title: Valvular heart operation is an independent risk factor for acute renal failure.
abstract: BACKGROUND
  Acute renal failure (ARF) after cardiac operation with cardiopulmonary bypass is associated with a high mortality rate. The purpose of this study was to determine and quantify whether valvular heart operation is an independent risk factor for developing ARF.
  
  
  METHODS
  We retrospectively analyzed 5,132 consecutive patients who underwent cardiac operation involving cardiopulmonary bypass between April 1997 and March 2001. Patients with significant renal impairment (preoperative serum creatinine > 200 micromol/L) were excluded. A multivariable logistic regression model was constructed to identify independent risk factors for the postoperative development of ARF.
  
  
  RESULTS
  In 151 (2.9%) patients ARF developed before hospital discharge. The crude incidence of ARF for isolated coronary artery bypass grafting, isolated valve(s) operation, and valve(s) with coronary artery bypass grafting operation was 1.9%, 4.4%, and 7.5%, respectively (p < 0.001). The results of the logistic regression analysis found that valve operation with or without coronary artery bypass grafting was an independent risk factor for the development of postoperative ARF (odds ratio 2.68, 95% confidence interval 1.89 to 3.79; p < 0.001). Other independent predictors of ARF were increased preoperative serum creatinine levels, urgent or emergent operation, insulin-dependent diabetes, and increased cardiopulmonary bypass time.
  
  
  CONCLUSIONS
  Valve operation is an independent risk factor for postoperative ARF. This risk is further increased by prolonged cardiopulmonary bypass.
authors.affiliation: Department of Research and Development, The Cardiothoracic Centre, Liverpool, United Kingdom. tony.grayson@ctc.nhs.uk
authors.forename: Antony D
authors.initials: AD
authors.lastname: Grayson
authors.forename: Magdy
authors.initials: M
authors.lastname: Khater
authors.forename: Mark
authors.initials: M
authors.lastname: Jackson
authors.forename: Mark A
authors.initials: MA
authors.lastname: Fox
mesh_terms: D058186:Acute Kidney Injury / Q000401:mortality*; D000328:Adult; D000368:Aged; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D003131:Combined Modality Therapy; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D003327:Coronary Disease / Q000401:mortality / Q000601:surgery*; D003404:Creatinine / Q000097:blood; D005260:Female; D006349:Heart Valve Diseases / Q000401:mortality / Q000601:surgery*; D019918:Heart Valve Prosthesis Implantation; D017052:Hospital Mortality; D006801:Humans; D007677:Kidney Function Tests; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000401:mortality*; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D016019:Survival Analysis
chemical_list: D003404:Creatinine