title: A clinical score to predict acute renal failure after cardiac surgery.
abstract: The risk of mortality associated with acute renal failure (ARF) after open-heart surgery continues to be distressingly high. Accurate prediction of ARF provides an opportunity to develop strategies for early diagnosis and treatment. The aim of this study was to develop a clinical score to predict postoperative ARF by incorporating the effect of all of its major risk factors. A total of 33,217 patients underwent open-heart surgery at the Cleveland Clinic Foundation (1993 to 2002). The primary outcome was ARF that required dialysis. The scoring model was developed in a randomly selected test set (n = 15,838) and was validated on the remaining patients. Its predictive accuracy was compared by area under the receiver operating characteristic curve. The score ranges between 0 and 17 points. The ARF frequency at each score level in the validation set fell within the 95% confidence intervals (CI) of the corresponding frequency in the test set. Four risk categories of increasing severity (scores 0 to 2, 3 to 5, 6 to 8, and 9 to 13) were formed arbitrarily. The frequency of ARF across these categories in the test set ranged between 0.5 and 22.1%. The score was also valid in predicting ARF across all risk categories. The area under the receiver operating characteristic curve for the score in the test set was 0.81 (95% CI 0.78 to 0.83) and was similar to that in the validation set (0.82; 95% CI 0.80 to 0.85; P = 0.39). In conclusion, a score is valid and accurate in predicting ARF after open-heart surgery; along with increasing its clinical utility, the score can help in planning future clinical trials of ARF.
authors.affiliation: Department of Nephrology and Hypertension, Cleveland Clinic Foundation, Cincinnati, OH, USA. thakarcv@ucmail.uc.edu
authors.forename: Charuhas V
authors.initials: CV
authors.lastname: Thakar
authors.forename: Susana
authors.initials: S
authors.lastname: Arrigain
authors.forename: Sarah
authors.initials: S
authors.lastname: Worley
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Yared
authors.forename: Emil P
authors.initials: EP
authors.lastname: Paganini
mesh_terms: D058186:Acute Kidney Injury / Q000209:etiology / Q000401:mortality* / Q000628:therapy; D000368:Aged; D006348:Cardiac Surgical Procedures / Q000401:mortality*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000401:mortality*; D011237:Predictive Value of Tests; D012372:ROC Curve; D006435:Renal Dialysis; D012307:Risk Factors