Acute Kidney Injury After Acute Repair of Type A Aortic Dissection

Effect of stress-induced hyperglycemia on long-term mortality in non-diabetic patients with acute type A aortic dissection: a retrospective analysis

BACKGROUND

Acute Type A Aortic Dissection (AAAD) is one of the most life-threatening diseases, often associated with transient hyperglycemia induced by acute physiological stress. The impact of stress-induced hyperglycemia on the prognosis of ST-segment elevation myocardial infarction has been reported. However, the relationship between stress-induced hyperglycemia and the prognosis of AAAD patients remains uncertain.

METHODS

The clinical data of 456 patients with acute type A aortic dissection were retrospectively reviewed. Patients were divided into two groups based on their admission blood glucose. Cox model regression analysis was performed to assess the relationship between stress-induced hyperglycemia and the 30-day and 1-year mortality rates of these patients.

RESULTS

Among the 456 patients, 149 cases (32.7%) had AAAD combined with stress-induced hyperglycemia (SIH). The results of the multifactor regression analysis of the Cox model indicated that hyperglycemia (RR = 1.505, 95% CI: 1.046-2.165, p = 0.028), aortic coarctation involving renal arteries (RR = 3.330, 95% CI: 2.237-4.957, p < 0.001), aortic coarctation involving superior mesenteric arteries (RR = 1.611, 95% CI: 1.056-2.455, p = 0.027), and aortic coarctation involving iliac arteries (RR = 2.034, 95% CI: 1.364-3.035, p = 0.001) were independent influences on 1-year postoperative mortality in AAAD patients.

CONCLUSION

The current findings indicate that stress-induced hyperglycemia measured on admission is strongly associated with 1-year mortality in patients with AAAD. Furthermore, stress-induced hyperglycemia may be related to the severity of the condition in patients with AAAD.

Sex disparities in the risk of urgent dialysis following acute aortic dissections in Japan

The global outcome of acute aortic dissection (AD) remains poor, with a high risk of the need for urgent dialysis. This study aimed to clarify the association between sex and the requirement for urgent dialysis within 30 days after admission among patients with AD. This study included 79,998 cases who were hospitalized due to AD in Japan from 2010 to 2020 using an administrative claims database. The association between the risk of urgent dialysis and sex was investigated using the Fine and Gray model. Patients were classified into two groups based on the Stanford classification: type A AD (TAAD) and type B AD (TBAD). The lower subdistribution hazard ratio (SHR) in women was observed in both groups: TAAD (SHR: 0.58, 95% confidence interval [CI]: 0.54-0.62); TBAD (SHR: 0.49, 95% CI: 0.41-0.58). Our study revealed that women had a lower risk of requiring urgent dialysis than men in TAAD and TBAD.

Machine learning-based model to predict severe acute kidney injury after total aortic arch replacement for acute type A aortic dissection

Background

Severe acute kidney injury (AKI) after total aortic arch replacement (TAAR) is related to adverse outcomes in patients with acute type A aortic dissection (ATAAD). However, the early prediction of severe AKI remains a challenge. This study aimed to develop a novel model to predict severe AKI after TAAR in ATAAD patients using machine learning algorithms.

Methods

A total of 572 ATAAD patients undergoing TAAR were enrolled in this retrospective study, and randomly divided into a training set (70 %) and a validation set (30 %). Lasso regression, support vector machine-recursive feature elimination and random forest algorithms were used to screen indicators for severe AKI (defined as AKI stage III) in the training set, respectively. Then the intersection indicators were selected to construct models through artificial neural network (ANN) and logistic regression. The AUC-ROC curve was employed to ascertain the prediction efficacy of the ANN and logistic regression models.

Results

The incidence of severe AKI after TAAR was 22.9 % among ATAAD patients. The intersection predictors identified by different machine learning algorithms were baseline serum creatinine and ICU admission variables, including serum cystatin C, procalcitonin, aspartate transaminase, platelet, lactic dehydrogenase, urine N-acetyl-β-d-glucosidase and Acute Physiology and Chronic Health Evaluation II score. The ANN model showed a higher AUC-ROC than logistic regression (0.938 vs 0.908, p < 0.05). Furthermore, the ANN model could predict 89.1 % of severe AKI cases beforehand. In the validation set, the superior performance of the ANN model was further confirmed in terms of discrimination ability (AUC = 0.916), calibration curve analysis and decision curve analysis.

Conclusion

This study developed a novel and reliable clinical prediction model for severe AKI after TAAR in ATAAD patients using machine learning algorithms. Importantly, the ANN model showed a higher predictive ability for severe AKI than logistic regression.

AKI-Pro score for predicting progression to severe acute kidney injury or death in patients with early acute kidney injury after cardiac surgery

BACKGROUND

No reliable clinical tools exist to predict acute kidney injury (AKI) progression. We aim to explore a scoring system for predicting the composite outcome of progression to severe AKI or death within seven days among early AKI patients after cardiac surgery.

METHODS

In this study, we used two independent cohorts, and patients who experienced mild/moderate AKI within 48 h after cardiac surgery were enrolled. Eventually, 3188 patients from the MIMIC-IV database were used as the derivation cohort, while 499 patients from the Zhongshan cohort were used as external validation. The primary outcome was defined by the composite outcome of progression to severe AKI or death within seven days after enrollment. The variables identified by LASSO regression analysis were entered into logistic regression models and were used to construct the risk score.

RESULTS

The composite outcome accounted for 3.7% (n = 119) and 7.6% (n = 38) of the derivation and validation cohorts, respectively. Six predictors were assembled into a risk score (AKI-Pro score), including female, baseline eGFR, aortic surgery, modified furosemide responsiveness index (mFRI), SOFA, and AKI stage. And we stratified the risk score into four groups: low, moderate, high, and very high risk. The risk score displayed satisfied predictive discrimination and calibration in the derivation and validation cohort. The AKI-Pro score discriminated the composite outcome better than CRATE score, Cleveland score, AKICS score, Simplified renal index, and SRI risk score (all P < 0.05).

CONCLUSIONS

The AKI-Pro score is a new clinical tool that could assist clinicians to identify early AKI patients at high risk for AKI progression or death.

Exploring Acute Kidney Injury Following Aortic Dissection: A Comprehensive Review of Machine Learning Models for Predicting Risk, Management Strategies, Complications, and Racial and Gender Disparities

Both types of aortic dissection (AD), Stanford type A and type B, can result in complications such as acute kidney injury (AKI) and aortic rupture. Renal complications in AD arise from compromised renal perfusion affecting the renal arteries. Understanding the intricate connection between AD and AKI is crucial for navigating the complexities of tailored treatment and formulating specific management plans. Concerning machine learning models, in patients with type A aortic dissection, factors such as decreased platelet count on admission, increased D-dimer level, longer cardiopulmonary bypass duration, elevated white blood cell levels, the need for blood transfusion, longer aortic clamp time, extended surgery duration, advanced age, and an elevated body mass index were positively associated with the development of AKI. For the risk of AKI after type B aortic dissection, elevated Nt-pro brain natriuretic peptide, prolonged activated partial thromboplastin time, elevated admission systolic blood pressure, and a higher contrast agent requirement during operative repair were found to predict the risk. Male gender was associated with a higher risk of AKI, and nonwhite race was linked to a higher risk of AKI, a greater likelihood of requiring more urgent procedures, and lower levels of insurance coverage. The treatment of AKI following AD requires a multifaceted approach. Identifying and addressing the underlying cause, such as low blood pressure, renal artery involvement, or medication-induced injury, is crucial for effective management and preventing further kidney damage. Maintaining proper fluid balance is essential for improving renal perfusion, but careful monitoring is necessary to avoid complications. The evolving landscape of research, particularly in biomarkers and AI programs, reveals a promising role in predicting the risk for and managing AKI post-AD.

A new minimal invasive technique with in-situ stent-graft fenestration for type A aortic dissection

Background

Aortic surgery successfully improves the prognosis of patients with type A aortic dissection. However, total arch replacement and reconstruction remain challenging. This study presents a new surgical modality, the in-situ stent-graft fenestration (ISSF) technique, for simplifying aortic arch reconstruction and assesses its short-term efficacy and safety in patients with type A aortic dissection.

Methods

Data from 177 patients with type A aortic dissection who underwent aortic arch reconstruction were retrospectively analyzed. Sun's procedure was performed in 90 patients and ISSF was performed in the other 87.

Results

The in-hospital mortality rate was 7.8% in the Sun's procedure group and 3.4% in the ISSF group (p = 0.357). Compared to the Sun's procedure group, the ISSF group had significantly shorter surgical duration, cardiopulmonary bypass time, circulatory arrest time, mechanical ventilation time, and aortic cross-clamp time (p < 0.05). Additionally, intraoperative blood loss was lower in the ISSF group than in the Sun's procedure group (p < 0.05). Patients who underwent ISSF also had a lower incidence of postoperative complications, including lung injury, renal failure, peripheral nerve injury, and chylothorax, than those who underwent Sun's procedure (p < 0.05). During the 6-month follow-up period after surgery, both groups showed significant improvements in the true lumen diameter of the descending thoracic aorta post-operation compared with the pre-operation measurements; meanwhile, the false lumen diameter decreased (p < 0.05).

Conclusions

The ISSF technique appears to be an effective and safe alternative to conventional surgical procedures for patients with type A aortic dissection, with the potential to simplify the procedure, shorten the operation time, and yield satisfactory operative results. However, further investigation is needed to determine its long-term benefits.

