Cardiac Surgery-associated Acute Kidney Injury Research Articles

Iron metabolism indexes as predictors of the incidence of cardiac surgery-associated acute kidney surgery

BackgroundAcute kidney injury (AKI) is a major complication following cardiac surgery. We explored the clinical utility of iron metabolism indexes for identification of patients at risk for AKI after cardiac surgery.MethodsThis prospective observational study included patients who underwent cardiac surgery between March 2023 and June 2023. Iron metabolism indexes were measured upon admission to the intensive care unit. Multivariable logistic regression analyses were performed to explore the relationship between iron metabolism indexes and cardiac surgery-associated AKI (CSA-AKI). Receiver operating characteristic (ROC) curve was used to assess the predictive ability of iron, APACHE II score and the combination of the two indicators. Restricted cubic splines (RCS) was used to further confirm the linear relationship between iron and CSA-AKI.ResultsAmong the 112 recruited patients, 38 (33.9%) were diagnosed with AKI. Multivariable logistic regression analysis indicated that APACHE II score (odds ratio [OR], 1.208; 95% confidence interval [CI], 1.003–1.455, P = 0.036) and iron (OR 1.069; 95% CI 1.009–1.133, P = 0.036) could be used as independent risk factors to predict CSA-AKI. ROC curve analysis showed that iron (area under curve [AUC] = 0.669, 95% CI 0.572–0.757), APACHE II score (AUC = 0.655, 95% CI 0.557–0.744) and iron and APACHE II score combination (AUC = 0.726, 95% CI 0.632–0.807) were predictive indicators for CSA-AKI. RCS further confirmed the linear relationship between iron and CSA-AKI.ConclusionsElevated iron levels were independently associated with higher risk of CSA-AKI, and there was a linear relationship between iron and CSA-AKI.

Characteristics of initiation timing and anticoagulation of continuous renal replacement therapy in patients following cardiac surgery: A retrospective analysis of 28 patients.

Continuous renal replacement therapy (CRRT) used in cardiac surgery-associated acute kidney injury (CSA-AKI) may have different characteristics from other diseases. We reviewed the medical records of patients with CSA-AKI requiring CRRT who underwent cardiac surgery from January 2020 to September 2021. Patients with AKI caused by other reasons who received CRRT during the same period were also evaluated. A total of 28 patients with CSA-AKI and 12 patients with AKI caused by other reasons were enrolled in this study. Compared with AKI patients caused by other reasons, patients with CSA-AKI were found to have lower mean arterial pressure, higher level of bilirubin, higher vasoactive-inotropic score, and larger daily diuretic dosage. The patients with CSA-AKI were prescribed CRRT earlier than the patients with AKI caused by other reasons. There was a significant difference in the CRRT anticoagulation method between patients with CSA-AKI and patients with AKI caused by other reasons. Six patients with CSA-AKI were treated with regional citrate anticoagulation (RCA), and the other 22 patients were treated with low molecular weight heparin or without anticoagulants. The timing of CRRT initiation in patients with CSA-AKI is earlier than that in patients with AKI caused by other reasons. Although RCA is recommended as the preferred anticoagulant for patients without contraindications, patients with CSA-AKI often have circulatory dysfunction and severe liver damage, so the risk of citrate accumulation is greater, whether to use RCA should be determined according to the individual condition of the patient.

Aminopeptidasic Enzymes as Early Biomarkers of Cardiac Surgery-Associated Acute Kidney Injury and Long-Term Events

Background: Diagnosis of acute kidney injury (AKI) relies on serum creatinine (SCr) changes. This study investigated if urinary aminopeptidases are early and predictive biomarkers of cardiac surgery-associated AKI (CSA-AKI). Methods: Glutamyl aminopeptidase (GluAp), alanyl aminopeptidase (AlaAp), dipeptidyl peptidase-4 (DPP4), proteinuria, albuminuria, N-acetyl-β-D-glucosaminidase (NAG), and neutrophile gelatinase-associated lipocalin (NGAL) were measured in urine samples from 44 patients at arrival in the intensive care unit (ICU) after cardiac surgery. Sensitivity, specificity, and positive and negative predictive value for diagnosis of stages 1, 2, and 3 of AKI were analyzed for the highest quartile of each marker. We also studied the relationship with SCr after surgery, 6- and 12-month glomerular filtration rates (GFRs), and other long-term events over the next 5 years. Results: GluAp diagnosed the maximal number of patients that developed stage 2 or 3 of AKI, increasing diagnostic sensitivity from 0% to 75%. In addition, GluAp and DPP4 were related to the decrease in GFR at 6 or 12 months after surgery. Conclusions: Urinary aminopeptidases are a potential tool for the early diagnosis of CSA-AKI, with GluAp being the most effective marker for diagnosing stage 2 or 3 of AKI at ICU admission. GluAp and DPP4 serve as predictive biomarkers for a decrease in GFR.

