Taipei, Taiwan; College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Ming-Shien
authors.initials: MS
authors.lastname: Wen
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital, Taipei, Taiwan; College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: I-Chang
authors.initials: IC
authors.lastname: Hsieh
authors.affiliation: Heart Failure Center, Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital, Keelung, Taiwan; College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Ming-Jui
authors.initials: MJ
authors.lastname: Hung
authors.affiliation: Heart Failure Center, Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital, Keelung, Taiwan; College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Chao-Hung
authors.initials: CH
authors.lastname: Wang
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital, Taipei, Taiwan; College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Chun-Chi
authors.initials: CC
authors.lastname: Chen
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital, Taipei, Taiwan; Department of cardiology, Chang Gung Memorial Hospital, Xiamen, China; College of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Tien-Hsing
authors.initials: TH
authors.lastname: Chen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000671:Amputation, Surgical / Q000009:adverse effects*; D017130:Angioplasty; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000209:etiology*; D005260:Female; D006801:Humans; D007717:Knee / Q000098:blood supply / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D058729:Peripheral Arterial Disease / Q000601:surgery* / Q000628:therapy; D016896:Treatment Outcome