title: The changing definition of contrast-induced nephropathy and its clinical implications: insights from the Blue Cross Blue Shield of Michigan Cardiovascular Consortium (BMC2).
abstract: BACKGROUND
  The traditional definition of contrast-induced nephropathy (CIN) has been an absolute rise of serum creatinine (Cr) of ≥0.5 mg/dL, although most recent clinical trials have included a ≥25% increase from baseline Cr. The clinical implication of this definition change remains unknown.
  
  
  RESULTS
  We compared the association of the two definitions with risk of death or need for dialysis among 58,957 patients undergoing percutaneous coronary intervention in 2007 to 2008 in a large collaborative registry. Patients with a preexisting history of renal failure requiring dialysis were excluded. Contrast-induced nephropathy as defined by a rise in Cr ≥0.5 mg/dL (CIN(Traditional)) developed in 1,601, whereas CIN defined either as Cr ≥0.5 mg/dL or ≥25% increase in baseline Cr (CIN(New)) developed in 4,308 patients. Patients meeting the definition of CIN(New) but not CIN(Traditional) were classified as CIN(Incremental) (n = 2,707). Compared with CIN(New), CIN(Traditional) was more commonly seen in patients with abnormal renal function, which was more likely to develop in patients with normal renal function at baseline. Compared with CIN(Incremental), patients meeting the definition of CIN(Traditional) were more likely to die (16.7% vs 1.7%) and require in-hospital dialysis (9.8% vs 0%).
  
  
  CONCLUSIONS
  Our data suggest that the traditional definition of CIN (a rise in Cr of ≥0.5 mg/dL) in patients undergoing PCI is superior to ≥25% increase in Cr at identifying patients at greater risk for adverse renal and cardiac events.
authors.affiliation: University of Michigan School of Medicine, Cardiovascular Center, 1500 E. Medical Center Dr., Ann Arbor, MI 48109-5853, USA.
authors.forename: Nicklaus K
authors.initials: NK
authors.lastname: Slocum
authors.forename: P Michael
authors.initials: PM
authors.lastname: Grossman
authors.forename: Mauro
authors.initials: M
authors.lastname: Moscucci
authors.forename: Dean E
authors.initials: DE
authors.lastname: Smith
authors.forename: Herbert D
authors.initials: HD
authors.lastname: Aronow
authors.forename: Simon R
authors.initials: SR
authors.lastname: Dixon
authors.forename: David
authors.initials: D
authors.lastname: Share
authors.forename: Hitinder S
authors.initials: HS
authors.lastname: Gurm
mesh_terms: D058186:Acute Kidney Injury / Q000139:chemically induced* / Q000145:classification* / Q000401:mortality; D000368:Aged; D000369:Aged, 80 and over; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects* / Q000379:methods; D054598:Blue Cross Blue Shield Insurance Plans / Q000592:standards; D003226:Congresses as Topic; D003287:Contrast Media / Q000009:adverse effects*; D003404:Creatinine / Q000097:blood / Q000592:standards*; D016208:Databases, Factual; D004305:Dose-Response Relationship, Drug; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate; D017052:Hospital Mortality / Q000639:trends*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017410:Practice Guidelines as Topic; D012189:Retrospective Studies; D018570:Risk Assessment; D015996:Survival Rate
chemical_list: D003287:Contrast Media; D003404:Creatinine