Machine Learning with Clinical and Intraoperative Biosignal Data for Predicting Cardiac Surgery-Associated Acute Kidney Injury.

Early identification of patients at high risk of cardiac surgery-associated acute kidney injury (CSA-AKI) is crucial for its prevention. We aimed to leverage perioperative clinical and intraoperative biosignal data to develop machine learning models that predict CSA-AKI. We introduced a novel approach for extracting relevant features from high-resolution intraoperative biosignals to reflect the patient's baseline status, the extent of unfavorable conditions encountered intraoperatively, and data variability. We developed XGBoost models from 2,003 patients across three consecutive perioperative phases using: 1) only preoperative, 2) pre- and intraoperative, and 3) pre-, intra-, and postoperative variables. The predictive performance progressively improved throughout the three consecutive perioperative phases (e.g., AUROC of 0.767 to 0.797 and 0.840), all surpassing the Thakar Score's performance. According to the SHAP method, intraoperative perfusion pressure was most important in the prediction, highlighting the importance of intraoperative patient management and the use of high-resolution biosignal data in predictive modeling to analyze hemodynamic fluctuations during surgery. Early postoperative biomarkers were also important predictors, highlighting the importance of intensified monitoring early after surgery.

Cardiac surgery associated acute kidney injury, incidence, and predictors. Prospective observational single center study.

Acute kidney injury (AKI) is a condition characterized by a sudden decline in kidney function, leading to accumulation of waste products and fluids in the body. It is a common and serious complication in patients with cardiovascular diseases, and it is associated with increased morbidity and mortality.<br /> <br /> <b>Aim</b><br /> In this study, we explore the relationship between cardiac issues and the development of AKI, as well as strategies for its prevention and management. The primary aim of this study is to examine the incidence and risk factors for the AKI in patients admitted to the cardiac intensive care unit/CICU), as well as the impact of AKI on patient outcomes.<br /> <b> </b><br /> <b>Methods</b><br /> We conducted prospective observational single center study. 292 consecutive patients admitted to ICU after open heart surgery by sternotomy were included. Patients were monitored in ICU for frequency of AKI, perioperative risk factors, cardiac surgery-associated acute kidney injury (CSA-AKI) and their impact on patients’ outcome.<br /> <b>Results</b><br /> After admission to the intensive care unit, 33 patients (11.3%) developed CSA-AKI in the postoperative period. According to the analysis, male gender (p=0.03), decreased GFR (p=0.02) as well as high EuroSCORE II (p=0.013), hemoglobin level before surgery (p = 0.002) and the presence of diabetes and chronic kidney disease (p=0.03) were independent predictors of AKI after open-heart surgery. In patients who developed AKI, the duration of artificial lung ventilation was increased (21.3 vs 9.9 hours p = 0.001) and the duration of stay in the intensive care unit (4.3 vs. 1.9 days, P = 0.02).<br /> <b> Conclusion:</b><br /> Patients often have AKI after heart surgery. EuroSCORE II, gender, diabetes, time of cardiopulmonary bypass and chronic kidney disease are independent predictors of AKI development. The appearance of AKI is due to an unfavorable outcome of events. The appearance of acute kidney injury is associated with adverse consequences.<br /> <b> Key words: </b>Acute kidney injury, cardiac surgery, predictors of AKI, postoperative period.<br /> <br />  <b>Conflict of interests: </b>The authors declare no conflict of interest.

Prediction of cardiac surgery associated acute kidney injury using response to loop diuretic and urine neutrophil gelatinase associated lipocalin.

