title: Predictors of outcome for renal artery stenting performed for salvage of renal function.
abstract: OBJECTIVE
  To identify preoperative clinical features that predict a durable improvement in renal function with renal artery stenting (RAS).
  
  
  METHODS
  Sixty-one patients with renal insufficiency (serum creatinine ≥ 1.5 mg/dL) underwent RAS for renal salvage. Patients were categorized as "responders" if estimated glomerular filtration rate (eGFR) at last follow-up was improved 20% or more over baseline. Patients with stable or worse renal function after RAS were labeled "non-responders." For the purpose of calculating changes in eGFR, patients on dialysis were represented by an eGFR of 10 ml/min/1.73 m(2). Renal volume was estimated as kidney length × width × depth/2.
  
  
  RESULTS
  The median age of the cohort was 66 years (interquartile range [IQR], 60-73 years). Median preoperative serum creatinine was 1.8 mg/dL (IQR, 1.6-2.3), and median estimated glomerular filtration rate (eGFR) was 34 mL/min/1.73 m(2) (IQR, 24-45). With stenting, 17 of 61 patients (27.9%) derived a durable improvement in renal function at a median follow-up of 24 months (IQR, 16-33 months). The largest proportion of stented patients (44.3%) had no improvement in renal function after stenting, while a subset (27.9%) experienced a decline in renal function. Responders enjoyed a 47% improvement in renal function from baseline, while non-responders had a 13% decrement in renal function (P < .0001). Responders had a higher baseline serum creatinine, lower eGFR, and a steeper decline in renal function prior to RAS, compared with non-responders. Kidney length, width, depth, and volume were not significantly different between responders and non-responders. Logistic regression analysis identified the rate of decline of renal function prior to stenting as the only independent preoperative predictor of improved renal function after RAS (odds ratio, 3.4; 95% confidence interval, 1.6 to 7.5; P = .0019). The rate of decline in eGFR per week was more than 20-fold greater for responders than non-responders (2.1% vs 0% decline in eGFR per week; P < .0001). No predictors of renal function deterioration after stenting were identified.
  
  
  CONCLUSIONS
  The current study found that a steep decline in preoperative renal function portends a higher likelihood of renal salvage from RAS among patients with renal insufficiency. Incorporating this finding into patient selection may improve outcomes for RAS.
authors.affiliation: Dallas Veterans Affairs Medical Center, Dallas, TX, USA. greg.modrall@utsouthwestern.edu
authors.forename: J Gregory
authors.initials: JG
authors.lastname: Modrall
authors.forename: Carlos H
authors.initials: CH
authors.lastname: Timaran
authors.forename: Eric B
authors.initials: EB
authors.lastname: Rosero
authors.forename: Jayer
authors.initials: J
authors.lastname: Chung
authors.forename: Frank A
authors.initials: FA
authors.lastname: Arko
authors.forename: R James
authors.initials: RJ
authors.lastname: Valentine
authors.forename: G Patrick
authors.initials: GP
authors.lastname: Clagett
authors.forename: Clayton
authors.initials: C
authors.lastname: Trimmer
mesh_terms: D000368:Aged; D017130:Angioplasty / Q000009:adverse effects / Q000295:instrumentation* / Q000401:mortality; D015415:Biomarkers / Q000097:blood; D016009:Chi-Square Distribution; D003404:Creatinine / Q000097:blood; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D053208:Kaplan-Meier Estimate; D007668:Kidney / Q000098:blood supply* / Q000473:pathology / Q000503:physiopathology*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D009929:Organ Size; D018579:Patient Selection; D020127:Recovery of Function; D012078:Renal Artery Obstruction / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D051437:Renal Insufficiency / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology*; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D015607:Stents; D015996:Survival Rate; D013781:Texas; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D003404:Creatinine