Renal Dysfunction at Discharge and Long-Term Survival in Acute Type A Aortic Dissection

INTRODUCTION

We aimed to investigate the association between renal dysfunction at discharge and long-term survival in acute type A aortic dissection (ATAAD) patients following surgery.

METHODS

From 2000 to 2021, 784 patients underwent aortic repair for an ATAAD. Patients were stratified based on creatinine (Cr) level at discharge alive or dead: normal Cr (n = 582) and elevated Cr defined as >1.3 mg/dL for males and >1.0 mg/dL for females or on dialysis at discharge (n = 202).

RESULTS

Preoperatively, both groups had similar rates of comorbidities except for the elevated-Cr group which had more diabetes, chronic obstructive pulmonary disease, and chronic and acute renal insufficiency. Both groups had similar open ATAAD repair procedures. Postoperative outcomes in the elevated-Cr group were significantly worse, including six times higher operative mortality (20% versus 3.4%, P < 0.0001). The landmark long-term survival after discharge alive was significantly worse in the elevated-Cr group than the normal-Cr group (10-y survival: 48% versus 69%, P = 0.0009). The elevated Cr on dialysis at discharge group had significantly worse five-year survival (40%) than the elevated Cr not on dialysis at discharge group (80%, P = 0.02) and the normal-Cr group (87%, P < 0.0001). Additionally, the elevated Cr not on dialysis had a worse five-year survival than the normal-Cr group (80% versus 87%, P = 0.02). Elevated Cr at discharge on dialysis was a significant risk factor for late mortality (hazard ratio = 4.22, 95% confidence interval: [2.07, 8.61], P < 0.0001).

CONCLUSIONS

Renal dysfunction at discharge was associated with significantly decreased short-term and long-term survival following open ATAAD repair. Surgeons should aggressively prevent renal dysfunction, especially new-onset dialysis, at discharge as it is correlated with significantly worse short-term and long-term outcomes.

Postoperative thrombocytopenia and subsequent consequences in acute type A aortic dissection

OBJECTIVES

To ascertain if postoperative thrombocytopenia following open aortic surgery with a median sternotomy can predict early- and intermediate-term morbidity and mortality.

METHODS

From January 2018 to December 2022, a comparison was made between patients who had and didn't have postoperative thrombocytopenia (defined as a nadir < 75 × 103/μL after 72 h of open aortic surgery with median sternotomy). Intermediate-term mortality during follow-up was the main result, with cerebrovascular accident and acute renal injury requiring dialysis as secondary events. Inverse probability treatment weighting (IPTW) was used to account for selection bias between groups. The Kaplan-Meier method with the log-rank test was used to assess intermediate-term survivals following IPTW modification. To identify the nonlinear link between platelet nadir and mortality probability, a generalized additive mix model was applied. To help increase power in testing for the overall effect of platelet nadir on outcomes in the generalized additive mix model, the hazard ratios and 95% CIs for each subgroup and their interactions were examined.

RESULTS

The study included 457 patients, 347 male (75.9%), with mean age of 54 ± 12 years. The last follow-up was done on April 14th, 2023 and the median follow-up time was 16 (6-31) months. Following IPTW, patient characteristics were balanced among cohorts. Platelet nadir was found to be significantly inversely related to early-term mortality (IPTW-adjusted hazard ratio = 0.968 (0.960, 0.977), p < 0.001), and AKI requiring dialysis (IPTW-adjusted hazard ratio = 0.979 (0.971, 0.986), p < 0.001). A nonlinear relationship between platelet nadir and mortality risk probability during follow-up visually showed that the likelihood of mortality decreased with platelet nadir increased. In confounder-adjusted survival ('postoperative thrombocytopenia not acquired' vs 'postoperative thrombocytopenia'; HR: 0.086 [95% CI: 0.045-0.163]; p < 0.01) analysis, non-acquired postoperative thrombocytopenia was associated with a lower risk of mortality, and the treatment benefit was validated in IPTW-adjusted analysis, which showed an HR of 0.067.

CONCLUSIONS

Early postoperative thrombocytopenia following type A aortic dissection surgery is a risk factor for morbidity and mortality. Because postoperative thrombocytopenia can indicate a poor prognosis, monitoring early postoperative platelets helps identify individuals who may develop late postoperative problems, which is performed by this affordable biomarker.

Impact of Recovery from Acute Kidney Injury After Aortic Arch Repair

BACKGROUND

The impact of recovery from acute kidney injury (AKI) after open thoracic aortic surgery on follow-up outcomes is unclear.

METHODS

This retrospective study included 214 patients who underwent aortic arch surgery requiring hypothermic circulatory arrest between 2007 and 2019. Patients who required preoperative renal replacement therapy and patients who died within 7 postoperative days were excluded. The incidence of recovery from AKI was examined. Renal outcomes were compared among patients with no AKI (Group N), recovery from AKI (Group R), and persistent AKI (Group P).

RESULTS

Preoperative kidney function was similar among the 3 groups. Among the 115 patients who developed postoperative AKI, 80.9% recovered from AKI at discharge. The 5-year cumulative mortality rate was 18.0%, 24.5%, and 68.4% in Group N, R, and P, respectively (P < .001, Group R vs Group P). The 5-year cumulative incidence of renal replacement therapy dependency was 0.0%, 5.4%, and 22.7%, respectively (P = .04, Group N vs Group R; P = .01, Group R vs Group P). The medians (interquartile range) of estimated glomerular filtration rate (mL/min/1.73 m2) 2 years after surgery were 65.2 (50.4-80.2), 54.3 (41.4-65.9), and 56.9 (40.2-67.5), respectively (P = .03, Group N vs Group R).

CONCLUSIONS

The majority of patients recovered from AKI after thoracic aortic repair by discharge. However, the prolonged impact of AKI recovery on kidney function was observed during the follow-up period. Diligent follow-up after discharge is warranted for early identification of patients at high risk of kidney disease progression.

Incidence of Acute Kidney Injury and Risk Factors of Prognosis in Patients with Acute Stanford Type A Aortic Dissection

PURPOSE

We aimed to investigate the prognosis and impact of postoperative acute kidney injury (AKI) in acute Stanford type A aortic dissection (ATAAD) patients, and to analyze the predictors of short- and medium-term survival.

METHODS

A total of 192 patients who underwent ATAAD surgery were included between May 2014 and May 2019. Perioperative data of these patients were analyzed. All of the discharged patients were followed up for 2 years.

RESULTS

Postoperative AKI was identified in 43 of 192 patients (22.4%). The two-year survival rate of patients with AKI after discharge was 88.2% and that without AKI was 97.2%.The difference was statistically significant (χ2 = 5.355, log-rank P = 0.021). Cox hazards regression showed that age (hazard ratio [HR], 1.070; P = 0.002), cardiopulmonary bypass (CPB) time (HR, 1.026; P = 0.026), postoperative AKI (HR, 3.681; P = 0.003), and red blood cell transfusion (HR, 1.548; P = 0.001) were independent risk factors for the short- and medium-term total mortality of ATAAD patients.

CONCLUSION

The incidence of postoperative AKI is high in ATAAD, and the mortality of patients with AKI increases significantly within 2 years. Age, CPB time, and red blood cell transfusion were also independent risk factors for short-and medium-term prognoses.

Incorporating intraoperative blood pressure time-series variables to assist in prediction of acute kidney injury after type a acute aortic dissection repair: an interpretable machine learning model

BACKGROUND

Acute kidney injury (AKI) is a common and serious complication after the repair of Type A acute aortic dissection (TA-AAD). However, previous models have failed to account for the impact of blood pressure fluctuations on predictive performance. This study aims to develop machine learning (ML) models combined with intraoperative medicine and blood pressure time-series data to improve the accuracy of early prediction for postoperative AKI risk.

METHODS

Indicators reflecting the duration and depth of hypotension were obtained by analyzing continuous mean arterial pressure (MAP) monitored intraoperatively with multiple thresholds (<65, 60, 55, 50) set in the study. The predictive features were selected by logistic regression and the least absolute shrinkage and selection operator (LASSO), and 4 ML models were built based on the above features. The performance of the models was evaluated by area under receiver operating characteristic curve (AUROC), calibration curve and decision curve analysis (DCA). Shapley additive interpretation (SHAP) was used to explain the prediction models.

RESULTS

Among the indicators reflecting intraoperative hypotension, 65 mmHg showed a statistically superior difference to other thresholds in patients with or without AKI (p < .001). Among 4 models, the extreme gradient boosting (XGBoost) model demonstrated the highest AUROC: 0.800 (95% 0.683-0.917) and sensitivity: 0.717 in the testing set and was verified the best-performing model. The SHAP summary plot indicated that intraoperative urine output, cumulative time of mean arterial pressure lower than 65 mmHg outside cardiopulmonary bypass (OUT_CPB_MAP_65 time), autologous blood transfusion, and smoking were the top 4 features that contributed to the prediction model.

CONCLUSION

With the introduction of intraoperative blood pressure time-series variables, we have developed an interpretable XGBoost model that successfully achieve high accuracy in predicting the risk of AKI after TA-AAD repair, which might aid in the perioperative management of high-risk patients, particularly for intraoperative hemodynamic regulation.

Extensive Aortic Dissection in a Low-Risk Male Causing Acute Kidney Injury: A Case Report

Aortic dissection is a major differential diagnosis in an elderly male with severe chest pain radiating to the back who has a history of hypertension, smoking, or connective tissue disorders such as Marfan and Ehlers-Danlos syndromes. It is a medical emergency with a high mortality rate if undetected and untreated. This report describes the case of a patient presenting with extensive aortic dissection with no significant risk factors who was diagnosed following a CT angiogram of the aorta. He was subsequently managed medically before being transferred for definitive surgical management with a good outcome.