Cardiac surgery associated acute kidney injury (CS-AKI) is common. Urine response to loop diuretic and urine neutrophil gelatinase associated lipocalin (uNGAL) are separately associated with CS-AKI. We aimed to determine whether urine response to loop diuretic and uNGAL together were associated with postoperative day 2-4 CS-AKI. Two-center prospective observational study (ages 0-18years). uNGAL (8-12h after admission) (ng/mL) and urine response to loop diuretic (6h for bolus furosemide and 12h for infusion bumetanide) (mL/kg/hr) were measured. All diuretic doses were converted to furosemide equivalents. The primary outcome was day 2-4 CS-AKI. Patients were sub-phenotyped using a priori cutoffs (uNGAL + ≥ 100ng/mL and UOP + < 1.5mL/kg/hr) and optimal cutoffs (uNGAL + ≥ 127ng/mL and UOP + ≤ 0.79mL/kg/hr): 1) uNGAL-/UOP-, 2) uNGAL-/UOP + , 3) uNGAL + /UOP-, and 4) uNGAL + /UOP + . Multivariable regression was used to assess the association of uNGAL, UOP and each sub-phenotype with outcomes. 476 patients were included. CS-AKI occurred in 52 (10.9%). uNGAL was associated with 2.59-fold greater odds (95%CI: 1.52-4.41) of CS-AKI. UOP was not associated with CS-AKI. Compared with uNGAL + alone, uNGAL + /UOP + improved prediction of CS-AKI using a priori and optimal cutoffs respectively (AUC 0.70 vs. 0.75). Both uNGAL + /UOP + (IQR OR:4.63, 95%CI: 1.74-12.32) and uNGAL + /UOP- (IQR OR:5.94, 95%CI: 2.09-16.84) were associated with CS-AKI when compared with uNGAL-/UOP-. uNGAL is associated with CS-AKI. The sub-phenotype association was largely driven by uNGAL. Future studies standardizing diuretic dose and timing may be needed to refine the combined performance for clinical decision making.

Machine learning-based prediction of off-pump coronary artery bypass grafting-associated acute kidney injury.

The cardiac surgery-associated acute kidney injury (CSA-AKI) occurs in up to 1 out of 3 patients. Off-pump coronary artery bypass grafting (OPCABG) is one of the major cardiac surgeries leading to CSA-AKI. Early identification and timely intervention are of clinical significance for CSA-AKI. In this study, we aimed to establish a prediction model of off-pump coronary artery bypass grafting-associated acute kidney injury (OPCABG-AKI) after surgery based on machine learning methods. The preoperative and intraoperative data of 1,041 patients who underwent OPCABG in Chest Hospital, Tianjin University from June 1, 2021 to April 30, 2023 were retrospectively collected. The definition of OPCABG-AKI was based on the 2012 Kidney Disease Improving Global Outcomes (KDIGO) criteria. The baseline data and intraoperative time series data were included in the dataset, which were preprocessed separately. A total of eight machine learning models were constructed based on the baseline data: logistic regression (LR), gradient-boosting decision tree (GBDT), eXtreme gradient boosting (XGBoost), adaptive boosting (AdaBoost), random forest (RF), support vector machine (SVM), k-nearest neighbor (KNN), and decision tree (DT). The intraoperative time series data were extracted using a long short-term memory (LSTM) deep learning model. The baseline data and intraoperative features were then integrated through transfer learning and fused into each of the eight machine learning models for training. Based on the calculation of accuracy and area under the curve (AUC) of the prediction model, the best model was selected to establish the final OPCABG-AKI risk prediction model. The importance of features was calculated and ranked by DT model, to identify the main risk factors. Among 701 patients included in the study, 73 patients (10.4%) developed OPCABG-AKI. The GBDT model was shown to have the best predictions, both based on baseline data only (AUC =0.739, accuracy: 0.943) as well as based on baseline and intraoperative datasets (AUC =0.861, accuracy: 0.936). The ranking of importance of features of the GBDT model showed that use of insulin aspart was the most important predictor of OPCABG-AKI, followed by use of acarbose, spironolactone, alfentanil, dezocine, levosimendan, clindamycin, history of myocardial infarction, and gender. A GBDT-based model showed excellent performance for the prediction of OPCABG-AKI. The fusion of preoperative and intraoperative data can improve the accuracy of predicting OPCABG-AKI.

