AKI associated with cardiac surgery

Five-gene signature predicts acute kidney injury in early kidney transplant patients

Patients with acute kidney injury (AKI) show high morbidity and mortality, and a lack of effective biomarkers increases difficulty in its early detection. Weighted gene co-expression network analysis (WGCNA) detected a total of 22 gene modules and 6 miRNA modules, of which 4 gene modules and 3 miRNA modules were phenotypically co-related. Functional analysis revealed that these modules were related to different molecular pathways, which mainly involved PI3K-Akt signaling pathway and ECM-receptor interaction. The brown modules related to transplantation mainly involved immune-related pathways. Finally, five genes with the highest AUC were used to establish a diagnosis and prediction model of AKI. The model showed a high area under curve (AUC) in the training set and validation set, and their prediction accuracy for AKI was as high as 100%. Similarly, the prediction accuracy of AKI after 24 h in the 0 h transplant sample was 100%. This study may provide new features for the diagnosis and prediction of AKI after kidney transplantation, and facilitate the diagnosis and drug development of AKI in kidney transplant patients.

Prevalence and Risk Factors for Acute Kidney Injury Among Adults Undergoing Cardiac Interventions in King Abdulaziz University Hospital: A Retrospective Review

Background

Acute kidney injury (AKI) is a syndrome that has been receiving considerable attention as a common risk in cardiac surgeries, which has consequences for short- and long-term survival implications, even for those who do not progress to renal failure. There have been limited studies in the Middle East, and specifically in the Kingdom of Saudi Arabia (KSA). Therefore, our study aimed to identify the prevalence of and risk factors for AKIs following adult cardiac interventions during 2010-2020 at the King Abdulaziz University Hospital (KAUH), Jeddah, Saudi Arabia.

Methods

Setting and Design: A retrospective medical record review was conducted among all the adult patients who underwent cardiac interventions and developed AKIs between 2010 and 2020. Google forms were used to extract the data from the hospital records. About statistical analysis binary logistic regression analyses, relative risks (RRs), and confidence intervals (CI) were used to determine the associations among the variables.

Results

After applying the inclusion and exclusion criteria, 564 patients were included. Their baseline demographic, clinical, biological, and operative characteristics were analyzed. AKIs developed in 110 (19.5%) patients and patients with diabetes were more likely to develop AKIs (P < 0.012, RR = 2.280, CI = 1.198-4.339). Hypertension showed a strong effect in the development of AKIs (P < 0.004, RR = 2.865, CI = 1.391-5.900). Moreover, patients who suffered from chronic heart failure were more prone to the development of AKIs (P < 0.008, RR = 4.189, CI =1.452-12.087). Furthermore, anemia with significant P-values (<0.002), and CIs of 1.509-6.822, indicated that these patients were more likely to develop AKIs (3.209 times).

Conclusion

We demonstrated that AKIs are frequent complications in adults after cardiac interventions and were associated with poor outcomes. Risk factors for the development of AKIs were identified to be diabetes mellitus, hypertension, chronic heart failure, and anemia. Further investigation of this cohort is necessary to better understand the problem of kidney injuries.

A COMPARISON OF AKIN, KDIGO AND RIFLE DEFINITIONS TO DIAGNOSE ACUTE KIDNEY INJURY AND PREDICT THE OUTCOMES AFTER CARDIAC SURGERY IN A SOUTH ASIAN COHORT

BACKGROUND

Acute kidney injury (AKI) after cardiac surgery is associated with an increased mortality and morbidity. Different definitions for AKI have been used such as Acute Kidney Injury Network (AKIN), Kidney Disease: Improving Global Outcomes (KDIGO) or risk, injury, failure, loss, end-stage kidney disease (RIFLE). Each of these definitions have their own benefits and limitations for predicting the degree of AKI and adverse outcomes following cardiac surgery. This study was aimed to compare the three AKI definitions to diagnose AKI and their predictive ability for mortality and morbidity after isolated coronary artery bypass surgery (CABG) in a South Asian cohort.

MATERIAL AND METHODS

A single center retrospective review was conducted on 1508 patients having undergone isolated CABG surgery during January 2015 to January 2019. AKI was assessed on three definitions and comparative receiver operating characteristics curves were built against the outcomes to assess discriminative power of each.

RESULTS

Mean age of participants was 59.43 (±1.12) years, predominantly males (82.6%). Patient with AKI were elder, more likely to be diabetic and hypertensive. AKI by any definition occurred in 58.7% (885/1508) patients. Frequency of AKI was 508 (33.7%), 517 (34.4%) and 871 (57.8%) on AKIN, KDIGO and RIFLE criteria, respectively. The proportion of patients with RIFLE- risk 619 (41%) was greater compared with AKIN stage 1 [342 (22.7%)], and KDIGO stage 1 [330 (21.9%)], while for stage 2 and 3 the proportions were comparable across the three systems. Area under the curve (AUC) for 30-day mortality for AKIN was [0.786, (95% CI: 0.764 to 0.806)], KDIGO: [0.796, (95% CI: 0.775 to 0.816)], and for RIFLE [0.844, (95% CI: 0.825 to 0.862)]. AUC for overall morbidity were in undesirable ranges (i.e. >0.5 to ≤ 0.7) for all three definitions.

CONCLUSION

In a South Asian cohort, performance of AKIN and KDIGO criteria was comparable to diagnose AKI, while RIFLE definition, though overestimated the incidence of AKI particularly stage 1, and had an excellent discriminatory power to predict mortality compared to other two definitions.

Efficacy of umbilical cord mesenchymal stem cell transfusion for the treatment of severe AKI: a protocol for a randomised controlled trial

INTRODUCTION

Acute kidney injury (AKI) is a common and severe clinical problem that is associated with high mortality, a long hospital stays and high healthcare resource consumption. Approximately a quarter of AKI survivors will develop chronic kidney disease. Mesenchymal stem cells (MSCs) are multipotent stem cells with antiapoptotic, immunomodulatory, antioxidative and proangiogenic properties. Therefore, MSCs have been considered as a potential new therapy for the treatment of AKI. Several clinical trials have been performed, but the results have been inconsistent. This trial investigated whether MSCs can improve renal recovery and mortality in patients with severe AKI.

METHODS AND ANALYSIS

One hundred subjects suffering from severe AKI will participate in this patient-blinded, randomised, placebo-controlled, parallel design clinical trial. Participants will be randomly assigned to receive two doses of MSCs or placebo (saline) on days 0 and 7. Urinary biomarkers of renal injury and repair will be measured using commercially available ELISA kits. The main outcome measures are changes in renal function levels within the first 28 days following MSC infusion.

ETHICS AND DISSEMINATION

The study was approved by the Ethics Committee of the Chinese PLA General Hospital. The findings of the study will be disseminated through public and scientific channels.

TRIAL REGISTRATION NUMBER

NCT04194671.

Use of Ultra High Performance Liquid Chromatography with High Resolution Mass Spectrometry to Analyze Urinary Metabolome Alterations Following Acute Kidney Injury in Post-Cardiac Surgery Patients

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Cardiac surgery-associated AKI results in dramatic changes in urinary metabolome.

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Urinary metabolite disorder observed in patients with cardiac surgery-associated AKI.

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When metaboloite disorder was due to ischaemia and medical treatment, kidneys could return to normal.

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This work provides data about urinary metabolic profiles and resources for further research on AKI.

Background

Cardiac surgery-associated acute kidney injury (AKI) can increase the mortality and morbidity, and the incidence of chronic kidney disease, in critically ill survivors. The purpose of this research was to investigate possible links between urinary metabolic changes and cardiac surgery-associated AKI.

Methods

Using ultra-high-performance liquid chromatography coupled with Q-Exactive Orbitrap mass spectrometry, non-targeted metabolomics was performed on urinary samples collected from groups of patients with cardiac surgery-associated AKI at different time points, including Before_AKI (uninjured kidney), AKI_Day1 (injured kidney) and AKI_Day14 (recovered kidney) groups. The data among the three groups were analyzed by combining multivariate and univariate statistical methods, and urine metabolites related to AKI in patients after cardiac surgery were screened. Altered metabolic pathways associated with cardiac surgery-induced AKI were identified by examining the Kyoto Encyclopedia of Genes and Genomes database.

Results

The secreted urinary metabolome of the injured kidney can be well separated from the urine metabolomes of uninjured or recovered patients using multivariate and univariate statistical analyses. However, urine samples from the AKI_Day14 and Before_AKI groups cannot be distinguished using either of the two statistical analyses. Nearly 4000 urinary metabolites were identified through bioinformatics methods at Annotation Levels 1–4. Several of these differential metabolites may also perform essential biological functions. Differential analysis of the urinary metabolome among groups was also performed to provide potential prognostic indicators and changes in signalling pathways. Compared with the uninjured kidney group, the patients with cardiac surgery-associated AKI displayed dramatic changes in renal metabolism, including sulphur metabolism and amino acid metabolism.

Conclusions

Urinary metabolite disorder was observed in patients with cardiac surgery-associated AKI due to ischaemia and medical treatment, and the recovered patients’ kidneys were able to return to normal. This work provides data on urine metabolite markers and essential resources for further research on AKI.

Are outcomes in congenital cardiac surgery better than ever?

BACKGROUND AND AIM OF THE STUDY

Congenital heart disease is the most common congenital defect among infants born in the United States. Within the first year of life, 1 in 4 of these infants will need surgery. Only one generation removed from an overall mortality of 14%, many changes have been introduced into the field. Have these changes measurably improved outcomes?

METHODS

The literature search was conducted through PubMed MEDLINE and Google Scholar from inception to October 31, 2021. Ultimately, 78 publications were chosen for inclusion.

RESULTS

The outcome of overall mortality has experienced continuous improvements in the modern era of the specialty despite the performance of more technically demanding surgeries on patients with complex comorbidities. This modality does not account for case-mix, however. In turn, clinical outcomes have not been consistent from center to center. Furthermore, variation in practice between institutions has also been documented. A recurring theme in the literature is a movement toward standardization and universalization. Examples include mortality risk-stratification that has allowed direct comparison of outcomes between programs and improved definitions of morbidities which provide an enhanced framework for diagnosis and management.

CONCLUSIONS

Overall mortality is now below 3%, which suggests that more patients are surviving their interventions than in any previous era in congenital cardiac surgery. Focus has transitioned from survival to improving the quality of life in the survivors by decreasing the incidence of morbidity and associated long-term effects. With the transformation toward standardization and interinstitutional collaboration, future advancements are expected.

