The Association Between Obesity and Risk of Acute Kidney Injury After Cardiac Surgery

Predictive Factors of Length of Stay in Intensive Care Unit after Coronary Artery Bypass Graft Surgery based on Machine Learning Methods

Introduction

Coronary artery bypass grafting (CABG) surgery requires an extended length of stay (LOS) in the intensive care unit (ICU). This study aimed to predict the factors affecting LOS in the ICU after CABG surgery using machine learning methods.

Methods

In this study, after extracting factors affecting the LOS of patients in the ICU after CABG surgery from the literature and confirming these factors by experts, the medical records of 605 patients at Farshchian Specialized Heart Hospital were reviewed between April 20 and August 9, 2024. Four machine learning models were trained and tested to predict the most desired factors, and finally, the performance of the models was evaluated based on the relevant criteria.

Results

The most important predictors of the LOS of CABG patients in the ICU were the length of intubation, body mass index (BMI), age, duration of surgery, and the number of postoperative transfusions of packed cells. The Random Forest model also performed best in predicting the effective factors (Mean square Error = 1.64, Mean absolute error = 0.93, and R2 = 0.28).

Conclusion

The insights gained from the mashine learning model highlight the significance of demographic and clinical variables in predicting LOS in ICU. By understanding these predictors, healthcare professionals can better identify patients at higher risk for prolonged ICU stays.

Sex-Specific Obesity Paradox in Critically Ill Patients With Severe Acute Kidney Injury: A Retrospective Analysis

OBJECTIVES

Although obesity is typically correlated with adverse outcomes in various diseases, certain acute critical illnesses exhibit a phenomenon known as the obesity paradox. This study evaluated sex-specific differences in the prognostic implications of the body mass index (BMI) of patients with severe acute kidney injury (AKI) requiring continuous renal replacement therapy (CRRT).

DESIGN

A multicenter retrospective cohort study.

SETTING

Data from eight tertiary hospitals in Korea.

PATIENTS

A total of 3805 critically ill patients receiving CRRT. Patients were categorized into four BMI groups: underweight, normal weight, overweight, and obese.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

There were 2308 male and 1497 female patients. The 90-day mortality risk significantly differed among BMI groups in the overall patient population and the male subpopulation but not the female subpopulation. Following adjustment for confounding variables, the 90-day mortality risk was higher in the underweight group than in the obese group (hazard ratio [HR], 1.20; 95% CI, 1.05-1.36; p = 0.006). Among male patients, the 90-day mortality risk was higher in both the underweight and normal weight groups than in the obese group (underweight: HR, 1.30; 95% CI, 1.10-1.53; p = 0.002 and normal weight: HR, 1.18; 95% CI, 1.04-1.35; p = 0.010); however, no such association was observed among female patients. Subgroup analysis demonstrated the obesity paradox in male patients of old age, with septic AKI, or with low albumin levels.

CONCLUSIONS

There were sex differences in the association between BMI and mortality in critically ill patients with severe AKI. Although the precise distribution of fat mass and muscle mass was not identified, obese male patients had a more favorable prognosis, which was not evident among female patients. These findings highlight the importance of considering sex-specific factors in understanding the complex relationship between obesity and mortality in critically ill patients with AKI.

A genotype-guided prediction model for the incidence of persistent acute kidney injury following lung transplantation

BACKGROUND

This study aimed to develop a nomogram for predicting persistent renal dysfunction in acute kidney injury (AKI) following lung transplantation (LTx).

METHOD

A total of 229 LTx patients were enrolled, and genotyping for 153 single nucleotide polymorphisms (SNPs) was performed. The cohort was randomly divided into training (n = 183) and validation (n = 46) sets in an 8:2 ratio. Statistically significant SNPs identified through pharmacogenomic analysis were combined with clinical factors to construct a comprehensive prediction model for persistent AKI using multivariate logistic regression analysis. Discrimination and calibration analyses were conducted to evaluate the performance of the model. Decision curve analysis was used to assess its clinical utility. Due to the small sample size, bootstrap internal sampling with 500 iterations was adopted for validation to prevent overfitting of the model.

RESULTS

The final nomogram comprised nine predictors, including body mass index, thrombin time, tacrolimus initial concentration, rs757210, rs1799884, rs6887695, rs1494558, rs2069762 and rs2275913. In the training set, the area under the receiver operating characteristic curve of the nomogram was 0.781 (95%CI: 0.715-0.846), while in the validation set it was 0.698 (95%CI: 0.542-0.855), indicating good model fit. As demonstrated by 500 Bootstrap internal sampling validations, the model has high discrimination and calibration. Additionally, decision curve analysis confirmed its clinical applicability.

CONCLUSION

This study presents a genotype-guided nomogram that can be used to assess the risk of persistent AKI following LTx and may assist in guiding personalized prevention strategies in clinical practice.

Investigating an appropriate indicator of acute kidney injury for patient prognosis following lung transplantation

OBJECTIVE

The purpose of this study was to investigate the correlation between different subtypes of acute kidney injury (AKI) and clinical outcomes following lung transplantation (LTx) and to identify a reliable indicator for predicting poor prognosis in the LTx population.

METHODS

We retrospectively analyzed the clinical data of 279 LTx patients from August 2016 to March 2023. The AKI subtypes included AKI, persistent AKI on Day 7 (P7-AKI) and Day 14 (P14-AKI) after LTx, and AKI stages. The correlations of these factors with respiratory outcomes, mortality at 90 days, mortality at 1 year and data finalization were assessed, and the risk factors for the selected AKI subtypes were evaluated.

RESULTS

AKI occurred in 215 patients (77.1%), with 129 (46.2%) experiencing P7-AKI and 95 (34.1%) experiencing P14-AKI. P7-AKI was associated with more respiratory and mortality outcomes than were AKI and AKI stages, and P7-AKI surpassed P14-AKI in terms of a shorter diagnostic time. After adjusting for age, sex, BMI, type of transplant, transplant diagnosis and comorbidities, P7-AKI independently correlated with increased mortality risk at 90 days [HR 12.312 (95% CI: 2.839-53.402)], 1 year [HR 3.847 (95% CI: 1.840-8.044)], and data finalization [HR 2.010 (95% CI: 1.331-3.033)]. Five variables were identified as independent predictors for P7-AKI, including preoperative body mass index, prothrombin activity, hemoglobin and serum creatinine, and intraoperative colloid administration.

CONCLUSION

P7-AKI has been identified as a reliable indicator for predicting adverse outcomes in LTx patients, which may assist healthcare professionals in identifying high-risk individuals.