Development of a Machine Learning Model of Postoperative Acute Kidney Injury Using Non-Invasive Time-Sensitive Intraoperative Predictors

Acute kidney injury (AKI) is a major postoperative complication that lacks established intraoperative predictors. Our objective was to develop a prediction model using preoperative and high-frequency intraoperative data for postoperative AKI. In this retrospective cohort study, we evaluated 77,428 operative cases at a single academic center between 2016 and 2022. A total of 11,212 cases with serum creatinine (sCr) data were included in the analysis. Then, 8519 cases were randomly assigned to the training set and the remainder to the validation set. Fourteen preoperative and twenty intraoperative variables were evaluated using elastic net followed by hierarchical group least absolute shrinkage and selection operator (LASSO) regression. The training set was 56% male and had a median [IQR] age of 62 (51-72) and a 6% AKI rate. Retained model variables were preoperative sCr values, the number of minutes meeting cutoffs for urine output, heart rate, perfusion index intraoperatively, and the total estimated blood loss. The area under the receiver operator characteristic curve was 0.81 (95% CI, 0.77-0.85). At a score threshold of 0.767, specificity was 77% and sensitivity was 74%. A web application that calculates the model score is available online. Our findings demonstrate the utility of intraoperative time series data for prediction problems, including a new potential use of the perfusion index. Further research is needed to evaluate the model in clinical settings.

Risk factors for postoperative acute kidney injury in overweight patients with acute type A aortic dissection

OBJECTIVE

To analyze the clinical characteristics of patients with overweight acute type A aortic dissection, and to explore the risk factors of acute kidney injury in patients with overweight acute type A aortic dissection.

METHODS

From March 2019 to February 2022, the clinical data of 71 patients with acute type a aortic dissection diagnosed by CTA and undergoing surgical treatment with BMI > 24 in the First People's Hospital of Yunnan Province were retrospectively analyzed, and analyzed by univariate and logistic multivariate analysis methods.

RESULTS

The mean BMI of all included patients was 27.23, The mean surface area of all included human populations was 1.833. The mean age of all patients was (52.06 ± 10.71) years old, and 35 patients developed acute kidney injury after surgery. Multi-factor Logistics regression analysis confirmed the risk factors for postoperative acute kidney injury in overweight patients with acute type A aortic dissection, including gender, CPB transit time and intraoperative infusion of suspended red blood cells. Seven patients in the AKI group died in hospital after surgery and two patients died in the non-AKI group.

CONCLUSIONS

Among patients with overweight acute Type A aortic dissection, the incidence of AKI is 49.30%. According to multi-factor Logistics regression analysis, gender, CPB transit time and intraoperative suspended red blood cell volume are independent risk factors for postoperative acute kidney injury in patients with overweight acute Type A aortic dissection.

Goal-directed perfusion for reducing acute kidney injury in cardiac surgery: A systematic review and meta-analysis

BACKGROUND

Acute kidney injury (AKI) is a common complication following cardiopulmonary bypass (CPB) which can affect morbidity and mortality. Goal-directed perfusion (GDP) intended to avoid the nadir oxygen delivery index below the critical value is associated with reduced postoperative AKI. However, current studies suggested that GDP can only decrease the incidence of AKI stage 1 but showed no effects on AKI stages 2-3 and mortality. The objective of the present meta-analysis is to deter the effects of GDP on postoperative AKI in any stage and mortality following cardiac surgery.

METHODS

MEDLINE, Embase, and the Cochrane Library were searched to identify all clinical trials comparing GDP with control (standard care) during cardiopulmonary bypass conducting in adults undergoing cardiac surgery. The primary outcome was postoperative acute kidney injury. Secondary outcomes included postoperative mortality and length of ICU stay. Data synthesis was obtained by using risk ratio with 95% confidence interval by a random-effects model.

RESULT

From 1094 potential studies, 3 trials enrolling 777 patients were included. Meta-analysis suggested the GDP strategy based on DO₂i reduced postoperative AKI compared with standard CPB management (RR = 0.52; 95% CI: 0.38-0.70; p < .0001), especially in AKI stage I (RR = 0.47; 95% CI: 0.33-0.66; p < .0001). But the GDP strategy did not reduce the incidence of severe AKI (stages 2-3) and postoperative mortality.

CONCLUSION

The GDP strategy based on DO₂i during CPB obviously reduces AKI stage 1 and thus reduces overall AKI incidence. But it shows no effects on severe AKI (stages 2-3) and mortality.

Acute Kidney Injury in Patients Undergoing Surgery for Type A Acute Aortic Dissection

BACKGROUND

Acute kidney injury (AKI) after repair of type A acute aortic dissection (TAAAD) has been shown to affect both short- and long-term outcomes. This study aimed to validate the impact of postoperative AKI on in-hospital and long-term outcomes in a large population of dissection patients presenting to multinational aortic centers. Additionally, we assessed risk factors for AKI including surgical details.

METHODS

Patients undergoing surgical repair for TAAAD enrolled in the International Registry of Acute Aortic Dissection database were evaluated to determine the incidence and risk factors for the development of AKI.

RESULTS

A total of 3307 patients were identified. There were 761 (23%) patients with postoperative AKI (AKI group) vs 2546 patients without (77%, non-AKI group). The AKI group had a higher rate of in-hospital mortality (n = 193, 25.4% vs n = 122, 4.8% in the non-AKI group, P < .001). Additional postoperative complications were also more common in the AKI group including postoperative cerebrovascular accident, reexploration for bleeding, and prolonged ventilation. Independent baseline characteristics associated with AKI included a history of hypertension, diabetes, chronic kidney disease, evidence of malperfusion on presentation, distal extent of dissection to abdominal aorta, and longer cardiopulmonary bypass time. Kaplan-Meier survival curves revealed decreased 5-year survival among the AKI group (P < .001).

CONCLUSIONS

AKI occurs commonly after TAAAD repair and is associated with a significantly increased risk of operative and long-term mortality. In this large study using the International Registry of Acute Aortic Dissection database, several factors were elucidated that may affect risk of AKI.

Evaluation of the contribution of gut microbiome dysbiosis to cardiac surgery-associated acute kidney injury by comparative metagenome analysis

Introduction

Cardiac surgery-associated acute kidney injury (CSA-AKI) is a common hospital-acquired AKI that carries a grave disease burden. Recently, gut-kidney crosstalk has greatly changed our understanding of the pathogenesis of kidney diseases. However, the relationship between gut microbial dysbiosis and CSA-AKI remains unclear. The purpose of this study was to investigate the possible contributions of gut microbiota alterations in CSA-AKI patients

Methods

Patients undergoing cardiac surgery were enrolled and divided into acute kidney injury (AKI) and Non-AKI groups. Faecal samples were collected before the operation. Shotgun metagenomic sequencing was performed to identify the taxonomic composition of the intestinal microbiome. All groups were statistically compared with alpha- and beta-diversity analysis, and linear discriminant analysis effect size (LEfSe) analysis was performed.

Results

A total of 70 individuals comprising 35 AKI and 35 Non_AKI were enrolled in the study. There was no significant difference between the AKI and Non_AKI groups with respect to the alpha-and beta-diversity of the Shannon index, Simpson or Chao1 index values except with respect to functional pathways (p &lt; 0.05). However, the relative abundance of top 10 gut microbiota in CSA-AKI was different from the Non_AKI group. Interestingly, both LEfSe and multivariate analysis confirmed that the species Escherichia coli, Rothia mucilaginosa, and Clostridium_innocuum were associated with CSA-AKI. Moreover, correlation heat map indicated that altered pathways and disrupted function could be attributed to disturbances of gut microbiota involving Escherichia_coli.

Conclusion

Dysbiosis of the intestinal microbiota in preoperative stool affects susceptibility to CSA-AKI, indicating the crucial role of key microbial players in the development of CSA-AKI. This work provides valuable knowledge for further study of the contribution of gut microbiota in CSA-AKI.

Hotspots and development frontiers of postoperative complications of AD: Bibliometric analysis - a review

The research on the postoperative complications of aortic dissection (AD) has received great attention from scholars all over the world, and the number of research articles in this field has consistently increased year after year. However, no bibliometric reports have been published yet to analyze the scientific output and the current situation in this field. The Bibliometrix R-package, VOSviewer, and CiteSpace software were used to conduct a bibliometric analysis of the hotspots and development frontiers of AD. A total of 1242 articles were retrieved. The USA, China, and Japan had the highest number of publications. The five keywords with the highest frequency were "analysis," "incidence," "acute type," "graft," and "risk factor." The results also indicated that the research in related fields had shifted from surgical treatment and utilizing experience to the evidence-based exploration of risk factors and the construction of prediction models to help better manage postoperative complications of AD. This is the first bibliometric analysis of global publications on the postoperative complications of AD. The current research hotspots focus on three areas: common postoperative complications of AD, exploration of the related risk factors, and management of complications. Future research could focus on identifying risk factors through meta-analysis and using a multicenter database for AD as well as building relevant models to predict the development of complications to better facilitate the clinical management of AD patients.

Incidence and outcomes of acute kidney disease in patients after type A aortic dissection surgery

BACKGROUND

Acute kidney injury (AKI), acute kidney disease (AKD) and CKD (chronic kidney disease) were a continuous process. There has been little discussion of risk factors for AKD in the population undergoing surgery for acute type A aortic dissection (AAAD).

