The incidence of acute kidney injury (AKI) increases after surgical aortic valve replacement (SAVR). This study aimed to characterize the risk factors of AKI after SAVR.

We conducted a retrospective registry study based on data from 299 consecutive patients undergoing SAVR. At 48 h after SAVR, 41 patients developed AKI. There was a significantly higher prevalence of older age, higher body mass index (BMI), and diabetes mellitus in the AKI group. Previous use of angiotensin-converting enzyme inhibitors/angiotensin receptor blocker (ACEI/ARB) and β-blocker, intake and output volumes within 24 h, mechanical ventilation time, length of intensive care unit and hospital stay, baseline creatinine, baseline, 24 h, and 48 h estimated glomerular filtration rate were strongly associated with the incidence of AKI. BMI >24, history of hypertension, use of ACEI/ARB and β-blocker, and mechanical ventilation time were associated with AKI. Univariate logistic regression indicated that overweight, hypertension, use of ACEI/ARB and β-blocker, and mechanical ventilation time were associated with AKI. Notably, the ACEF score was an independent predictor of AKI. The receiver operating characteristic curve was employed to assess the ACEF score for predicting AKI and the best cutoff was 1.1. After dividing ACEF into quartiles, each one-unit increment in ACEF led to a 2.27-fold risk in the incidence of AKI among patients.

AKI is a generalizable phenomenon occurring frequently after SAVR. The ACEF score is an independent predictor of AKI among patients undergoing SAVR.

Acute kidney injury (AKI) is a frequent complication of cardiac surgery, contributing to increased morbidity, longer hospital stays, and higher mortality. Evidence suggests amino acid (AA) supplementation may enhance renal blood flow and glomerular filtration rate (GFR), potentially reducing AKI risk; however, findings remain inconclusive. This study evaluated the efficacy of perioperative AA supplementation in preventing AKI and related complications post-cardiac surgery.

PubMed, Embase, and Cochrane databases were searched for randomized controlled trials (RCTs) comparing AA supplementation versus standard care in preventing cardiac surgery-associated AKI. Main outcomes included AKI incidence (defined by the Kidney Disease Improving Global Outcomes (KDIGO) criteria), 30-day mortality, and renal replacement therapy (RRT) requirement. Pooled risk ratios (RRs) with 95% confidence intervals (CIs) were calculated using random-effects models. Statistical significance was set at p < 0.05. The certainty of the evidence (CoE) was assessed using the GRADE approach.

Six RCTs involving 4501 cardiac surgery patients were included. AA mixture interventions significantly reduced the risk of AKI stage 1 (RR: 0.56; 95% CI: 0.77-0.96; p = .009; CoE: Moderate) and Stage 3 (RR: 0.53; 95% CI: 0.34-0.83; p = .005; CoE: Moderate), but not stage 2 (RR: 1.24; 95% CI: 0.60-2.55; p = .568; CoE: Low). Preliminary findings from glutamic acid and glutamine (single AA interventions) showed potential benefits in reducing AKI incidence (CoE: Very low) and improving surrogate biomarkers, respectively. No significant effects were observed on mortality or RRT incidence for any intervention.

AA mixtures likely reduce AKI incidence following cardiac surgery but show limited effects on mortality and RRT. Further trials are needed to confirm the benefits of glutamic acid and glutamine supplementation.

Use of amino acid supplementation for the prevention of acute kidney injury after cardiac surgery may be effective, but more trial data and confidence in a beneficial effect is needed for this to be implemented in everyday clinical practice.

Secreted protein acidic and rich in cysteine (SPARC), a collagen-binding matricellular protein, is reported to facilitate inflammation and fibrosis in various tissues including the kidneys. Ischemia/reperfusion (I/R) is a major process of acute kidney injury. To investigate whether SPARC inhibition might attenuate renal I/R injury, we injected small interfering RNA (siRNA) targeting SPARC into male BALB/c mice one day before 45 min of renal ischemia followed by 72 h of reperfusion. Serum creatinine concentration, blood urea nitrogen, histological tubular damage, tubulointerstitial fibrosis, and expression of collagen I and transforming growth factor-β were increased after I/R. Expression of 4-hydroxy-2-nonenal, an oxidative stress marker, and the inflammatory cytokines monocyte chemoattractant protein-1 and tumor necrosis factor-α, were also upregulated in I/R kidneys. Overexpression of SPARC mRNA was observed after I/R, and immunohistochemistry revealed that SPARC was localized mainly in damaged tubuloepithelial cells. Additionally, a disintegrin and metalloproteinase with thrombospondin type 1 motif (ADAMTS1) expression colocalized with SPARC. Injection of siRNA targeting SPARC attenuated renal dysfunction, histological abnormalities, collagen deposition, oxidative stress, and renal inflammation. In addition, SPARC gene knockdown suppressed the I/R-induced increases in ADAMTS1 and matrix metalloproteinase-2/9 expression. In conclusion, I/R-induced SPARC could be a novel therapeutic target against acute kidney injury.

This study aimed to investigate the impact of the proportion of hematologic malignancy patients in hospitals on the prognosis of chronic lymphocytic leukemia (CLL) patients undergoing cardiac surgery. Perioperative management of CLL patients is complex, particularly regarding immunosuppression and infection risks.

This retrospective study utilized data from the National Inpatient Sample (NIS) from 2010 to 2021. Adult CLL patients undergoing cardiac surgery were included, categorizing hospitals into five quintiles based on hematologic malignancy patient proportions. Outcomes included in-hospital mortality, acute kidney injury (AKI), postoperative bleeding, and infections.

AKI incidence was significantly lower in the Q5 group (OR: 0.68, 95% CI: 0.49-0.97), as was the rate of respiratory failure (OR: 0.53, 95% CI: 0.35-0.79). However, the rates of transfusion and acute heart failure were significantly higher in Q5 (acute heart failure OR: 1.70, 95% CI: 1.07-2.77). No significant differences were found in in-hospital mortality or other complications.

The proportion of hematologic malignancy patients affects CLL patient outcomes, with higher proportions linked to lower AKI and respiratory failure rates but increased transfusion and heart failure risks. Further research is warranted.

Acute kidney injury (AKI) is common in hospitalized adults and a risk factor for chronic kidney disease and mortality. The effect of angiotensin-converting enzyme inhibitors (ACEi) or angiotensin receptor blockers (ARBs) post-AKI on mortality and long-term kidney function remains unclear.

Propensity-weighted retrospective observational cohort study.

A total of 3,289 patients with AKI admitted to a tertiary care hospital from November 2015-October 2016, with follow-up until September 2020.

ACEi/ARB use within 180 days post-AKI.

All-cause mortality, and major adverse kidney events (MAKE) as defined by composite of renal replacement therapy post-AKI, sustained estimated glomerular filtration rate (eGFR) decline >30% from baseline, or eGFR ≤15 mL/min/1.73 m2.

We generated propensity weights for ACEi/ARB use post-AKI, using age, sex, comorbid conditions, prior medication, intensive care unit admission, severe sepsis, and index AKI Kidney Disease: Improving Global Outcomes severity. Cox proportional hazard models were used to test associations of post-AKI ACEi/ARB with mortality, MAKE, and joint models for eGFR slopes.

