Acute Kidney Injury Based on KDIGO (Kidney Disease Improving Global Outcomes) Criteria in Patients with Elevated Baseline Serum Creatinine Undergoing Cardiac Surgery

Abstract

IntroductionPreoperatively elevated serum creatinine (SCr) is considered an independent risk factor for morbidity and mortality after cardiac surgery. The aim of this study was to apply the Kidney Disease Improving Global Outcomes classification for acute kidney injury in a population of patients with preoperatively elevated serum creatinine who underwent cardiac surgery (coronary artery bypass grafting or cardiac valve surgery) and to evaluate the acute worsening of renal function as a predictor of 30-day mortality.MethodsThis was a single-center retrospective study that included patients from the Postoperative Cardiac Surgery Intensive Care Unit of the Hospital de Base, São José do Rio Preto Medical School. Demographics, type of surgery, laboratory data and pre, peri and postoperative data were obtained from a prospectively collected database. From January 2003 to June 2013, 2,878 patients underwent cardiac surgery, either coronary artery bypass grafting or cardiac valve surgery, at the Hospital de Base of São José do Rio Preto Medical School. Out of those, 918 showed elevated preoperative serum creatinine, with SCr > 1.30 mg/dL for men and > 1.00 mg/dL for women. Five hundred and forty nine patients (60%) undergoing coronary artery bypass grafting and 369 patients (40%) undergoing cardiac valve surgery. A Multivariate Cox Proportional Hazard Model (stepwise) was used to assess the relationship between AKI and mortality at 30 days.ResultsOut of the 918 patients studied, 391 (43%) had postoperative AKI: 318 (35%) had Kidney Disease Improving Global Outcomes stage 1, 27 (2.9%) had Kidney Disease Improving Global Outcomes stage 2, and 46 (5.0%) had Kidney Disease Improving Global Outcomes stage 3. Patients in every stage of acute kidney injury showed progressive increase in EuroSCORE values, 30-day mortality ratescardiopulmonary bypass duration, and intensive care length of stay. Among patients classified as Kidney Disease Improving Global Outcomes stage 3, 76% required dialysis with a 30-day mortality of 66%. The Cox proportional hazards model showed that the hazard ratio for 30-day mortality was 4.8 for Kidney Disease Improving Global Outcomes stage 1 patients, 13.5 for Kidney Disease Improving Global Outcomes stage 2 patients, and 20.8 for Kidney Disease Improving Global Outcomes stage 3 patients (P<0.001 for all). Subgroup analyses (coronary artery bypass grafting and cardiac valve surgery) had similar results.ConclusionIn this population, acute kidney injury based on the Kidney Disease Improving Global Outcomes criteria was a powerful predictor of 30-day mortality in patients with elevated preoperative serum creatinine who underwent cardiac surgery (coronary artery bypass grafting or cardiac valve surgery).

Trend, not severity, of acute kidney injury affects graft outcome in deceased donor kidney transplantation

“…Recently, several studies have defined AKI using current AKI criteria, including the Acute Kidney Injury Network (AKIN) criteria, RIFLE (Risk, Injury, Failure, Loss of kidney function, and End‐stage kidney disease) classification, and the Kidney Disease: Improving Global Outcomes (KDIGO), by comparing the measured sCr at the time of brain death with the terminal sCr measured just before kidney transplantation. In this study, we adopted the KDIGO AKI criteria to define AKI due to its superior predictability over the AKIN criteria or the RIFLE classification for hospitalized patients, including DDKs, patients undergoing cardiac surgery, and critically ill patients . Although many studies have suggested that DDKs with AKI are not inferior to DDKs without AKI, Boffa et al revealed that the primary nonfunction graft was higher in recipients given AKIN stage 3 DDKs .…”

“…In this study, we adopted the KDIGO AKI criteria to define AKI due to its superior predictability over the AKIN criteria or the RIFLE classification for hospitalized patients, 17 including DDKs, 18 patients undergoing cardiac surgery, 29 and critically ill patients. 30 TA B L E 5 Cox regression analysis for graft survival not reflect kidney function.…”

Renal recovery and long‐term survival following acute kidney injury after coronary artery surgery: a nationwide study

“…20,21 As Landspitali University Hospital is the sole institution performing open heart surgery in Iceland, the study represents a cohort of over 300,000 individuals for 13 years which may be considered, from most aspects of healthcare, similar to the majority of other Western countries. 20,21 As Landspitali University Hospital is the sole institution performing open heart surgery in Iceland, the study represents a cohort of over 300,000 individuals for 13 years which may be considered, from most aspects of healthcare, similar to the majority of other Western countries.…”

Outcomes of Moderate-to-Severe Acute Kidney Injury following Left Ventricular Assist Device Implantation

“…While some patients with high preoperative creatinine develop AKI postoperatively [18], others with CRS may have improvements in renal function following LVAD placement [7, 14, 19-21]. Many studies note these transient renal functional improvements, with return to baseline dysfunction after 1 or more years [6, 7].…”

“…Prevention of CRS should be the clinical goal, because once initiated, CRS cannot be readily aborted and is not completely reversible [22]. These reports emphasize the capacity of correcting reversible CRS, though the long-term impact of LVAD as destination therapy in these patients is not completely understood [18]. As renal dysfunction associated with heart failure may improve with device placement, it is difficult to assess the risk of moderate/severe AKI without an optimal laboratory tool for prediction and/or assessment [23].…”