OBJECTIVE

The main objective of this study was to investigate the risk factors for AKD after surgery for acute type A aortic dissection and the impact of AKD on early and late mortality.

DESIGN

AKI was to be defined as an increase in serum creatinine to >0.3 mg/dL or 1.5 times above baseline within 7 days. AKD was defined as the kidney damage within 90 days after AKI. Logistic regression models were performed to identify the risk factors of AKD and the association between AKD and early mortality after AAAD surgery.

PARTICIPANTS

Patients with AKI after AAAD surgery admitted in ICU from March 2009 to September 2021 were included.

KEY RESULTS

Among the 328 patients who developed AKI after AAAD surgery, 98 patients (29.9%) progressed to AKD. Multivariable analysis revealed that AKI stage 2 (OR, 3.032) and AKI stage 3 (OR, 4.001) have been shown to be independent risk factors for the development of AKD. AKD (OR, 3.175) proved to be an independent risk factor for early mortality, while no significant difference in late mortality was observed between patients in the AKD and non-AKD groups.

CONCLUSION

The severity of AKI after surgery of AAAD was independently associated with AKD. The occurrence of AKD had a negative impact on early mortality.

CLINICAL TRIAL REGISTRATION

ChiCTR, ChiCTR1900021290. Registered 12 February 2019, http://www.chictr.org.cn/showproj.aspx?proj=35795.

Association between preoperative serum myoglobin and acute kidney injury after Stanford Type A aortic dissection surgery

BACKGROUND

Acute kidney injury (AKI) is a common complication after Type A aortic dissection (TAAD) surgery, and it is associated with poor outcomes. The nephrotoxic effect of myoglobin was established, but its correlation with AKI following TAAD repair still lacks sufficient evidence. We clarified the correlation between preoperative serum myoglobin (pre-sMyo) concentrations and AKI after TAAD surgery.

METHOD

A retrospective analysis was performed on the perioperative data of 382 patients treated with TAAD surgery at Beijing Anzhen Hospital. AKI was defined and classified according to the criteria established by the Kidney Disease: Improving Global Outcomes Acute Kidney Injury Work Group. We attempted to determine the correlation between pre-sMyo concentrations and postoperative AKI.

RESULTS

The incidences of Stage 1, 2, and 3 AKI were 37.3 % (57/153), 23.5 % (36/153), and 39.2 % (60/153), respectively. The pre-sMyo concentrations of the AKI group were significantly increased than the non-AKI group [43.1 (21.4, 107.5) vs 26.4 (18.0, 37.2), P < 0.001]. Pre-sMyo concentrations have a linear correlation with preoperative renal function-related indicators. The multivariable logistic regression analysis showed that Ln (pre-sMyo) was an independent risk factor for AKI. When the pre-sMyo concentration was at the fourth quartile [109.3 (64.8, 213.4) ng/ml], the risk of developing any-stage and severe AKI was significantly increased (OR = 4.333, 95 % CI: 2.364-7.943, P < 0.001; OR = 3.862, 95 %, CI: 2.011-7.419, P < 0.001). This difference persisted after adjustment (OR = 3.830, 95 % CI: 1.848-7.936, P < 0.001; OR = 2.330, 95 % CI: 1.045-5.199, P = 0.039). Furthermore, pre-sMyo concentrations were not affected by lower limb malperfusion, myocardial malperfusion, and cardiac tamponade.

CONCLUSIONS

Increased pre-sMyo concentrations correlated with postoperative AKI in TAAD, which may increase the risk of developing any-stage AKI and severe AKI after TAAD surgery.

Risk factor prediction of severe postoperative acute kidney injury at stage 3 in patients with acute type A aortic dissection using thromboelastography

Objective

Perioperative blood transfusions and postoperative drainage volume not only are the commonly recognized risk factors for acute kidney injury (AKI) but also are indirect indicators of coagulopathy in patients with acute type A aortic dissection (ATAAD). However, standard laboratory tests fail to accurately reflect and assess the overall coagulopathy profile in patients with ATAAD. Thus, this study aimed to explore the association between the hemostatic system and severe postoperative AKI (stage 3) in patients with ATAAD using thromboelastography (TEG).

Methods

We selected 106 consecutive patients with ATAAD who underwent emergency aortic surgery at Beijing Anzhen Hospital. All participants were categorized into the stage 3 and non-stage 3 groups. The hemostatic system was evaluated using routine laboratory tests and TEG preoperatively. We undertook univariate and multivariate stepwise logistic regression analyses to determine the potential risk factors for severe postoperative AKI (stage 3), with a special investigation on the association between hemostatic system biomarkers and severe postoperative AKI (stage 3). The receiver operating characteristic (ROC) curves were generated to assess the predictive ability of hemostatic system biomarkers for severe postoperative AKI (stage 3).

Results

A total of 25 (23.6%) patients developed severe postoperative AKI (stage 3), including 21 patients (19.8%) who required continuous renal replacement therapy (RRT). Multivariate logistic regression analysis demonstrated that the preoperative fibrinogen level (OR, 2.02; 95% CI, 1.03 to 3.00; p = 0.04), platelet function (MA level) (OR, 1.23; 95% CI, 1.09 to 1.39; p = 0.001), and cardiopulmonary bypass (CPB) time (OR, 1.01; 95% CI, 1.00 to 1.02; p = 0.02) were independently associated with severe postoperative AKI (stage 3). The cutoff values of preoperative fibrinogen and platelet function (MA level) for predicting severe postoperative AKI (stage 3) were determined to be 2.56 g/L and 60.7 mm in the ROC curve [area under the curve (AUC): 0.824 and 0.829; p < 0.001].

Conclusions

The preoperative fibrinogen level and platelet function (measured by the MA level) were identified as potential predictive factors for developing severe postoperative AKI (stage 3) in patients with ATAAD. Thromboelastography could be considered a potentially valuable tool for real-time monitoring and rapid assessment of the hemostatic system to improve postoperative outcomes in patients.

The preoperative plasma histamine level as a possible protective biomarker for postoperative acute kidney injury

Acute kidney injury (AKI) is a life-threatening complication of acute type A aortic dissection (ATAAD) patients. Increasing evidence suggests that histamine ameliorates the pathology of renal injury. However, data on the association between histamine levels and postoperative AKI in ATAAD patients are limited. The purpose of our study was to explore the incidence and independent risk factors of postoperative AKI, with special emphasis on the relationship between preoperative plasma histamine levels and the severity of postoperative ATAAD-AKI. This retrospective single-center study evaluated 160 patients with ATAAD admitted to the Beijing Anzhen Hospital aortic surgery database between April 2020 and December 2021. Univariate and multivariate logistic regression analyses were performed to determine the potential risk factors for postoperative ATAAD-AKI. A subgroup analysis was performed to investigate the association between preoperative plasma histamine levels and the severity of postoperative ATAAD-AKI or continuous renal replacement therapy (CRRT). ATAAD-AKI occurred in 84 of 160 patients (52.5%), including 32 with stage 1 (38.1%), 14 with stage 2 (16.7%), 38 with stage 3 (45.2%), and 34 (21.3%) received postoperative CRRT. The in-hospital mortality rate was 19.0% (16/84) in the AKI group and 2.6% (2/76) in the non-AKI group (P = .02). Preoperative lower plasma histamine levels (odds ratio [OR], 1.31; 95% confidence interval [CI], 1.10-1.52; P = .004) were an important factor related to postoperative ATAAD-AKI in multivariate logistic regression analysis. Subgroup analysis revealed that low preoperative plasma histamine level was independently associated with postoperative ATAAD-AKI (stage 3) (OR, 1.38; 95% CI, 1.10-1.73; P = .005) and CRRT (OR, 1.44; 95% CI, 1.13-1.79; P = .008). Low preoperative plasma histamine level was an independent prognostic indicator of postoperative AKI in patients with ATAAD, especially for postoperative AKI (stage 3) and CRRT. Preoperative plasma histamine levels may serve as potential protective biomarkers of postoperative ATAAD-AKI.

Risk factors for acute kidney injury after Stanford type A aortic dissection repair surgery: a systematic review and meta-analysis

Background: Risk factors for acute kidney injury (AKI) after Stanford type A aortic dissection (TAAD) repair are inconsistent in different studies. This meta-analysis systematically analyzed the risk factors so as to early identify the therapeutic targets for preventing AKI.

Methods: Studies exploring risk factors for AKI after TAAD repair were searched from four databases from inception to June 2022. The synthesized incidence and risk factors of AKI and its impact on mortality were calculated.

Results: Twenty studies comprising 8223 patients were included. The synthesized incidence of postoperative AKI was 50.7%. Risk factors for AKI included cardiopulmonary bypass (CPB) time >180 min [odds ratio (OR), 4.89, 95% confidence interval (CI), 2.06–11.61, I² = 0%], prolonged operative time (>7 h) (OR, 2.73, 95% CI, 1.95–3.82, I² = 0), advanced age (per 10 years) (OR, 1.34, 95% CI, 1.21–1.49, I² = 0], increased packed red blood cells (pRBCs) transfusion perioperatively (OR, 1.09, 95% CI, 1.07–1.11, I² = 42%), elevated body mass index (per 5 kg/m²) (OR, 1.23, 95% CI, 1.18–1.28, I² = 42%) and preoperative kidney injury (OR, 3.61, 95% CI, 2.48–5.28, I² = 45%). All results were meta-analyzed using fixed-effects model finally (p < 0.01). The in-hospital or 30-day mortality was higher in patients with postoperative AKI than in that without AKI [risk ratio (RR), 3.12, 95% CI, 2.54–3.85, p < 0.01].