A total of 2,309 (70.2%) participants died or experienced MAKE by end of follow-up. 161 (4.9%) and 406 (12.3%) patients initiated or resumed prior ACEi/ARB use within 180 days post-AKI, respectively. Although the overall cohort had no significant mortality association with post-AKI ACEi/ARB use, a significant association with lower mortality was observed in patients with KDIGO 3 AKI (HR, 0.40; 95% CI, 0.21-0.75; P interaction = 0.003). However, post-AKI ACEi/ARB use was associated with increased MAKE in patients without cardiovascular indications for ACEi/ARB use (HR, 1.52; 95% CI, 1.17-1.98; P interaction = 0.03). Although post-AKI use of ACEi/ARB was associated with acute eGFR decline (initial eGFR change -2.3 mL/min/1.73 m2/year; 95% CI, -3.1 to -1.5; P < 0.001), no association with longer-term eGFR decline was observed.

Retrospective observational study on heterogeneous AKI cohort without data on ACEi/ARB cumulative exposure.

Early ACEi/ARB post-AKI was not associated with better long-term survival or kidney function but was associated with lower mortality in patients with KDIGO 3 AKI.

In the PROTECTION trial (Intravenous Amino Acid Therapy for Kidney Protection in Cardiac Surgery), intravenous amino acids decreased the occurrence of acute kidney injury in cardiac surgery patients with cardiopulmonary bypass. Recruitment of renal functional reserve may be responsible for such protection. However, patients with chronic kidney disease have diminished renal functional reserve, and amino acids may be less protective in such patients. Thus, a separate investigation of such patients is warranted.

For this study chronic kidney disease was defined as an estimated glomerular filtration rate of less than 60 ml · min -1 · 1.73 m -2 , and patients with estimated glomerular filtration rates greater than or equal to 60 ml · min -1 · 1.73 m -2 served as controls. The primary outcome was the occurrence of acute kidney injury. Secondary outcomes included severity of acute kidney injury, need for and duration of renal replacement therapy, and all-cause mortality.

Among chronic kidney disease patients (n = 812), compared with placebo, amino acids significantly decreased the rate of acute kidney injury (43.1% vs 50.3%; relative risk, 0.86; 95% CI, 0.74 to 0.99; P = 0.041; number needed to treat = 14) with a median percentage increase in estimated glomerular filtration rate from baseline to postoperative day 3 of 12.7% versus 6.5% ( P = 0.002). In estimated glomerular filtration rate-based chronic kidney disease subgroups (30 to 39, 40 to 49, and 50 to 59 ml · min -1 · 1.73 m -2 ), the amino acid effect was similar (interaction P = 0.50). Finally, amino acid infusion decreased the occurrence of severe (stage 3) acute kidney injury (2.7% vs . 5.6%; relative risk 0.48; 95% CI, 0.24 to 0.98; P = 0.038).

Amino acid infusion protected chronic kidney disease patients undergoing cardiopulmonary bypass from developing acute kidney injury, with an absolute risk reduction of 7% and a number needed to treat of 14 in a cohort with a greater than 45% rate of acute kidney injury. Moreover, it delivered a greater than 50% relative risk reduction in severe acute kidney injury.

Cardiac surgery-associated acute kidney injury (CSA-AKI) significantly increases postoperative mortality and healthcare costs. Despite the growing volume of CSA-AKI research, the field remains fragmented, with challenges in identifying high-impact studies, collaborative networks, and emerging trends. Bibliometric analysis addresses these gaps by systematically mapping knowledge structures, revealing research priorities, and guiding resource allocation for both researchers and clinicians.

We analyzed 4,474 CSA-AKI-related publications (2014-2023) from the Web of Science Core Collection (WoSCC) using VOSviewer, CiteSpace, the Bibliometrix Package in R, and the bibliometric online analysis platform.

Annual publications increased steadily, with the USA and China leading productivity. The Journal of Cardiothoracic and Vascular Anesthesia serves as the foremost preferred journal within this domain. Critical Care (IF = 15.1) has the highest impact factor. Yunjie Li published the most papers. John A Kellum has the highest H-index. The definition, pathogenesis or etiology, diagnosis, prediction, prevention and treatment, which are the research basis in CSA-AKI. Machine learning (ML) and prediction models emerged as dominant frontiers (2021-2023), reflecting a shift toward personalized risk stratification and real-time perioperative decision-making. These advancements align with clinical demands for early AKI detection and precision prevention.

This study not only maps the evolution of CSA-AKI research but also identifies priority areas for innovation: multicenter validation of predictive models to strengthen generalizability, preventive nephrology frameworks for long-term AKI survivor monitoring, and randomized controlled trials to confirm efficacy of machine learning-based CSA-AKI prediction tools.

Acute kidney injury (AKI) affects approximately 30% of patients undergoing cardiac surgery with conventional non-pulsatile cardiopulmonary bypass (CPB). Pulsatile flow has long been proposed for mitigating this complication. While the 2019 EACTS guidelines recommend pulsatile perfusion for high-risk renal patients, most evidence is based on intra-aortic balloon pump (IABP) studies, with limited evidence for centrifugal pumps. We aimed to evaluate whether pulsatile CPB using a centrifugal pump reduces postoperative AKI in patients undergoing cardiac surgery.

This retrospective study analyzed 824 patients who underwent cardiac surgery between December 2008 and December 2023. The patients were divided into pulsatile perfusion (PP) and non-pulsatile perfusion (NP) groups. Propensity score matching was adjusted for the baseline characteristics, resulting in 265 matched pairs. The primary endpoint was postoperative AKI, defined by the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Subgroup analyses were performed based on estimated glomerular filtration rate (eGFR).

In the matched cohort, the PP group had a significantly lower incidence of AKI than the NP group (20.8 vs. 34.3%; odds ratio, 0.5; 95% confidence interval, 0.33-0.75; P < 0.001). A subgroup analysis showed that patients with a preoperative eGFR of 15-60 had a significantly lower incidence of AKI in the PP group (28.3 vs. 47.1%; P = 0.005). No significant differences were observed in secondary outcomes, including hemodialysis, cerebrovascular events, and in-hospital mortality.

Pulsatile CPB using a centrifugal pump significantly reduced the incidence of postoperative AKI in cardiac surgery patients, particularly in those with preoperative renal impairment.

Background: This study aimed to develop and validate a straightforward clinical risk model utilizing white blood cell (WBC) counts to predict acute kidney injury (AKI) in critically sick patients with hepatocellular carcinoma (HCC). Methods: Data were taken from the Medical Information Mart for Intensive Care-IV (MIMIC-IV) database for the training cohort. Data for an internal validation cohort were obtained from the eICU Collaborative Research Database (eICU-CRD), while patients from our hospital were utilized for external validation. A risk model was created utilizing significant indicators identified through multivariate logistic regression, following logistic regression analysis to determine the primary predictors of WBC-related biomarkers for AKI prediction. The Kaplan-Meier curve was employed to evaluate the prognostic efficacy of the new risk model. Results: A total of 1628 critically sick HCC patients were enrolled. Among these, 23 (23.2%) patients at our hospital, 84 (17.9%) patients in the eICU-CRD database, and 379 (35.8%) patients in the MIMIC-IV database developed AKI. A unique risk model was developed based on leukocyte-related indicators following the multivariate logistic regression analysis, incorporating white blood cell to neutrophil ratio (WNR), white blood cell to monocyte ratio (WMR), white blood cell to hemoglobin ratio (WHR), and platelet to lymphocyte ratio (PLR). This risk model exhibited robust predictive capability for AKI, in-hospital mortality, and ICU mortality across the training set, internal validation set, and external validation set. Conclusion: This risk model seems to have practical consequences as an innovative and accessible tool for forecasting the prognosis of critically ill HCC patients, which may, to some degree, aid in identifying equitable risk assessments and treatment strategies.