Can Obesity Serve as a Barrier to Minimally Invasive Mitral Valve Surgery? Overcoming the Limitations-A Multivariate Logistic Regression Analysis

Background/Objectives: Over the past two decades, significant advancements in mitral valve surgery have focused on minimally invasive techniques. Some surgeons consider obesity as a relative contraindication for minimally invasive mitral valve surgery (MIMVS). The aim of this study is to evaluate whether the specific characteristics of obese patients contribute to increased surgical complexity and whether this, in turn, leads to worse clinical outcomes compared to non-obese patients. Furthermore, we aim to explore whether these findings could substantiate the consideration of limiting this treatment option for obese patients. We investigated the outcomes of MIMVS in obese and non-obese patients at a high-volume center in Germany staffed by an experienced surgical team well-versed in perioperative management. Methods: A total of 934 MIMVS were performed in our high-volume center in Germany from 2011 to 2023. Of these, 196 patients had a BMI of 30 or higher (obese group), while 738 patients had a BMI below 30 (non-obese group), all of whom underwent MIMVS by right minithoracotomy. Demographic information, echocardiographic assessments, surgical data, and clinical outcome parameters were collected for all patients. Results: There was no significant difference in in-hospital, 30-day, and late mortality between groups (obese vs. non-obese: 6 [3.0%] vs. 14 [1.8%], p = 0.40; 6 [3.0%] vs. 14 [1.8%], p = 0.40; 13 [6.6%] vs. 39 [5.3%], p = 0.48, respectively). Respiratory insufficiency and arrhythmia occurred more frequently in the obese group (obese vs. non-obese: 25 [12.7%] vs. 35 [4.7%], p < 0.001; 35 [17.8%] vs. 77 [10.4%], p = 0.006). Conclusions: Obesity was not associated with increased early or late mortality in patients undergoing MIMVS. However, obese patients experienced higher incidences of postoperative complications, including respiratory insufficiency, arrhythmias, delirium, and wound dehiscence. Nonetheless, a multivariate logistic regression analysis indicated that obesity itself does not contraindicate MIMVS and should not be viewed as a barrier to offering this minimally invasive approach to obese patients.

Vitamin D deficiency may increase the risk of acute kidney injury in patients with diabetes and predict a poorer outcome in patients with acute kidney injury

BACKGOUND

People with diabetes are much more likely to develop acute kidney injury (AKI) than people without diabetes. Low 25-hydroxy-vitamin D [25(OH)D] concentrations increased the risk of AKI in specific populations. Few studies have explored the relationship between the 25(OH)D level and AKI in patients with diabetes. We conducted this study to investigate the relationship between the plasma level of 25(OH)D and the risk of AKI in patients with diabetes, and to evaluate whether the 25(OH)D level could be a good prognostic marker for AKI progression.

METHODS

A total of 347 patients with diabetes were retrospectively reviewed. The primary endpoint was the first event of AKI. The secondary endpoint is need-of-dialysis. AKI patients were further followed up for 6 months with the composite endpoint of end-stage renal disease (ESRD) or all-cause death. Kaplan-Meier survival analysis and Cox proportional hazards models were used.

RESULTS

During a median follow-up of 12 weeks (12.3 ± 6.7), 105 incident AKI were identified. The middle and high tertiles of baseline 25(OH)D levels were associated with a significantly decreased risk of AKI and dialysis compared to the low tertile group (HR = 0.25, 95% CI 0.14-0.46; HR = 0.24, 95% CI 0.13-0.44, respectively, for AKI; HR = 0.15; 95% CI 0.05-0.46; HR = 0.12; 95% CI 0.03-0.42, respectively, for dialysis). Sensitivity analysis revealed similar trends after excluding participants without history of CKD. Furthermore, AKI patients with 25(OH)D deficiency were associated with a higher risk for ESRD or all-cause death (HR, 4.24; 95% CI, 1.80 to 9.97, P < 0.001).

CONCLUSION

A low 25 (OH) vitamin D is associated with a higher risk of AKI and dialysis in patients with diabetes. AKI patients with 25(OH)D deficiency were associated with a higher risk for ESRD or all-cause death.

Perioperative Changes in Plasma Nitrite and IL-6 Levels Predict Postoperative Atrial Fibrillation (POAF) and Acute Kidney Injury (AKI) after Cardiac Surgery

Background: Postoperative atrial fibrillation (POAF) and acute kidney injury (AKI) are common yet significant complications after cardiac surgery, with incidences of up to 40% for each. Here, we assessed plasma nitrite and serum interleukin-6 (IL-6) levels before and after cardiac surgery to quantify the extent to which oxidative stress and inflammation contribute to POAF and AKI occurrence. Methods: We prospectively enrolled 206 cardiac surgical patients. Plasma nitrite and serum IL-6 levels were determined preoperatively and at 24 h, 48 h and 72 h postoperatively. The patients had continuous EKG monitoring for occurrence of POAF, while daily serum creatinine was measured for determination of stage 1 + AKI. Results: Postoperatively, 78 (38%) patients experienced AF, and 47 (23%) patients experienced stage 1 + AKI. POAF analysis: Age, ACE-inhibitor use, valve surgery and percent change in baseline plasma nitrite at 24 h postoperatively were associated with POAF in multiple logistic regression analysis. The inclusion of this new biomarker significantly improved the POAF prediction model (AUC 0.77 for clinical risk factors alone, to AUC 0.81). AKI analysis: A history of diabetes mellitus was associated with AKI in multiple logistic regression analysis, and the addition of preoperative IL-6 levels improved the prediction model for AKI occurrence (AUC 0.69 to AUC 0.74). Conclusions: We previously observed selective upregulation of NADPH oxidase isoform 4 (NOX4) in patients with AF, a critical causal role of NOX4 for AF in zebrafish and a robust inhibitory effect of nitric oxide (NO) on NOX4. Our data innovatively demonstrate that a reduction in circulating nitrite levels, likely implicative of elevated NOX4-mediated oxidative stress, independently associates with POAF and improves POAF prediction, whereas the inclusion of circulating IL-6 levels improves the prediction model for AKI. Therefore, therapeutic strategies to mitigate these pathophysiological sequalae of surgical stress may reduce the incidence of severe postoperative complications of POAF and AKI.

Low estimated glomerular filtration rate and high body mass index are risk factors for acute kidney injury in systemic lupus erythematosus patients after cardiac surgery

Objective

The occurrence of acute kidney injury (AKI) is common following cardiac surgery, especially among patients characterized with systemic lupus erythematosus (SLE), but studies on this clinical scenario have been limited by the rarity of SLE. We aimed to explore the risk predictors and outcomes with regards to postoperative AKI among cardiac-surgical patients concomitant with SLE.

