title: Development of an easily applicable risk score model for contrast-induced nephropathy prediction after percutaneous coronary intervention: a novel approach tailored to current practice.
abstract: BACKGROUND
  Several risk factors for contrast-induced nephropathy (CIN) after percutaneous coronary intervention (PCI) have been identified. The cumulative effect of these risk factors on renal function has been assessed with the development of risk score models in a number of studies. However, concerns were raised that estimates of the risk attributable to individual factors may be unreliable. We sought to develop a simple risk score for developing CIN after PCI irrespective of use of prophylactic measures and also capturing the effect of pre-intervention medication and presence of various co-morbidities.
  
  
  METHODS
  Consecutive patients treated with elective or urgent PCI at our cardiac catheterization laboratory were enrolled (derivation cohort n = 488, validation cohort n = 200). CIN was defined as increase ≥ 25% and/or ≥ 0.5 mg/dl in serum creatinine at 48 h after PCI vs baseline. Multivariable logistic regression analysis was then performed to identify independent predictors of CIN (pre-existing renal disease, metformin use, history of previous PCI, peripheral arterial disease and ≥ 300 ml of contrast volume).
  
  
  RESULTS
  The incidence of CIN in the development cohort was 10.2% with a significant trend across increasing score values (p < 0.001). The model demonstrated good discriminating power (c-statistic 0.759) and excellent calibration (calibration slope 0.91). The model was validated internally by bootstrapping in 1000 samples (c-statistic 0.753) and in a cohort of 200 patients (c-statistic 0.864) demonstrating stable performance.
  
  
  CONCLUSIONS
  The proposed risk score is easily applicable and allows for practically simple risk assessment compared to other published scores while at the same time overcomes drawbacks of previous model designs.
authors.affiliation: University Cardiology Department, Democritus University of Thrace, Alexandroupolis, Greece. dtziakas@med.duth.gr
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Tziakas
authors.forename: Georgios
authors.initials: G
authors.lastname: Chalikias
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Stakos
authors.forename: Stavros
authors.initials: S
authors.lastname: Apostolakis
authors.forename: Thomaidi
authors.initials: T
authors.lastname: Adina
authors.forename: Petros
authors.initials: P
authors.lastname: Kikas
authors.forename: Apostolos
authors.initials: A
authors.lastname: Alexoudis
authors.forename: Ploumis
authors.initials: P
authors.lastname: Passadakis
authors.forename: Elias
authors.initials: E
authors.lastname: Thodis
authors.forename: Vassilis
authors.initials: V
authors.lastname: Vargemezis
authors.forename: Stavros
authors.initials: S
authors.lastname: Konstantinides
mesh_terms: D000368:Aged; D015331:Cohort Studies; D003287:Contrast Media / Q000009:adverse effects*; D005260:Female; D005500:Follow-Up Studies; D005544:Forecasting / Q000379:methods; D006801:Humans; D007674:Kidney Diseases / Q000139:chemically induced* / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D062645:Percutaneous Coronary Intervention / Q000009:adverse effects*; D017410:Practice Guidelines as Topic / Q000592:standards; D011237:Predictive Value of Tests; D012307:Risk Factors; D012720:Severity of Illness Index
chemical_list: D003287:Contrast Media