Acute kidney injury (AKI) following cardiac surgery is common and is associated with poor outcomes. The combination of urinary tissue inhibitor of metalloproteinase 2 (TIMP-2) and insulin-like growth factor-binding protein 7 (IGFBP7) is a strong predictor of AKI after cardiac surgery. However, most studies have focused on non-Asian populations, and comparisons with other AKI biomarkers or the optimal timing for measurement have yet to be explored.

We prospectively enrolled adult patients at Kochi Medical School Hospital in Kochi, Japan, to assess the predictive values of [TIMP-2]•[IGFBP7], TIMP-2, IGFBP7, neutrophil gelatinase-associated lipocalin (NGAL), and liver fatty acid-binding protein (L-FABP) measured preoperatively and at 2, 4, 6, and 8 h, as well as on day 1 and day 2 after postoperative intensive care unit (ICU) admission, using receiver operating characteristic curve (ROC) analysis.

Of the 38 patients, 13 (34.2%) developed AKI: seven (18.4%) with stage 1, four (10.5%) with stage 2, and two (5.2%) with stage 3. ROC analysis showed that the area under the curve (AUC) for predicting any stage of AKI peaked at 0-4 h, with the highest value at 2 h after ICU admission. Among the biomarkers, [TIMP-2]•[IGFBP7] showed the best AUC at 2 h after ICU admission, followed by TIMP-2, IGFBP7, L-FABP, and NGAL.

Our study demonstrated the good predictive performance of urine biomarkers, including [TIMP-2]•[IGFBP7], TIMP-2, IGFBP7, NGAL, and L-FABP, for any stage of cardiac surgery-associated AKI (CSA-AKI). The combination of TIMP-2 and IGFBP7 measured 2 h after postoperative ICU admission effectively predicted CSA-AKI, identifying patients at higher risk.

Cardiac surgery associated acute kidney injury (CSA-AKI) is a frequent and severe complication. Goal Directed Perfusion (GDP) during cardiopulmonary bypass (CPB) has been developed to reduce post-operative complications, in particular CSA-AKI. Hence, we aimed to assess the implementation of a GDP strategy during CPB on the incidence of CSA-AKI in a large, unselected cardiac surgery population.

We conducted a retrospective, before and after study, including all patients admitted to our surgical intensive care unit (ICU) following a cardiac surgery with CPB in the year prior to GDP implementation (No-GDP group), and in the year following its implementation (GDP group). Primary endpoint was the incidence of acute kidney injury (AKI) according to KDIGO classification in each group. Secondary endpoints were ICU mortality and length of stay, and the main post-operative complications after cardiac surgery. Risk factors of AKI were evaluated using a multivariable logistic regression model.

Among 903 patients in our analysis, 314 (34 %) developed AKI. The incidence of AKI was lower after the implementation of GDP strategy (n = 111; 27.6 % vs n = 203; 40.5 %, p < 0.001). In the multivariable analysis, GDP was an independent factor of AKI reduction (OR 0.37, 95 %CI [0.27-0.52], p < 0.001). This benefit was significant regarding stage 1 AKI, but not stage 2 or 3 AKI. GDP was not associated with a change in post-operative ICU mortality, length of stay or any other post-operative complication.

GDP strategy implantation during CPB is associated with a reduction of postoperative AKI.

The nadir oxygen delivery index (DO2i) during cardiopulmonary bypass (CPB) is reportedly associated with acute kidney injury (AKI) in patients undergoing cardiac surgery. However, there are few reports on the relationship between patient sex and the nadir DO2i threshold to prevent AKI. The aim of this study was to seek and evaluate the optimal DO2i threshold differences between males and females to avoid AKI during on-pump cardiac surgery.

We retrospectively analyzed a total of 430 patients who underwent cardiac surgery between March 2017 and February 2023. A receiver operating characteristic analysis and univariable and multivariable regression analyses were performed to evaluate the association between perioperative variables, including the nadir DO2i and incidence of AKI, in males and females.

The nadir DO2i was significantly lower (median, 294 [interquartile range (IQR), 272-317] mL/min/m2 versus 277 [IQR, 262-295] mL/min/m2; P < .001) and cumulative time below the DO2i of 270 mL/min/m2 was longer (0.3 [IQR, 0-4.2] minutes vs 3.0 [IQR, 0-11.7] minutes; P < .001) in the female patients. However, the incidence rate of AKI was similar in males and females (15.2% [n = 39/256] vs 16.7% [n = 29/174]; P = .68). The best cut-off values of nadir DO2i for AKI were <301 mL/min/m2 (sensitivity, 82.1%; specificity, 39.5%) in males and <273 mL/min/m2 (sensitivity, 69.0%; specificity, 61.4%) in females.

The optimal DO2i to prevent AKI during cardiac surgery differs between males and females. Therefore, CPB management should be adjusted by sex based on the different cut-off values of nadir DO2i.

To compare the effects of fluid bolus therapy (FBT) with 20% albumin to crystalloid FBT on the incidence of cardiac surgery-associated acute kidney injury (CSA-AKI) and its severity and duration.

Secondary analysis of the multicenter, parallel-group, open-label, randomized HAS FLAIR-II trial.

Six intensive care units.

Patients who required clinician-determined FBT after cardiac surgery requiring cardiopulmonary bypass.

Patients were randomized to receive FBT with 20% albumin (up to 400 mL/day) or crystalloid fluid for all FBTs in the intensive care unit.

A total of 452 patients were included in the modified intention-to-treat population (224 in the 20% albumin group and 228 in the crystalloid group). AKI occurred in 54 (24%) patients in the 20% albumin group and 50 (22%) in the crystalloid group (odds ratio: 1.13, 95% confidence interval [CI]: 0.73 to 1.76). However, in patients who developed stages 2 and 3 AKI, those allocated to 20% albumin had a significantly lower median time-weighted average (TWA) creatinine: 144 µmol/L (interquartile range [IQR]: 109 to 162) versus 254 µmol/L (IQR: 182 to 294) than the crystalloid group (difference -105 µmol/L, [95% CI -170 to -41], p = 0.003) and a lower peak serum creatinine (-110 µmol/L [-189 to -32], p = 0.01). The reduced TWA creatinine in the 20% albumin group was seen in patients with both a low (p = 0.04) and normal preoperative serum albumin concentration (p < 0.001).

FBT with 20% albumin compared with crystalloid-based regimen did not reduce the occurrence of AKI in patients after cardiac surgery. However, it reduced the severity and duration of stages 2 and 3 AKI.