Abnormal Iron and Lipid Metabolism Mediated Ferroptosis in Kidney Diseases and Its Therapeutic Potential

Ferroptosis is a newly identified form of regulated cell death driven by iron-dependent phospholipid peroxidation and oxidative stress. Ferroptosis has distinct biological and morphology characteristics, such as shrunken mitochondria when compared to other known regulated cell deaths. The regulation of ferroptosis includes different molecular mechanisms and multiple cellular metabolic pathways, including glutathione/glutathione peroxidase 4(GPX4) signaling pathways, which are involved in the amino acid metabolism and the activation of GPX4; iron metabolic signaling pathways, which are involved in the regulation of iron import/export and the storage/release of intracellular iron through iron-regulatory proteins (IRPs), and lipid metabolic signaling pathways, which are involved in the metabolism of unsaturated fatty acids in cell membranes. Ferroptosis plays an essential role in the pathology of various kidneys diseases, including acute kidney injury (AKI), chronic kidney disease (CKD), autosomal dominant polycystic kidney disease (ADPKD), and renal cell carcinoma (RCC). Targeting ferroptosis with its inducers/initiators and inhibitors can modulate the progression of kidney diseases in animal models. In this review, we discuss the characteristics of ferroptosis and the ferroptosis-based mechanisms, highlighting the potential role of the main ferroptosis-associated metabolic pathways in the treatment and prevention of various kidney diseases.

Low Triiodothyronine Syndrome Increased the Incidence of Acute Kidney Injury After Cardiac Surgery

Background

Acute kidney injury (AKI) is a severe complication of cardiac surgery. This study was designed to explore the association between the preoperative low T3 syndrome and cardiac surgery-associated acute kidney injury (CSA-AKI).

Methods

This was a retrospective single-center study. Data on 784 patients undergoing elective coronary artery bypass grafting (CABG) or valve surgery were collected from January 2016 to July 2019. AKI was defined according to Kidney Disease: Improving Global Outcomes guidelines. The effect of preoperative low T3 syndrome (fT3 < 3.5pmol/L) on the risk of the postoperative AKI was analyzed in a logistic regression model.

Results

There were 171 (21.8%) patients developing AKI. Preoperative T3 and FT3 levels were lower in patients with AKI than in those without AKI (P < 0.001). The incidence of postoperative AKI was higher in patients with low T3 syndrome than in those without (31.0% vs 19.8%; P = 0.003). Multivariate logistic regression analysis showed that low T3 syndrome was an independent risk factor for CSA-AKI patients (OR = 1.609, 95% CI: 1.033–2.504; P = 0.035), after adjusting for confounding factors, such as age, albumin, and uric acid. Subgroup analyses showed that preoperative low T3 syndrome also increased incidence of CSA-AKI in those with high risk factors, such as age ≧60 yrs (OR: 1.891, 95% CI: 1.183–3.022, P = 0.008), hypertension (OR: 2.104, 95% CI: 1.218–3.3.635, P = 0.008), and hyperuricemia (OR: 2.052, 95% CI: 1.037–4.06, P = 0.039).

Conclusion

Low T3 syndrome independently increases the risk of CSA-AKI. Patients with low T3 syndrome should be considered at higher risk and be evaluated before cardiac surgery.

Association of high-sensitivity C-reactive protein and anemia with acute kidney injury in neonates

BACKGROUND

The association of high-sensitivity C-reactive protein (hsCRP) and anemia with postoperative acute kidney injury (AKI) in neonates with congenital heart disease (CHD) is still unclear. The purpose of this study was to examine whether anemia-associated AKI is modulated by hsCRP in neonates.

METHODS

This study included 253 consecutive neonatal patients who underwent CHD surgery in a national tertiary hospital. We investigated the association between postoperative AKI with baseline hsCRP, anemia, and their interaction by multivariable logistic regression analyses.

RESULTS

The incidence of AKI was 24.1% in the entire cohort. After being adjusted for covariates, hsCRP level was negatively correlated with AKI (P < 0.01 for 1 mg/L threshold), whereas anemia emerged as an independent risk factor of AKI (P = 0.02). In addition, there was a significant interaction between anemia and hsCRP level (P = 0.01). In neonates with hsCRP < 1 mg/L, anemia was positively associated with AKI (P = 0.03). However, no significant association was found between anemia and AKI in the context of hsCRP ≥ 1 mg/L. Combination of anemia and hsCRP < 1 mg/L was independently correlated with the risk of AKI (P < 0.01), while concomitant anemia and hsCRP ≥ 1 mg/L or hsCRP < 1 mg/L combined with non-anemia was not.

CONCLUSIONS

In neonates with CHD, the risk of anemia-associated AKI may be modulated by hsCRP level. Attention should be paid to neonates with preoperative anemia and baseline hsCRP < 1 mg/L to reduce the risk of postoperative AKI.

Neutrophil gelatinase-associated lipocalin as a biomarker for predicting acute kidney injury after coronary artery bypass grafting

Background

Early and precocious determination of acute kidney injury (AKI) is essential to prevent morbidity and mortality following coronary artery bypass grafting (CABG). Evaluation of the perioperative renal function is substantial using novel biomarkers other than the late traditional method of using serum creatinine. Plasma neutrophil gelatinase-associated lipocalin (NGAL) is a biomarker investigated for early detection of AKI in patients undergoing coronary artery bypass grafting, and its role has to be determined in this study.

Results

Twenty-five patients undergoing elective CABG were enrolled in this cohort study and were assigned into two groups: group I include the patients that did not develop AKI (no AKI group) and group II include the patients that developed AKI (AKI group). Acute kidney injury based on Kidney Disease: Improving Global Outcomes (KDIGO) classification had been developed in 7 patients (28%). Plasma NGAL levels at 6 h were higher in patients who developed AKI compared with those who did not (302 ± 88.02 vs. 116.50 ± 17.33 ng/m, p value < 0.001). The cut-off value of plasma NGAL levels measured 6 h postoperatively was 145 ng/ml and the area under the receiver-operating characteristic (ROC) curve was 0.965. Results of this study showed that plasma NGAL is a robust early biomarker of AKI, which preceded the rise in serum creatinine by many hours.

Conclusion

This study revealed that earlier diagnosis of acute kidney injury in patients undergoing CABG can be achieved by measuring postoperative plasma NGAL concentration at 6 h.

The Role of Race on Acute Kidney Injury Following Cardiac Surgery

BACKGROUND

Acute kidney injury (AKI) frequently complicates cardiac surgery and is more common among Black patients. We evaluated determinants of race-based differences in AKI rates.

METHODS

Serum creatinine-based criteria was used to identify adult cardiac surgical patients developing post-operative AKI in the PERForm registry (7/1/2014-6/30/2019). Patient characteristics, operative details and outcomes were compared by race (Black versus White) after excluding patients with pre-operative dialysis, missing pre- or post-operative creatinine, or other races. A mixed effect model (adjusting for demographics, comorbidities, surgical factors) used hospital as a random effect to predict post-operative stage 2 or 3 AKI. Propensity score analyses were conducted to evaluate robustness of the primary analyses.

RESULTS

The study cohort included 34,520 patients (8% Black). More Black than White patients were female (43 versus 27%, p<.001), had hypertension (93 versus 87%, p<.001) and diabetes (51 versus 41%, p<.001). AKI >Stage 2 occurred among 1,780 (5%) patients, more often among Black than White patients (8 versus 5%, p<.001). Intra-operatively, Black patients had lower nadir hematocrits (23 versus 26, p<.001), and were more likely to be transfused (22 versus 14%, p<.001). After adjustment, Black (compared to White) race independently predicted odds for post-operative AKI (adjOR 1.50, 95% CI 1.26-1.78). The multivariable findings were similar in propensity score analyses.

CONCLUSIONS

Despite accounting for differences in risk factors and intra-operative practices, Black patients had a 50% increased odds for developing moderate-severe post-operative AKI compared to White patients. Additional evaluations are warranted to identify potential targets to address racial disparities in AKI outcomes.

Remote Ischemic Preconditioning Reduces Acute Kidney Injury After Cardiac Surgery: A Systematic Review and Meta-analysis of Randomized Controlled Trials

BACKGROUND

Results from previous studies evaluating the effects of remote ischemic preconditioning (RIPC) on morbidity and mortality after cardiac surgery are inconsistent. This meta-analysis of randomized controlled trials (RCTs) aims to determine whether RIPC improves cardiac and renal outcomes in adults undergoing cardiac surgery.

METHODS

PubMed, EMBASE, and Cochrane Library were comprehensively searched to identify RCTs comparing RIPC with control in cardiac surgery. The coprimary outcomes were the incidence of postoperative myocardial infarction (MI) and the incidence of postoperative acute kidney injury (AKI). Meta-analyses were performed using a random-effect model. Subgroup analyses were conducted according to volatile only anesthesia versus propofol anesthesia with or without volatiles, high-risk patients versus non-high-risk patients, and Acute Kidney Injury Network (AKIN) or Kidney Disease Improving Global Outcomes (KDIGO) criteria versus other criteria for AKI diagnosis.

RESULTS

A total of 79 RCTs with 10,814 patients were included. While the incidence of postoperative MI did not differ between the RIPC and control groups (8.2% vs 9.7%; risk ratio [RR] = 0.87, 95% confidence interval [CI], 0.76-1.01, P = .07, I2 = 0%), RIPC significantly reduced the incidence of postoperative AKI (22% vs 24.4%; RR = 0.86, 95% CI, 0.77-0.97, P = .01, I2 = 34%). The subgroup analyses showed that RIPC was associated with a reduced incidence of MI in non-high-risk patients, and that RIPC was associated with a reduced incidence of AKI in volatile only anesthesia, in non-high-risk patients, and in the studies using AKIN or KDIGO criteria for AKI diagnosis.

CONCLUSIONS

This meta-analysis demonstrates that RIPC reduces the incidence of AKI after cardiac surgery. This renoprotective effect of RIPC is mainly evident during volatile only anesthesia, in non-high-risk patients, and when AKIN or KDIGO criteria used for AKI diagnosis.

