Clinical NephrologyA Clinical Score to Predict Acute Renal Failure after Cardiac SurgeryThakar, Charuhas V.*,§; Arrigain, Susana†; Worley, Sarah†; Yared, Jean-Pierre‡; Paganini, Emil P.* Author Information Departments of*Nephrology and Hypertension,†Biostatistics and Epidemiology, and‡Cardiothoracic Anesthesiology, Cleveland Clinic Foundation; and§Division of Nephrology and Hypertension, University of Cincinnati Medical Center, Cincinnati, Ohio Address correspondence to: Dr. Charuhas V. Thakar, Division of Nephrology and Hypertension, University of Cincinnati Medical Center, 231 Albert B. Sabin Way, Cincinnati, OH 45267. Phone: 513-558-4783; Fax: 513-558-4309; E-mail: [email protected] Received April 27, 2004. Accepted September 28, 2004. Published online ahead of print. Publication date available atwww.jasn.org. Journal of the American Society of Nephrology 16(1):p 162-168, January 2005. | DOI: 10.1681/ASN.2004040331 Buy Metrics 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. Copyright © 2005 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.