Sodium-glucose transporter-2 (SGLT2) inhibitors reduced the incidence of acute kidney injury in large cardiovascular outcome trials in patients with chronic heart and kidney failure. Acute kidney injury is a common complication following cardiac surgery. We hypothesized that perioperative SGLT2 inhibition could reduce kidney injury after cardiac surgery, measured with the biomarker neutrophil gelatinase-associated (NGAL).

In this open-label phase IV, randomized, parallel-group, pilot study, adult patients undergoing elective cardiac surgery with cardiopulmonary bypass were randomized to receive either an SGLT2 inhibitor, empagliflozin (10 mg; oral) once daily, from three days before surgery until postoperative day two, or standard-of-care. The primary outcome was the between-group difference of serum NGAL on the second postoperative day. Moreover, other biomarkers for acute kidney injury were measured, including serum kidney injury molecule-1 (KIM-1), hypoxia-inducible factor-1 alpha (HIF-1α), and urine NGAL/Creatinine and KIM-1/Creatinine ratios. Additional outcomes included acute kidney injury incidence within the first seven days following cardiac surgery according to Kidney Disease: Improving Global Outcomes criteria and metabolic parameters, including ketone body concentrations and glycemic control.

Between March 2022 and April 2023, 55 patients were included (sex: 73 % male, age: 66 ± 10 years, BMI: 28 ± 4 kg/m2, empagliflozin n = 25, control n = 30) in the intention-to-treat analysis. There were no significant between-group differences in serum and urine NGAL or KIM-1. However, empagliflozin significantly reduced the incidence of acute kidney injury (20 % vs 66.7 %; absolute difference 46.7 %, 95 % CI, -69.7 - -23.6; P < .001). A significant increase in serum HIF-1α after surgery was solely observed in the control group. We observed no between-group differences in the incidence of (euglycemic) ketoacidosis or hypoglycemic events.

In this pilot study, perioperative SGLT2 inhibition was not associated with lower NGAL levels. We observed that SGLT2 inhibition reduced the incidence of acute kidney injury in this small study population. As the results of this pilot study are hypotheses-generating, further validation is needed in a large-scale, double-blind, placebo-controlled, randomized trial, which is currently ongoing.

Acute kidney injury (AKI) develops in 20-50% of patients undergoing cardiac surgery (CS). We aimed to assess the predictive value of urinary biomarkers (UBs) for predicting CS-associated AKI. We also aimed to investigate the accuracy of the combination of UB measurements and their incorporation in predictive models to guide physicians in identifying patients developing CS-associated AKI.

All clinical studies reporting on the diagnostic accuracy of individual or combined UBs were eligible for inclusion. We searched three databases (MEDLINE, EMBASE, and CENTRAL) without any filters or restrictions on the 11th of November, 2022 and reperformed our search on the 3rd of November 2024. Random and mixed effects models were used for meta-analysis. The main effect measure was the area under the Receiver Operating Characteristics curve (AUC). Our primary outcome was the predictive values of each individual UB at different time point measurements to identify patients developing acute kidney injury (KDIGO). As a secondary outcome, we calculated the performance of combinations of UBs and clinical models enhanced by UBs.

We screened 13,908 records and included 95 articles (both randomised and non-randomised studies) in the analysis. The predictive value of UBs measured in the intraoperative and early postoperative period was at maximum acceptable, with the highest AUCs of 0.74 [95% CI 0.68, 0.81], 0.73 [0.65, 0.82] and 0.74 [0.72, 0.77] for predicting severe CS-AKI, respectively. To predict all stages of CS-AKI, UBs measured in the intraoperative and early postoperative period yielded AUCs of 0.75 [0.67, 0.82] and 0.73 [0.54, 0.92]. To identify all and severe cases of acute kidney injury, combinations of UB measurements had AUCs of 0.82 [0.75, 0.88] and 0.85 [0.79, 0.91], respectively.

The combination of urinary biomarkers measurements leads to good accuracy.

Early detection of surgical complications allows for timely therapy and proactive risk mitigation. Machine learning (ML) can be leveraged to identify and predict patient risks for postoperative complications. We developed and validated the effectiveness of predicting postoperative complications using a novel surgical Variational Autoencoder (surgVAE) that uncovers intrinsic patterns via cross-task and cross-cohort presentation learning.

This retrospective cohort study used data from the electronic health records of adult surgical patients over 4 years (2018-2021). Six key postoperative complications for cardiac surgery were assessed: acute kidney injury, atrial fibrillation, cardiac arrest, deep vein thrombosis or pulmonary embolism, blood transfusion, and other intraoperative cardiac events. We compared surgVAE's prediction performance against widely-used ML models and advanced representation learning and generative models under 5-fold cross-validation.

89 246 surgeries (49% male, median [IQR] age: 57 [45-69]) were included, with 6502 in the targeted cardiac surgery cohort (61% male, median [IQR] age: 60 [53-70]). surgVAE demonstrated generally superior performance over existing ML solutions across postoperative complications of cardiac surgery patients, achieving macro-averaged AUPRC of 0.409 and macro-averaged AUROC of 0.831, which were 3.4% and 3.7% higher, respectively, than the best alternative method (by AUPRC scores). Model interpretation using Integrated Gradients highlighted key risk factors based on preoperative variable importance.

Our advanced representation learning framework surgVAE showed excellent discriminatory performance for predicting postoperative complications and addressing the challenges of data complexity, small cohort sizes, and low-frequency positive events. surgVAE enables data-driven predictions of patient risks and prognosis while enhancing the interpretability of patient risk profiles.

Atrial fibrillation has been linked with poor outcomes in patients with cardiac amyloidosis. We evaluate the in-hospital outcomes of patients with atrial fibrillation and concomitant cardiac amyloidosis with and without catheter ablation.

The National Inpatient Sample databases (2016 to 2021) were queried to identify patients admitted with atrial fibrillation and concomitant cardiac amyloidosis using ICD 10 codes. The study population aged >18 years was divided into two cohorts; ablation (AB) vs. no ablation (NAB). Multivariate logistic regression model adjusting for baseline characteristics and comorbidities. The primary outcome was all-cause in-hospital mortality. Secondary outcomes were acute heart failure, cardiogenic shock, ventricular fibrillation, major bleeding, stroke, length of stay, and hospitalization cost.

73,160 patients were identified. 595(0.8 %) underwent ablation and 72,656 (99.2 %) did not. Both NAB and AB patients were predominantly white (69.6 % and 60.3 %) respectively. AB patients were younger with median age [74 years (IQR 66-80) vs. 78 years (IQR 71-84), p < 0.01], compared with NAB patients. AB patients were more likely to have heart failure (76.5 % vs. 65.3 %, p = 0.04), and have a family history of CAD (11.1 % vs. 4.8 %, p = 0.03). Contrarily, NAB patients were more likely to have dementia (11.5 % vs. 2.5 %, p = 0.01). After adjusting for baseline characteristics and comorbidity, there was no difference in all-cause mortality (OR 0.3, CI 0.08-1.35, p = 0.12), stroke (OR 1.1, CI 0.4-2.8, p = 0.87), or major bleeding (OR 1.4, CI 0.7-2.6, p = 0.37). Undergoing ablation was associated with higher odds of acute heart failure (OR 1.9, CI 1.1-3.3, p<0.01). After adjusting for inflation using the consumer price index, adjusted total cost of hospitalization was for higher AB patients was compared to NAB patients ($41,499.22 vs. $13,085.11) with a significantly longer length of stay among AB patients (7 days vs. 5days, p < 0.01).

