Acute kidney injury following surgical aortic valve replacement

Early Creatinine Changes After Aortic Valve Replacement and Late Survival, Heart Failure, and Chronic Kidney Disease in a National Registry

BACKGROUND

The impact of small increases in serum creatinine after surgical aortic valve replacement (SAVR) that fail to meet the acute kidney injury stage 1 criteria is unknown. The aim of this study was to investigate prognosis after primary SAVR in patients with small increases in postoperative serum creatinine.

METHODS

This observational cohort study included all adult patients who underwent primary SAVR in Sweden from 2009 to 2022. The primary outcome was all-cause mortality. Secondary outcomes were chronic kidney disease and heart failure. Regression standardization addressed confounding.

RESULTS

In 16,766 patients, 4074 (24.2%) had no change in postoperative serum creatinine, 5764 (34.3%) had a small increase in postoperative serum creatinine (0.06 mg/dL ≤ Δserum creatinine <0.3 mg/dL), and 2753 (16.4%) fulfilled the Kidney Disease Improving Global Outcomes acute kidney injury stage 1 criteria. The mean age was 67 years, and 31% of patients were female. No significant difference in long-term all-cause mortality was observed in the no change group at 13 years compared with the small increase group (absolute survival difference, 2.3% [95% CI, 0%-4.6%]). A stepwise increase in the risk of 30-day mortality was observed with increasing changes in serum creatinine. At 13 years of follow-up, there was a significant difference in the risk of chronic kidney disease (absolute difference, 2.8% [95% CI, 1.0%-4.5%]) and heart failure (absolute difference, 3.5% [95% CI, 1.3%-5.7%]) between the no change and small increase groups.

CONCLUSIONS

A small increase in postoperative serum creatinine after SAVR was associated with an increased risk of adverse outcomes. The acute kidney injury definition may benefit from including more reliable and specific biomarkers together with small creatinine increases to detect kidney injury.

Association between the intraoperative fluid balance during cardiac surgery and postoperative sequential organ failure assessment score: a post hoc analysis of the BROTHER study, a retrospective multicenter cohort study

Although intraoperative intravenous fluids are commonly administered to reverse intraoperative hypotension during cardiac surgery, the appropriate volume remains unclear. This study aimed to evaluate the relationship between the intraoperative fluid balance and sequential organ failure assessment (SOFA) score in patients undergoing cardiac surgery to determine the impact of intraoperative intravenous fluids on their organs. This was a post hoc analysis using data from a multicenter, retrospective, observational study across 14 intensive care units (ICUs) in Japan. Adult patients admitted to ICUs after elective coronary artery bypass grafting or valve surgery from January 1 to December 31, 2018 were enrolled. We compared patients with intraoperative fluid balance < 20 ml/kg to those with fluid balance ≥ 20 ml/kg and conducted a multiple regression analysis for the SOFA score within 24 h of ICU admission. Of the 1567 included patients, 870 met the eligibility criteria. A total of 725 patients (83%) had an intraoperative fluid balance of ≥ 20 ml/kg. In the univariate analysis, the SOFA score (interquartile range) was 7 (6-8) and 7 (6-9) in the intraoperative fluid balance < 20 ml/kg and ≥ 20 ml/kg groups, respectively (p = 0.017). Multiple regression analysis showed a positive association between intraoperative fluid balance and SOFA score within 24 h of ICU admission [standardized coefficient 0.0065 (95% confidence interval 0.0036-0.0095), p < 0.001]. Intraoperative fluid balance in patients undergoing cardiac surgery was significantly associated with higher SOFA scores within 24 h of ICU admission.

Transcatheter aortic valve implantation versus surgical aortic valve replacement in dialysis-dependent patients: a meta-analysis

OBJECTIVES

This meta-analysis aims to compare the clinical outcomes of transcatheter aortic valve implantation (TAVI) versus aortic valve replacement (AVR) for aortic stenosis in dialysis-dependent patients.

METHODS

Literature searches employed PubMed, Web of Science, Google Scholar and Embase to identify relevant studies. Bias-treated data were prioritized, isolated and pooled for analysis; raw data were utilized where bias-treated data were unavailable. Outcomes were analysed to assess for study data crossover.