The Importance of Monitoring Blood Glucose Test in Patients Post-operative Coronary Artery Bypass Graft Surgery

Hyperglycemia is a risk factor for cardiac surgery-associated acute kidney injury in post-operative coronary artery bypass graft surgery patients. Glycemic control is important to prevent cardiac surgery-associated acute kidney injury. Postoperative glycemic control suggested 110-150 mg/dL. The aims of this study were to lower blood glucose levels and reduce the risk of occurrence or severity of cardiac surgery-associated acute kidney injury in post coronary artery bypass graft surgery patients. This study was conducted with a case study design involving 2 post operative coronary artery bypass graft patients who experienced hyperglycemia on the 1st to the 3rd day of treatment. Data collection was carried out from May 22 to May 23, 2023. The results of the case study showed that monitoring blood glucose in post-cardiac surgery patients is very important. Both patients experienced hyperglycemia in the early postoperative phase. With close monitoring and administration of insulin therapy according to the doctor's advice, the blood sugar levels of both patients were controlled. Monitoring urine output and evaluating serum creatinine levels showed that the first patient had cardiac surgery-associated acute kidney injury stage 1 on day 2 and showed improvement on day 3. The second patient did not develop cardiac surgery-associated acute kidney injury. The role of critical nurses in monitoring blood glucose levels and administering insulin doses is supported by related research. Strict monitoring and target ranges of blood glucose levels, in collaboration with the medical team are necessary to reduce the risk of cardiac surgery-associated acute kidney injury events.

EValuating the Effect of periopeRaTIve empaGliflOzin on cardiac surgery associated acute kidney injury: rationale and design of the VERTIGO study.

Cardiac surgery-associated acute kidney injury (CSA-AKI) is a serious complication in patients undergoing cardiac surgery with extracorporeal circulation (ECC) that increases postoperative complications and mortality. CSA-AKI develops due to a combination of patient- and surgery-related risk factors that enhance renal ischemia-reperfusion injury. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) such as empagliflozin reduce renal glucose reabsorption, improving tubulo-glomerular feedback, reducing inflammation and decreasing intraglomerular pressure. Preclinical studies have observed that SGLT2i may provide significant protection against renal ischemia-reperfusion injury due to their effects on inadequate mitochondrial function, reactive oxygen species activity or renal peritubular capillary congestion, all hallmarks of CSA-AKI. The VERTIGO (EValuating the Effect of periopeRaTIve empaGliflOzin) trial is a Phase 3, investigator-initiated, randomized, double-blind, placebo-controlled, multicenter study that aims to explore whether empagliflozin can reduce the incidence of adverse renal outcomes in cardiac surgery patients. The VERTIGO study (EudraCT: 2021-004938-11) will enroll 608 patients that require elective cardiac surgery with ECC. Patients will be randomly assigned in a 1:1 ratio to receive either empagliflozin 10mg orally daily or placebo. Study treatment will start 5days before surgery and will continue during the first 7days postoperatively. All participants will receive standard care according to local practice guidelines. The primary endpoint of the study will be the proportion of patients that develop major adverse kidney events during the first 90days after surgery, defined as ≥25% renal function decline, renal replacement therapy initiation or death. Secondary, tertiary and safety endpoints will include rates of AKI during index hospitalization, postoperative complications and observed adverse events. The VERTIGO trial will describe the efficacy and safety of empagliflozin in preventing CSA-AKI. Patient recruitment is expected to start in May 2024.

Acute Kidney Injury after Cardiac Surgery.

Cardiac surgery-associated acute kidney injury (CS-AKI) remains a vexing issue. Clinical trials for the prevention of CS-AKI have been disappointing despite enormous initial enthusiasm based on experimental data. The schism in experimental and clinical data has triggered a relook at our understanding of CS-AKI and the experimental and preclinical models. In this review, we discuss the therapeutic targets of major clinical trials. The silver lining in the midst is the standardization of anesthetic and perioperative care proposed by national societies. Implementation of the KDIGO bundle is a reasonable option to decrease the incidence of CS-AKI despite lack of proven robust benefits.

Urine metabolite changes after cardiac surgery predict acute kidney injury.