Atrial fibrillation and concomitant cardiac amyloidosis in patients undergoing catheter ablation are associated with an increased risk of acute heart failure, higher cost, and a longer length of stay.

To evaluate the efficacy of intravenous (IV) amino acids in preventing acute kidney injury (AKI) in patients undergoing cardiac surgery.

PubMed, EMBASE, and Cochrane Library databases were systematically searched for all relevant randomised controlled trials (RCTs) published from inception to July 25, 2024. A random effects model was used to pool the risk ratios (RR) for dichotomous outcomes, and the combined data was visually represented using forest plots.

3 studies involving 3646 patients were included in the meta-analysis. IV amino acids did not significantly lower the overall AKI incidence compared with control measures. However, they significantly reduced the risk of Stage 1 AKI and Stage 3 AKI. No differences were observed between intervention and control for Stage 2 AKI or need for kidney replacement therapy.

IV amino acids may offer protective benefits against severe AKI stages in cardiac surgery patients. Further studies are warranted to validate our findings.

Ischemia-reperfusion (IR) is a leading cause of acute kidney injury (AKI), and pigs are commonly used in preclinical AKI models. However, existing models often vary in the methods used to induce ischemia, and the resulting AKI tends to be mild-to-moderate. Moreover, follow-up is often performed under volatile anesthesia, which, in contrast to total intravenous anesthesia (TIVA), can induce malignant hyperthermia and cause hemodynamic instability. Here we present a novel surgical model of IR-induced AKI using bilateral renal artery clamping under TIVA. Anesthesia was induced via TIVA with diazepam, ketamine, and morphine. After retroperitoneal exposure, the renal arteries were isolated and clamped with a plastic tube for 90 min, followed by 8 h of reperfusion. The IR group (n = 6) was compared with a Sham group (n = 5) that underwent the same procedure without IR. The IR group developed moderate-to-severe AKI as evidenced by reduced glomerular filtration, a 158% increase in plasma creatinine versus 21% in the Sham group, and elevated neutrophil gelatinase-associated lipocalin levels (+280% in IR vs. 0% in Sham), indicating tubular injury. Histopathology confirmed these findings. Thus, this preclinical model successfully induced moderate-to-severe AKI in pigs. The TIVA anesthetic protocol offered several advantages compared to halogenated gas anesthesia.

Acute kidney injury (AKI) is a common and serious complication after cardiac surgery that significantly affects patient outcomes. Given the limited treatment options available, identifying modifiable risk factors is critical. Frailty and obesity, two heterogeneous physiological states, have significant implications for identifying and preventing AKI. Our study investigated the interplay among frailty, body composition, and AKI risk after cardiac surgery to inform patient management strategies.

This retrospective cohort study included three international cohorts. Primary analysis was conducted on adult patients who underwent cardiac surgery between 2014 and 2019 at Wuhan Union Hospital, China. We tested the generalizability of our findings with data from two independent international cohorts, the Medical Information Mart for Intensive Care IV (MIMIC-IV) and the eICU Collaborative Research Database. Frailty was assessed using a clinical lab-based frailty index (FI-LAB), while total body fat percentage (BF%) was calculated based on a formula accounting for BMI, sex, and age. Logistic regression models were used to analyze the associations between frailty, body fat, and AKI, adjusting for pertinent covariates.

A total of 8785 patients across three international cohorts were included in the study. In the primary analysis of 3569 patients from Wuhan Union Hospital, moderate and severe frailty were associated with an increased AKI risk after cardiac surgery. Moreover, a nonlinear relationship was observed between BF% and AKI risk. When stratified by the degree of frailty, lower body fat correlated with a decreased incidence of AKI. Extended analyses using the MIMIC-IV and eICU cohorts ( n =3951 and n =1265, respectively) validated these findings and demonstrated that a lower total BF% was associated with decreased AKI incidence. Moderation analysis revealed that the effect of frailty on AKI risk was moderated by the BF%. Sensitivity analyses demonstrated results consistent with the main analyses.

Higher degrees of frailty were associated with an elevated risk of AKI following cardiac surgery, and total BF% moderated this relationship. This research underscores the significance of integrating frailty and body fat assessments into routine cardiovascular care to identify high-risk patients for AKI and implement personalized interventions to improve patient outcomes.

Acute kidney injury (AKI) occurs in up to 50% of cardiac surgical patients and is often hemodynamically mediated. Point-of-care ultrasound is a non-invasive tool that has the potential to characterize intrarenal hemodynamics and predict the risk of AKI.

We aimed to determine the predictive characteristics of intrarenal arterial and venous Doppler markers for postoperative AKI in cardiac surgical patients.

This study is the secondary analysis of a prospective cohort study.

This study is carried out in a care academic cardiac surgical center in Montreal, Quebec, Canada.

Adult patients undergoing cardiac surgery with the use of cardiopulmonary bypass.

Point-of-care ultrasound assessments were performed preoperatively and at intensive care unit admission. Arterial measurements included the renal resistive index (RRI) and intrarenal artery velocity-time integral normalized to peak systolic velocity (VTI/PSV). Venous measurements included intrarenal venous flow (IRVF) pattern and renal venous stasis index (RVSI).

We used area under the receiving operating characteristic curves (AUCs) with net reclassification index (NRI) and multivariable logistic regression to determine predictive characteristics for postoperative AKI. Furthermore, we used hierarchical clustering to identify potential groups with similar Doppler parameters and performed comparisons of patients' characteristics and outcomes between groups.

We included 136 patients with 47 (34.6%) developing postoperative AKI. At intensive care unit admission, arterial indices showed similar discrimination for the prediction of AKI (RRI: AUC = 0.64; 95% confidence interval (CI) = 0.55 to 0.74; and VTI/PSV: AUC = 0.67; 95% CI = 0.57 to 0.77). Venous Doppler indices including IRVF patterns (AUC = 0.64; 95% CI = 0.53 to 0.74) and RVSI (AUC = 0.60; 95% CI = 0.50 to 0.71) also showed similar performance. The combined model of RRI and IRVF pattern (AUC = 0.69; 95% CI = 0.59 to 0.78) improved the prediction of AKI compared to either RRI (NRI = 0.50; 95% CI = 0.17 to 0.84) or IRVF pattern (NRI = 0.38; 95% CI = 0.04 to 0.70) alone. Through hierarchical clustering, we identified 3 groups (1: low RRI, 2: high RRI/low RVSI, and 3: high RRI/high RVSI) with different patient characteristics and outcomes. The patient in group 3 had a higher risk of AKI and worse clinical outcomes compared with other groups.

Single-center design in cardiac surgical patients limits generalizability.

Although more complex indices of intrarenal Doppler indices including the VTI/PSV and RVSI did not improve prediction of postoperative AKI, combining RRI and IRVF pattern improved risk prediction for AKI. Intrarenal arteriovenous Doppler subphenotypes identified patient groups at high risk of postoperative AKI.

