title: Cystatin C blood level as a risk factor for death after heart surgery.
abstract: OBJECTIVE
  Pre-operative renal dysfunction is a known risk factor for mortality and morbidity after heart surgery. Despite limited accuracy, serum creatinine is widely used to estimate glomerular filtration rate (GFR). Cystatin C is more accurate for assessing GFR. The aim of the present study was to assess associations between GFR estimated from serum cystatin C levels before heart surgery and hospital mortality, hospital morbidity, and 1 year mortality.
  
  
  RESULTS
  In a prospective single-centre observational study, clinical risk factors for morbidity and mortality were recorded and serum creatinine and cystatin C levels were measured in patients admitted for heart surgery. Hospital mortality and morbidity and 1 year mortality were recorded. Over an 8 month period, 499 patients were screened, among whom 376 (74.5%) were included in the study. Hospital mortality was 5.6% (21 patients) and 1 year mortality was 10.2%. Hospital morbidity, defined by a length of stay above the 75th percentile, was 22.1% (83 patients). In the multivariable analysis, GFR estimated from serum cystatin C, but not GFR estimated from serum creatinine, was an independent risk factor for hospital morbidity/mortality (odds ratio per 10 mL/min of GFR decrease, 1.20 (1.07-1.34), P = 0.001) and for 1 year mortality (hazards ratio per 10 mL/min of GFR decrease, 1.26 (1.09-1.46), P = 0.002).
  
  
  CONCLUSIONS
  Pre-operative GFR estimation from serum cystatin C may provide a better risk assessment than pre-operative GFR estimation from serum creatinine in patients scheduled for heart surgery.
authors.affiliation: Intensive Care Unit, Liège University Hospital, Sart Tilman Bat B35, B-4000 Liège, Belgium. dledoux@chu.ulg.ac.be
authors.forename: Didier
authors.initials: D
authors.lastname: Ledoux
authors.forename: Mehran
authors.initials: M
authors.lastname: Monchi
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Chapelle
authors.forename: Pierre
authors.initials: P
authors.lastname: Damas
mesh_terms: D000368:Aged; D006348:Cardiac Surgical Procedures / Q000401:mortality*; D003404:Creatinine / Q000097:blood; D055316:Cystatin C; D015891:Cystatins / Q000097:blood*; D005260:Female; D005919:Glomerular Filtration Rate; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D008875:Middle Aged; D011300:Preoperative Care; D011379:Prognosis; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013903:Thoracic Surgery
chemical_list: C525030:CST3 protein, human; D055316:Cystatin C; D015891:Cystatins; D003404:Creatinine