Acute kidney injury (AKI) is a serious complication in patients undergoing cardiac surgery, with the underlying mechanism remaining elusive and a lack of specific biomarkers for cardiac surgery-associated AKI (CS-AKI). We performed an untargeted metabolomics analysis of urine samples procured from a cohort of patients with or without AKI at 6 and 24 h following cardiac surgery. Based on the differential urinary metabolites discovered, we further examined the expressions of the key metabolic enzymes that regulate these metabolites in kidney during AKI using a mouse model of ischemia-reperfusion injury (IRI) and in hypoxia-treated tubular epithelial cells (TECs). The urine metabolomic profiles in AKI patients were significantly different from those in non-AKI patients, including upregulation of tryptophan metabolism- and aerobic glycolysis-related metabolites, such as l-tryptophan and d-glucose-1-phosphate, and downregulation of fatty acid oxidation (FAO) and tricarboxylic acid (TCA) cycle-related metabolites. Spearman correlation analysis showed that serum creatinine was positively correlated with urinary l-tryptophan and indole, which had high accuracy for predicting AKI. In animal experiments, we demonstrated that the expression of rate-limiting enzymes in glycolysis, such as hexokinase II (HK2), was significantly upregulated during renal IRI. However, the TCA cycle-related key enzyme citrate synthase was significantly downregulated after IRI. In vitro, hypoxia induced downregulation of citrate synthase in TECs. In addition, FAO-related gene peroxisome proliferator-activated receptor alpha (PPARα) was remarkably downregulated in kidney during renal IRI. This study presents urinary metabolites related to CS-AKI, indicating the rewiring of the metabolism in kidney during AKI, identifying potential AKI biomarkers.

Carboxyhemoglobin as Potential Biomarker for Cardiac Surgery Associated Acute Kidney Injury

Carboxyhemoglobin (CO-Hb) is a marker of hemolysis and inflammation, both risk factors for cardiac surgery-associated AKI (CSA-AKI). However, the association between CO-Hb and CSA-AKI remains unknown. A retrospective cohort study. Tertiary university-affiliated metropolitan hospital: single center. Adult on-pump cardiac surgery patients from July 2014 to June 2022 (N = 1,698). None. Patients were stratified into quartiles based on CO-Hb levels at intensive care unit (ICU) admission. A progressive increased risk of CSA-AKI was observed with higher CO-Hb levels at ICU admission. On multivariable logistic regression analysis, the highest quartile (CO-Hb ≥ 1.4%) showed an independent association with the occurrence of CSA-AKI (odds ratio 1.45 compared to the lowest quartile [CO-Hb < 1.0%], 95% CI 1.023-2.071; p = 0.038). Compared to patients with CO-Hb <1.4%, patients with CO-Hb ≥ 1.4% at ICU admission had significantly higher postoperative creatinine (135 vs 116 μmol/L, p < 0.001), higher rates of postoperative RRT (6.7% vs 2.3%, p < 0.001) and AKI (p < 0.001) on univariable analysis and shorter time to event for AKI or death (p < 0.001). CO-Hb ≥ 1.4% at ICU admission is an independent risk factor for CSA-AKI, which is easily obtainable and available on routine arterial blood gas measurements. Thus, CO-Hb may serve as a practical and biologically logical biomarker for risk stratification and population enrichment in trials of CSA-AKI prevention.

Risk factors for progression to chronic kidney disease in patients with cardiac valve replacement surgery-associated acute kidney injury

Objective: To explore the risk factors for progression to chronic kidney disease (CKD) in patients with cardiac valve replacement surgery-associated acute kidney injury (AKI). Methods: A retrospective, nested case-control study was conducted at Fuwai Central China Cardiovascular Hospital. The study subjects were patients who underwent cardiac valve replacement surgery from January 1, 2018 to December 31, 2020, with a baseline estimated glomerular filtration rate (eGFR)>60 ml·min-1·(1.73 m2)-1 and postoperative complication of AKI. The patients were followed up for 90 days after discharge from hospital. The endpoint event was defined as progression to CKD 90 days after the occurrence of cardiac valve replacement surgery-associated AKI. The patients were divided into CKD group and non-CKD group based on whether they experienced endpoint event. The baseline clinical data were compared between the two groups. The measurement data with non-normal distribution was represented as M (Q1,Q3). Logistic regression model was used to analyze the risk factors of endpoint event. The receiver-operating characteristic (ROC) curve was drawn to evaluate the performance for predicting CKD in cardiac valve replacement surgery-associated AKI patients. Results: A total of 149 cardiac valve replacement surgery-associated AKI patients (86 males and 63 females) were included in the study, aged (59.0±10.2) years. There were 27 patients (18.1%) who progressed to new-onset CKD 90 days after the occurrence of cardiac valve replacement surgery-associated AKI. Compared with non-CKD group, patients in CKD group had older age [66 (58, 70) vs 59 (53, 64) years], lower baseline eGFR [76.3 (65.8, 98.5) vs 92.7 (78.5, 101.6) ml·min-1·(1.73 m2)-1], higher proportion of preoperative hypertension [51.9% (14/27) vs 27.9% (34/122)] and serum creatinine at discharge [136 (101, 165) vs 86 (65, 104) μmol/L], and the differences were statistically significant (all P<0.05). The multivariate logistic regression analysis results revealed that older age (OR=1.063, 95%CI: 1.001-1.129, P=0.047), preoperative hypertension (OR=3.070, 95%CI: 1.105-8.532, P=0.031) and higher serum creatinine at discharge (OR=1.026, 95%CI:1.013-1.038, P<0.001) were risk factors for progression to CKD in patients with cardiac valve replacement surgery-associated AKI. The clinical risk model including age, preoperative hypertension, preoperative baseline eGFR, and serum creatinine at discharge produced a moderate performance for predicting progression to CKD in patients with cardiac valve replacement surgery-associated AKI [the area under the curve (AUC)=0.865, 95%CI: 0.790-0.940, P<0.001]. Conclusion: Older age, preoperative hypertension and higher serum creatinine at discharge are risk factors for progression to CKD in patients with cardiac valve replacement surgery-associated AKI.