Acute kidney injury (AKI) is a frequent and important complication of cardiac surgery. Decreased perfusion is a key mechanism. This decreased perfusion may be attenuated by intravenous amino acids (AAs) through recruitment of renal functional reserve.

The study investigators performed a PubMed search of all articles published from 1980 to August 30, 2024, with combined search criteria of "renal functional reserve," "amino acids," "cardiac surgery," and "cardiopulmonary bypass" by using MEDLINE (PubMed), Embase, and the Cochrane Central Register of Clinical Trials. Included were studies describing the effect of AAs on renal functional reserve and studies of adult cardiac surgery patients with information on renal function. A narrative review was developed.

Multiple experimental and human studies over >40 years have recurrently and consistently shown that the administration of an oral protein load or intravenous AAs increase renal blood flow and glomerular filtration rate by >30%. Moreover, several pilot investigations in cardiac surgery with cardiopulmonary bypass consistently showed renal benefits with intravenous AAs. Finally, a pivotal trial of 3511 cardiac surgery patients (the PROTECTION trial) recently confirmed such beneficial effects in a double-blind multicenter international setting.

Intravenous AAs consistently recruit renal functional reserve and improve kidney function in cardiac surgery patients. These findings have been confirmed by the PROTECTION (Intravenous Amino Acid Therapy for Kidney Protection in Cardiac Surgery) trial. Intravenous AA therapy is the only proven treatment to prevent and/or attenuate the severity of cardiac surgery-associated AKI.

To investigate the association between preoperative nutritional scores and moderate-to-severe acute kidney injury (AKI) after coronary artery bypass graft (CABG) surgery and the predictive significance of nutritional indices for moderate to severe AKI.

This study retrospectively included older patients underwent CABG surgery from the Medical Information Mart for Intensive Care (MIMIC) database. Nutritional scores were calculated by the Geriatric Nutritional Risk Index (GNRI) and the Prognostic Nutritional Index (PNI), respectively. Moderate-to-severe injury was determined by KDIGO criteria. Logistic regression, subgroup analysis, and restricted cubic splines were utilized to investigate the association. The predictive value was also assessed by the area under the curve (AUC), net reclassification index (NRI), and integrated discrimination improvement (IDI).

A total of 1,007 patients were retrospectively included, of which 100 (9.9%) and 380 (37.7%) had malnutrition calculated by GNRI and PNI scores. The incidence of moderate-to-severe AKI was 524 (52.0%). After adjustment for selected risk factors, worse nutritional scores were associated with a higher incidence of moderate-to-severe AKI (PGNRI<0.001; PPNI=0.001). Integrating these indices into different base models improves their performance, as manifested by significant improvements in AUCs and NRIs (p < 0.05).

Worse preoperative nutritional status was associated with an elevated risk of postoperative moderate-to-severe AKI. Integrating these indices into base models improve their predictive performance. These results highlight the importance of assessing nutritional status among older patients had CABG surgery.

Background Cardiac surgery-associated acute kidney injury (CSA-AKI) remains a significant complication following coronary artery bypass grafting (CABG), affecting 22%-30% of patients. This study evaluates the efficacy of NephroCheck, a biomarker-based test measuring insulin-like growth factor-binding protein 7 (IGFBP7) and tissue inhibitor of metalloproteinases-2 (TIMP2), in predicting postoperative AKI. Methods In this retrospective observational cohort study, 21 patients undergoing isolated CABG were analyzed. NephroCheck values were measured preoperatively, upon ICU admission, and at 24 hours post-admission. Patients with chronic kidney disease (CKD), heart failure, or preoperative serum creatinine of ≥2 mg/dL were excluded. AKI was defined using the Kidney Disease Improving Global Outcomes (KDIGO) criteria through postoperative day 7. Results Seven patients developed postoperative AKI. Preoperative NephroCheck values were significantly elevated in the AKI group compared to controls (1.34 (ng/ml)2/1000 ± 1.33 vs 0.54 (ng/ml)2/1000 ± 0.43, p = 0.009), while traditional renal function parameters showed no significant differences. Regression analysis identified preoperative NephroCheck as the only significant predictor of postoperative AKI (OR: 17.85, p = 0.047). Traditional risk factors, including preoperative renal function, Society of Thoracic Surgeons (STS) score, and operative times, showed no significant predictive value. Conclusions Preoperative NephroCheck testing demonstrates significant utility in predicting CSA-AKI following CABG, outperforming traditional risk assessment methods. These findings suggest that incorporating NephroCheck into routine preoperative assessments could enable more targeted preventive interventions, potentially reducing CSA-AKI incidence and its associated complications.

To investigate the safety and efficacy of ANG-3777, a hepatocyte growth factor mimetic, in mitigating the risk of acute kidney injury (AKI) in patients undergoing cardiac surgery with cardiopulmonary bypass.

In this double-blind placebo-controlled study (Guard Against Renal Damage [GUARD]), patients were randomized to receive intravenous ANG-3777 2 mg/kg or placebo once daily for 4 days. The primary end point was severity of AKI, measured by mean area under the concentration-time curve on percent increase in serum creatinine from days 2 to 6. Secondary end points included the proportions of patients who developed major adverse kidney events by day 30 or 90 and the percentage of patients diagnosed with AKI through day 5.

In total, 259 patients received study treatment (ANG-3777, n = 129; placebo, n = 130). Through day 6, there was no significant difference in least-squares mean change in serum creatinine between ANG-3777 and placebo (1.1%; 95% confidence interval, -6.2 to 8.4; P = .77), or in proportions of patients who developed major adverse kidney events by day 30 (18.6% vs 16.2%; P = .60) or day 90 (14.7% vs 21.5%; P = .16). Similar proportions of patients were diagnosed with AKI through day 5 (ANG-3777, 47.3%; placebo, 48.5%); however, exploratory analysis revealed more patients diagnosed with AKI postoperatively showed signs of recovery after treatment with ANG-3777 than placebo. Overall, ANG-3777 was well tolerated, with similar incidences of treatment-emergent adverse events between treatment arms.

Findings from this study do not support the efficacy of ANG-3777 in preventing the development of AKI after cardiopulmonary bypass.

Cardiac Surgery-Associated Acute Kidney Injury (CSA-AKI) is a serious complication seen in approximately 20-30% of cardiac surgery patients. The underlying pathophysiology is complex, often involving both patient- and procedure related risk factors. In contrast to AKI occurring after other types of major surgery, the use of cardiopulmonary bypass comprises both additional advantages and challenges, including non-pulsatile flow, targeted blood flow and pressure as well as the ability to manipulate central venous pressure (congestion). With an increasing focus on the impact of CSA-AKI on both short and long-term mortality, early identification and management of high-risk patients for CSA-AKI has evolved. The present narrative review gives an up-to-date summary on definition, diagnosis, underlying pathophysiology, monitoring and implications of CSA-AKI, including potential preventive interventions. The review will provide the reader with an in-depth understanding of how to identify, support and provide a more personalized and tailored perioperative management to avoid development of CSA-AKI.