Protective Effect of Ginsenoside Rb1 Nanoparticles Against Contrast-Induced Nephropathy by Inhibiting High Mobility Group Box 1 Gene/Toll-Like Receptor 4/NF-κB Signaling Pathway

With the progress made in the widespread application of interventional radiology procedures, there has been an increasing number of patients who suffer from cardiovascular diseases and go through imaging and interventional treatment with iodine contrast medium (ICM) year by year. In turn, there has been an increasing amount of concern over acute kidney injury (AKI) brought about by ICM. As evidenced by numerous studies, the initiation of inflammatory response plays a critical role in the development of ICM-induced AKI. Correspondingly, the strategy of targeting renal inflammatory response and cytokine release could provide an effective solution to mitigating the ICM-induced AKI. Moreover, Ginsenoside Rb1 (GRb1) constitutes one of the major active components of ginseng and features a wide range of vital biological functions. Judging from the research findings, GRb1 could impose antioxidant and anti-inflammatory effects on cardiovascular diseases, in addition to lung, liver and kidney diseases. However, reports on whether GRb1 could impose a protective effect against contrast-induced nephropathy (CIN) are absent. In this study, we have examined the therapeutic effects imposed by GRb1 as well as the potential molecular mechanism by establishing an in vivo and in vitro model of CIN. In addition, we have set up a mouse model of CIN through sequential intravenous injection of indomethacin, N(ω)-nitro-Larginine methyl ester (L-NAME), and iopromide. To further enhance the bioavailability of GRb1, we have encapsulated GRb1 with polyethylene glycol (PEG)/poly lactic-co-glycolic acid (PLGA) nanocarriers to generate GRb1 nanoparticles (NPs) conducting the in vivo experiments. During the in vitro experiments, we have adopted GRb1 to treat NRK-52E cells or cells transfected with the high mobility group box 1 gene (HMGB1) overexpression plasmid. As shown by the in vivo experimental results, GRb1 NPs could evidently improve the renal dysfunction in CIN, diminish the extent of apoptosis of tubular epithelial cells, and reduce the expression of high mobility group box 1 (HMGB1) and cytokines (tumor necrosis factor (TNF-α), interleukin (IL) 6 and IL-1β). In addition, GRb1 NPs are found to be capable of preventing the activation of Toll-like receptor 4 (TLR4)/NF-κB signaling pathway triggered by contrast medium. The in vitro experimental results have exactly confirmed the findings of the in vivo experiments. In the meantime, through the observation of the in vitro assays, overexpression of HMGB1 can partially counteract the beneficial effects imposed by GRb1. Judging from our research data, GRb1 could impose a protective effect against CIN by inhibiting inflammatory response via HMGB1/TLR4/NF-κB pathway, whereas HMGB1 constitutes a critical molecular target of GRb1.

Urine Alpha-1-Microglobulin Levels and Acute Kidney Injury, Mortality, and Cardiovascular Events following Cardiac Surgery

INTRODUCTION

Urine alpha-1-microglobulin (Uα1m) elevations signal proximal tubule dysfunction. In ambulatory settings, higher Uα1m is associated with acute kidney injury (AKI), progressive chronic kidney disease (CKD), cardiovascular (CV) events, and mortality. We investigated the associations of pre- and postoperative Uα1m concentrations with adverse outcomes after cardiac surgery.

METHODS

In 1,464 adults undergoing cardiac surgery in the prospective multicenter Translational Research Investigating Biomarker Endpoints for Acute Kidney Injury (TRIBE-AKI) cohort, we measured the pre-and postoperative Uα1m concentrations and calculated the changes from pre- to postoperative concentrations. Outcomes were postoperative AKI during index hospitalization and longitudinal risks for CKD incidence and progression, CV events, and all-cause mortality after discharge. We analyzed Uα1m continuously and categorically by tertiles using multivariable logistic regression and Cox proportional hazards regression adjusted for demographics, surgery characteristics, comorbidities, baseline estimated glomerular filtration rate, urine albumin, and urine creatinine.

RESULTS

There were 230 AKI events during cardiac surgery hospitalization; during median 6.7 years of follow-up, there were 212 cases of incident CKD, 54 cases of CKD progression, 269 CV events, and 459 deaths. Each 2-fold higher concentration of preoperative Uα1m was independently associated with AKI (adjusted odds ratio [aOR] = 1.36, 95% confidence interval 1.14-1.62), CKD progression (adjusted hazard ratio [aHR] = 1.46, 1.04-2.05), and all-cause mortality (aHR = 1.19, 1.06-1.33) but not with incident CKD (aHR = 1.21, 0.96-1.51) or CV events (aHR = 1.01, 0.86-1.19). Postoperative Uα1m was not associated with AKI (aOR per 2-fold higher = 1.07, 0.93-1.22), CKD incidence (aHR = 0.90, 0.79-1.03) or progression (aHR = 0.79, 0.56-1.11), CV events (aHR = 1.06, 0.94-1.19), and mortality (aHR = 1.01, 0.92-1.11).

CONCLUSION

Preoperative Uα1m concentrations may identify patients at high risk of AKI and other adverse events after cardiac surgery, but postoperative Uα1m concentrations do not appear to be informative.

Predictive Value of Plasma NGAL:Hepcidin-25 for Major Adverse Kidney Events After Cardiac Surgery with Cardiopulmonary Bypass: A Pilot Study

Background

Neutrophil gelatinase-associated lipocalin (NGAL) and hepcidin-25 are involved in catalytic iron-related kidney injury after cardiac surgery with cardiopulmonary bypass. We explored the predictive value of plasma NGAL, plasma hepcidin-25, and the plasma NGAL:hepcidin-25 ratio for major adverse kidney events (MAKE) after cardiac surgery.

Methods

We compared the predictive value of plasma NGAL, hepcidin-25, and plasma NGAL:hepcidin-25 with that of serum creatinine (Cr) and urinary output and protein for primary-endpoint MAKE (acute kidney injury [AKI] stages 2 and 3, persistent AKI >48 hours, acute dialysis, and in-hospital mortality) and secondary-endpoint AKI in 100 cardiac surgery patients at intensive care unit (ICU) admission. We performed ROC curve, logistic regression, and reclassification analyses.

Results

At ICU admission, plasma NGAL, plasma NGAL:hepcidin-25, plasma interleukin-6, and Cr predicted MAKE (area under the ROC curve [AUC]: 0.77, 0.79, 0.74, and 0.74, respectively) and AKI (0.73, 0.89, 0.70, and 0.69). For AKI prediction, plasma NGAL:hepcidin-25 had a higher discriminatory power than Cr (AUC difference 0.26 [95% CI 0.00-0.53]). Urinary output and protein, plasma lactate, C-reactive protein, creatine kinase myocardial band, and brain natriuretic peptide did not predict MAKE or AKI (AUC <0.70). Only plasma NGAL:hepcidin-25 correctly reclassified patients according to their MAKE and AKI status (category-free net reclassification improvement: 0.82 [95% CI 0.12-1.52], 1.03 [0.29-1.77]). After adjustment to the Cleveland risk score, plasma NGAL:hepcidin-25 ≥0.9 independently predicted MAKE (adjusted odds ratio 16.34 [95% CI 1.77-150.49], P=0.014).

Conclusions

Plasma NGAL:hepcidin-25 is a promising marker for predicting postoperative MAKE.

Inferior outcomes following cardiac surgery in patients with a functioning renal allograft

OBJECTIVES

Renal transplantation is an effective treatment for end-stage renal failure. The aim of this study was to evaluate outcomes for these patients undergoing cardiac surgery.

METHODS

A retrospective analysis identified patients with a functioning renal allograft at the time of surgery. A 2:1 propensity matching was performed. Patients were matched on: age, sex, left ventricle function, body mass index, preoperative creatinine, operation priority, operation category and logistic EuroSCORE.

RESULTS

Thirty-eight patients undergoing surgery with a functioning renal allograft were identified. The mean age was 62.4 years and 66% were male. A total of 44.7% underwent coronary artery bypass grafting and 26.3% underwent a single valve procedure. The mean logistic EuroSCORE was 10.65. The control population of 76 patients was well matched. Patients undergoing surgery following renal transplantation had a prolonged length of intensive care unit (3.19 vs 1.02 days, P < 0.001) and hospital stay (10.3 vs 7.17 days, P = 0.05). There was a higher in-hospital mortality (15.8% vs 1.3%, P = 0.0027). Longer-term survival on Kaplan-Meier analysis was also inferior (P < 0.001). One-year survival was 78.9% vs 96.1% and 5-year survival was 63.2% vs 90.8%. A further subpopulation of 11 patients with a failed renal allograft was identified and excluded from the main analysis; we report demographic and outcome data for them.

CONCLUSIONS

Patients with a functioning renal allograft are at higher risk of perioperative mortality and inferior long-term survival following cardiac surgery. Patients in this population should be appropriately informed at the time of consent and should be managed cautiously in the perioperative period with the aim of reducing morbidity and mortality.

Effect of levosimendan on renal function in background of left ventricular dysfunction: a meta-analysis of randomized trials

OBJECTIVE

Levosimendan, an inotrope, is widely used in the management of heart failure (HF) and cardiac surgery, but it remains uncertain whether levosimendan can improve renal function in patients with left ventricular dysfunction (LVD).

METHODS

PubMed, Embase, and Cochrane CENTRAL from the inception to June 2020 were systematically screened for randomized controlled trials (RCTs) to investigate whether levosimendan offers kidney-related advantages in cardiovascular patients with LVD. We pooled the effects using a random-effect model.

RESULTS

Twenty-eight studies enrolling 5069 patients were included. Levosimendan reduced the sCr (SMD -0.28, 95% CI (-0.48, -0.09), P = 0.005, I² = 52.5%, high quality) and the risk of ARF (relative risk 0.75, 95%CI (0.60, 0.95), P = 0.017, I² = 11.3%, moderate-quality) in patients with LVD compared with control group. The reduction of sCr was more pronounced in patients with a relatively higher baseline sCr level. For secondary outcomes, levosimendan therapy was associated with the improvement of GFR (SMD 0.32, 95%CI (-0.05, 0.68), P = 0.092, I² = 55.1%, low-quality) and urine output (SMD 0.42, 95%CI (0.06, 0.79), P = 0.024, I² = 50.0%, very low-quality), but there was no significant reduction in BUN (SMD -0.14, 95%CI (-0.97, 0.70), P = 0.774, I² = 77.9%, very low-quality).

CONCLUSIONS

Levosimendan might improve renal function of patients with LVD.