Benzylic rearrangement for urinary analysis of guanidino and ureido compounds in cardiac surgery-associated acute kidney injury using high-performance liquid chromatography-tandem mass spectrometry.

RationaleBecause acute kidney injury (AKI) is closely related to poor prognosis in critically ill patients, developing biomarkers for its prediction and early diagnosis is particularly important. Endogenous guanidino compounds (GCs) and ureido compounds (UCs) can participate in various biochemical processes because of their important physiological activities. The aim of this study was to investigate the alteration profiles of urinary GCs/UCs as potential biomarkers in patients with cardiac surgery–associated acute kidney injury (CSA‐AKI) at different stages.MethodsGCs/UCs were reacted with benzil via benzylic rearrangement, and their derivatives were used to investigate fragmentation mechanisms using tandem mass spectrometry (MS/MS) in positive ion mode. Furthermore, a high‐performance liquid chromatography (HPLC)–MS/MS method was developed to measure the concentrations of GCs/UCs in urine samples taken from patients with CSA‐AKI at different time points.ResultsMS/MS analysis in positive ion mode showed that benzylic GCs/UCs exhibited similar fragmentation processes, which could produce the characteristic ion (C13H12N+) at m/z 182.0. Furthermore, an obviously different fragmentation pattern of benzylic UCs in the positive ion mode might be due to the neutral loss of the H2CO2 group under low collision energy. Of the eight selected GCs/UCs, methylguanidine exhibited significantly increased concentrations in urine when CSA‐AKI occurred, whereas guanidinoethyl sulfonate (GDS), homoarginine (HArg) and homocitrulline (HCit) exhibited decreased concentrations. After recovery from AKI, the urinary concentrations of the aforementioned GCs/UCs returned to normal. Some of the aforementioned metabolites with significant changes (GDS, HArg and HCit) had large areas under the curve in the receiver operating characteristic curve for distinguishing AKI stages on the third day after surgery.ConclusionsIn patients with CSA‐AKI, urinary GCs/UCs were significantly disrupted due to injured kidney, and some GC/UC metabolites exhibited a good ability to become potential biomarkers for AKI stages. The present study provides essential resources and new therapeutic targets for further research on CSA‐AKI.

A Case of Cardiac Surgery-Associated Acute Kidney Injury

Approximately 2 million patients undergo cardiac surgery annually with 20% to 30% developing the cardiac surgery-associated acute kidney injury. Patient who has undergone cardiac surgery in the past week and meets the criteria for acute kidney injury can be classified as a cardiac surgery-associated acute kidney injury. The cardiac surgery-associated acute kidney injury may be caused by various factors during perioperative period. Preoperative risk factors include advanced age, female gender, pre-existing renal insufficiency, heart failure, left main coronary artery disease, diabetes, chronic obstructive pulmonary disease, peripheral vascular disease, liver disease, low cardiac output and hypotension. Intraoperative risk factors include the type of surgery (valve surgery, combined valve and coronary artery surgery, emergency and reoperations), low-flow cardiopulmonary bypass, hypothermic cardiopulmonary bypass, deep hypothermic circulatory arrest, cardiopulmonary bypass duration &amp;gt;100-120 minutes, hemodilution, hemolysis and hemoglobinuria due to prolonged cardiopulmonary bypass duration. We present the case of a 53-year-old female with severe valvular heart disease complicated by infecting human immunodeficiency virus. She experienced an acute kidney injury after cardiac surgery. The rationale for this case report is to learn about the risk factors of cardiac surgery-associated acute kidney injury and take measures to prevent it.