Cardiac surgery-associated acute kidney injury (CSA-AKI) is prevalent and increasingly reported. Its diagnosis traditionally follows the Kidney Disease: Improving Global Outcomes (KDIGO) AKI criteria. However, little evidence supports its appropriateness for cardiac surgery patients, particularly regarding the subtle serum creatinine change (ΔSCr) that defines mild AKI.

The purpose of the study was to investigate the ΔSCr threshold specific to CSA-AKI and compare its impact on CSA-AKI incidence and prognosis with the KDIGO AKI criteria threshold.

A 10-year coronary surgery cohort with serial perioperative SCr measurements was retrospectively analyzed. The relationship and prognostically significant threshold of 48-hour absolute ΔSCr with 30-day mortality were explored using multivariate restricted cubic spline analysis and receiver-operating characteristic curve analysis. AKI incidence and prognostic value were compared between adopting the KDIGO or new thresholds.

Among 37,706 patients, 20,290 (53.8%) developed KDIGO-defined AKI. For stage-1 AKI (18,835, 49.9%), the majority (75.2%) were solely attributed to the KDIGO absolute criterion (48-hour ΔSCr ≥0.3 mg/dL). The 48-hour ΔSCr threshold associated with an adjusted odds ratio ≥1.00 for 30-day mortality was 0.549 mg/dL. A similar threshold (0.553 mg/dL) was also identified based on the Youden index cutoff. Applying the 0.55 mg/dL threshold to define stage 1 CSA-AKI, the overall and stage-1 CSA-AKI incidence decreased to 21.0% and 17.2%, with 27.7% of the stage-1 CSA-AKI solely attributed to the new criterion. The prognostic value for AKI defined by this new threshold was significantly higher than the KDIGO criteria.

A cardiac surgery-specific ΔSCr threshold in defining AKI was notably higher compared with the current general AKI definition.

Haemolysis occurring during cardiac surgery with cardiopulmonary bypass (CPB) is assumed to be a risk factor for postoperative acute kidney injury (AKI). Plasma alpha-1 microglobulin (A1M) may have a protective role as haem scavenger. The aim of this study was to evaluate the association between AKI and the degree of haemolysis and the course of A1M concentrations during cardiac surgery, respectively. We analysed plasma concentrations of free haemoglobin (pfHb) and A1M in 25 patients undergoing cardiac surgery: before CPB; during CPB in 15 min intervals; after CPB; and at four additional time points until 24 h after surgery. Markers of kidney function were followed until 4 days after surgery. Detection of AKI was based on the KDIGO (Kidney Disease, Improving Global Outcome) criteria. The plasma concentration of free haemoglobin during CPB was found to be significantly higher in patients with postoperative AKI at 60 min after start of CPB [mean 1379 µg/mL (95% CI: 1037-1721)]; compared to [820 µg/mL (622-1018)]; p = 0.034, in patients without AKI, and at one hour post-CPB [2600 µg/mL (969-4230)] vs [1037 µg/mL (722-1353)]; p = 0.044]. There was no significant difference found for pA1M levels between the groups with and without postoperative AKI development. Haemolysis during cardiac surgery with CPB increases the risk of postoperative AKI. Levels of pA1M did not differ for patients who developed postoperative AKI compared with those who did not. The data did not allow conclusions regarding the hypothesis that pA1M has a reno-protective effect.

This study examined the association between cardiopulmonary bypass (CPB) hematocrit and postoperative acute renal failure (ARF) in patients undergoing aortic arch surgery with hypothermic circulatory arrest.

The Society of Thoracic Surgeons Adult Cardiac Surgery Database was queried from 2011 to 2019 for patients undergoing aortic arch surgery with hypothermic circulatory arrest. A multivariable logistic regression model estimated the adjusted odds of postoperative ARF on the basis of CPB hematocrit. Effects were stratified by preoperative kidney function and the duration of hypothermic circulatory arrest by using interaction terms. The study also investigated the association between postoperative ARF and major postoperative outcomes by using multivariable regression models.

On adjusted analysis, higher CPB hematocrit (>20%-25%, >25%-30%, >30%) was associated with lower odds of ARF as compared with lower CPB hematocrit (≤20%) (>20-25%, aOR, 0.78; 95% CI, 0.65-0.93; P = .006; >25%-30%, aOR, 0.65; 95% CI, 0.50-0.84; P = .0007; >30%, aOR, 0.45; 95% CI, 0.28-0.72; P = .0008). The predicted probability of postoperative ARF by CPB hematocrit was higher in patients with lower preoperative renal function (estimated glomerular filtration rate, <60 mL/min/1.73 m2) (interaction P = .03). The association between hematocrit and postoperative ARF was not significantly modified by hypothermic circulatory arrest time (interaction P = .74). All postoperative outcomes were significantly worse in patients with postoperative ARF (all P < .0001).

Among patients undergoing aortic arch surgery, a higher CPB hematocrit level is associated with reduced likelihood of postoperative ARF. Preoperative renal function, but not hypothermic circulatory arrest duration, significantly modified this association. The maintenance of higher CPB hematocrit may reduce the incidence of postoperative ARF, especially for patients with poor preoperative renal function.

To investigate if intraoperative very short-term variability in blood pressure measured by sample entropy improves discrimination of postoperative acute kidney injury after noncardiac surgery.

Adult surgical patients undergoing general, thoracic, urological, or gynecological surgery between August 2016 to June 2017 at Seoul National University Hospital were included. The primary outcome was acute kidney injury stage 1, defined by the Kidney Disease: Improving Global Outcomes guidelines. Exploratory and explanatory variables included sample entropy of the mean arterial pressure and standard demographic, surgical, anesthesia and hypotension over time indices known to be associated with acute kidney injury respectively. Random forest classification and L1 logistic regression were used to assess four models for discriminating acute kidney injury: (1) Standard risk factors which included demographic, anesthetic, and surgical variables (2) Standard risk factors and cumulative hypotension over time (3) Standard risk factors and sample entropy (4) Standard risk factors, cumulative hypotension over time and sample entropy.

Two hundred and thirteen (7.4%) cases developed postoperative acute kidney injury. The median and interquartile range for sample entropy of mean arterial pressure was 0.34 and [0.26, 0.42] respectively. C-statistics were identical between the random forest and L1 logistic regression models. Results demonstrated no improvement in discrimination of postoperative acute kidney injury with the addition of the sample entropy of mean arterial pressure: Standard risk factors: 0.81 [0.76, 0.85], Standard risk factors and hypotension over time indices: 0.80 [0.75, 0.85], Standard risk factors and sample entropy of mean arterial pressure: 0.81 [0.76, 0.85] and Standard risk factors, sample entropy of mean arterial pressure and hypotension over time indices: 0.81 [0.76, 0.86].

Assessment of very short-term blood pressure variability does not improve the discrimination of postoperative acute kidney injury in patients undergoing non-cardiac surgery in this sample.

To investigate whether postoperative systemic immune-inflammation index (SII) is associated with acute kidney injury (AKI) after cardiac surgery.

We included patients undergoing cardiac surgery from the Medical Information Mart for Intensive Care-Ⅳ database to conduct a retrospective cohort study. The outcomes are AKI, severe AKI, and 30-day mortality after cardiac surgery. Analytical techniques including receiver operating characteristic (ROC) analysis, restricted cubic splines (RCS), and multivariable logistic regression were used to assess the association between SII and outcomes. Sensitivity analyses using inverse probability of treatment weighting (IPTW) and the E-value were conducted to validate the stability of the results.