RESULTS

Literature search identified 10 retrospective studies; following data source analysis, five studies were included. Upon pooling of bias-treated data, TAVI was significantly favoured in early mortality [odds ratio (OR), 0.42; 95% confidence interval (95% CI), 0.19-0.92; I2  = 92%; P  = 0.03], 1-year mortality (OR, 0.88; 95% CI 0.80-0.97; I2  = 0%; P  = 0.01), rates of stroke/cerebrovascular events (OR, 0.71; 95% CI 0.55-0.93; I2  = 0%; P  = 0.01) and blood transfusions (OR, 0.36; 95% CI 0.21-0.62; I2  = 86%; P  = 0.0002). Pooling demonstrated fewer new pacemaker implantations in the AVR group (OR, 3.33; 95% CI 1.94-5.73; I2  = 74%; P  ≤ 0.0001) and no difference in the rate of vascular complications (OR, 2.27; 95% CI 0.60-8.59; I2  = 83%; P  = 0.23). Analysis including raw data revealed the length of hospital stay to favour TAVI with a mean difference of -9.20 days (95% CI -15.58 to -2.82; I2  = 97%; P  = 0.005).

CONCLUSION

Bias-treated meta-analysis comparing surgical AVR and TAVI favoured TAVI in early mortality, 1-year mortality, rates of stroke/cerebrovascular events and blood transfusions. There was no difference in the rates of vascular complications; however, TAVI required more pacemaker implantations. Data pooling including raw data revealed that the length of hospital admission favours TAVI.

Kidney Injury after Cardiac Surgery: Prevention-Associated Cost Reduction

INTRODUCTION

Cardiac surgery may induce acute kidney injury and the need for renal replacement therapy. It is also associated with higher hospital costs, morbidity and mortality. The aims of this study were to investigate predictors of cardiac surgery associated acute kidney injury in our population and to determine the burden of acute kidney injury in elective cardiac surgery, evaluating the potential cost effectiveness of preventing it through the application of the Kidney Disease: Improving Global Outcomes bundle of care to high-risk patient groups identified by the [TIMP-2]x[IGFBP7] used as a screening test.

MATERIAL AND METHODS

In a University Hospital single-center retrospective cohort study we analyzed a consecutive sample of adults who underwent elective cardiac surgery between January and March 2015. A total of 276 patients were admitted during the study period. Data from all patients was analyzed until hospital discharge or the patient's death. The economic analysis was performed from the hospital costs' perspective.

RESULTS

Cardiac surgery associated acute kidney injury occurred in 86 patients (31%). After adjustment, higher preoperative serum creatinine (mg/L, ORadj = 1.09; 95% CI: 1.01 - 1.17), lower preoperative hemoglobin (g/dL, ORadj = 0.79; 95% CI: 0.67 - 0.94), chronic systemic hypertension (ORadj = 5.00; 95% CI: 1.67 - 15.02), an increase in cardiopulmonary bypass time (min, ORadj = 1.01; 95% CI: 1.00 - 1.01) and perioperative use of sodium nitroprusside (ORadj = 6.33; 95% CI: 1.80 - 22.28) remained significantly associated with cardiac surgery related acute kidney injury. The expected cumulative surplus cost for the hospital linked with cardiac surgery associated acute kidney injury (86 patients) was €120 695.84. Based on a median absolute risk reduction of 16.6%, by dosing kidney damage biomarkers in every patient and using preventive measures in high-risk patients, we would expect a break-even point upon screening 78 patients, which would translate, in our patient cohort, into an overall cost benefit of €7145.

CONCLUSION

Preoperative hemoglobin, serum creatinine, systemic hypertension, cardiopulmonary bypass time and perioperative use of sodium nitroprusside were independent predictors of cardiac surgery associated acute kidney injury. Our cost-effectiveness modelling suggests that the use of kidney structural damage biomarkers combined with an early prevention strategy could be associated with potential cost savings.

Impact of postoperative acute kidney injury on short-term outcomes of patients with Bentall surgery for any reason

BACKGROUND

Acute kidney injury (AKI) after cardiac surgery is a well-known risk factor for increased postoperative mortality and morbidity. The effect of postoperative developed AKI on postoperative outcomes in patients after Bentall procedure has been incompletely investigated. The present study was dedicated to assessing the impact of postoperative AKI on morbidity and 30-day mortality in this specific cohort.

METHODS

In a retrospective observational study, we investigated 249 patients undergoing Bentall procedure from January 2014 to March 2018 at the University Hospital of Cologne, Germany. After excluding patients with preoperative renal impairment, patients were divided into an AKI group (n = 88) and a non-AKI group (n = 97). Postoperative outcomes and 30-day mortality were analyzed using univariate regression analysis. AKI was defined by AKIN criteria.