Methods

This was a single-center retrospective study performed in a tertiary hospital. Adult patients diagnosed with SLE who underwent cardiac surgery within the last 22 years were enrolled. Essential variables, including patient-, surgery- and anesthesia-related information, were collected from the medical record system. The definition of AKI was derived from the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Risk predictors suspected to be linked with post-surgical AKI were calculated using the univariable and multivariable analyses.

Results

Of all 59 SLE patients undergoing cardiac surgery, 57 were ultimately enrolled into the analysis. AKI occurred in 29 patients (50.9%), who had significantly longer extubation time (median difference 1.0 day, P < 0.001), ICU length of stay (median difference 2.0 days, P = 0.001), postoperative length of stay (median difference 5.0 days, P = 0.026), and more postoperative major complications (odds ratio 10.29, P = 0.025) than the others. Preoperative estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m2 (odds ratio 5.31, P = 0.021) and body mass index (BMI) ≥ 24 kg/m2 (odds ratio 4.32, P = 0.043) were the only two factors in the multivariable analysis that were significantly correlated with the development of postoperative AKI in patients with SLE after cardiac surgery.

Conclusion

AKI in SLE patients after cardiac surgery is common and requires scrutiny, especially in overweight patients with moderate to severe preoperative renal dysfunction.

The Burden of Obesity in Cardiac Surgery: A 14 years' Follow-Up of 14.754 Patients

Aims

The prevalence of obesity is rapidly increasing during the past decades. While previous research has focused on the early outcome after cardiac surgery or specific complications, the current study covers the whole burden of obesity in the field of cardiac surgery over short term and long term. Endpoints of the study were all-cause mortality, perioperative outcome, and wound-healing disorders (WHDs).

Methods

14.754 consecutive patients who underwent cardiac surgery over a 14 years' time period were analyzed. BMI classifications were used according to the WHO definition.

Results

Mean survival was 11.95 years ± 0.1; CI 95% [12.04-12.14]. After adjustment for clinical baseline characteristics, obesity classes' I-III (obesity) did not affect 30-day mortality or all-cause mortality during the whole observational period. After adjustment for known risk factors, the risk for WHDs doubled at least in obesity patients as follows: obesity I (OR = 2.06; CI 95% [1.7-2.5]; p < 0.0001), obesity II (OR = 2.5; CI 95% [1.83-3.41]; p < 0.0001), and obesity III (OR = 4.12; CI 95% [2.52-6.74]; p < 0.0001). The same applies to the risk for sternal reconstruction that is substantially elevated in obesity I (OR = 2.23; CI 95% [1.75-2.83]; p < 0.0001), obesity II (OR = 2.81; CI 95% [1.91-4.13]; p < 0.0001), and obesity III (OR = 2.31; CI 95% [1.08-4.97]; p=0.03). No significant correlation could be found between obesity and major adverse events in the perioperative course like renal failure, ventilation >24 h, re-exploration, or cerebrovascular events.

Conclusions

Cardiac surgery is safe in obesity as short- and long-term mortality are not increased, and major adverse events during the perioperative course are similar to control patients. The burden of obesity lies in substantially increased rates of wound-healing disorders and sternal reconstructions.

Severe Acute Kidney Injury Postheart Transplantation: Analysis of Risk Factors

Background

Acute kidney injury (AKI) is a common complication postheart transplantation and is associated with significant morbidity and increased mortality.

Methods

We conducted a single-center, retrospective, observational cohort study of 109 consecutive patients undergoing heart transplantation between September 2019 and September 2021 to determine major risk factors for, and the incidence of, severe postoperative AKI as defined by Kidney Disease Improving Global Outcomes criteria in the first 48-h posttransplantation and the impact that this has on mortality and dialysis dependence.

Results

One hundred nine patients were included in our study, 83 of 109 (78%) patients developed AKI, 42 (39%) developed severe AKI, and 37 (35%) required renal replacement therapy in the first-week posttransplantation. We found preoperative estimated glomerular filtration rate (eGFR), postoperative noradrenaline dose, and the need for postoperative mechanical circulatory support to be independent risk factors for the development of severe AKI. Patients who developed severe AKI had a 19% 12-mo mortality compared with 1% for those without. Of those who survived to hospital discharge, 20% of patients in the severe AKI group required dialysis at time of hospital discharge compared with 3% in those without severe AKI.

Conclusion

Severe AKI is common after heart transplantation. Preoperative kidney function, postoperative vasoplegia with high requirements for vasoactive drugs, and graft dysfunction with the need for mechanical circulatory supports were independently associated with the development of severe AKI in the first-week following heart transplantation. Severe AKI is associated with a significantly increased mortality and dialysis dependence at time of hospital discharge.

Outcomes of Minimally Invasive Aortic Valve Replacement in Obese Patients: A Propensity-Matched Study

INTRODUCTION

Obese patients are at risk of complications after cardiac surgery. The aim of this study is to investigate safety and efficacy of a minimally invasive approach via upper sternotomy in this setting.

METHODS

We retrospectively reviewed 203 obese patients who underwent isolated, elective aortic valve replacement between January 2014 and January 2023 - 106 with minimally invasive aortic valve replacement (MIAVR) and 97 with conventional aortic valve replacement (CAVR). To account for baseline differences, a propensity-matching analysis was performed obtaining two balanced groups of 91 patients each.

RESULTS

The 30-day mortality rate was comparable between groups (1.1% MIAVR vs. 0% CAVR, P=0.99). MIAVR patients had faster extubation than CAVR patients (6 ± 2 vs. 9 ± 2 hours, P<0.01). Continuous positive airway pressure therapy was less common in the MIAVR than in the CAVR group (3.3% vs. 13.2%, P=0.03). Other postoperative complications did not differ significantly. Intensive care unit stay (1.8 ± 1.2 vs. 3.2 ± 1.4 days, P<0.01), but not hospital stay (6.7 ± 2.1 vs. 7.2 ± 1.9 days, P=0.09), was shorter for MIAVR than for CAVR patients. Follow-up survival was comparable (logrank P-value = 0.58).

CONCLUSION

MIAVR via upper sternotomy has been shown to be a safe and effective option for obese patients. Respiratory outcome was promising with shorter mechanical ventilation time and reduced need for post-extubation support. The length of stay in the intensive care unit was reduced. These advantages might be important for the obese patient to whom minimally invasive surgery should not be denied.