The Relationship Between Perioperative Blood Product Use and the Incidence of Postoperative Renal Injury in Infants Undergoing Cardiac Surgery

Cardiac Surgery Associated Acute Kidney Injury (CS-AKI) is a serious complication that occurs in patients following cardiac surgery. It is characterized by the rapid decline in kidney function, leading to potential long-term kidney damage or even kidney failure. CS-AKI is a significant health concern, as it not only prolongs hospital stays and recovery time but also increases the risk of mortality. This study, conducted as a prospective observational study, aimed to investigate the relationship between perioperative blood product use and the incidence of postoperative acute kidney injury (AKI) in infants and young children undergoing cardiac surgery. It examined the perioperative use of these blood products and its association with the occurrence of AKI. The findings of this study revealed a significant association between the use of red blood cell suspension and platelets and the development of postoperative AKI. This suggests that the administration of these blood products during cardiac surgery may increase the risk of kidney injury in infants and young children. However, it is important to note that the study did not find a statistically significant association between plasma transfusion volume and the incidence of AKI. This suggests that while the use of certain blood products may contribute to the risk of AKI, the volume of plasma transfused does not seem to have a significant impact. The findings of this study provide valuable insights into the perioperative management of infants and young children undergoing cardiac surgery. It underscores the importance of carefully considering the use of blood products during surgery and taking necessary measures to minimize the risk of AKI.

Evaluating the Prevalence of Cardiac Surgery–associated Acute Kidney Injury After Septal Myectomy Combined With Concomitant Procedures in Obstructive Hypertrophic Cardiomyopathy

ObjectivesHypertrophic obstructive cardiomyopathy (HOCM) may be treated by septal myectomy. Cardiac surgery-associated acute kidney injury (CSA-AKI) is a common complication, but little is known about its incidence after septal myectomy. The objectives were to (i) evaluate the prevalence of CSA-AKI after septal myectomy and (ii) identify potential perioperative and phenotype-related factors contributing to CSA-AKI. DesignRetrospective database analysis with new data analysis. SettingSingle expertise university academic centre for septal myectomy HOCM patients. ParticipantData from 238 HOCM patients operated with septal myectomy between 2005-2022. InterventionsCSA-AKI was stratified by the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines by measurement of creatinine and urine production. Important HOCM phenotype-related and perioperative factors were analysed for their possible association with CSA-AKI. Measurements and Main ResultsCSA-AKI occurred in 45% of patients, of these, 55% were classified as KDIGO stage I, and the remaining 45% as stage II, with no chronic kidney damage being observed. Moreover, there were no phenotypical or perioperative characteristics that were more prevalent in the CSA-AKI cohort. However, the use of beta-blockers and coronary artery disease were more prevalent in the CSA-AKI cohort. ConclusionsCSA-AKI is a common complication after septal myectomy, but was transient and kidney function recovered in all patients.

Mechanism and clinical role of TIMP-2 and IGFBP-7 in cardiac surgery-associated acute kidney injury: A review.

Acute kidney injury (AKI) is a common postoperative complication, but there is still a lack of accurate biomarkers. Cardiac surgery-associated AKI is the most common cause of major-surgery-related AKI, and patients requiring renal replacement therapy have high mortality rates. Early diagnosis, intervention, and management are crucial for improving patient prognosis. However, diagnosing AKI based solely on changes in serum creatinine level and urine output is insufficient, as these changes often lag behind actual kidney damage, making early detection challenging. Biomarkers such as tissue inhibitor of metalloproteinases-2 (TIMP-2) and insulin-like growth factor-binding protein-7 (IGFBP-7) have been found to be significant predictors of moderate-to-severe AKI when combined with urine content analysis. This article reviews the mechanism of biomarkers TIMP-2 and IGFBP-7 in AKI and provides a comprehensive overview of the clinical effects of TIMP-2 and IGFBP-7 in cardiac surgery-associated AKI, including prediction, diagnosis, and progression.