RESULTS

Mortality during ICU and hospital stay, as well as 30-day mortality, was significantly higher in the AKI group (all p < 0.001). Patients with postoperative developed AKI revealed 9.3-fold higher odds for ICU mortality and 6.7-fold higher odds for 30-day mortality in comparison to non-AKI group (all p < 0.004) as well as 4.5-fold higher odds for stroke. Coronary artery bypass time, as well as cross-clamp time, were similarly distributed between groups, whereas incidences of postoperative bleeding, myocardial infarction, and need for rethoracotomy occurred significantly more often in patients with postoperatively developed AKI (all p < 0.04).

CONCLUSION

Patients undergoing Bentall surgery who postoperatively developed AKI showed significantly higher morbidity and mortality. AKI points out to be an early predictor for poor outcomes. Thus, as a consequence, patients with postoperatively developed AKI should be highly monitored for immediate intervention.

Early recognition of cardiac surgery-associated acute kidney injury: lack of added value of TIMP2 IGFBP7 over short-term changes in creatinine (an observational pilot study)

Background

For the detection of cardiac surgery-associated acute kidney injury (CS-AKI), the performance of urine tissue inhibitor of metalloproteinase 2 insulin-like growth factor-binding protein 7 (TIMP2 IGFBP7) has never been compared with that of very early changes in plasma creatinine (∆pCr). We hypothesized that, in the context of perioperative haemodilution, lack of postoperative decrease in pCr would be of honourable performance for the detection of CS-AKI. We therefore aimed at comparing these biomarkers and their kinetics (primary objective). As secondary objectives, we assessed plasma neutrophil gelatinase-associated lipocalin (pNGAL), cystatin C (pCysC) and urea (pUrea). We also determined the ability of these biomarkers to early discriminate persistent from transient CS-AKI.

Methods

Patients over 75 years-old undergoing aortic valve replacement with cardiopulmonary bypass (CPB) were included in this prospective observational study. Biomarkers were measured before/after CPB and at the sixth postoperative hour (H6).

Results

In 65 patients, CS-AKI occurred in 27 (42%). ∆pCr from post-CPB to H6 (∆pCr_postCPB-H6): outperformed TIMP2 IGFBP7 at H6 and its intra- or postoperative changes: area under the receiver operating characteristic curve (AUC_ROC) of 0.84 [95%CI:0.73–0.92] vs. ≤0.67 [95%CI:0.54–0.78], p ≤ 0.03. The AUC_ROC of pNGAL, pCysC and pUrea did not exceed 0.72 [95%CI:0.59–0.83]. Indexing biomarkers levels for blood or urine dilution did not improve their performance. Combining TIMP2 IGFBP7 and ∆pCr_postCPB-H6 was of no evident added value over considering ∆pCr_postCPB-H6 alone. For the early recognition of persistent CS-AKI, no biomarker outperformed ∆pCr_postCPB-H6 (AUC_ROC = 0.69 [95%CI:0.48–0.85]).

Conclusions

In this hypothesis-generating study mostly testing early detection of mild CS-AKI, there was no evident added value of the tested modern biomarkers over early minimal postoperative changes in pCr: despite the common perioperative hemodilution in the setting of cardiac surgery, if pCr failed to decline within the 6 h after CPB, the development of CS-AKI was likely. Confirmatory studies with more severe forms of CS-AKI are required.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-021-01387-6.

Brain and Muscle Oxygen Saturation Combined with Kidney Injury Biomarkers Predict Cardiac Surgery Related Acute Kidney Injury

Background: Early identification of patients at risk for cardiac surgery-associated acute kidney injury (CS-AKI) based on novel biomarkers and tissue oxygen saturation might enable intervention to reduce kidney injury. Aims: The study aimed to ascertain whether brain and muscle oxygenation measured by near-infrared spectroscopy (NIRS), in addition to cystatin C and NGAL concentrations, could help with CS-AKI prediction. Methods: This is a single-centre prospective observational study on adult patients undergoing cardiac surgery using cardiopulmonary bypass (CPB). Brain and muscle NIRS were recorded during surgery. Cystatin C was measured on the first postoperative day, while NGAL directly before and 3 h after surgery. Results: CS-AKI was diagnosed in 18 (16%) of 114 patients. NIRS values recorded 20 min after CPB (with cut-off value ≤ 54.5% for muscle and ≤ 62.5% for the brain) were revealed to be the most accurate predictors of CS-AKI. Preoperative NGAL ≥ 91.5 ng/mL, postoperative NGAL ≥ 140.5 ng/mL, and postoperative cystatin C ≥ 1.23 mg/L were identified as independent and significant CS-AKI predictors. Conclusions: Brain and muscle oxygen saturation 20 min after CPB could be considered early parameters possibly related to CS-AKI risk, especially in patients with increased cystatin C and NGAL levels.