Gender differences and risk factors for acute kidney injury following cardiac surgery: A single center retrospective cohort study

Background

We studied AKI incidence and prognosis in cardiac surgery patients under and over 60 years old.

Methods

We studied AKI in patients who underwent cardiac surgery at the First Affiliated Hospital of Wenzhou Medical University between Jan 2020 and Dec 2021, using improved global prognostic criteria for diagnosis.

Results

After analyzing 781 patients (402 males, 379 females), AKI incidence after surgery was 30.22 %. Adjusting for propensity scores revealed no significant difference in AKI incidence between young males (24.1 %) and females (19.3 %). However, young females had higher AKI stages. Among older patients, AKI incidence was comparable between males (43.4 %) and females (42.2 %), but females had longer intubation times. Independent risk factors for AKI included age, male gender, and BMI, while intraoperative hemoglobin level was protective.

Conclusions

No gender gap in AKI frequency for <60 years old and ≥60 years old post-cardiac surgery, yet women display increased AKI severity and extended intubation duration.

Cardiac surgery-associated acute kidney injury and perioperative plasma viscosity: is there a relationship?

Plasma viscosity (PV) is a key factor in microcirculatory flow resistance and capillary perfusion during hemodilution, we hypothesized a possible relationship between cardiac surgery-associated acute kidney injury (CSA-AKI) and PV. We conducted a prospective, observational, single-center study on 50 adult cardiac surgery patients with cardiopulmonary bypass (age 64 years, male sex 80%, baseline serum creatinine 1.04 mg/dL). We assessed perioperative characteristics, management, short-term outcomes, blood analysis, PV, serum creatinine, and diuresis. CSA-AKI was identified using KDIGO criteria. Data were collected at 10 time points during the first perioperative week. CSA-AKI occurred in 17 patients (34%): 12 (24%) stage 1, 1 (2%) stage 2, and 4 (8%) stage 3. Most patients (88%) developed CSA-AKI within 48 h post-surgery. Patients with CSA-AKI had higher body mass index (BMI), more frequent chronic kidney disease (CKD), and lower hemoglobin and hematocrit levels. The median baseline PV for the entire cohort was 1.50 cP on EDTA and 1.37 cP on citrate. No significant differences in PV levels were found between patients with CSA-AKI and normal kidney function, both at baseline and at the 48-h. Logistic and Cox regression analyses showed no significant relationship between PV and CSA-AKI. However, CSA-AKI was related to increased BMI, lower hemoglobin and hematocrit levels, and pre-existing CKD. The present study found no significant association between PV and CSA-AKI. Nevertheless, more research is needed to validate this finding and to investigate the role of PV in other clinical settings.

Postoperative acute kidney injury after on-pump cardiac surgery in patients with connective tissue disease

Objective

Patients with connective tissue disease have a poor prognosis after receiving cardiac surgery. This study described the clinical scenarios and investigated factors correlated with acute kidney injury (AKI) after on-pump cardiac surgery in patients with systemic lupus erythematosus (SLE) or vasculitis.

Methods

Patients with SLE or vasculitis who underwent on-pump cardiac surgery from March 2002 to March 2022 were enrolled, while patients with preoperative renal dysfunction were excluded. AKI was defined according to the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Uni- and multivariable analyses were performed to identify potential factors associated with postoperative AKI.

Results

Among 123 patients enrolled, 39 (31.7%) developed AKI within seven days after receiving on-pump cardiac surgery. Four patients died in the hospital, resulting in an overall in-hospital mortality of 3.3%, and all deaths occurred in the AKI group. Patients in the AKI group also had longer ICU stays (median difference 3.0 day, 95% CI: 1.0-4.0, P < 0.001) and extubation time (median difference 1.0 days, 95% CI: 0-2.0, P < 0.001) than those in the non-AKI group. Multivariable logistic regression revealed that BMI over 24 kg/m2 (OR: 3.00, 95% CI: 1.24-7.28) and comorbid SLE (OR: 4.73, 95% CI: 1.73-12.93) were independently correlated with postoperative AKI.

Conclusion

Factors potentially correlated with AKI following on-pump cardiac surgery in patients with connective tissue disease were explored. Clinicians should pay more attention to preoperative evaluation and intraoperative management in patients with risk factors.

Impact of Bariatric Surgery on Mortality of Mitral Valve Surgery: A National Analysis

OBJECTIVE

Obesity is a common comorbidity of cardiac surgery patients. The goal of this study is to determine if a lower weight achieved through bariatric surgery has any association with mitral valve (MV) replacement or repair surgery mortality.

METHODS

This study used a retrospective analysis of the National Inpatient Sample dataset from 2012 to 2020. Adult patients who underwent MV surgery with normal weight following bariatric surgery (n = 1,125) and patients with obesity (n = 48,555) were compared. The primary outcome was in-hospital mortality.

RESULTS

This study included 49,680 patients. The median age was 64 (55 to 71) years, and the majority were female (55%). Bariatric surgery was found to significantly decrease the odds of mortality, even after adjusting for important covariates, indicating a reduction of mortality risk by 54% (adjusted odds ratio = 0.46, p = 0.024). Other significant protective factors include isolated and elective surgery. Significant risk factors were older age, female sex, and diabetes mellitus. Patients who were obese demonstrated longer lengths of stay (LOS), greater transfers to other facilities, and higher hospital costs.

CONCLUSIONS

In patients receiving MV surgery, bariatric surgery demonstrated significant survival benefits during hospitalization, in addition to reducing LOS and cost. Our data support prior evidence of bariatric surgery improving cardiovascular outcomes. Therefore, bariatric surgery may be a meaningful method of weight loss to improve surgical patient outcomes in patients with obesity. However, longer-term data are needed.

Incidence and predictors of postoperative acute kidney injury in older adults with hip fractures

OBJECTIVES

Main Purpose: To clarify the incidence and predictors of acute kidney injury (AKI) after hip fracture surgery; Secondary Purpose: To investigate the impact of AKI on the length of stay (LOS) and mortality of patients.

METHODS

We retrospectively evaluated data from 644 hip fracture patients at Peking University First Hospital from 2015 to 2021, and divided the patients into AKI and Non-AKI groups according to whether AKI occurred after surgery. Logistic regression was used to clarify the risk factors for AKI, draw ROC curves, and analyze the odds ratio (OR) for LOS and death at 30 days, 3 months, and 1 year for patients with AKI.