3,799 subjects were included in this study. We used ROC to calculate an optimal cutoff value for predicting AKI after cardiac surgery, and subsequently patients were divided into two groups based on the cutoff value (Low SII: ≤ 949 × 109/L; High SII: > 949 × 109/L). ROC showed moderately good performance of SII for predicting AKI, while RCS also indicated a positive association between SII and AKI. The multivariate logistic analysis further affirmed the heightened risk of AKI in patients in the high SII group (OR, 5.33; 95%CI, 4.34-6.53; P < 0.001). Similar associations were observed between SII and severe AKI. Sensitivity and subgroup analyses indicated the robustness of the findings.

Elevated SII was independently associated with a higher risk of AKI in adults undergoing cardiac surgery. The potential causal relationship between postoperative SII and cardiac surgery associated AKI warrants prospective research.

Remote ischemic preconditioning (RIPC) has 2 time windows for organ protection: acute and delayed. Previous studies have mainly focused on the organoprotective effects of acute RIPC. We aimed to determine whether delayed RIPC can reduce the occurrence of acute kidney injury (AKI) and postoperative complications in patients undergoing cardiac surgery.

This prospective, single-center, double-blind, randomized controlled trial involved 509 patients at high risk for AKI who were scheduled for elective cardiac surgery requiring cardiopulmonary bypass. Patients were randomized to receive RIPC (4 cycles of 5-minute inflation and 5-minute deflation on 1 upper arm with a blood pressure cuff) 24 hours before surgery or a sham condition (control group) that was induced by 4 cycles of 5-minute inflation to a pressure of 20 mm Hg followed by 5-minute cuff deflation. The primary end point was the incidence of AKI within the prior 7 days after cardiac surgery. The secondary end points included renal replacement therapy during hospitalization, change in urinary biomarkers of AKI and markers of myocardial injury, duration of intensive care unit stay and mechanical ventilation, and occurrence of nonfatal myocardial infarction, stroke, and all-cause mortality by day 90.

A total of 509 patients (mean age, 65.2±8.2 years; 348 men [68.4%]) were randomly assigned to the RIPC group (n=254) or control group (n=255). AKI was significantly reduced in the RIPC group compared with the control group (69/254 [27.2%] versus 90/255 [35.3%]; odds ratio, 0.68 [95% CI, 0.47-1.00]; P=0.048). There were no significant between-group differences in the secondary end points of perioperative myocardial injury (assessed by the concentrations of cardiac troponin T, creatine kinase myocardial isoenzyme, and NT-proBNP [N-terminal pro-brain natriuretic peptide]), duration of stay in the intensive care unit and hospital, and occurrence of nonfatal myocardial infarction, stroke, and all-cause mortality by day 90.

Among high-risk patients undergoing cardiac surgery, delayed RIPC significantly reduced the occurrence of AKI.

URL: https://www.chictr.org.cn; Unique identifier: ChiCTR2000035568.

Acute kidney injury (AKI) is defined and staged by reduced urine output (UO) and increased serum creatinine (SCr). UO is typically measured manually and documented in the electronic health record, making early and reliable detection of oliguria-based AKI and electronic data extraction challenging. The authors investigated the diagnostic performance of continuous UO, enabled by active drain line clearance-based alerts (Accuryn AKI Alert), compared with AKI stage 2 SCr criteria and their associations with length of stay, need for continuous renal replacement therapy, and 30-day mortality.

This study was a prospective and retrospective observational study.

Nine tertiary centers participated.

Cardiac surgery patients were enrolled.

None.

A total of 522 patients were analyzed. AKI stages 1, 2, and 3 were diagnosed in 32.18%, 30.46%, and 3.64% of patients based on UO, compared with 33.72%, 4.60%, and 3.26% of patients using SCr, respectively. Continuous UO-based alerts diagnosed stage ≥1 AKI 33.6 (IQR =15.43, 95.68) hours before stage ≥2 identified by SCr criteria. A SCr-based diagnosis of AKI stage ≥2 has been designated a Hospital Harm by the Centers for Medicare & Medicaid Services. Using this criterion as a benchmark, AKI alerts had a discriminative power of 0.78. The AKI Alert for stage 1 was significantly associated with increased intensive care unit and hospital length of stay and continuous renal replacement therapy, and stage ≥2 alerts were associated with mortality.

AKI Alert, based on continuous UO and enabled by active drain line clearance, detected AKI stages 1 and 2 before SCr criteria. Early AKI detection allows for early kidney optimization, potentially improving patient outcomes.

The aim of this study was to investigate the association of postoperative acute kidney injury and unplanned re-admission rate due to heart failure at 2 years follow-up in patients who had extra-cardiac Fontan conversion. This was a retrospective single-center study of patients who underwent conversion from classic Fontan to extra-cardiac Fontan between January 2014 and December 2021. Acute kidney injury was defined using the Kidney Disease Improving Global Outcomes criteria. A total of 47 patients underwent Fontan conversion. Acute kidney injury occurred in 22 patients (46.8%) and 5 patients with acute kidney injury needed renal replacement therapy. Unplanned re-admission rate at 2-year follow-up was significantly higher in patients with acute kidney injury even when renal function returned to baseline (8 [36.4%] vs. 3 [12.0%], p = 0.026 by the log-rank test). In conclusion, postoperative acute kidney injury after extra-cardiac Fontan conversion was associated with unplanned re-admission due to heart failure at 2-year follow-up even though renal function was recovered.

Cardiac surgery with cardiopulmonary bypass (CPB) is associated with hemolysis. Yet, there is no easily available and frequently measured marker to monitor this hemolysis. However, carboxyhemoglobin (CO-Hb), formed by the binding of carbon monoxide (a product of heme breakdown) to hemoglobin, may reflect such hemolysis. We hypothesized that CO-Hb might increase after cardiac surgery and show associations with operative risk factors and indirect markers for hemolysis.

We conducted a retrospective descriptive cohort study of data from on-pump cardiac surgery patients. We analyzed temporal changes in CO-Hb levels and applied a generalized linear model to assess patient characteristics associated with peak CO-Hb levels. Additionally, we examined their relationship with red blood cell (RBC) transfusion and bilirubin levels.

We studied 38,487 CO-Hb measurements in 1735 patients. CO-Hb levels increased significantly after cardiac surgery, reaching a peak CO-Hb level 2.1 times higher than baseline ( P < .001) at a median of 17 hours after the initiation of surgery. Several factors were independently associated with higher peak CO-Hb, including age ( P < .001), preoperative respiratory disease ( P = .001), New York Heart Association Class IV ( P = .019), the number of packed RBC transfused ( P < .001), and the duration of CPB ( P = .002). Peak CO-Hb levels also significantly correlated with postoperative total bilirubin levels (Rho = 0.27, P < .001).

CO-Hb may represent a readily obtainable and frequently measured biomarker that has a moderate association with known biomarkers of and risk factors for hemolysis in on-pump cardiac surgery patients. These findings have potential clinical implications and warrant further investigation.