Early post-operative acute kidney injury after cardiac transplantation: Incidence and predictive factors

BACKGROUND

Heart transplantation, as a therapeutic option for patients with advanced heart failure, possesses a high rate of morbidity and mortality. One of the complications associated with this procedure is the development of postoperative acute kidney injury (AKI) MATERIAL AND METHODS: We aimed to evaluate the incidence of early postoperative AKI and the need for continuous renal replacement therapy (RRT) after heart transplantation. Data of 126 patients who underwent heart transplantation from January 2015 to November 2019 were collected. Statistical analysis was performed to identify the predictors of postoperative AKI.

RESULTS

Out of 126 patients, 74 (58.7 %) developed AKI and 13 (10%) required RRT after transplant. Independent predictors of AKI are shown to be factors associated with surgical procedures such as graft ischemic time as were previous cardiac operation, administered Voluven (starch) dose > 400 ml and transfusion of more than four blood units.

CONCLUSION

Our findings suggest that modifiable factors exist that can affect the risk of developing AKI following heart transplantation. This article is protected by copyright. All rights reserved.

Dynamics in perioperative neutrophil-to-lymphocyte*platelet ratio as a predictor of early acute kidney injury following cardiovascular surgery

BACKGROUND

In this study, we applied a composite index of neutrophil-lymphocyte * platelet ratio (NLPR), and explore the significance of the dynamics of perioperative NLPR in predicting cardiac surgery-associated acute kidney injury (CSA-AKI).

METHODS

During July 1^st and December 31^th 2019, participants were prospectively derived from the 'Zhongshan Cardiovascular Surgery Cohort'. NLPR was determined using neutrophil counts, lymphocyte and platelet count at the two-time points. Dose-response relationship analyses were applied to delineate the non-linear odds ratio (OR) of CSA-AKI in different NLPR levels. Then NLPRs were integrated into the generalized estimating equation (GEE) to predict the risk of AKI.

RESULTS

Of 2449 patients receiving cardiovascular surgery, 838 (34.2%) cases developed CSA-AKI with stage 1 (n = 658, 26.9%), stage 2-3 (n = 180, 7.3%). Compared with non-AKI patients, both preoperative and postoperative NLPR were higher in AKI patients (1.1[0.8, 1.8] vs. 0.9[0.7,1.4], p < 0.001; 12.4[7.5, 20.0] vs. 10.1[6.4,16.7], p < 0.001). Such an effect was a 'J'-shaped relationship: CSA-AKI's risk was relatively flat until 1.0 of preoperative NLPR and increased rapidly afterward, with an odds ratio of 1.13 (1.06-1.19) per 1 unit. Similarly, patients whose postoperative NLPR value >11.0 were more likely to develop AKI with an OR of 1.02. Integrating the dynamic NLPRs into the GEE model, we found that the AUC was 0.806(95% CI 0.793-0.819), which was significantly higher than the AUC without NLPR (0.799, p < 0.001).

CONCLUSION

Dynamics of perioperative NPLR is a promising marker for predicting acute kidney injury. It will facilitate AKI risk management and allow clinicians to intervene early so as to reverse renal damage.

Recent research progress on the role of ulinastatin in chronic kidney disease

With the continuous improvement in living standards, lifestyle changes and ageing of the population, the prevalence of chronic kidney disease (CKD) has increased significantly, and its prevention and treatment have become important public health issues worldwide. Renal fibrosis is the main pathological basis of CKD progression to end-stage renal disease. Preventing the progression of renal fibrosis has always been the focus of clinical and scientific research. Ulinastatin is a serine protease inhibitor that is found in human blood and urine and inhibits the inflammatory response, regulates immunity and improves the microcirculation. It is widely used in patients with sepsis and septic shock in clinical practice. Recent studies have shown that ulinastatin can also play an important anti-fibrotic and organ protective role and can provide a new therapeutic hope for CKD patients. This review mainly introduced the research progress of UTI in inflammation, oxidative stress, apoptosis, acute kidney injury and renal fibrosis. By investigating the role of ulinastatin in CKD, we can determine the possible mechanisms for its renal protection and improvement of renal fibrosis, so as to provide new ideas for the treatment of CKD.

Preservation of renal endothelial integrity and reduction of renal edema by aprotinin does not preserve renal perfusion and function following experimental cardiopulmonary bypass

BACKGROUND

Acute kidney injury is a severe complication following cardiopulmonary bypass (CPB) and is associated with capillary leakage and microcirculatory perfusion disturbances. CPB-induced thrombin release results in capillary hyperpermeability via activation of protease-activated receptor 1 (PAR1). We investigated whether aprotinin, which is thought to prevent thrombin from activating PAR1, preserves renal endothelial structure, reduces renal edema and preserves renal perfusion and reduces renal injury following CPB.

METHODS

Rats were subjected to CPB after treatment with 33.000 KIU/kg aprotinin (n = 15) or PBS (n = 15) as control. A secondary dose of 33.000 KIU/kg aprotinin was given 60 min after initiation of CPB. Cremaster and renal microcirculatory perfusion were assessed using intravital microscopy and contrast echography before CPB and 10 and 60 min after weaning from CPB. Renal edema was determined by wet/dry weight ratio and renal endothelial structure by electron microscopy. Renal PAR1 gene and protein expression and markers of renal injury were determined.

RESULTS

CPB reduced cremaster microcirculatory perfusion by 2.5-fold (15 (10-16) to 6 (2-10) perfused microvessels, p < 0.0001) and renal perfusion by 1.6-fold (202 (67-599) to 129 (31-292) au/sec, p = 0.03) in control animals. Both did not restore 60 min post-CPB. This was paralleled by increased plasma creatinine (p < 0.01), neutrophil gelatinase-associated lipocalin (NGAL; p = 0.003) and kidney injury molecule-1 (KIM-1; p < 0.01). Aprotinin treatment preserved cremaster microcirculatory perfusion following CPB (12 (7-15) vs. 6 (2-10) perfused microvessels, p = 0.002), but not renal perfusion (96 (35-313) vs. 129 (31-292) au/s, p > 0.9) compared to untreated rats. Aprotinin treatment reduced endothelial gap formation (0.5 ± 0.5 vs. 3.1 ± 1.4 gaps, p < 0.0001), kidney wet/dry weight ratio (4.6 ± 0.2 vs. 4.4 ± 0.2, p = 0.046), and fluid requirements (3.9 ± 3.3 vs. 7.5 ± 3.0 ml, p = 0.006) compared to untreated rats. In addition, aprotinin treatment reduced tubulointerstitial neutrophil influx by 1.7-fold compared to untreated rats (30.7 ± 22.1 vs. 53.2 ± 17.2 neutrophil influx/section, p = 0.009). No differences were observed in renal PAR1 expression and plasma creatinine, NGAL or KIM-1 between groups.

CONCLUSIONS

Aprotinin did not improve renal perfusion nor reduce renal injury during the first hour following experimental CPB despite preservation of renal endothelial integrity and reduction of renal edema.

Patient characteristics and cardiac surgical outcomes at a tertiary care hospital in Kenya, 2008-2017: a retrospective study

Background

Cardiac surgeries are high risk procedures that require specialized care and access to these procedures is often limited in resource-poor countries. Although fatalities for surgical patients across Africa are twice that of the global rate, cardiac surgical mortality continent-wide is only slightly higher than all-surgical mortality. Understanding demographic and health characteristics of patients and the associations of these characteristics with morbidity and mortality events is important in guiding care decisions. Therefore, the objectives of this study were to: (a) describe the characteristics of cardiac surgical patients; (b) identify the associations between these characteristics and morbidity and mortality events following cardiac surgery.

Methods

Patient characteristics and post-surgical complications were abstracted for all cardiac surgical patients treated at a tertiary care hospital in Kenya from 2008 to 2017. Descriptive analyses of demographic factors, co-morbidities, peri-operative conditions, and post-surgical complications were conducted for adult and pediatric patients. Cochran-Armitage trend test was used to assess temporal trends in risk of death. Multivariable ordinary logistic and Firth logistic models were used to investigate predictors of surgical outcomes.

Results

The study included a total of 181 patients (150 adult and 31 pediatric patients). Most (91.3%) adult patients had acquired conditions while 45.2% of the pediatric patients had congenital defects. Adult patients tended to have co-morbid conditions including hypertension (16.7%), diabetes mellitus (7.3%), and nephropathy (6.7%). Most patients (76.0% adults and 96.8% pediatric patients) underwent ≤ 2 surgical procedures during their hospital stay. Seventy percent of adult and 54.8% of the pediatric patients experienced at least one post-surgical complication including mediastinal hemorrhage, acute kidney injury and death. Patient characteristics played the greatest roles in predicting post-surgical complications. For adult patients, significant predictors of acute kidney injury included atrial fibrillation (OR = 18.25; p = .001), mitral valve replacement (OR = 0.14; p = .019), and use of cardiopulmonary bypass (OR = 0.06; p = .002). Significant predictors of 30-day mortality were age (OR = 1.05; p = .015) and atrial fibrillation (OR = 4.12, p = .018). Although the number of surgeries increased over the decade-long study period, there were no significant (p = .467) temporal trends in the risk of death.

Conclusions

Awareness of demographic and peri-surgical factors that are predictors of complications is useful in guiding clinical decisions to reduce morbidity and mortality. Identification of co-morbidities as the most useful predictors of post-surgical complications suggests that patient characteristics may be a larger contributor to the incidence of complications than surgical practices.