Conclusions: AKI after TAAD repair increased the in-hospital or 30-day mortality. Reducing CPB time and pRBCs transfusion, especially in elderly or heavier weight patients, or patients with preoperative kidney injury were important to prevent AKI after TAAD repair surgery.

Impact of shift work on surgical outcomes at different times in patients with acute type A aortic dissection: A retrospective cohort study

Background

To investigate the effect of shift work on surgical outcomes at different times in patients with acute type A aortic dissection (ATAAD).

Materials and methods

Patients with ATAAD who underwent total arch replacement at Qilu Hospital of Shandong University from January 2015 to March 2022 were retrospectively analyzed. All patients were managed according to the green channel emergency management strategy, and a professional cardiac team was arranged during off-hours. Based on surgery time and symptom onset to procedure time, the patients were divided into weekday, weekend and holiday groups; daytime and nighttime groups; intervention time ≤48 h and >48 h groups; working hours and off-hours groups. In-hospital mortality between these groups was compared.

Results

In total, 499 ATAAD patients underwent surgery within 7 days of symptom onset, and the in-hospital mortality rate was 10% (n = 50/499). Among the 499 patients, 320 (64.13%), 128 (25.65%) and 51 (10.22%) underwent surgery on weekdays, weekends and holidays, respectively. In-hospital mortality and 7-day mortality showed no significant difference among the three groups. Two hundred twenty-seven (45.5%) underwent daytime surgery, and 272 (54.5%) underwent nighttime surgery. Durations of ICU stay and hospital stay were significantly different between the two groups (P < 0.05). There was no significant differences in in-hospital mortality (9.2% vs. 10.7%) and 7-day mortality (4.4% vs. 6.6%). 221 patients (44.3%) and 278 patients (55.7%) were included in the intervention time ≤48 h and >48 h groups, respectively. Acute renal injury, ICU stay and hospital stay were significantly different (P < 0.05) whereas 7-day mortality (5.0% vs. 6.1%) and in-hospital mortality (8.6% vs. 11.1%) were not. Furthermore, 7-day (1.9% vs. 6.6%) and in-hospital mortality (11.1% vs. 9.8%) showed no difference between working hours group (n = 108) and off-hours group (n = 391). Cox regression analysis showed that postoperative acute renal injury (HR = 2.423; 95% CI, 1.214–4.834; P = 0.012), pneumonia (HR = 2.542; 95% CI, 1.186–5450; P = 0.016) and multiple organ dysfunction (HR = 11.200; 95% CI, 5.549–22.605; P = 0.001) were the main factors affecting hospital death in ATAAD patients.

Conclusion

Under the management of a professional cardiac surgery team with dedicated off-hours shifts, surgery time was not related to in-hospital mortality in ATAAD patients.

Development and validation of a nomogram for postoperative severe acute kidney injury in acute type A aortic dissection

BACKGROUND

Postoperative acute kidney injury (AKI) is a major complication associated with increased morbidity and mortality after surgery for acute type A aortic dissection (AAAD). To the best of our knowledge, risk prediction models for AKI following AAAD surgery have not been reported. The goal of the present study was to develop a prediction model to predict severe AKI after AAAD surgery.

METHODS

A total of 485 patients who underwent AAAD surgery were enrolled and randomly divided into the training cohort (70%) and the validation cohort (30%). Severe AKI was defined as AKI stage III following the Kidney Disease: Improving Global Outcomes criteria. Preoperative variables, intraoperative variables and postoperative data were collected for analysis. Multivariable logistic regression analysis was performed to select predictors and develop a nomogram in the study cohort. The final prediction model was validated using the bootstrapping techniques and in the validation cohort.

RESULTS

The incidence of severe AKI was 23.0% (n = 78), and 14.7% (n = 50) of patients needed renal replacement treatment. The hospital mortality rate was 8.3% (n = 28), while for AKI patients, the mortality rate was 13.1%, which increased to 20.5% for severe AKI patients. Univariate and multivariate analyses showed that age, cardiopulmonary bypass time, serum creatinine, and D-dimer were key predictors for severe AKI following AAAD surgery. The logistic regression model incorporated these predictors to develop a nomogram for predicting severe AKI after AAAD surgery. The nomogram showed optimal discrimination ability, with an area under the curve of 0.716 in the training cohort and 0.739 in the validation cohort. Calibration curve analysis demonstrated good correlations in both the training cohort and the validation cohort.

CONCLUSIONS

We developed a prognostic model including age, cardiopulmonary bypass time, serum creatinine, and D-dimer to predict severe AKI after AAAD surgery. The prognostic model demonstrated an effective predictive capability for severe AKI, which may help improve risk stratification for poor in-hospital outcomes after AAAD surgery.

Short- and Mid-Term Survival Prediction in Patients with Acute Type A Aortic Dissection Undergoing Surgical Repair: Based on the Systemic Immune-Inflammation Index

Purpose

The postoperative survival of patients with acute type A aortic dissection (aTAAD) remains unsatisfactory. The current study developed an easy-to-use survival prediction model and calculator.

Methods

A total of 496 patients with aTAAD undergoing surgical repair were included in this study. The systemic immune-inflammation index (SII) and other clinical features were collected and subjected to logistic and Cox regression analyses. The survival prediction model was based on Cox regression analyses and exhibited as a nomogram. For convenience of use, the nomogram was further developed into calculator software.

Results

We demonstrated that a higher preoperative SII was associated with in-hospital death (OR: 4.116, p < 0.001) and a higher postoperative overall survival rate (HR: 2.467, p < 0.001) in aTAAD patients undergoing surgical repair. A survival prediction model and calculator based on SII and four other clinical features were developed. The overall C-index of the model was 0.743. The areas under the curves (AUCs) of the 1- and 3-month and 1- and 3-year survival probabilities were 0.73, 0.71, 0.71 and 0.72, respectively. The model also showed good calibration and clinical utility.

Conclusion

Preoperative SII is significantly associated with postoperative survival. Based on SII and other clinical features, we created the first easy-to-use prediction model and calculator for predicting the postoperative survival rate in aTAAD patients, which showed good prediction performance.

Prediction model of acute kidney injury after different types of acute aortic dissection based on machine learning

Objective

A clinical prediction model for postoperative combined Acute kidney injury (AKI) in patients with Type A acute aortic dissection (TAAAD) and Type B acute aortic dissection (TBAAD) was constructed by using Machine Learning (ML).

Methods

Baseline data was collected from Acute aortic division (AAD) patients admitted to First Affiliated Hospital of Xinjiang Medical University between January 1, 2019 and December 31, 2021. (1) We identified baseline Serum creatinine (SCR) estimation methods and used them as a basis for diagnosis of AKI. (2) Divide their total datasets randomly into Training set (70%) and Test set (30%), Bootstrap modeling and validation of features using multiple ML methods in the training set, and select models corresponding to the largest Area Under Curve (AUC) for follow-up studies. (3) Screening of the best ML model variables through the model visualization tools Shapley Addictive Explanations (SHAP) and Recursive feature reduction (REF). (4) Finally, the pre-screened prediction models were evaluated using test set data from three aspects: discrimination, Calibration, and clinical benefit.

Results

The final incidence of AKI was 69.4% (120/173) in 173 patients with TAAAD and 28.6% (81/283) in 283 patients with TBAAD. For TAAAD-AKI, the Random Forest (RF) model showed the best prediction performance in the training set (AUC = 0.760, 95% CI:0.630–0.881); while for TBAAD-AKI, the Light Gradient Boosting Machine (LightGBM) model worked best (AUC = 0.734, 95% CI:0.623–0.847). Screening of the characteristic variables revealed that the common predictors among the two final prediction models for postoperative AKI due to AAD were baseline SCR, Blood urea nitrogen (BUN) and Uric acid (UA) at admission, Mechanical ventilation time (MVT). The specific predictors in the TAAAD-AKI model are: White blood cell (WBC), Platelet (PLT) and D dimer at admission, Plasma The specific predictors in the TBAAD-AKI model were N-terminal pro B-type natriuretic peptide (BNP), Serum kalium, Activated partial thromboplastin time (APTT) and Systolic blood pressure (SBP) at admission, Combined renal arteriography in surgery. Finally, we used in terms of Discrimination, the ROC value of the RF model for TAAAD was 0.81 and the ROC value of the LightGBM model for TBAAD was 0.74, both with good accuracy. In terms of calibration, the calibration curve of TAAAD-AKI's RF fits the ideal curve the best and has the lowest and smallest Brier score (0.16). Similarly, the calibration curve of TBAAD-AKI's LightGBM model fits the ideal curve the best and has the smallest Brier score (0.15). In terms of Clinical benefit, the best ML models for both types of AAD have good Net benefit as shown by Decision Curve Analysis (DCA).

Conclusion

We successfully constructed and validated clinical prediction models for the occurrence of AKI after surgery in TAAAD and TBAAD patients using different ML algorithms. The main predictors of the two types of AAD-AKI are somewhat different, and the strategies for early prevention and control of AKI are also different and need more external data for validation.

High platelet distribution width is an independent risk factor of postoperative pneumonia in patients with type A acute aortic dissection

Background

Platelet distribution width (PDW), as a widely applied and reliable marker of platelet activation, was associated with adverse outcomes in cardiovascular diseases. However, there is little literature on the relationship between PDW and postoperative pneumonia in patients with type A acute aortic dissection (AAAD).

