title: When to call it a day: incremental risk of amputation and death after multiple revascularization.
abstract: BACKGROUND
  Patients with critical limb ischemia (CLI) often undergo revascularization before amputation. The exact relationship between multiple procedures and increased risk of amputation is unclear. We sought to determine the increased risk of amputation for each additional revascularization.
  
  
  METHODS
  The 2007-2009 California State Inpatient Database (SID) was used to identify a cohort of CLI patients undergoing revascularization and conduct a time-to-event analysis for patients undergoing one or more revascularization procedures. One-year estimates were generated with Kaplan-Meier curves and compared with the log-rank test. The Wei-Lin-Weissfeld (WLW) marginal proportional hazards model was used to assess independent effects of number of revascularization procedures on amputation and death.
  
  
  RESULTS
  A total of 11,190 patients with CLI underwent revascularization between July 2007 and December 2009. Their mean age was 71.0 years (interquartile range 62-80 years) and 6255 (55.9%) were male. Over half the subjects (55.2%) were smokers and there was a high burden of comorbidities in the cohort. One-year estimates of amputation by number of revascularizations (1: 23.3%; 2: 27.1%; 3: 30.3%; 4: 26.7%; 5(+): 28.6%; P < 0.001) and death (1: 18.7%; 2: 21.1%; 3: 26.3%; 4: 23.6%; 5+: 32.1%; P = 0.012) increased significantly as procedures increased. In the WLW model for amputation, the hazard increased significantly for patients with 2 revascularization versus 1 (HR = 1.22; 95% CI 1.09-1.37; P = 0.001) and 3 revascularizations versus 2 (HR = 1.33; 95% CI 1.10-1.62; P = 0.004). In the multivariable WLW models for death, the increase in revascularization procedures for 2 compared with 1 (HR = 1.18; 95% CI 1.04-1.34; P = 0.010) was significant.
  
  
  CONCLUSIONS
  The risk of amputation increases with each additional revascularization procedure. These findings hold true for both percutaneous transluminal angioplasty only and lower extremity bypass only subsets. In addition, increased revascularization procedures appear to result in an increased risk of death. We advocate for continued communication between clinicians and patients on the true risks and benefits of additional revascularization procedures.
authors: Center for Surgery and Public Health, Boston, MA; Brigham & Women's Hospital, Boston, MA.
authors: Alexander T
authors: AT
authors: Hawkins
authors: Center for Surgery and Public Health, Boston, MA; Brigham & Women's Hospital, Boston, MA.
authors: Maria J
authors: MJ
authors: Schaumeier
authors: Center for Surgery and Public Health, Boston, MA; Brigham & Women's Hospital, Boston, MA.
authors: Ann D
authors: AD
authors: Smith
authors: Center for Surgery and Public Health, Boston, MA; Brigham & Women's Hospital, Boston, MA.
authors: Nathanael D
authors: ND
authors: Hevelone
authors: Center for Surgery and Public Health, Boston, MA; Brigham & Women's Hospital, Boston, MA; Harvard Medical School, Boston, MA. Electronic address: llnguyen@partners.org.
authors: Louis L
authors: LL
authors: Nguyen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000671:Amputation, Surgical / Q000401:mortality; D000800:Angioplasty, Balloon / Q000009:adverse effects* / Q000401:mortality; D002140:California; D016009:Chi-Square Distribution; D015897:Comorbidity; D016638:Critical Illness; D003661:Decision Support Techniques; D005260:Female; D006801:Humans; D007511:Ischemia / Q000175:diagnosis / Q000401:mortality / Q000601:surgery / Q000628:therapy*; D053208:Kaplan-Meier Estimate; D035002:Lower Extremity / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D018579:Patient Selection; D016016:Proportional Hazards Models; D012086:Reoperation; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects / Q000401:mortality; D013997:Time Factors; D016896:Treatment Outcome; D014656:Vascular Surgical Procedures / Q000009:adverse effects* / Q000401:mortality