Preoperative Serum GDF-15, Endothelin-1 Levels, and Intraoperative Factors as Short-Term Operative Risks for Patients Undergoing Cardiovascular Surgery

Objectives: The Society of Thoracic Surgeons (STS) risk score is widely used for the risk assessment of cardiac surgery. Serum biomarkers such as growth differentiation factor-15 (GDF-15) and endothelin-1 (ET-1) are also used to evaluate risk. We investigated the relationships between preoperative serum GDF-15, ET-1 levels, and intraoperative factors and short-term operative risks including acute kidney injury (AKI) for patients undergoing cardiovascular surgery. Methods: In total, 145 patients were included in this study (92 males and 53 females, age 68.4 ± 13.2 years). The preoperative STS score was determined, and the serum GDF-15 and ET-1 levels were measured by ELISA. These were related to postoperative risks, including AKI, defined according to the Acute Kidney Injury Network (AKIN) classification criteria. Results: AKI developed in 23% of patients. The GDF-15 and ET-1 levels correlated with the STS score. The STS score and GDF-15 and ET-1 levels all correlated with preoperative eGFR, Alb, Hb, and BNP levels; perioperative data (urine output); ICU stay period; and postoperative admission days. Patients with AKI had longer circulatory pulmonary bypass (CPB) time, and male patients with AKI had higher ET-1 levels than those without AKI. In multivariable logistic regression analysis, the preoperative ET-1 level and CPB time were the independent determinants of AKI, even adjusted by age, sex, and BMI. The preoperative GDF-15 level, CPB time, and RCC transfusion were independent determinants of 30-day mortality plus morbidity. Conclusion: Preoperative GDF-15 and ET-1 levels as well as intraoperative factors such as CPB time may be helpful to identify short-term operative risks for patients undergoing cardiovascular surgery.

Perioperative Serum Free Hemoglobin and Haptoglobin Levels in Valvular and Aortic Surgery With Cardiopulmonary Bypass: Their Associations With Postoperative Kidney Injury

OBJECTIVE

To observe the perioperative free hemoglobin and haptoglobin levels and to assess their associations with the risk of postoperative acute kidney injury (pAKI) in adult patients undergoing valvular and aortic surgery requiring cardiopulmonary bypass (CPB).

DESIGN

A single-center, prospective, observational study.

SETTING

Public teaching hospital.

PARTICIPANTS

The study comprised 74 adult patients without chronic renal failure who underwent cardiovascular surgery requiring CPB from 2014 to 2020.

MEASUREMENTS AND MAIN RESULTS

Perioperative free hemoglobin and haptoglobin levels during the study period were obtained from study participants. The primary outcome was pAKI defined by the Kidney Disease: Improving Global Outcomes criteria. Of the 74 patients in this study, pAKI occurred in 25 patients (33.8%). The free hemoglobin level began to increase after the initiation of CPB and reached a peak level at 30 minutes after weaning from CPB. It returned to the baseline level on postoperative day one. Haptoglobin levels were the highest after anesthesia induction and decreased continuously until postoperative day one. In the multivariate analysis, maximum free hemoglobin and minimum haptoglobin were associated independently with increased risk of pAKI (adjusted odds ratio 1.33 [95% confidence interval 1.12-1.58; p = 0.001] and 0.95 [95% confidence interval 0.91-1.00; p = 0.03], respectively). The free hemoglobin level began to have an independent association with pAKI at one hour after commencement of CPB, and the independent association disappeared at postoperative day one.

CONCLUSIONS

This study found that the perioperative increase of the free hemoglobin level and the decrease of the haptoglobin level had independent associations with the risk of pAKI.

Assessment of long-term outcomes: aortic valve reimplantation versus aortic valve and root replacement with biological valved conduit in aortic root aneurysm with tricuspid valve

OBJECTIVES

We compared the long-term outcomes between aortic valve reimplantation [David V (DV)] and aortic valve and root replacement with biological valved conduit [Bentall-De Bono (BD)] for the patients with aortic root aneurysm with tricuspid valve.

METHODS

Among 876 patients who underwent aortic root replacement in our institution between 2005 and 2018, 371 patients who underwent DV (n = 199) or BD (n = 172) for aortic root aneurysm with tricuspid valve were retrospectively reviewed. Exclusion criteria included aortic stenosis, infective endocarditis, previous prosthetic aortic valve, bicuspid aortic valve, aortic dissection and mechanical Bentall procedure. Propensity score matching was performed based on the patient characteristics, matching 90 patients in each group. The primary end point was all-cause mortality. Secondary end points were reoperation for any cause and specifically for aortic valve-related cause.

RESULTS

After propensity score matching, DV and BD groups each had 1 in-hospital mortality (1.1%). Survival at 10 years was 95.3% [95% confidence interval (CI) 85.8-98.5] in DV and 98.6% (95% CI 90.8-99.8) in BD (P = 0.345). The cumulative incidences of reoperation at 10 years in DV versus BD were 3.9% (95% CI 0.7-11.8) vs 18.1% (95% CI 6.9-33.4) for any cause (P = 0.046) and 1.9% (95% CI 0.1-8.8) vs 15.9% (95% CI 5.5-31.4) for aortic valve-related causes (P = 0.032). The reasons for valve-related reoperation were aortic insufficiency (3/5 in DV vs 5/10 in BD), aortic stenosis (0/5 vs 2/10) and infective endocarditis (2/5 vs 3/10).

CONCLUSIONS

Both DV and BD procedures for patients with aortic root aneurysm with tricuspid valve resulted in excellent 10-year survival. All-cause and aortic valve-related reoperations were significantly less frequent with valve-sparing root replacement, suggesting an advantage of DV over biological BD.

Platelet-rich plasma promotes MSCs exosomes paracrine to repair acute kidney injury via AKT/Rab27 pathway

Acute kidney injury (AKI) is defined by rapid deterioration of renal function, and is a common complication in hospitalized patients. Among the recent therapeutic options, mesenchymal stem cells (MSCs) are considered a promising therapeutic strategy for damaged tissue repair. Platelet rich plasma (PRP) regulates mesenchymal cells to repair tissue damage through the release of growth factors. In this study, we proposed a possible therapeutic use of MSCs stimulated by platelet-rich plasma (PRP-MSCs) in a glycerin-induced AKI murine model. In vivo and in vitro studies, showed that PRP-MSCs could significantly attenuate serum blood urea nitrogen and creatinine levels, and reverse the histopathological kidney damage. PRP-MSCs treatment reduced renal tubular cell apoptosis stimulated by glycerin. We confirmed that PRP promoted the proliferation and reinforced the stemness of MSCs by inducing YAP nucleus expression, and that PRP promoted MSCs exosomes in a paracrine manner to repair AKI through an activated AKT/Rab27 pathway. Our results revealed that the PRP stimulated MSCs paracrine pathway could effectively alleviate glycerin-induced AKI. Therefore, PRP pretreatment may be a new method to improve the therapeutic effect of MSCs.

Fighting Oxidative Stress with Sulfur: Hydrogen Sulfide in the Renal and Cardiovascular Systems

Hydrogen sulfide (H2S) is an essential gaseous signaling molecule. Research on its role in physiological and pathophysiological processes has greatly expanded. Endogenous enzymatic production through the transsulfuration and cysteine catabolism pathways can occur in the kidneys and blood vessels. Furthermore, non-enzymatic pathways are present throughout the body. In the renal and cardiovascular system, H2S plays an important role in maintaining the redox status at safe levels by promoting scavenging of reactive oxygen species (ROS). H2S also modifies cysteine residues on key signaling molecules such as keap1/Nrf2, NFκB, and HIF-1α, thereby promoting anti-oxidant mechanisms. Depletion of H2S is implicated in many age-related and cardiorenal diseases, all having oxidative stress as a major contributor. Current research suggests potential for H2S-based therapies, however, therapeutic interventions have been limited to studies in animal models. Beyond H2S use as direct treatment, it could improve procedures such as transplantation, stem cell therapy, and the safety and efficacy of drugs including NSAIDs and ACE inhibitors. All in all, H2S is a prime subject for further research with potential for clinical use.

ACUTE KIDNEY INJURY AFTER OPEN-HEART SURGERY PROCEDURES

Cardiac surgery-associated acute kidney injury (CS-AKI) is a major complication associated with increased morbidity and mortality. There are multiple diagnostic criteria for CS-AKI. Despite many new investigations available for improved AKI diagnostics, creatinine and urea remain the cornerstone of diagnostics in everyday clinical practice. There are three major pathophysiological mechanisms that contribute to kidney injury, i.e. renal hypoperfusion, inflammation with oxidative stress, and use of nephrotoxic agents. Some risk factors have been identified that can be modified during the course of treatment (use of nephrotoxic agents, duration of cardiopulmonary bypass, type of extracorporeal circulation, postoperative low cardiac output or hypotension). The aim of AKI prevention should always be to prevent aggravation of renal failure and, if possible, to avoid progression to renal replacement therapy, which in turn brings worse long-term outcomes.

Cardiac Output Values and Correlation of Renal Injury with Neutrophil Gelatinase-Associated Lipocalin Levels in Off-Pump Coronary Artery Bypass Patients

Objective

To investigate the correlation between cardiac output values and renal neutrophil gelatinase-associated lipocalin (NGAL) levels as a biomarker of renal ischemia.

Methods

Forty patients, who underwent off-pump coronary artery bypass (OPCAB) surgery and in whom the positioning of the heart was fixed with simple suspension sutures without a mechanical stabilizer, were included in the study. Continuous cardiac output (CO) measurements were recorded using the arterial pressure waveform analysis method (FloTrac sensor system) in the perioperative period. CO was recorded every minute during non-anatomical cardiac positioning for left anterior descending artery (LAD), diagonal artery (D), circumflex artery (Cx), and right coronary artery (RCA) bypasses. Serum NGAL samples were analyzed in the preoperative, perioperative, and postoperative periods.

Results

The CO values measured at various non-anatomical cardiac positions during distal anastomosis for LAD, D, Cx, and RCA were significantly lower than pre- and postoperative values measured with the heart in normal anatomical position (3.45±0.78, 2.9±0.71, 3.11±0.56, 3.19±0.81, 5.03±1.4, and 4.85±0.78, respectively, P=0.008). There was no significant difference between CO values measured at various non-anatomical cardiac positions during distal anastomosis. Although there was no significant correlation between NGAL levels and age, duration of surgery, preoperative CO, D-CO, RCA-CO, and postoperative CO measurements, there was a significant correlation between NGAL levels and LAD-CO (P=0.044) and Cx-CO (P=0.018) at the postoperative 12^th hour.

Conclusion

Full revascularization may be achieved by employing the OPCAB technique while using simple suspension sutures without a mechanical stabilizer and by providing safe CO levels and low risk of renal ischemia.

Novel Potential Biomarker of Adult Cardiac Surgery-Associated Acute Kidney Injury

Background

Acute kidney injury (AKI) occurs in about 30% of patients with cardiac surgery, but the pathogenesis of cardiac surgery-associated acute kidney injury (CSA-AKI) remains unclear and there are no predictive biomarkers or diagnostic criteria specific for CSA-AKI beyond the general clinical variables for AKI like serum creatinine (SCr).