RESULTS

The prevalence of AKI after hip fracture was 12.1%. Age, BMI, and postoperative brain natriuretic peptide (BNP) levels were risk factors for AKI after hip fracture surgery. The risk of AKI in underweight patients, overweight patients and obese patients was 2.24, 1.89, and 2.58 times. Compared to patients with BNP levels <800 pg/ml, the risk of AKI was 22.34-fold for postoperative BNP levels>1500 pg/ml. The risk of a one-grade increase in LOS was 2.84 times higher in the AKI group and the mortality of patients with AKI were higher.

CONCLUSION

The incidence of AKI after hip fracture surgery was 12.1%. Advanced age, low BMI, and postoperative high level BNP were risk factors for AKI. Surgeons need to pay more attention to patients with older age, low BMI and high postoperative BNP levels in order to proactively prevent the development of postoperative AKI.

Association of underweight and obesity with adverse postoperative renal outcomes in infants and young children undergoing congenital heart surgery

Postoperative acute kidney injury (AKI) is a prevalent condition and associated with increased morbidity and mortality following cardiac surgery. This study aimed to investigate the association of underweight and obesity with adverse postoperative renal outcomes in infants and young children undergoing congenital heart surgery. This retrospective cohort study included patients aged from 1 month to 5 years who underwent congenital heart surgery with cardiopulmonary bypass at the Second Xiangya Hospital of Central South University from January 2016 to March 2022. On the basis of the percentile of body mass index (BMI) for age and sex, eligible participants were divided into three nutritional groups: normal bodyweight, underweight (BMI P5), and obesity (BMI P95). Primary outcomes included postoperative AKI and major adverse kidney events within 30 days (MAKE30). Multivariable logistic regression was performed to determine the association of underweight and obesity with postoperative outcomes. The same analyses were reproduced for classifying patients using weight-for-height instead of BMI. A total of 2,079 eligible patients were included in the analysis, including 1,341 (65%) patients in the normal bodyweight group, 683 (33%) patients in the underweight group, and 55 (2.6%) patients in the obesity group. Postoperative AKI (16% vs. 26% vs. 38%; P < 0.001) and MAKE30 (2.5% vs. 6.4% vs. 9.1%; P < 0.001) were more likely to occur in the underweight and obesity groups. After adjusting for potential confounders, underweight (OR1.39; 95% CI 1.08-1.79; P = 0.008) and obesity (OR 3.85; 95% CI 1.97-7.50; P < 0.001) were found to be associated with an increased risk of postoperative AKI. In addition, both underweight (OR 1.89; 95% CI 1.14-3.14; P = 0.014) and obesity (OR 3.14; 95% CI 1.08-9.09; P = 0.035) were independently associated with MAKE30. Similar results were also found when weight-for-height was used instead of BMI.    Conclusion: In infants and young children undergoing congenital heart surgery, underweight and obesity are independently associated with postoperative AKI and MAKE30. These results may help assess prognosis in underweight and obese patients, and will guide future quality improvement efforts. What is Known: • Postoperative acute kidney injury (AKI) is prevalent and associated with increased morbidity and mortality following pediatric cardiac surgery. • Major adverse kidney events within 30 days (MAKE30) have been recommended as a patient-centered endpoint for evaluating AKI clinical trajectories. A growing concern arises for underweight and obesity in children with congenital heart disease. What is New: • Prevalence of underweight and obesity among infants and young children undergoing congenital heart surgery was 33% and 2.6%, respectively. • Both underweight and obesity were independently associated with postoperative AKI and MAKE30 following congenital heart surgery.

Effect of body mass index on clinical outcomes after robotic cardiac surgery: is there an obesity paradox?

BACKGROUND

To investigate the effect of body mass index (BMI) on clinical outcomes after robotic cardiac surgery, and to explore the postoperative obesity paradox.

METHODS

The data of 146 patients who underwent robotic cardiac surgery under cardiopulmonary bypass (CPB) from July 2016 to June 2022 in Daping Hospital of Army Medical University were retrospectively analyzed, and their demographic data and related clinical data were statistically analyzed. The mean age was (42.88 ± 13.01) years, 55 (37.67%) were male and 91 (62.33%) were female. Patients were divided into 3 groups according to preoperative BMI: lean group (BMI < 18.5 kg/m²; n = 17; 11.64%), normal group (BMI 18.5 kg/m² to 23.9 kg/m²; n = 81; 55.48%), and overweight and obese group (BMI ≥ 24 kg/m²; n = 48; 32.88%). Multivariate analysis was performed to compare clinical outcomes across BMI groups.

RESULTS

Preoperative data in different BMI groups showed that there were statistically significant differences in age, height, weight, body surface area (BSA), diabetes, left atrial anteroposterior diameter (LAD), triglyceride (TG), and high-density lipoprotein (HDL) (all P < 0.05). Postoperative clinical outcomes showed that there was no statistical difference between the lean group and the normal group; the intensive care unit stay and postoperative hospital stay in the overweight and obese group were significantly higher than those in the normal group (P < 0.05), and the risk of postoperative cardiac surgery-related acute kidney injury (CSA-AKI) was significantly increased (P = 0.021); further Multiple Binary Logistic Regression Analysis suggested that preoperative TG (OR = 1.772, 95% CI 1.068-2.942, P = 0.027) and operation time ≥ 300 min (OR = 3.823, 95% CI 1.098-13.308, P = 0.035) were independent risk factors for postoperative CSA-AKI.

CONCLUSIONS

Overweight and obese patients had significantly prolonged intensive care unit stay and postoperative hospital stay after robotic cardiac surgery, and significantly increased incidence of postoperative CSA-AKI, which did not support the obesity paradox; preoperative TG and operation time ≥ 300 min were independent risk factors for postoperative CSA-AKI.

Obese elderly patients with hip fractures may have better survival outcomes after surgery

BACKGROUND

In recent years, there has been an increasing amount of research on the "obesity paradox". So our primary objective was to explore whether this phenomenon exists in our study, and secondary objective was to determine the effect of body mass index (BMI) on major complications, and the incidence of acute kidney injury (AKI) after hip fracture surgery after controlling for confounding factors.

METHODS

We included patients over 70 years old with hip fracture who were admitted to the Department of Orthopedics, Peking University First Hospital between 2015 and 2021. Patients were classified as underweight (UW, < 18.5 kg/m²), normal weight (NW, 18.5-24.9 kg/m²), overweight (OW, 25.0-29.9 kg/m²) and obese (OB, ≥ 30.0 kg/m²). We analyzed demographic characteristics, operation information and postoperative outcomes. Using multivariate regression with normal-weight patients as the reference, we determined the odds of 1-year mortality, major complications, and AKI by BMI category.

