A Comparison of AKIN, KDIGO, and RIFLE Definitions to Diagnose Acute Kidney Injury and Predict the Outcomes after Cardiac Surgery in a South Asian Cohort

Abstract

Background: Acute kidney injury (AKI) after cardiac surgery is associated with an increased mortality and morbidity. Different definitions for AKI have been used such as Acute Kidney Injury Network (AKIN), Kidney Disease: Improving Global Outcomes (KDIGO) or risk, injury, failure, loss, end-stage kidney disease (RIFLE). Each of these definitions have their own benefits and limitations for predicting the degree of AKI and adverse outcomes following cardiac surgery. This study was aimed to compare the three AKI definitions to diagnose AKI and their predictive ability for mortality and morbidity after isolated coronary artery bypass surgery (CABG) in a South Asian cohort. Material and Methods: A single center retrospective review was conducted on 1508 patients having undergone isolated CABG surgery during January 2015 to January 2019. AKI was assessed on three definitions and comparative receiver operating characteristics curves were built against the outcomes to assess discriminative power of each. Results: Mean age of participants was 59.43 (±1.12) years, predominantly males (82.6%). Patient with AKI were elder, more likely to be diabetic and hypertensive. AKI by any definition occurred in 58.7% (885/1508) patients. Frequency of AKI was 508 (33.7%), 517 (34.4%) and 871 (57.8%) on AKIN, KDIGO and RIFLE criteria, respectively. The proportion of patients with RIFLE- risk 619 (41%) was greater compared with AKIN stage 1 [342 (22.7%)], and KDIGO stage 1 [330 (21.9%)], while for stage 2 and 3 the proportions were comparable across the three systems. Area under the curve (AUC) for 30-day mortality for AKIN was [0.786, (95% CI: 0.764 to 0.806)], KDIGO: [0.796, (95% CI: 0.775 to 0.816)], and for RIFLE [0.844, (95% CI: 0.825 to 0.862)]. AUC for overall morbidity were in undesirable ranges (i.e. >0.5 to ≤ 0.7) for all three definitions. Conclusion: In a South Asian cohort, performance of AKIN and KDIGO criteria was comparable to diagnose AKI, while RIFLE definition, though overestimated the incidence of AKI particularly stage 1, and had an excellent discriminatory power to predict mortality compared to other two definitions.

Nephroprotective effects of cilastatin in people at risk of acute kidney injury: A systematic review and meta-analysis

“…We followed a pre-specified study protocol that was registered in the International Prospective Register of Systematic Reviews (PROSPERO) database (ID: CRD42023488809) 36 and adhered to the Preferred Reporting for Systematic Review and Meta-analysis (PRISMA) guidelines. 37…”

“…Eligible studies were those including treatment with cilastatin either alone or in combination with imipenem and included a comparator group not treated with cilastatin; this could include an inactive control group with or without a placebo, or one or more active comparator groups not receiving cilastatin. Studies were included if they reported one or more outcomes of interest related to nephrotoxicity including a measure of kidney function (e.g., urine output, serum creatinine, cystatin C, measured or estimated glomerular filtration rate using any technique), kidney structure (e.g., albuminuria/proteinuria, abnormal urine sediment, kidney injury biomarkers including markers of tubular damage such as neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), interleukin-18 (IL-18), kidney imaging, or kidney biopsy features), at risk of AKI based on serum creatinine changes or urine output criteria aligned with the Kidney Disease: Improving Global Outcomes (KDIGO), Acute Kidney Injury Network (AKIN), or risk, injury, failure, loss, end-stage kidney disease (RIFLE) criteria, 38 or as defined by the study authors. Additional outcomes of interest included downstream clinical outcomes of AKI, including all-cause mortality, development or progression of CKD, kidney failure, and cardiovascular events.…”

“…The specific data elements acquired included the primary author names, year of publication, geographical origin, study design, sample size, nature of the study population, participant age, sex distribution, and the documented study outcomes and their definitions. We sought to preferentially use definitions of AKI that aligned with the KDIGO, AKIN, RIFLE criteria 38 where possible, but used the definition provided by the study authors if the former were not reported. For studies where measures of kidney function were taken at multiple time points, we used the results from the last time point reported up to 90 days to define short-term changes and measurements after 90 days to identify long-term kidney function from each study.…”

Cardiac Surgery–Associated Acute Kidney Injury

“… 14 – 17 While KDIGO demonstrates promise, further research is necessary to identify the optimal diagnostic criteria for this patient population. 18 , 19 …”

Diagnosis, pathophysiology and preventive strategies for cardiac surgery-associated acute kidney injury: a narrative review

“…Luo et al prospectively analysed a clinical database of 3,107 adult patients who were admitted to the ICU and found that compared with the RIFLE criteria, KDIGO was more predictive of in-hospital mortality, but there was no significant difference between AKIN and KDIGO [ 13 ]. Yaqub et al retrospectively reviewed data from 1508 patients who underwent isolated (Coronary artery bypass grafting) CABG surgery and found that the performances of the AKIN and KDIGO criteria were comparable in diagnosing AKI, whilst the RIFLE definition, although overestimating the incidence of AKI, had a better power to predict mortality than the other two definitions [ 14 ].…”