Methods

In this retrospective cohort study, we collected consecutive patients who underwent emergency surgery for AAAD at Xiangya Hospital of Central South University from January 1, 2014 and June 30, 2020. Patients were divided into three tertiles on the basis of the PDW. The independent effect of the PDW on postoperative pneumonia was evaluated using multivariate logistic regression analysis, and smooth curve fitting was performed to visualize the linear relationship between PDW and the risk of postoperative pneumonia in patients with AAAD.

Results

A total of 210 patients with AAAD were enrolled and the overall incidence of postoperative pneumonia was 25.24% (n = 53). Multivariate logistic regression revealed that PDW was positively associated with the risk of postoperative pneumonia (OR: 1.07, 95% CI: 1.02–1.13, P < 0.05) after adjusting the confounders. Compared with the lowest PDW tertile, the risk of postoperative pneumonia increased by 1.21-fold in the medium PDW tertile (OR: 2.21, 95% CI: 0.73–6.72) and by 3.16-fold in the highest PDW tertile (OR: 4.16, 95% CI: 1.40–12.33). A straight-line relationship was observed between PDW and postoperative pneumonia risk in smoothing spline fitting.

Conclusion

Our findings indicate that high PDW is an independent risk factor of postoperative pneumonia in patients with AAAD. Preoperative PDW may serve as an available indicator of pneumonia, which helps identify AAAD patients with a high risk of postoperative pneumonia.

Delayed sternal closure for intractable bleeding after acute type A aortic dissection repair: outcomes and risk factors analyses

BACKGROUND

Perioperative coagulopathy and intractable bleeding are severe complications in acute type A aortic dissection (ATAAD) repair surgery. Mediastinal packing with delayed sternal closure (DSC) is a commonly adapted technique to stabilize the hemorrhagic tendency. This retrospective study aims to investigate the early and late outcomes and risk factors in patients who underwent DSC procedure during ATAAD repair surgery.

METHODS

This study investigated 704 consecutive patients who underwent ATAAD repair at this institution between January 2007 and September 2020. These patients were dichotomized into the DSC (n = 109; 15.5%) and primary sternal closure (PSC) groups (n = 595; 84.5%). The clinical features, surgical information, postoperative complications, 5-years cumulative survival, and freedom from reoperation rates were compared. A multivariate logistic regression analysis was used to identify the independent risk factors for patients who underwent DSC.

RESULTS

The DSC group showed a higher rate of hemopericardium and preoperative malperfusion, and was associated with longer cardiopulmonary bypass and aortic clamping times and a higher rate of intraoperative extracorporeal membrane oxygenation (ECMO) support. The DSC group showed higher blood transfusion volumes and rate of reexploration for bleeding after surgery. However, the in-hospital mortality rates (17.4% vs. 13.3%; P = 0.249), 5-year survival rates (66.9% vs. 68.2%; P = 0.635), and freedom from reoperation rates (89.1% vs. 82.5%; P = 0.344) were comparable between the DSC and PSC groups. Multivariate analysis revealed that hemopericardium, preoperative malperfusion, and intraoperative ECMO support were risk factors for implementing DSC.

CONCLUSIONS

DSC is an efficient life-saving technique to stabilize patients with intractable bleeding after undergoing ATAAD repair surgery, which leads to acceptable short- and long-term outcomes. Patients who were at risk for intractable bleeding should have early decision-making for implementing DSC.

A nomogram for reduced cardiac function in postoperative acute type A aortic dissection patients with acute kidney injury undergoing continuous renal replacement therapy

Background

This study aimed to develop a nomogram to predict reduced cardiac function for acute kidney injury (AKI) patients who received continuous renal replacement therapy (CRRT) after acute type A aortic dissection (ATAAD) surgery.

Methods

This study was a retrospective analysis. ATAAD patients with preoperative normal ejection fraction (EF) and postoperative AKI with CRRT admitted between January 2014 and November 2021 were included. The reduced cardiac function was defined as EF <50%. The data were analyzed by the univariate and multivariate logistic regression analyses. A diagnostic model was established by a nomogram, and its discriminative performance was validated by the received operating characteristic (ROC) curve and concordance (C) statistic. The calibration of the diagnostic model was tested by calibration curves and the HosmerLemeshow test. The clinical utility was evaluated by the decision curve analysis (DCA).

Result

In total, 208 patients were eligible for analysis, of which 98 patients with reduced cardiac function. The logistic regression analyses showed age ≥60 years old, history of coronary atherosclerotic disease, preoperative pericardial tamponade, and cardiopulmonary bypass time were risk factors for reduced cardiac function, which were further employed in the nomogram. As results, nomogram revealed a high predictive power (C statistic = 0.723, 0.654–0.792; the bootstrap-corrected concordance C statistic = 0.711, the area under the ROC curve = 0.723). The calibration curves showed good consistency between the predicted and the actual probabilities (calibration curve: Brier points = 0.208, Emax = 0.103, Eavg = 0.021; Hosmer-Lemeshow test, P = 0.476). DCA showed that the nomogram could augment net benefits and exhibited a wide range of threshold probabilities in the prediction of EF reduction.

Conclusion

This nomogram is an effective diagnostic model for predicting the reduced cardiac function in postoperative ATAAD patients with AKI undergoing CRRT and can be used to protect postoperative renal functions and facilitate patient-specific care after ATAAD surgery.

Effects of a frozen elephant trunk on postoperative renal dysfunction in acute type A aortic dissection extending into the renal artery

BACKGROUND

We investigated the effects of frozen elephant trunk (FET) implantation on clinical outcomes in patients with acute type A aortic dissection (ATAAD) extending into the renal artery (RA).

METHODS

Between May 2016 and April 2021, 136 patients underwent surgery for ATAAD at our hospital. Patients who died within 7 days postoperatively and those without preoperative contrast-enhanced computed tomography (CT) data were excluded from the study. The remaining 125 patients were included in this study. A preoperative CT-documented RA abnormality was found in 53 patients. Clinical outcomes, including renal dysfunction and CT findings, were compared between 29 patients with and 24 patients without the FET prosthesis.

RESULTS

Among the 53 patients with RA abnormalities, origin of the RA from the false lumen was the most common type of abnormality. The percentage of men and rate of arch repair were higher, and the operation, cardiopulmonary bypass, and lower body hypothermic circulatory arrest times were longer in the FET than in the non-FET group. Early mortality rates were similar between groups. The incidence of postoperative acute kidney injury (AKI) was lower in the FET group (35% vs. 67%, p = 0.028). Multivariable analysis showed that FET implantation was associated with a low incidence of AKI (odds ratio: 0.28, 95% confidence interval: 0.08-0.96; p = 0.043). Among the 125 patients with or without RA abnormalities, no predictor of AKI was identified.

CONCLUSION

FET implantation protected against postoperative AKI in patients with ATAAD extension into the RA.

Influence of Dynamic and Static Obstructive Renal Artery on Early Prognosis in Stanford Type A Aortic Dissection

BACKGROUND

Acute kidney injury (AKI) after acute Stanford type A aortic dissection (STAAD) surgery has a high mortality rate. Clarifying what type of renal artery problem (dynamic obstructive renal artery, DORA, or static obstructive renal artery, SORA) secondary to STAAD benefits from true lumen opening is helpful in providing a reference for the indication of renal artery intervention.

METHODS

From May 2018 to December 2019, 292 acute STAAD patients who underwent aortic surgery were enrolled in this study. DORA, SORA, and renal malperfusion were diagnosed according to preoperative aortic enhanced computed tomography (CTA). Renal artery problems secondary to STAAD were divided into three types: type 1, normal renal artery; type 2, DORA; and type 3, SORA. Acute kidney injury was divided into three stages: Stage 1, Stage 2, and Stage 3, according to 2012 Kidney Disease: Improving Global Outcomes (KDIGO). The primary endpoint was all-cause 30-day in-hospital death, and the secondary endpoint was postoperative dialysis requirement. Univariate and multivariate analyses were performed to assess the difference among the three types.

RESULTS

Postoperative AKI occurred in 154 of 292 (52.7%) patients, and postoperative dialysis was present in 27 of 292 (9.2%) patients with STAAD. Postoperative AKI and dialysis were significantly more prevalent in the SORA group (AKI: 71% in SORA group vs 51.5% in DORA group vs 22.2% in normal group; postoperative dialysis: 22.2% in SORA group vs 5.4% in DORA group vs 6.1 in normal group). Thirty-day (30-day) mortality was also significantly higher in the SORA group (Log-rank test, p=0.012). Preoperative acute myocardial infarction and body mass index were the independent risk factors for 30-day mortality. Static obstructive renal artery, cardiopulmonary bypass time, and renal blood cell transfusion >3 units were the independent risk factors for postoperative dialysis requirement.

CONCLUSION

Static obstructive renal artery led to higher 30-day in-hospital mortality and more postoperative dialysis. Open surgery reduced renal ischaemia injury caused by DORA, but it could not reduce renal ischaemia injury caused by SORA.

The long-term impact of acute renal failure after aortic arch replacement for acute type A aortic dissection

OBJECTIVE

To determine the long-term impact of developing acute renal failure (ARF) on survival after open aortic arch reconstruction for acute type A aortic dissection (ATAAD).

METHODS

This was an observational study of consecutive aortic surgeries from 2007 to 2021. Patients with ATAAD were identified via a prospectively maintained institutional database and were stratified by the presence or absence of postoperative ARF (by RIFLE criteria). Kaplan-Meier survival estimation and multivariable Cox regression analysis were performed.