RESULTS

A total of 644 patients were included. Nine percent of patients died after 1 year, 18% had major postoperative complications, and 12% had AKI. There was a U-shaped relationship between BMI and the rates of major complications or AKI. However, there was a linear decreasing relationship between 1-year mortality and BMI. After controlling for confounding factors, multivariate regression analysis showed that the risk of 1-year mortality after surgery was 2.24 times higher in underweight patients than in normal-weight patients (P < 0.05, OR: 2.24, 95% CI 1.14-4.42). Compared with normal-weight patients, underweight patients had a 2.07 times increased risk of major complications (P < 0.05, OR 2.07, 95% CI 1.21-3.55), and the risk of major complications in obese patients was 2.57 times higher than that in normal-weight patients (P < 0.05, OR 2.57, 95% CI 1.09-6.09). Compared with normal-weight, underweight patients had a 2.18 times increased risk of AKI (P < 0.05, OR 2.18, 95% CI 1.17-4.05).

CONCLUSIONS

The 1-year mortality risk of patients with higher BMI was significantly reduced. Besides, compared with normal-weight patients, underweight patients and obese patients have a higher risk of major complications; low-weight and obese patients are at higher risk for AKI.

Association of Body Mass Index and Acute Kidney Injury Incidence and Outcome: A Systematic Review and Meta-Analysis

This study aims to provide pooled estimates for the incidence of acute kidney injury (AKI) in overweight, obese, and normal body mass index (BMI) patients, and to assess impact of BMI on mortality and chronic kidney disease (CKD) rates. We conducted literature search using online databases to analyze outcomes of BMI. This meta-analysis included 22 studies. Compared to normal BMI, underweight, overweight, or obese patients had higher risk of having AKI. Underweight individuals had 17% lower CKD risk (relative risk [RR]: 0.83, 95% confidence interval [CI]: 0.75, 0.90) while patients that were overweight (RR: 1.15, 95% CI: 1.08, 1.22) and obese (RR: 1.21, 95% CI: 1.10, 1.33) had higher risk of having CKD. Lower than normal BMI was associated with higher mortality risk (RR: 1.58, 95% CI: 1.35, 1.85), while being overweight or obese correlated with the decreased risk of mortality. An increased risk of AKI combined with an increased risk of mortality calls for renal protective strategies in subjects who are underweight at the time of hospital admission.

Using Bayesian networks with Tabu-search algorithm to explore risk factors for hyperhomocysteinemia

Hyperhomocysteinemia (HHcy) is a condition closely associated with cardiovascular and cerebrovascular diseases. Detecting its risk factors and taking some relevant interventions still represent the top priority to lower its prevalence. Yet, in discussing risk factors, Logistic regression model is usually adopted but accompanied by some defects. In this study, a Tabu Search-based BNs was first constructed for HHcy and its risk factors, and the conditional probability between nodes was calculated using Maximum Likelihood Estimation. Besides, we tried to compare its performance with Hill Climbing-based BNs and Logistic regression model in risk factor detection and discuss its prospect in clinical practice. Our study found that Age, sex, α1-microgloblobumin to creatinine ratio, fasting plasma glucose, diet and systolic blood pressure represent direct risk factors for HHcy, and smoking, glycosylated hemoglobin and BMI constitute indirect risk factors for HHcy. Besides, the performance of Tabu Search-based BNs is better than Hill Climbing-based BNs. Accordingly, BNs with Tabu Search algorithm could be a supplement for Logistic regression, allowing for exploring the complex network relationship and the overall linkage between HHcy and its risk factors. Besides, Bayesian reasoning allows for risk prediction of HHcy, which is more reasonable in clinical practice and thus should be promoted.

Recent advances in molecular mechanisms of acute kidney injury in patients with diabetes mellitus

Several insults can lead to acute kidney injury (AKI) in native kidney and transplant patients, with diabetes critically contributing as pivotal risk factor. High glucose per se can disrupt several signaling pathways within the kidney that, if not restored, can favor the instauration of mechanisms of maladaptive repair, altering kidney homeostasis and proper function. Diabetic kidneys frequently show reduced oxygenation, vascular damage and enhanced inflammatory response, features that increase the kidney vulnerability to hypoxia. Importantly, epidemiologic data shows that previous episodes of AKI increase susceptibility to diabetic kidney disease (DKD), and that patients with DKD and history of AKI have a generally worse prognosis compared to DKD patients without AKI; it is therefore crucial to monitor diabetic patients for AKI. In the present review, we will describe the causes that contribute to increased susceptibility to AKI in diabetes, with focus on the molecular mechanisms that occur during hyperglycemia and how these mechanisms expose the different types of resident renal cells to be more vulnerable to maladaptive repair during AKI (contrast- and drug-induced AKI). Finally, we will review the list of the existing candidate biomarkers of diagnosis and prognosis of AKI in patients with diabetes.

Predicting the risk factors of diabetic ketoacidosis-associated acute kidney injury: A machine learning approach using XGBoost

Objective

The purpose of this study was to develop and validate a predictive model based on a machine learning (ML) approach to identify patients with DKA at increased risk of AKI within 1 week of hospitalization in the intensive care unit (ICU).

Methods

Patients diagnosed with DKA from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database according to the International Classification of Diseases (ICD)-9/10 code were included. The patient's medical history is extracted, along with data on their demographics, vital signs, clinical characteristics, laboratory results, and therapeutic measures. The best-performing model is chosen by contrasting the 8 Ml models. The area under the receiver operating characteristic curve (AUC), sensitivity, accuracy, and specificity were calculated to select the best-performing ML model.

Results

The final study enrolled 1,322 patients with DKA in total, randomly split into training (1,124, 85%) and validation sets (198, 15%). 497 (37.5%) of them experienced AKI within a week of being admitted to the ICU. The eXtreme Gradient Boosting (XGBoost) model performed best of the 8 Ml models, and the AUC of the training and validation sets were 0.835 and 0.800, respectively. According to the result of feature importance, the top 5 main features contributing to the XGBoost model were blood urea nitrogen (BUN), urine output, weight, age, and platelet count (PLT).

Conclusion

An ML-based individual prediction model for DKA-associated AKI (DKA-AKI) was developed and validated. The model performs robustly, identifies high-risk patients early, can assist in clinical decision-making, and can improve the prognosis of DKA patients to some extent.

