Predicting cardiac surgery–associated acute kidney injury: The CRATE score

Abstract

a b s t r a c t a r t i c l e i n f oKeywords: Cardiac surgery Renal insufficiency Risk prediction Risk score Purpose: Acute kidney injury (AKI) is a frequent complication after cardiac surgery and is associated with increased mortality. The aim was to design a nondialytic AKI score in patients with previously normal renal function undergoing cardiac surgery. Methods: Data were collected on 909 patients who underwent cardiac surgery with cardiopulmonary bypass between 2012 and 2014. A total of 810 patients fulfilled the inclusion criteria. Patients were classified as having AKI based on the RIFLE criteria. Postoperative AKI occurred in 137 patients (16.9%). Several parameters were recorded preoperatively, intraoperatively, and at intensive care unit admission, looking for a univariate and multivariate association with AKI risk. A second data set of 741 patients, from 2 different hospitals, was recorded as a validation cohort. Results: Four independent risk factors were included in the CRATE score: creatinine (odds ratio [OR], 9.66; 95% confidence interval [CI], 4.77-19.56; P b .001), EuroSCORE (OR, 1.40; CI, 1.29-1.52; P b .001), lactate (OR, 1.03; CI, 1.01-1.04; P b .001), and cardiopulmonary bypass time (OR, 1.01; CI, 1.01-1.02; P b .001). The accuracy of the model was good, with an area under the curve of 0.89 (CI, 0.85-0.92). The CRATE score retained good discrimination in validation cohort, with an area under the curve of 0.81 (95% CI, 0.78-0.85). Conclusions: CRATE score is an accurate and easy to calculate risk score that uses affordable and widely available variables in the routine care surgical patients.

The KDIGO acute kidney injury guidelines for cardiac surgery patients in critical care: a validation study

“…This represents the first study to explore the associations between different criteria for multiple stages of KDIGO-defined AKI and morbidity and mortality after cardiac surgery. The frequency of AKI in our population was broadly similar to that previously reported in cardiac surgery patients [ 1 , 19 , 20 ]. RRT was more frequent than reported elsewhere [ 1 , 6 – 8 , 14 ] possibly as a substantial number of high risk tertiary referral, transplant and mechanical circulatory support patients are referred to our centre.…”

Cardiac and Vascular Surgery–Associated Acute Kidney Injury: The 20th International Consensus Conference of the ADQI (Acute Disease Quality Initiative) Group

“…Although many risk‐prediction scores for AKI after cardiac surgery have been published, only 8 have been externally validated with C statistics ranging from 0.72 to 0.89 (Table ) . In general, these scoring systems have good discrimination in assessing low‐risk groups but relatively poor discrimination in moderate to high‐risk patients .…”

“…Less severe forms of AKI are commonly seen after cardiac surgery with reported rates of Kidney Disease Improving Global Outcomes (KDIGO) stage 1 AKI reported between 20% and 70% depending on the patient risk factors and the inclusion of KDIGO serum creatinine (sCr) and/or urine output (UO) criteria for AKI . Three of the prediction rules have assessed risk of less severe forms of AKI defined using sCr criteria only . Of these, one used the RIFLE criteria of AKI, and another used the Acute Kidney Injury Network criteria …”

“…Three of the prediction rules have assessed risk of less severe forms of AKI defined using sCr criteria only . Of these, one used the RIFLE criteria of AKI, and another used the Acute Kidney Injury Network criteria …”

Perioperative Renal Pharmacological Protection During Cardiovascular Surgery

“…Importantly, duration of renal ischemia is a key determinant of postoperative AKI in abdominal aortic procedures. To aid clinicians in stratifying risk objectively, risk scores for postoperative AKI have been developed [33][34][35][36][37][38][39][40]. Importantly, most of these risk scores have been developed to predict need for RRT after cardiac surgery, while specific scores for vascular surgery are currently lacking [41].…”