RESULTS

A total of 601 patients undergoing open surgery for ATAAD were identified, of which 516 (85.9%) did not develop postoperative ARF, while 85 (14.1%) developed ARF, with a median follow-up time of 4.6 years (1.6, 7.9). Baseline characteristics were similar across each group, except for higher rates of branch vessel malperfusion and lower preoperative ejection fraction in the ARF group. Patients with ARF underwent more total arch replacement and elephant trunk procedures, with longer cardiopulmonary bypass and circulatory arrest times than patients without ARF. ARF was associated with worse short-term outcomes, including increased in-hospital mortality, prolonged mechanical ventilation, higher rates of sepsis, more blood transfusions, and longer length of hospital stay. Unadjusted Kaplan-Meier survival estimates were significantly lower in the ARF group, compared to the group without ARF (p < .001, log-rank test). After multivariable adjustment, the development of postoperative ARF was significantly associated with an increased hazard of death over the study's follow-up time-period (hazard ratio: 2.74, 95% confidence interval: 1.95, 3.86, p < .001).

CONCLUSIONS

ARF is a highly morbid postoperative event that may adversely impact long-term survival after aortic surgery.

Acute renal failure after acute type A aortic dissection repair. Insidious postoperative complication with poor short- and long-term prognosis

Acute type A aortic dissection (ATAAD) is a life-threatening aortic disease. Many systems and organs are affected by malperfusion which presents preoperatively and postoperatively. Postoperative acute renal failure after ATAAD constitutes a severe and insidious complication. Acute renal damage is observed in many patients with ATAAD preoperatively and it burdens the renal function postoperatively. Renal replacement therapy represents an additional risk factor for short-, mid-, and long-term outcomes after ATAAD repair. Brown et al.'s present study highlight the clinical significance of this complication. Also, they remind us of the importance of optimizing perioperative renal protective strategies in patients undergoing ATAAD repair.

Effect of nadir hematocrit during cardiopulmonary bypass on the early outcomes after surgical repair of acute type A aortic dissection

OBJECTIVE

Although hemodilution during hypothermic cardiopulmonary bypass (CPB) had been thought to improve microcirculation and reduce blood viscosity, there has been no report investigating the effect of low nadir hematocrit (Hct) values caused by severe hemodilution on the surgical outcomes of patients with acute type A aortic dissection (ATAAD).

METHODS

We retrospectively reviewed 112 consecutive patients who emergently underwent emergency surgical repair of ATAAD at our institution. The patients were classified into the high Hct (nadir Hct ≥ 21% during CPB; n = 51) and low Hct (nadir Hct < 21% during CPB; n = 61) groups. After propensity score matching of preoperative characteristics, surgical outcomes were compared between the groups.

RESULTS

Although there was no difference in the surgical procedure, longer CPB time and more blood transfusion during surgery were needed in the low Hct group than in the high Hct group. After surgery, estimated glomerular filtration rate was significantly lower (p = .015), lactaic acid was higher (p = .045), and intubation time was longer (p = .018) in the low Hct group than in the high Hct group, although there was no difference in hospital mortality between the groups. The AUC of the nadir Hct during CPB as a prognostic indicator of prolonged postoperative ventilator support was 0.8, with the highest accuracy at 16.7% (sensitivity 88%, specificity 76.9%). In all cohorts, female sex was an independent risk factor for a lower nadir Hct value of <21% during CPB.

CONCLUSION

A lower nadir Hct value of <21% during CPB may be associated with postoperative renal dysfunction and prolonged ventilator support in patients with ATAAD.

Procalcitonin, Interleukin-6 and C-reactive Protein Levels Predict Renal Adverse Outcomes and Mortality in Patients with Acute Type A Aortic Dissection

Background

Acute type A aortic coarctation (AAAD) is a highly deadly and serious life-threatening disease. The purpose of this study was to estimate the predictive value of peak procalcitonin, interleukin-6, and C-reactive protein levels on adverse renal outcomes and mortality in patients undergoing surgery for AAAD.

Methods

Perioperative peak PCT, CRP, and IL-6 levels were retrospectively collected in 331 patients hospitalized with AAAD from 2009 to 2021. The primary endpoints were AKI stage 2–3 and mortality. The receiver operating characteristic (ROC) curves were used to compare the predictive values of peak PCT, CRP, and IL-6 for different clinical outcomes. Multivariable logistic regression analysis was used to find risk factors for AKI and 30-day mortality.

Results

The incidence of AKI stage 2–3 following AAAD was 50.8% (168/331). The 30-day and overall mortality were significantly greater in the AKI 2–3 group than in the AKI 0–1 group (P = 0.000). ROC curve analysis showed that peak PCT, with an area under the ROC curve (AUC) of 0.712, was a more accurate predictor of adverse renal outcomes than peak IL-6 and CRP. Multivariable logistic regression analysis revealed that PCT > 0.39 ng/mL was an independent risk factor for AKI stage 2–3. Peak IL-6 > 259 pg/mL was found to be an independent risk factor for 30-day mortality.

Conclusion

In patients with surgery for AAAD, peak PCT provides a well-predictive indicator of AKI stage 2–3 and peak IL-6 indicates a favorable predictor of 30-day mortality.

Association of dissected ascending aorta diameter with preoperative adverse events in patients with acute type A aortic dissection

BACKGROUND

Acute type A aortic dissection (ATAAD) is a life-threatening disease associated with high morbidity and mortality.

AIM

To evaluate the diameter of dissected ascending aorta in patients diagnosed with ATAAD and whether the aortic diameter is associated with preoperative adverse events.

METHODS

A total of 108 patients diagnosed with ATAAD who underwent emergency operation under hypothermic circulatory arrest were enrolled in this study. Demographic characteristics and perioperative data were recorded. In all patients, preoperative chest and abdomen computed tomography (CT) scans were performed.

RESULTS

Median age of the patients was 61.5 (52.5-70.5) years and median body mass index (BMI) was 28.2 (25.1-32.6) cm². The number of female patients was 37 (25%). Median diameter of the ascending aorta was 5.0 (4.5-6) cm and 53.8% of the patients had an aortic diameter < 5.0 cm, while 32.3% of the patients had an aortic diameter of 4.5cm and 72.0% had an ascending aorta diameter < 5.5 cm. The diameter of the ascending aorta did not differ in patients with vs without preoperative adverse events: Preoperative neurological dysfunction (P = 0.53) and hemodynamic instability (P = 0.43). Median age of patients with preoperative hemodynamic instability was 65 (57.5-74) years, while it was 60 (51-68) years in patients without (P = 0.04)

CONCLUSION

Although current guidelines suggest replacing the ascending aorta with a diameter > 5.5 cm, most of the patients with ATAAD had an aortic diameter of less than 5.5 cm. The diameter of the ascending aorta in patients diagnose with ATAAD is not associated with preoperative adverse events.

Transfusion in Root Replacement for Aortic Dissection: STS Adult Cardiac Surgery Database Analysis

BACKGROUND

Transfusion in acute aortic syndromes has been studied in a limited fashion. We sought to describe contemporary transfusion practice for root replacement in acute (Stanford) type A aortic dissection (ATAAD).

METHODS

The STS Adult Cardiac Surgery Database was interrogated to identify patients who underwent primary aortic root replacement for ATAAD (July 2014 - June 2017). Patients (n = 1558) were stratified by type of root replacement. Multivariate regression was used to determine those variables associated with transfusion and postoperative morbidity.

RESULTS

Transfusion was required in 90.5% of cases (n = 1410). Operative mortality for all patients was 17.3% (261 deaths). Intraoperative red blood cell (RBC) transfusion portended reduced short-term survival (odds ratio {OR} 2.00, p = 0.025). Massive postoperative transfusion was associated with prolonged ventilation (OR 13.47, p < 0.001), sepsis (OR 4.13, p < 0.001), and new dialysis-dependent renal-failure (OR 2.43, p < 0.001). Females were more likely to require transfusion (OR 3.03, p < 0.001), as were patients who had coronary bypass (OR 1.57, p = 0.009), and those in shock (OR 2.27, p < 0.001). Valve-sparing aortic root replacement (VSARR) was associated with reduced transfusion requirements vs. composite roots. Institutional case volume was not appreciably correlated with transfusion.

CONCLUSIONS

Most patients undergoing root replacement for aortic dissection require blood products. Composite root replacement is associated with a greater likelihood of transfusion than a valve-sparing operation. Transfusion independently foreshadows greater operative mortality.

Identification of risk factors for postoperative stage 3 acute kidney injury in patients who received surgical repair for acute type A aortic dissection

BACKGROUND

Acute kidney injury (AKI) is a serious complication that often occurred after acute type A aortic dissection (ATAAD) surgery. Previous studies proved that the Kidney Disease Improving Global Outcomes (KDIGO) defined stage 3 AKI was associated with lower long-term survival rate. However, the risk factors for developing stage 3 AKI had not been identified. The aim of the study was to explore the risk factors for developing KDIGO stage 3 after ATAAD operation.

METHODS

This study included 993 patients who received ATAAD operation from 2014 to 2019 at the Nanjing Drum Tower Hospital. Postoperative AKI was diagnosed according to the KDIGO criteria. Multivariate logistic regression analyses were applied to identify risk factors for stage 3 AKI. Kaplan-Meier survival analyses and Cox proportional hazards regression model were conducted to explore the association between different AKI stages and postoperative survival rate.