Methods and Results

We measured the plasma levels of 48 cytokines within 24 h after cardiac surgery in a total of 306 adult patients including 204 with and 102 without AKI, and then evaluated the diagnostic efficacy of these cytokines for the development of CSA-AKI via ANOVA and Pearson correlation analysis. Among these 48 cytokines, 20 of them were significantly different in the AKI patients compared with the non-AKI patients. In particularly, 13 cytokines displayed tremendous changes with the P < 1E^–5. Moreover, 10 of the 48 cytokines in the plasma were significantly different among the patients with different stages of AKI. Specifically, 6 cytokines exhibited immense differences with the P < 1E^–5. Additionally, 7 of the 48 cytokines have the correlation coefficient of r > 0.5 with the postoperative changes of SCr after cardiac surgery.

Conclusion

Taken all the results together, IFN-γ and SCGF-β were the most relevant two cytokines that were not only remarkably changed in adult CSA-AKI patients during the first 24 h after cardiac surgery, but also significantly correlated with the postoperative changes of SCr after cardiac surgery. Therefore, IFN-γ and SCGF-β might be novel predictive plasma biomarker, as well as potential therapeutic targets specific for adult CSA-AKI.

The Incidence, Risk Factors and In-Hospital Mortality of Acute Kidney Injury in Patients After Surgery for Acute Type A Aortic Dissection: A Single-Center Retrospective Analysis of 335 Patients

Background: Acute kidney injury (AKI) is a common complication of cardiac surgery, which could lead to increased morbidity and mortality. Acute type A aortic dissection (AAAD) is a life-threatening cardiac disease and can be closely related to post-operative AKI. However, data on the incidence of AKI defined by the newest Kidney Disease: Improving Global Outcomes (KDIGO) criteria and in-hospital mortality of a homogeneous population who underwent AAAD are limited. We aimed to investigate the incidence of AKI defined by the KDIGO criteria and the risk factors associated with the outcomes among AAAD-induced AKI patients. Methods: We reviewed 335 patients who underwent surgical treatment for AAAD between March 2009 and June 2016. We screened the patients' AKI status and analyzed probably risk factors of AKI and in-hospital mortality. Independent-sample t-test or Chi-square test was performed to identify differences between AKI and non-AKI groups and survivors with AKI and non-survivors with AKI, respectively. The logistic regression model was applied to identify independent risk factors. Results: AKI occurred in 71.94% of AAAD patients, including 85 stage 1 (35.26%), 77 stage 2 (31.95%), and 79 stage 3 (32.78%) patients. The in-hospital mortality rate was 21.16%. Logistic regression analysis showed that the body mass index, chronic kidney disease, chronic liver disease, cardiopulmonary bypass duration, red blood cell transfusion, and hypoproteinemia were the independent significant risk factors of the occurrence of post-operative AKI. The risk factors associated with in-hospital mortality among AAAD-induced AKI patients included AKI stage (odds ratio (OR), 3.322), deep hypothermic circulatory arrest (OR, 2.586), lactic acidosis (OR, 3.407), and continuous renal replacement therapy (OR, 3.156). Conclusion: For AAAD patients undergoing surgery, AKI was a common complication, and it increased patients' mortality risk. Therefore, identifying the risk factors of AKI and preventing post-operative AKI are important for improving the post-operative outcomes of AAAD patients. Clinical Trial Registration: ChiCTR, ChiCTR1900021290. Registered 12 February 2019, http://www.chictr.org.cn/showproj.aspx?proj=35795.

The Role of Ribonuclease 1 and Ribonuclease Inhibitor 1 in Acute Kidney Injury after Open and Endovascular Thoracoabdominal Aortic Aneurysm Repair

Acute kidney injury (AKI) is one of the most common post-operative complications and is closely associated with increased mortality after open and endovascular thoracoabdominal aortic aneurysm (TAAA) repair. Ribonuclease (RNase) 1 belongs to the group of antimicrobial peptides elevated in septic patients and indicates the prediction of two or more organ failures. The role of RNase 1 and its antagonist RNase inhibitor 1 (RNH1) after TAAA repair is unknown. In this study, we analyzed RNase 1 and RNH1 serum levels in patients undergoing open (n = 14) or endovascular (n = 19) TAAA repair to determine their association with post-operative AKI and in-hospital mortality. Increased RNH1 serum levels after open TAAA repair as compared with endovascular TAAA repair immediately after surgery and 12, 48, and 72 h after surgery (all p < 0.05) were observed. Additionally, elevated RNase 1 and RNH1 serum levels 12, 24, and 48 h after surgery were shown to be significantly associated with AKI (all p < 0.05). RNH1 serum levels before and RNase 1 serum levels 12 h after TAAA repair were significantly correlated with in-hospital mortality (both p < 0.05). On the basis of these findings, RNase 1 and RNH1 may be therapeutically relevant and may represent biomarkers for post-operative AKI and in-hospital mortality.

Long-term outcomes of treatment with different stent grafts in acute DeBakey type I aortic dissection

BACKGROUND

We developed an integrated triple-branched stent to treat acute DeBakey type I aortic dissection (AD) and modified it to enhance its adaptability. However, whether the patients treated by the modified stent would achieve better long-term prognosis is unknown.

METHODS

This study enrolled 147 patients with acute DeBakey type I AD. The original integrated triple-branched stents were used in 57 patients (Group A) between July 2012 and August 2013, and the modified stents in 90 patients (Group B) between September 2013 and March 2015. Clinical characteristics, surgical data, postoperative complications, mortality, and follow-up data of the two groups were analyzed.

RESULTS

The two groups presented comparable early death rates (Group A = 7.0%, Group B = 5.9%; p = .719). The incidence of postoperative acute kidney injury (AKI) was lower in Group B (10.0%) versus Group A (24.6%) (p = .018). Compared with the original integrated triple-branched stent graft, the modified stent could reduce the risk of early postoperative AKI (OR [95% CI] = 0.36 [0.14, 0.94]). Early endoleak rates were significantly lower in Group B (1.0%) compared to Group A (9.4%) (p = .004). During follow-up, there were five deaths in Group A (9.4%) and six deaths in Group B (7.2%) (p = .646). Chronic kidney injury (7.5% vs. 3.6%; p = .311), delayed endoleak (11.3% vs. 4.8%; p = .157), and late reinterventions (7.5% vs. 2.4%; p = .155) in the two groups were similar.

CONCLUSIONS

In patients with acute DeBakey type I AD, the modified stent showed feasible and safe treatment outcomes and reduced early endoleak rates. However, the long-term effects were similar to the original treatment.

The impact of diabetes mellitus on acute kidney injury after coronary artery bypass grafting

Background

Diabetes mellitus(DM) is an indicator affects postoperative mortality and morbidity after coronary artery bypass grafting (CABG). Acute kidney injury (AKI) is one of the frequent postoperative complications after CABG. This multi-centre register study designed to investigate the impact of DM on postoperative AKI in primary isolated CABG patients.

Methods

We included all patients (n = 4325) from Jiangsu Province CABG register who underwent primary isolated CABG from September 2017 to August 2019. The patients were divided into 3 groups: No-DM group(n = 3067), DM-oral group (DM with oral hypoglycemic agents, n = 706) and DM-insulin group (DM with insulin treatment, n = 552). The development and severity of AKI were based on Acute Kidney Injury Network (AKIN) criteria.

Results

There were totally 338, 108 and 145 patients developed AKI in No-DM, DM-oral and DM-insulin group respectively. Comparing with No-DM group, DM-oral group had a higher rate of AKI(χ² = 10.071, p = 0.002), DM-insulin group had a higher rate(χ² = 94.042, p<0.001) and severity of AKI(χ² = 10.649, p = 0.005). The adjusted odds ratio for AKI was 1.26 (95% CI 1.03–1.57) in DM-oral group and 3.92 (95% CI 3.27–5.16) in DM-insulin group, in comparison with No-DM group.

Conclusions

Independent of baseline renal function or cardiac function, DM was associated with an increased risk of AKI after CABG, especially in patients with insulin treatment, who also had a higher severity of AKI.

Development and accuracy evaluation of a degree of occlusion visualization system for roller pumps used in cardiopulmonary bypass

In roller pumps used for cardiopulmonary bypass (CPB), the degree of blockage within the tube resulting from compression of the tube by the rollers, or the degree of occlusion, is closely related to hemolysis, with both tight occlusive and non-occlusive degrees promoting hemolysis. There are as yet no international standards regarding methods of adjusting occlusiveness, and the amount of mechanical stress exerted upon blood remains unknown. To prevent hemolysis during CPB using roller pumps, there is a need to clarify and quantitatively assess the mechanical stress of the occlusiveness of the roller pump. In this study, we have developed a degree of occlusion quantification system which constructs the flow channel shape within an occluded tube from red optical density images, and we have verified the validity of this system. Utilizing a linear actuator, an acrylic roller and raceway, a solution colored with simulated blood powder, and a 3/8-inch vinyl chloride tube, this system uses a camera to capture red optical density images within an occluded tube and constructs the tube flow channel shape using a formula manipulation system. To verify the accuracy of this system, we compared the thickness of a cross-section of the flow channel constructed with the degree of occlusion quantification system with the thickness of a cross-section of silicone cured under the same occlusion conditions. Our experiments indicated that for areas with a small tube gap, this system can construct highly accurate three-dimensional shapes and obtain quantitative indicators assessing the degree of occlusion.

Neutrophil Gelatinase-associated Lipocalin as a Marker of Postoperative Acute Kidney Injury Following Cardiac Surgery in Patients with Preoperative Kidney Impairment

INTRODUCTION

Acute kidney injury (AKI) is a serious complication of cardiac surgery. The current 'gold standard' for determining AKI is change in serum creatinine and urine output, however, this change occurs relatively late after the actual injury occurs. Identification of new biomarkers that detect early AKI is required. Recently, new biomarkers, such as the NephroCheck® Test and AKIRisk have also been tested and found to be good indicators of AKI. Neutrophil gelatinase-associated lipocalin (NGAL) has shown promise in paediatric patients but has displayed varied results in adult populations, particularly post cardiac surgery. The aim of this study was to assess the value of urinary NGAL as a biomarker of AKI in patients with pre-existing renal impairment (eGFR >15ml/min to eGFR<60ml/min).

