A clinical score to predict acute renal failure after cardiac surgery

• Published in: Journal of the American Society of Nephrology Vol. 16; no. 1; pp. 162 - 168
• Main Authors: THAKAR, Charuhas V, ARRIGAIN, Susana, WORLEY, Sarah, YARED, Jean-Pierre, PAGANINI, Emil P
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD Lippincott Williams & Wilkins 2005
• Subjects: Acute Kidney Injury - etiology; Acute Kidney Injury - mortality; Acute Kidney Injury - therapy; Aged; Biological and medical sciences; Cardiac Surgical Procedures - mortality; Female; Humans; Male; Medical sciences; Middle Aged; Nephrology. Urinary tract diseases; Nephropathies. Renovascular diseases. Renal failure; Postoperative Complications - mortality; Predictive Value of Tests; Renal Dialysis; Renal failure; Risk Factors; ROC Curve; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Surgery of the heart; Kidney disease; Heart; Human; Nephrology; Score; Urinary system disease; Prognosis; Surgery; Renal failure; Complication; Circulatory system; Urology
• ISSN: 1046-6673; 1533-3450
• DOI: 10.1681/asn.2004040331

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.