RESULTS

The mean age of all enrolled patients was 53.0 ± 13.1 years. A total of 236 (23.8%) patients suffered postoperative stage 3 AKI including 165 patients who required renal replacement therapy. Advanced age (odds ratio [OR] 1.031; 95% confidence interval [CI] 1.005-1.057; P = 0.018), prolonged cardiopulmonary bypass (CPB) duration (OR 1.010; 95% CI 1.002-1.018; P = 0.013), and higher drainage volume 24 h after surgery (OR 1.000; 95% CI 1.000-1.001; P = 0.033) were identified as independent risk factors for developing stage 3 AKI. In addition, our result showed that the mortality rate was correlated significantly with the severity of AKI defined by KDIGO criteria and the Cox regression analysis showed that only stage 3 AKI, but not stage 1 and 2, was an independent risk factor for mortality (Hazard ratio 10.365, 95% CI 4.208 to 25.528; P < 0.001) after adjusting for important confounding factors.

CONCLUSIONS

Our study suggested that stage 3 postoperative AKI was significantly associated with decreased postoperative survival rate after ATAAD surgery. Advanced age, increased CPB duration and drainage volume 24 h after surgery were identified as risk factors for developing stage 3 AKI.

Significant Prediction of In-hospital Major Adverse Events by D-Dimer Level in Patients With Acute Type A Aortic Dissection

Background

Acute type A aortic dissection (ATAAD) is a rare, life-threatening condition affecting the aorta. This study explores the relationship between the level of admission D-dimer, which was assessed during the first 2 h from admission, and in-hospital major adverse events (MAE) with ATAAD.

Methods

A total of 470 patients with enhanced computed tomography (CT) confirmed diagnosis of ATAAD who underwent operation treatment in Guangdong Provincial People's hospital between September 2017 and June 2021 were enrolled in the present study. The X-tile program was used to determine the optimal D-dimer thresholds for risk. Restricted cubic spline (RSC) was performed to assess the association between D-dimer and endpoint. The perioperative data were compared between the two groups, univariate and multivariate analyses were used to investigate the risk factors of major adverse events (in-hospital mortality, gastrointestinal bleeding, paraplegia, acute kidney failure, reopen the chest, low cardiac output syndrome, cerebrovascular accident, respiratory insufficiency, MODS, gastrointestinal bleeding, and severe infection).

Results

Among 470 patients, 151 (32.1%) had MAE. In-hospital mortality was 7.44%. The patients with D-dimer >14,500 ng/ml were more likely to present with acute kidney failure, low cardiac output, cerebrovascular accident, multiple organ dysfunction syndromes (MODS), gastrointestinal bleeding, and severe infection. D-dimer level was an independent risk factor for acute kidney failure (OR 2.09, 95% CI: 1.25–3.51, p = 0.005), MODS (OR 6.40, 95% CI: 1.23–33.39, p = 0.028), gastrointestinal bleeding (OR 17.76, 95% CI: 1.99–158.78, p = 0.010) and mortality (OR 3.17, 95% CI: 1.32–7.63, p = 0.010). Multivariate regression analysis of adverse events also suggested that D-dimer >14,500 ng/ml (OR 1.68, 95% CI: 1.09–2.61, p = 0.020) was the independent risk factor of major adverse events.

Conclusions

Increasing D-dimer levels were independently associated with the in-hospital MAE and thus can be used as a useful prognostic biomarker before the surgery.

Incidence- and In-hospital Mortality-Related Risk Factors of Acute Kidney Injury Requiring Continuous Renal Replacement Therapy in Patients Undergoing Surgery for Acute Type a Aortic Dissection

Background: Few studies on the risk factors for postoperative continuous renal replacement therapy (CRRT) in a homogeneous population of patients with acute type A aortic dissection (AAAD). This retrospective analysis aimed to investigate the risk factors for CRRT and in-hospital mortality in the patients undergoing AAAD surgery and to discuss the perioperative comorbidities and short-term outcomes. Methods: The study collected electronic medical records and laboratory data from 432 patients undergoing surgery for AAAD between March 2009 and June 2021. All the patients were divided into CRRT and non-CRRT groups; those in the CRRT group were divided into the survivor and non-survivor groups. The univariable and multivariable analyses were used to identify the independent risk factors for CRRT and in-hospital mortality. Results: The proportion of requiring CRRT and in-hospital mortality in the patients with CRRT was 14.6 and 46.0%, respectively. Baseline serum creatinine (SCr) [odds ratio (OR), 1.006], cystatin C (OR, 1.438), lung infection (OR, 2.292), second thoracotomy (OR, 5.185), diabetes mellitus (OR, 6.868), AKI stage 2-3 (OR, 22.901) were the independent risk factors for receiving CRRT. In-hospital mortality in the CRRT group (46%) was 4.6 times higher than in the non-CRRT group (10%). In the non-survivor (n = 29) and survivor (n = 34) groups, New York Heart Association (NYHA) class III-IV (OR, 10.272, P = 0.019), lactic acidosis (OR, 10.224, P = 0.019) were the independent risk factors for in-hospital mortality in patients receiving CRRT. Conclusion: There was a high rate of CRRT requirement and high in-hospital mortality after AAAD surgery. The risk factors for CRRT and in-hospital mortality in the patients undergoing AAAD surgery were determined to help identify the high-risk patients and make appropriate clinical decisions. Further randomized controlled studies are urgently needed to establish the risk factors for CRRT and in-hospital mortality.

U-shaped relationship between platelet-lymphocyte ratio and postoperative in-hospital mortality in patients with type A acute aortic dissection

Background

The platelet-lymphocyte ratio (PLR), a novel inflammatory marker, is generally associated with increased in-hospital mortality risk. We aimed to investigate the association between PLR and postoperative in-hospital mortality risk in patients with type A acute aortic dissection (AAAD).

Methods

Patients (n = 270) who underwent emergency surgery for AAAD at Xiangya Hospital of Central South University between January 2014 and May 2019 were divided into three PLR-based tertiles. We used multiple regression analyses to evaluate the independent effect of PLR on in-hospital mortality, and smooth curve fitting and a segmented regression model with adjustment of confounding factors to analyze the threshold effect between PLR and in-hospital mortality risk.

Results

The overall postoperative in-hospital mortality was 13.33%. After adjusting for confounders, in-hospital mortality risk in the medium PLR tertile was the lowest (Odds ratio [OR] = 0.20, 95% confidence interval [CI] = 0.06–0.66). We observed a U-shaped relationship between PLR and in-hospital mortality risk after smoothing spline fitting was applied. When PLR < 108, the in-hospital mortality risk increased by 10% per unit decrease in PLR (OR = 0.90, P = 0.001). When the PLR was between 108 and 188, the mortality risk was the lowest (OR = 1.02, P = 0.288). When PLR > 188, the in-hospital mortality risk increased by 6% per unit increase in PLR (OR = 1.06, P = 0.045).

Conclusions

There was a U-shaped relationship between PLR and in-hospital mortality in patients with AAAD, with an optimal PLR range for the lowest in-hospital mortality risk of 108–188. PLR may be a useful preoperative prognostic tool for predicting in-hospital mortality risk in patients with AAAD and can ensure risk stratification and early treatment initiation.

En Bloc Arch Reconstruction With the Frozen Elephant Trunk Technique for Acute Type a Aortic Dissection

Objective: The study objective was to evaluate the effect of en bloc arch reconstruction with frozen elephant trunk (FET) technique for acute type A aortic dissection.

Methods: 41 patients with acute Stanford type A dissection underwent en bloc arch reconstruction combined with FET implantation between April 2018 and August 2020. The mean age of the patients was 46 ± 13 years, and 9 patients were female. One patient had Marfan syndrome. Six patients had pericardial tamponade, 9 had pleural effusion, 5 had transient cerebral ischemic attack, and 3 had chronic kidney disease.

Results: The hospital mortality rate was 9.8% (4 patients). 2 (4.9%) patients had stroke, 23 (56.1%) had acute kidney injury, and 5 (12.2%) had renal failure requiring hemodialysis. During follow-up, the rate of complete false lumen thrombosis was 91.6% (33/36) around the FET, 69.4% (25/36) at the diaphragmatic level, and 27.8% (10/36) at the superior mesenteric artery level. The true lumen diameter at the same three levels of the descending aorta increased significantly while the false lumen diameter reduced at the two levels: pulmonary bifurcation and the diaphragm. The 1-, 2-and 3-year actuarial survival rates were 90.2% [95% confidence interval (CI), 81.2–99.2], 84.2% (95% CI, 70.1–98.3) and 70.2% (95% CI, 42.2–98), respectively.

Conclusions: In patients with acute type A dissection, en bloc arch reconstruction with FET technique appeared to be feasible and effective with early clinical follow-up results. Future studies including a large sample size and long-term follow-up are required to evaluate the efficacy.

Acute Kidney Injury following Cardiopulmonary Bypass: A Challenging Picture

Recent studies have recognized several risk factors for cardiopulmonary bypass- (CPB-) associated acute kidney injury (AKI). However, the lack of early biomarkers for AKI prevents practitioners from intervening in a timely manner. We reviewed the literature with the aim of improving our understanding of the risk factors for CPB-associated AKI, which may increase our ability to prevent or improve this condition. Some novel early biomarkers for AKI have been introduced. In particular, a combinational use of these biomarkers would be helpful to improve clinical outcomes. Furthermore, we discuss several interventions that are aimed at managing CPB-associated AKI, may increase the effect of renal replacement therapy (RRT), and may contribute to preventing CPB-associated AKI. Collectively, the conclusions of this paper are limited by the availability of clinical trial evidence and conflicting definitions of AKI. A guideline is urgently needed for CPB-associated AKI.