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 Obesity on Early In-Hospital Outcomes after Coronary Artery Bypass Grafting Surgery in Acute Coronary Syndrome: A Propensity Score Matching Analysis

Recent advances in perioperative care have considerably improved outcomes after coronary artery bypass graft (CABG) surgery. However, obesity can increase postoperative complication rates and can lead to increased morbidity and mortality. Between June 2011 and October 2019, a total of 1375 patients with acute coronary syndrome (ACS) underwent cardiac surgery and were retrospectively analyzed. Patients were divided into 2 groups: non-obese (body mass index (BMI) < 30 kg/m2, n = 967) and obese (BMI ≥ 30 kg/m2, n = 379). Underweight patients (n = 29) were excluded from the analysis. To compare the unequal patient groups, a propensity score-based matching (PSM) was applied (non-obese group (n = 372) vs. obese group (n = 372)). The mean age of the mentioned groups was 67 ± 10 (non-obese group) vs. 66 ± 10 (obese group) years, p = 0.724. All-cause in-hospital mortality did not significantly differ between the groups before PSM (p = 0.566) and after PSM (p = 0.780). The median length of ICU (p = 0.306 before PSM and p = 0.538 after PSM) and hospital stay (p = 0.795 before PSM and p = 0.131 after PSM) was not significantly higher in the obese group compared with the non-obese group. No significant differences regarding further postoperative parameters were observed between the unadjusted and the adjusted group. Obesity does not predict increased all-cause in-hospital mortality in patients undergoing CABG procedure. Therefore, CABG is a safe procedure for overweight patients.

Association of Preoperative Pulse Pressure and Oxygen Delivery Index During Cardiopulmonary Bypass With Postoperative Acute Kidney Injury

OBJECTIVE

To investigate if oxygen delivery index during cardiopulmonary bypass (DO₂I) was more strongly associated with acute kidney injury (AKI), the higher the patient's preoperative pulse pressure (PP).

DESIGN

Retrospective cohort of 1064 patients undergoing cardiac surgery.

SETTING

Single academic healthcare center.

PARTICIPANTS

Adult patients undergoing coronary artery bypass grafting, valve, aortic, or combined surgery requiring cardiopulmonary bypass.

INTERVENTIONS

Hemoglobin, arterial oxygen saturation, and pump flow recorded no fewer than every 30 min were extracted from the patients' perfusion records, and DO₂I was calculated. The AKI was assessed from the pre- and postoperative creatinine and urine output values using the Acute Kidney Injury Network criteria. The sample was stratified in 5 categories of progressively higher PP. The patient characteristics and intraoperative variables were evaluated in univariate analysis for a relationship with AKI. The significant risk factors from the univariate analysis then were evaluated in a multivariate analysis and assessed for logistic fit with respect to AKI.

PRIMARY OUTCOME

The AKI assessed as a binary outcome.

MEASUREMENTS AND MAIN RESULTS

Age, body surface area, DO₂I, history of heart failure, and baseline creatinine were associated significantly with AKI, as was an interaction term between the PP category and DO₂I (p = 0.0067). The higher the PP category, the stronger the observed association between DO₂I and AKI, and the higher the variability in the predicted risk of AKI dependent on DO₂I.

CONCLUSIONS

A lower DO₂I during cardiopulmonary bypass appeared more strongly associated with a higher likelihood of developing AKI, the higher the patient's preoperative pulse pressure.

Pre-Habilitation of Cardiac Surgical Patients, Part 2: Frailty, Malnutrition, Respiratory disease, Alcohol/Smoking cessation and Depression

The concept of "pre-habilitation" comprises screening for and identification of pre-existing disorders followed by medical optimization. This is performed for many types of surgeries, but may have profound impacts on outcomes, particularly in cardiac surgery given the multiple comorbidities typically carried by these patients. Components of pre-habilitation include direct medical intervention by preoperative specialists as well as significant care coordination and shared decision-making. In this second part of a two-part review, the authors describe existing evidence to support the optimization of various preoperative problems and present a few institutional protocols utilized at out center for cardiac presurgical care. This second installment will focus on alcohol and smoking cessation and the management of frailty, malnutrition, respiratory disease, and depression.

Using Bayesian network model with MMHC algorithm to detect risk factors for stroke

Stroke is a major chronic non-communicable disease with high incidence, high mortality, and high recurrence. To comprehensively digest its risk factors and take some relevant measures to lower its prevalence is of great significance. This study aimed to employ Bayesian Network (BN) model with Max-Min Hill-Climbing (MMHC) algorithm to explore the risk factors for stroke. From April 2019 to November 2019, Shanxi Provincial People's Hospital conducted opportunistic screening for stroke in ten rural areas in Shanxi Province. First, we employed propensity score matching (PSM) for class balancing for stroke. Afterwards, we used Chi-square testing and Logistic regression model to conduct a preliminary analysis of risk factors for stroke. Statistically significant variables were incorporated into BN model construction. BN structure learning was achieved using MMHC algorithm, and its parameter learning was achieved with Maximum Likelihood Estimation. After PSM, 748 non-stroke cases and 748 stroke cases were included in this study. BN was built with 10 nodes and 12 directed edges. The results suggested that age, fasting plasma glucose, systolic blood pressure, and family history of stroke constitute direct risk factors for stroke, whereas sex, educational levels, high density lipoprotein cholesterol, diastolic blood pressure, and urinary albumin-to-creatinine ratio represent indirect risk factors for stroke. BN model with MMHC algorithm not only allows for a complicated network relationship between risk factors and stroke, but also could achieve stroke risk prediction through Bayesian reasoning, outshining traditional Logistic regression model. This study suggests that BN model boasts great prospects in risk factor detection for stroke.

Impact of body mass index on postoperative oxygenation impairment in patients with acute aortic syndrome

Objective: Oxygenation impairment is a common complication of acute aortic syndrome (AAS) patients after surgical repair. The aim of this study is to identify the relationship between body mass index (BMI) and the risk of postoperative oxygenation impairment in AAS patients.

Methods: A total of 227 consecutive patients who were diagnosed as AAS and underwent surgical repair were recruited. They were divided into two groups based on the postoperative oxygenation impairment (non-oxygenation impairment group and oxygenation impairment group). Logistic regression was conducted to evaluate the association between BMI and the risk of oxygenation impairment after surgery. Dose-response curve and subgroup analysis were used to test the reliability of the results of regression analysis. A meta-analysis was then performed to further confirm these results using Pubmed, Embase, and Web of Science databases.