METHODS

A post-hoc analysis of urinary NGAL concentrations from 125 patients with pre-existing kidney impairment, who participated in a randomised trial of haemofiltration during cardiac surgery, was undertaken. Urinary NGAL was measured using ELISA at baseline, post-operatively and 24 and 48 hours after surgery, and serum creatinine was measured pre and postoperatively and then at 24, 48, 72 and 96 hours as routine patient care. NGAL concentrations were compared in patients with and without AKI determined by changes in serum creatinine concentrations. A Kaplan-Meier plot compared survival for patients with or without AKI and a Cox proportional hazards analysis was performed to identify factors with the greatest influence on survival.

RESULTS

Following surgery, 43% of patients developed AKI (based on KDIGO definition). Baseline urinary NGAL was not found to be significantly different between patients that did and did not develop AKI. Urinary NGAL concentration was increased in all patients following surgery, regardless of whether they developed AKI and was also significant between groups at 24 (p=0.003) and 48 hours (p<0.0001). Urinary NGAL concentrations at 48 hours correlated with serum creatinine concentrations at 48 hours (r=0.477, p<0.0001), 72 hours (r=0.488, p<0.0001) and 96 hours (r=0.463, p<0.0001). Urinary NGAL at 48 hours after surgery strongly predicted AKI (AUC=0.76; P=0.0001). A Kaplan- Meier plot showed that patients with postoperative AKI had a significantly lower 7-year survival compared with those without AKI. Postoperative urinary NGAL at 48 hours >156ng/mL also strongly predicted 7-year survival. However, additive EuroSCORE, age, current smoking and post-operative antibiotics usage were distinctly significantly more predictive of 7-year survival as compared with postoperative urinary NGAL at 48 hours >156ng/mL.

CONCLUSIONS

Our study demonstrated that postoperative urinary NGAL levels at 48 hours postsurgery strongly predicts the onset or severity of postoperative AKI based on KDIGO classification in patients with preoperative kidney impairment and were also strongly related to 7-year survival.

Protective effect of combined therapy with hyperbaric oxygen and autologous adipose-derived mesenchymal stem cells on renal function in rodent after acute ischemia-reperfusion injury

BACKGROUND

This study tested the hypothesis that combined hyperbaric oxygen (HBO) and autologous adipose-derived mesenchymal stem cell (ADMSC) therapy was superior to either alone at protecting renal function in rodents after acute ischemia-reperfusion (IR) injury.

METHODS AND RESULTS

Adult-male SD rats (n = 40) were equally categorized: group 1 (sham-operated control); group 2 (IR + 50 μg medium intra-renal artery administration); group 3 [IR + HBO (at 1.5 h and days 1 and 2 after IR)]; group 4 [IR + ADMSC (2.0×10⁶ cells/5.0×10⁵/per each renal artery and 1.0×10⁶ by intravenous injection at 1.5 h after IR]; and group 5 (IR + HBO-ADMSC). By 72 hr after IR, the circulating levels of BUN/creatinine and ratio of urine protein/creatinine were significantly highest in group 2, lowest in group 1, significantly increased in group 5 than in groups 3 and 4, but not different between latter two groups, whereas the circulating levels of EPCs and soluble-angiogenesis biomarkers (SDF-1α/HIF-1α) exhibited an opposite pattern to BUN/creatinine among the five groups (all P<0.001). The kidney injury score, ROS (fluorescent intensity of H₂DCFDA dye in kidney), inflammation (F4/80+, CD14+ cells) and glomerular-tubular injury score (WT-1/KIM-1) displayed an identical pattern whereas the integrity of podocyte components exhibited an opposite pattern to BUN/creatinine among the five groups (all P<0.0001). The protein expressions of inflammatory (MMP-9/TNF-α/NF-κB/ICAM-1), oxidative-stress (NOX-1/NOx-2/oxidized protein) and apoptotic (mitochondrial-Bax/cleaved-caspase3/PARP) markers showed an identical pattern to BUN/creatinine (all P<0.001).

CONCLUSION

Combined ADMSC-HBO therapy was superior to either one alone at protecting the kidney from acute IR injury.

The predictive value of the intraoperative Renal Pulsatility Index for acute kidney injury in patients undergoing cardiac surgery

BACKGROUND

The incidence of cardiac surgery-associated acute kidney injury (CSA-AKI) is very high. The Renal Resistive Index (RRI) is measured by transesophageal echocardiography (TEE) and can be used to predict the occurrence of CSA-AKI, but few studies have examined the Renal Pulsatility Index (RPI). The objective of this study was to explore the predictive value of intraoperative RPI for CSA-AKI.

METHODS

This study was a prospective observational study. Seventy-eight patients meeting the inclusion criteria were enrolled. The RPI was measured by TEE after the induction of general anesthesia (T1) and immediately after the surgery (T2). Serum creatinine (Scr) was measured one day before and seven days after the surgery. The diagnosis of AKI was based on the KDIGO diagnostic criteria. Multivariate logistic regression analysis was used to analyze the risk factors for postoperative AKI and to draw the receiver operating characteristic curve (ROC) and analyze its diagnostic value for AKI.

RESULTS

The incidence of postoperative AKI was 29.5%. The RPI at T2 was higher in the AKI group than in the non-AKI group (2.05±0.69 versus 1.49±0.48, P<0.001). The results of multivariate analysis showed that the RPI at T2 was an independent risk factor for the occurrence of AKI (OR=4.683, 95% CI: 1.592-13.772; P=0.006). The area under the curve (AUC) of the RPI was 0.733 (95% CI: 0.621-0.827) with a cut-off value of 1.86 (sensitivity 60.87%, specificity 85.45% and Youden Index 0.46).

CONCLUSIONS

An RPI at T2>1.86 is correlated with a higher incidence of postoperative AKI. Treatment guided and personalized on the base of this parameter should be investigated by further dedicated studies.

Carbon monoxide: An emerging therapy for acute kidney injury

Treating acute kidney injury (AKI) represents an important unmet medical need both in terms of the seriousness of this medical problem and the number of patients. There is also a large untapped market opportunity in treating AKI. Over the years, there has been much effort in search of therapeutics with minimal success. However, over the same time period, new understanding of the underlying pathobiology and molecular mechanisms of kidney injury have undoubtedly helped the search for new therapeutics. Along this line, carbon monoxide (CO) has emerged as a promising therapeutic agent because of its demonstrated cytoprotective, and immunomodulatory effects. CO has also been shown to sensitize cancer, but not normal cells, to chemotherapy. This is particularly important in treating cisplatin-induced AKI, a common clinical problem that develops in patients receiving cisplatin therapies for a number of different solid organ malignancies. This review will examine and make the case that CO be developed into a therapeutic agent against AKI.

High Preoperative Serum Syndecan-1, a Marker of Endothelial Glycocalyx Degradation, and Severe Acute Kidney Injury after Valvular Heart Surgery

Degradation of endothelial glycocalyx (EG) is associated with inflammation and endothelial dysfunction, which may contribute to the development of acute kidney injury (AKI). We investigated the association between a marker of EG degradation and AKI after valvular heart surgery. Serum syndecan-1 concentrations were measured at induction of anesthesia and discontinuation of cardiopulmonary bypass in 250 patients. Severe AKI was defined as Kidney Disease: Improving Global Outcomes Criteria Stage 2 or 3. Severe AKI occurred in 13 patients (5%). Receiver operating characteristic analysis of preoperative syndecan-1 to predict severe AKI showed area under curve of 0.714 (95% confidence interval (CI), 0.575–0.853; p = 0.009). The optimal cut-off value was 90 ng/mL, with a sensitivity of 61.5% and specificity of 78.5%. In multivariable analysis, both preoperative syndecan-1 ≥ 90 ng/mL and Cleveland Clinic Foundation score independently predicted severe AKI. Severe tricuspid regurgitation was more frequent (42.4% vs. 17.8%, p < 0.001), and baseline right ventricular systolic pressure (41 (33–51) mmHg vs. 33 (27–43) mmHg, p = 0.001) and TNF-α (1.85 (1.37–2.43) pg/mL vs. 1.45 (1.14–1.92) pg/mL, p <0.001) were higher in patients with high preoperative syndecan-1. Patients with high preoperative syndecan-1 had longer hospital stay (16 (12–24) days vs. 13 (11–17) days, p = 0.001). In conclusion, a high preoperative syndecan-1 concentration greater than 90 ng/mL was able to predict severe AKI after valvular heart surgery and was associated with prolonged hospitalization.

Timing of initiation of renal replacement therapy in acute kidney injury: an updated meta-analysis of randomized controlled trials

Purpose

The results from randomized controlled trials (RCTs) concerning the timing of initiation of renal replacement therapy (RRT) for patients with acute kidney injury (AKI) are still inconsistent.

Materials and methods

We searched for RCTs, as well as relevant references, focusing on the timing of RRT for AKI patients in the Medline, Embase, Cochrane Library, Google Scholar and Chinese databases from their inception to December 2018.

Results

We included 18 RCTs from 1997 to 2018 involving 2856 patients. Pooled analyses of all RCTs showed no significant difference in mortality between early initiation and delayed initiation of RRT (RR 0.98, 95% CI: 0.89 to 1.08, p = .7) (I² = 2%), and similar results were found in critically ill and community-acquired AKI patients, as well as in a subgroup of patients with sepsis and in cardiac surgery recipients. There was also no difference in the incidence of dialysis independence (RR 0.75, 95% CI: 0.47 to 1.2, p = .2) (I² = 0). However, an early RRT strategy was associated with a significantly higher incidence of the need for RRT for AKI patients (RR 1.24, 95% CI: 1.13 to 1.36, p < .01) (I² = 34%).

Conclusions

As no life-threatening complications occurred, there was no evidence to show any benefit of an early RRT strategy for critically ill or community-acquired AKI patients; in contrast, a delayed strategy might avert the need for RRT.

Association of postoperative fluid overload with adverse outcomes after congenital heart surgery: a systematic review and dose-response meta-analysis

BACKGROUND

Pediatric cardiac surgery is commonly associated with acute kidney injury (AKI) and significant fluid retention, which complicate postoperative management and lead to increased rates of morbidity. This meta-analysis aimed to accumulate current literature evidence and evaluate the correlation of fluid overload degree with adverse outcome in patients undergoing congenital heart surgery.

METHODS

Medline, Scopus, CENTRAL, Clinicaltrials.gov, and Google Scholar were systematically searched from inception. All studies reporting the effects of fluid overload on postoperative clinical outcomes were selected. A dose-response meta-analytic method using restricted cubic splines was implemented in R-3.6.1.