#2593 Comparison of four predictive scoring models as assessment tools for cardiac surgery-associated acute kidney injury in post cardiac surgery patients

Abstract Background and Aims Cardiac surgery-associated acute kidney injury (CSA-AKI) is a predominant contributor to hospital-acquired AKI in ICU following sepsis. Despite a rising frequency of CSA-AKI, currently examined predictive models have not consistently delivered accurate stratification. Utilizing risk stratification systems offers clinicians the opportunity to identify patients at high risk, extend monitoring intervals, facilitate timely referral to nephrology services, and promptly initiate effective preventive and therapeutic interventions known to enhance renal function. This study seeks to identify the most effective model by comparing four established predictive scoring systems. The objective of this single-center retrospective, cross sectional study is to compare the clinical values of the Cleveland Clinical Score, Mehta Score, Simplified Renal Index and Acute Kidney Injury following Cardiac Surgery (AKICS) Score in predicting CS-AKI among patients who underwent cardiac surgery. Method A comprehensive examination of medical records was conducted for all individuals who underwent open-heart surgery between January 2010 and January 2019. Those patients who had CSA-AKI were subsequently identified. These identified individuals underwent assessment using the four predictive scoring models, leading to their categorization into high or low-risk groups for AKI development. Binary logistics regression was then used to describe the association between CSA-AKI development and the four scoring methods as predictors. Results Among the 114 cases of open-heart surgeries, 86 were eligible for inclusion in the study. Half of the patients, specifically 43 individuals (50%), developed CS-AKI, with 5 requiring renal replacement therapy. Among the four scoring methods evaluated, only the Mehta score (95% CI, p 0.019) and AKICS score (95% CI, p 0.011) demonstrated statistical significance in predicting CS-AKI. The odds ratios for both the Mehta Score (1.10) and AKICS Score (1.19) exceeded 1, suggesting that an increase in either score is associated with a higher likelihood of AKI occurrence. Conversely, the Cleveland Clinical Score (p 0.106) and Simplified Renal Index (p 0.399) were not found to be predictive. Conclusion In this single-center study, both the Mehta score and the AKICS scoring system demonstrated predictability for AKI after open-heart surgery. However, the Cleveland Clinical Scoring and Simplified Renal Index did not exhibit predictive capability in this context.

#624 The impact of hemoadsorption in patients with borderline chronic kidney disease undergoing coronary artery bypass grafting

Abstract Background and Aims With an annual incidence of up to 30%, cardiac surgery–associated acute kidney injury (CSA-AKI) may be one of the most underappreciated yet frequent complications and renal protective adjustments are crucial. We evaluated the impact of hemoadsorption as adjunctive therapy on clinical outcome in Kidney Disease Improving Global Outcomes (KDIGO) G2/A2) patients undergoing coronary artery bypass grafting (CABG). Method During a three-year period, 40 patients undergoing CABG with borderline chronic kidney disease (KDIGO-G2/A2) were treated with adjunctive hemoadsorption therapy and were compared by propensity score-matched 40 patients (KDIGO G2/A2) (Control). Primary endpoints were the need for renal replacement therapy (RRT)/dialysis and/or worsening of KDIGO stage in the perioperative period. Secondary endpoints were the change in inflammatory biomarkers, vasopressor requirement and ICU/hospital stay. In the study group, a 300 mL hemoadsorber (Cytosorbents Inc, NJ) was used for the entire duration of cardiopulmonary bypass (CPB). All patients were prepared via enhanced recovery after surgery (ERAS) protocol and surgical procedures were performed under moderate hypothermia with pulsatile flow and ultrafiltration. Patients with septic shock, limited life expectancy and refused to give consent were excluded. Results After institutional ethics committee approval was obtained, written informed consent was received from each patient. No significant difference was noted between groups in demographic, operative data and preoperative baseline laboratory. At the end of CPB; s-Creatinine (mg/dL) (1.85 ± 0.6 vs 2.751 ± 0.6; p = 0.035), NT-proBNP (pg/L) (130 ± 30 vs 180 ± 40; p = 0.04), IL-6 (pg/mL) (8.2 ± 4 vs 22.2 ± 4; p = 0.012) and myoglobulin (pg/L) (210 ± 75 vs 310 ± 80; p = 0.04) levels were significantly lower in the study group versus control. Clinical outcome is summarized in Figure. Conclusion This pioneering study demonstrated the additional protective effects of hemoadsorption in patients with borderline chronic kidney disease (KDIGO-G2/A2) undergoing CABG. Elimination of inflammatory parameters might be a complementary mechanism resulting in lesser worsening of kidney function/need of RRT and ICU stay. These findings require validation in large, multicenter trials.