Results: For the retrospective study, a significant association was observed after adjusting for a series of variables. BMI was significantly correlated with postoperative oxygenation impairment in patients with AAS (OR, 95% CI, P: 1.27, 1.17–1.46, 0.001). Compared with the normal weight group (18.5 kg/m² ≤ BMI <23.0 kg/m²), patients with excessive BMI were at a higher risk of oxygenation impairment for the overweight group (23.0 kg/m² ≤ BMI <25 kg/m²) and obesity group (BMI ≥25 kg/m²) (OR, 95% CI, P: 4.96, 1.62–15.15, 0.005; 9.51, 3.06–29.57, <0.001). The dose-response curve showed that the risk of oxygenation impairment after surgery increased with the increased BMI. Besides, subgroup analysis showed that AAS patients who have an excess weight with a TNF-α ≥ 8.1 pg/ml carried an excess risk of postoperative oxygenation impairment. For the meta-analysis, the pooled result also indicated that AAS patients with high BMI had a significantly increased risk of oxygenation impairment after surgery (OR, 95% CI, P: 1.40, 1.18–1.66, 0.001).

Conclusion: Excessive BMI was an independent risk factor for AAS with postoperative oxygenation impairment.

Prehabilitation of Cardiac Surgical Patients, Part 1: Anemia, Diabetes Mellitus, Obesity, Sleep Apnea, and Cardiac Rehabilitation

The concept of "prehabilitation" consists of screening for and identification of pre-existing disorders followed by medical optimization. This is performed for many types of surgery, but may have profound impacts on outcomes particularly in cardiac surgery given the multiple comorbidities typically carried by these patients. Components of prehabilitation include direct medical intervention by preoperative specialists as well as significant care coordination and shared decision making. In this two-part review, the authors describe existing evidence to support the optimization of various preoperative problems and present a few institutional protocols utilized by our center for cardiac presurgical care. This first installment will focus on the management of anemia, obesity, sleep apnea, diabetes, and cardiac rehabilitation prior to surgery. The second will focus on frailty, malnutrition, respiratory disease, alcohol and smoking cessation, and depression.

Predictors of Mortality Following Aortic Valve Replacement in Aortic Stenosis Patients

Background: Understanding of the risk factors for the development of adverse outcomes after aortic valve replacement is necessary to develop timely preventive measures and to improve the results of surgical treatment. Methods: We analyzed patients with aortic stenosis (n = 742) who underwent surgical treatment in the period 2014−2020. The average age was 63 (57;69) years—men 58%, women 42%. Results: The hospital mortality rate was 3% (22 patients). The following statistically significant threshold values (cut-off points) were obtained in the ROC analysis: aortic cross-clamp time > 93 min AUC (CI) 0.676 (0.640−0.710), p = 0.010; cardiopulmonary bypass time > 144 min AUC (CI) 0.809 (0.778−0.837), p < 0.0001, hemoglobin before op <120 g/L. AUC (CI) 0.762 (0.728−0.793), p < 0.0001, hematocrit before op <39% AUC (CI) 0.755 (0.721−0.786), p < 0.001, end-diastolic dimension index >2.39 AUC (CI) 0.647 (0.607−0.686), p = 0.014, end-systolic dimension index > 1.68 AUC (CI) 0.657 (0.617−0.695), p = 0.009. Statistically significant independent predictors of hospital mortality were identified: BMI > 30 kg/m2 (OR 2.84; CI 1.15−7.01), ischemic heart disease (OR 3.65; CI 1.01−13.2), diabetes (OR 3.88; CI 1.38−10.9), frequent ventricular ectopy before operation (OR 9.78; CI 1.91−50.2), mitral valve repair (OR 4.47; CI 1.76−11.3), tricuspid valve repair (OR 3.06; CI 1.09−8.58), 3 and more procedures (OR 4.44; CI 1.67−11.8). Conclusions: The hospital mortality rate was 3%. The main indicators associated with the risk of death were: diabetes, overweight (body mass index more than 30 kg/m2), frequent ventricular ectopy before surgery, hemoglobin level below 120 g/L, hematocrit level below 39%, longer cardiopulmonary bypass time and aortic cross-clamp time, additional mitral and tricuspid valve interventions.

Experimental models of acute kidney injury for translational research

Preclinical models of human disease provide powerful tools for therapeutic discovery but have limitations. This problem is especially apparent in the field of acute kidney injury (AKI), in which clinical trial failures have been attributed to inaccurate modelling performed largely in rodents. Multidisciplinary efforts such as the Kidney Precision Medicine Project are now starting to identify molecular subtypes of human AKI. In addition, over the past decade, there have been developments in human pluripotent stem cell-derived kidney organoids as well as zebrafish, rodent and large animal models of AKI. These organoid and AKI models are being deployed at different stages of preclinical therapeutic development. However, the traditionally siloed, preclinical investigator-driven approaches that have been used to evaluate AKI therapeutics to date rarely account for the limitations of the model systems used and have given rise to false expectations of clinical efficacy in patients with different AKI pathophysiologies. To address this problem, there is a need to develop more flexible and integrated approaches, involving teams of investigators with expertise in a range of different model systems, working closely with clinical investigators, to develop robust preclinical evidence to support more focused interventions in patients with AKI.

Analysis of Risk Factors for Perioperative Acute Kidney Injury and Management Strategies

Acute kidney injury (AKI) is a serious clinical syndrome, and one of the common comorbidities in the perioperative period. AKI can lead to complications in surgical patients and is receiving increasing attention in clinical workup. In recent years, the analysis of perioperative risk factors has become more in-depth and detailed. In this review, the definition, diagnosis, and pathophysiological characteristics of perioperative AKI are reviewed, and the main risk factors for perioperative AKI are analyzed, including advanced age, gender, certain underlying diseases, impaired clinical status such as preoperative creatinine levels, and drugs that may impair renal function such as non-steroidal anti-inflammatory drugs (NASIDs), ACEI/ARB, and some antibiotics. Injectable contrast agents, some anesthetic drugs, specific surgical interventions, anemia, blood transfusions, hyperglycemia, and malnutrition are also highlighted. We also propose potential preventive and curative measures, including the inclusion of renal risk confirmation in the preoperative assessment, minimization of intraoperative renal toxin exposure, intraoperative management and hemodynamic optimization, remote ischemic preadaptation, glycemic control, and nutritional support. Among the management measures, we emphasize the need for careful perioperative clinical examination, timely detection and management of AKI complications, administration of dexmedetomidine for renal protection, and renal replacement therapy. We aim that this review can further increase clinicians' attention to perioperative AKI, early assessment and intervention to try to reduce the risk of AKI.

Size does matter: Yet BMI extremes are manageable in minimally invasive cardiac surgery

The obesity paradox has been recently challenged in the literature to spotlight a vague and ill-defined relationship between obesity extremes and cardiac morbidity and mortality. Patient size and incision size both remain important determinants of outcomes. Today, with obesity rates rising around the world, extremely obese patients require experienced teams and substantially improved care.