RESULTS

Twelve studies were included, with a total of 3111 pediatric patients. Qualitative synthesis indicated that fluid overload was linked to significantly higher risk of mortality, AKI, prolonged hospital, and intensive care unit (ICU) stay, as well as with increased duration of mechanical ventilation, inotrope need, and infection rate. Meta-analysis demonstrated a linear correlation between fluid overload and the risk of mortality (χ² = 6.22, p value = 0.01) and AKI (χ² = 35.84, p value < 0.001), while a positive curvilinear relationship was estimated for the outcomes of hospital (χ² = 18.84, p value = 0.0001) and ICU stay (χ² = 63.69, p value = 0.0001).

CONCLUSIONS

The present meta-analysis supports that postoperative fluid overload is significantly linked to elevated risk of prolonged hospital stay, AKI development, and mortality in pediatric patients undergoing cardiac surgery. These findings warrant replication by future prospective studies, which should define the optimal cutoff values and assess the effectiveness of therapeutic strategies to limit fluid overload in the postoperative setting.

Volatile Anesthetics versus Propofol for Cardiac Surgery with Cardiopulmonary Bypass

Background

The aim of this systematic review and meta-analysis was to assess the effect of anesthesia maintenance with volatile agents compared with propofol on both short- and long-term mortality (primary outcomes) and major clinical events in adults undergoing cardiac surgery with cardiopulmonary bypass.

Methods

Randomized clinical trials on the effects of current volatile anesthetics versus propofol in adults undergoing cardiac surgery with cardiopulmonary bypass were searched (1965 to September 30, 2019) in PubMed, the Cochrane Library, and article reference lists. A random effect model on standardized mean difference for continuous outcomes and odds ratio for dichotomous outcomes were used to meta-analyze data.

Results

In total, 37 full-text articles (42 studies, 8,197 participants) were included. The class of volatile anesthetics compared with propofol was associated with lower 1-yr mortality (5.5 vs. 6.8%; odds ratio, 0.76 [95% CI, 0.60 to 0.96]; P = 0.023), myocardial infarction (odds ratio, 0.60 [95% CI, 0.39 to 0.92]; P = 0.023), cardiac troponin release (standardized mean difference, −0.39 [95% CI, −0.59 to −0.18], P = 0.0002), need for inotropic medications (odds ratio, 0.40 [95% CI, 0.24 to 0.67]; P = 0.0004), extubation time (standardized mean difference, −0.35 [95% CI, −0.68 to −0.02]; P = 0.038), and with higher cardiac index/output (standardized mean difference, 0.70 [95% CI, 0.37 to 1.04]; P &lt; 0.0001). The class of volatile anesthetics was not associated with changes in short-term mortality (1.63 vs. 1.65%; odds ratio, 1.04 [95% CI, 0.73 to 1.49]; P = 0.820) and acute kidney injury (odds ratio, 1.25 [95% CI, 0.77 to 2.03]; P = 0.358).

Conclusions

In adults undergoing cardiac surgery with cardiopulmonary bypass, the class of volatile anesthetics was superior to propofol with regard to long-term mortality, as well as to many secondary outcomes indicating myocardial protection.

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The Human Chorionic Gonadotropin Derivate EA-230 Modulates the Immune Response and Exerts Renal Protective Properties: Therapeutic Potential in Humans

The extent of the systemic inflammatory response following infectious or noninfectious insults is related to impaired patient outcome. Pregnancy is associated with immunotolerance and an increased glomerular filtration rate. EA-230 is a newly developed synthetic linear tetrapeptide derived from the "pregnancy hormone" human chorionic gonadotropin. In this review, we describe the immunomodulatory and renoprotective properties of EA-230 in preclinical animal models, phase 1 studies in humans and phase 2a studies performed during human experimental endotoxemia. In addition, details pertaining to the design of a recently completed phase 2b study in 180 patients who underwent cardiac surgery to investigate the safety and immunomodulatory and renoprotective properties of EA-230 are discussed.

Quantifying systemic congestion with Point-Of-Care ultrasound: development of the venous excess ultrasound grading system

Background

Organ congestion is a mediator of adverse outcomes in critically ill patients. Point-Of-Care ultrasound (POCUS) is widely available and could enable clinicians to detect signs of venous congestion at the bedside. The aim of this study was to develop several grading system prototypes using POCUS and to determine their respective ability to predict acute kidney injury (AKI) after cardiac surgery. This is a post-hoc analysis of a single-center prospective study in 145 patients undergoing cardiac surgery for which repeated daily measurements of hepatic, portal, intra-renal vein Doppler and inferior vena cava (IVC) ultrasound were performed during the first 72 h after surgery. Five prototypes of venous excess ultrasound (VExUS) grading system combining multiple ultrasound markers were developed.

Results

The association between each score and AKI was assessed using time-dependant Cox models as well as conventional performance measures of diagnostic testing. A total of 706 ultrasound assessments were analyzed. We found that defining severe venous congestion as the presence of severe flow abnormalities in multiple Doppler patterns with a dilated IVC (≥ 2 cm) showed the strongest association with the development of subsequent AKI compared with other combinations (HR: 3.69 CI 1.65–8.24 p = 0.001). The association remained significant after adjustment for baseline risk of AKI and vasopressor/inotropic support (HR: 2.82 CI 1.21–6.55 p = 0.02). Furthermore, this severe VExUS grade offered a useful positive likelihood ratio (+LR: 6.37 CI 2.19–18.50) when detected at ICU admission, which outperformed central venous pressure measurements.

Conclusions

The combination of multiple POCUS markers may identify clinically significant venous congestion.

Association of acute kidney injury with readmissions after hospitalization for acute exacerbation of chronic obstructive pulmonary disease: a population-based study

Background

Little is known about the relationship between acute kidney injury (AKI) and outcomes after acute exacerbation of chronic obstructive pulmonary disease (AECOPD). We aimed to investigate associations between AKI and readmission risks after hospitalization for AECOPD.

Methods

A retrospective, population-based cohort study using State Inpatient Databases from seven U.S. states (Arkansas, California, Florida, Iowa, Nebraska, New York, and Utah) from 2010 through 2013. We identified all adults (aged ≥40 years) hospitalized for AECOPD during the study period. Among them, we further identified patients with a concurrent diagnosis of new AKI. The outcome measures were any-cause readmissions within 30 days and 90 days after hospitalization for AECOPD. To determine associations between AKI and readmission risk, we constructed Cox proportional hazards models examining the time-to-readmission. We also identified the primary reason of readmission.

Results

We identified 356,990 patients hospitalized for AECOPD. The median age was 71 years and 41.9% were male. Of these, 24,833 (7.0%) had a concurrent diagnosis of AKI. Overall, patients with AKI had significantly higher risk of 30-day all-cause readmission compared to those without AKI (hazard ratio 1.47; 95% CI 1.43–1.51; P < 0.001). Likewise, patients with AKI had significantly higher risk of 90-day all-cause readmission (hazard ratio 1.35; 95% CI 1.32–1.38; P < 0.001). These associations remained significant after adjustment for confounders (both P < 0.05). Additionally, patients with AKI were likely to be readmitted for non-respiratory reasons including sepsis, acute renal failure, and congestive heart failure.

Conclusions

Among patients hospitalized for AECOPD, patients with AKI were at higher risk of 30-day and 90-day readmission, particularly with non-respiratory reasons.

Acute Kidney Injury and Postoperative Atrial Fibrillation In Patients Undergoing Cardiac Surgery

OBJECTIVE

To test the hypothesis that acute kidney injury (AKI) in the postoperative period could be an additional risk factor for the development of atrial fibrillation (AF) and to examine the risk factors for postoperative AF in the authors' cohort of patients.

DESIGN

A retrospective observational study.

SETTING

Large regional cardiothoracic surgical center in the UK.

PARTICIPANTS

Patients undergoing elective cardiac surgery at the authors' institution between July 1, 2013, and December 31, 2018.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 5,588 patients were included in the study. The incidence of postoperative AF was 1,384 (24.8%), and postoperative AKI occurred in 686 patients (12.3%). Postoperative AKI was significantly associated with postoperative AF after adjustment for preoperative variables (adjusted odds ratio = 1.572; 95% confidence interval = 1.295-1.908; p < 0.001). Other factors associated with postoperative AF were increasing age; increasing body mass index; New York Heart Association class ≥III; previous congestive heart failure; and recent myocardial infarction, coronary artery bypass graft with valve surgery, and aortic surgery (all p < 0.05).

CONCLUSIONS

This analysis of a large, contemporary cohort of patients identifies postoperative AKI as an associated risk factor for postoperative AF, along with other perioperative variables. Early identification of this patient cohort would allow targeted preventative treatment to reduce the incidence of postoperative AF.

AZD4547 Attenuates Lipopolysaccharide-Induced Acute Kidney Injury by Inhibiting Inflammation: The Role of FGFR1 in Renal Tubular Epithelial Cells

Introduction

Inflammation plays an important role in the pathogenesis of acute kidney injury (AKI). Fibroblast growth factor receptor 1 (FGFR1) signaling is implicated in kidney pathology. AZD4547 is a small molecule inhibitor of FGFR1.

Materials and Methods

Here, we investigated whether AZD4547 could mitigate inflammatory responses in AKI. C57BL/6 mice were injected with lipopolysaccharide (LPS) to induce AKI. FGFR1 was blocked using AZD4547 or CRISPR/Cas9 genome editing. After immunofluorescent double-staining of kidney tissues showing that P-FGFR1 was localized to renal tubular epithelial cells, a tubular epithelial cell line (NRK-52E) was used for in vitro analysis.

Results

AZD4547 significantly reduced renal inflammation, cell apoptosis, and kidney dysfunction in AKI mice. In vitro, treatment of NRK-52E cells with AZD4547 attenuated LPS-induced inflammatory responses and was associated with downregulated P-FGFR1 levels. These findings were further confirmed in NRK-52E cells by knocking down the expression of FGFR1.

Conclusion

Our findings provide direct evidence that FGFR1 mediates LPS-induced inflammation leading to renal dysfunction. We also show that AZD4547 is a potential therapeutic agent to reduce inflammatory responses in AKI. Both FGFR1 and AZD4547 may interesting therapeutic options to combat AKI.