Impact of pre-existing comorbidities on outcomes of patients undergoing surgical aortic valve replacement - rationale and design of the international IMPACT registry

Background

Degenerative aortic valve disease accounts for 10–20% of all cardiac surgical procedures. The impact of pre-existing comorbidities on the outcome of patients undergoing surgical aortic valve replacement (SAVR) needs further research.

Methods

The IMPACT registry is a non-interventional, prospective, open-label, multicenter, international registry with a follow-up of 5 years to assess the impact of pre-existing comorbidities of patients undergoing SAVR with the INSPIRIS RESILIA aortic valve on outcomes. IMPACT will be conducted across 25 sites in Austria, Germany, The Netherlands and Switzerland and intends to enroll approximately 500 patients. Patients will be included if they are at least 18 years of age and are scheduled to undergo SAVR with the INSPIRIS RESILIA Aortic Valve with or without concomitant ascending aortic root replacement and/or coronary bypass surgery. The primary objective is to determine all-cause mortality at 1, 3, and 5 years post SAVR. Secondary objectives include cardiac-related and valve-related mortality and structural valve deterioration including hemodynamics and durability, valve performance and further clinical outcomes in the overall study population and in specific patient subgroups characterized by the presence of chronic kidney disease, hypertension, metabolic syndrome and/or chronic inflammation.

Discussion

IMPACT is a prospective, multicenter European registry, which will provide much-needed data on the impact of pre-existing comorbidities on patient outcomes and prosthetic valve performance, and in particular the performance of the INSPIRIS RESILIA, in a real-world setting. The findings of this study may help to support and expand appropriate patient selection for treatment with bioprostheses.

Trial registration

ClinicalTrials.gov identifier: NCT04053088.

Development and validation of a model for predicting acute kidney injury after cardiac surgery in patients of advanced age

Objective

To develop a clinical model for predicting postoperative acute kidney injury (AKI) in patients of advanced age undergoing cardiac surgery.

Methods

A total of 848 patients (aged ≥ 60 years) undergoing cardiac surgery were consecutively enrolled. Among them, 597 were randomly selected for the development set and the remaining 251 for the validation set. AKI was the primary outcome. To develop a model for predicting AKI, visualized as a nomogram, we performed logistic regression with variables selected by Lasso regression analysis. The discrimination, calibration, and clinical usefulness of the new model were assessed and compared with those of Cleveland Clinic score and Simplified Renal Index (SRI) score in the validation set.

Results

The incidence of AKI was 61.8% in the development set. The new model included seven variables including preoperative serum creatinine, hypertension, preoperative uric acid, New York Heart Association classification ≥ 3, cardiopulmonary bypass time > 120 min, intraoperative red blood cell transfusion, and postoperative prolonged mechanical ventilation. In the validation set, the areas under the receiver operating characteristic curves for assessing discrimination of the new model, Cleveland Clinic score, and SRI score were 0.801, 0.670, and 0.627, respectively. Compared with the other two scores, the new model presented excellent calibration according to the calibration curves. Decision curve analysis presented the new model was more clinically useful than the other two scores.

Conclusions

We developed and validated a new model for predicting AKI after cardiac surgery in patients of advanced age, which may help clinicians assess patients' risk for AKI.

Predicting Acute Kidney Injury after Cardiac Surgery by Machine Learning Approaches

Cardiac surgery-associated AKI (CSA-AKI) is common after cardiac surgery and has an adverse impact on short- and long-term mortality. Early identification of patients at high risk of CSA-AKI by applying risk prediction models allows clinicians to closely monitor these patients and initiate effective preventive and therapeutic approaches to lessen the incidence of AKI. Several risk prediction models and risk assessment scores have been developed for CSA-AKI. However, the definition of AKI and the variables utilized in these risk scores differ, making general utility complex. Recently, the utility of artificial intelligence coupled with machine learning, has generated much interest and many studies in clinical medicine, including CSA-AKI. In this article, we discussed the evolution of models established by machine learning approaches to predict CSA-AKI.

Impacto do controle glicêmico intensivo na lesão renal aguda: ensaio clínico randomizado

Resumo Objetivo Avaliar o impacto do controle glicêmico intensivo na redução da incidência de lesão renal aguda em pacientes adultos submetidos à cirurgia cardíaca. Métodos Ensaio clínico randomizado que avaliou 95 pacientes submetidos a duas estratégias de controle glicêmico. Os pacientes foram randomizados para o grupo intervenção (GI), com a meta de manutenção da glicemia pós-operatória entre 90 e 110 mg/dl. Nos pacientes alocados no grupo convencional (GC) o objetivo era a manutenção da glicemia entre 140 e 180 mg/dl. O ajuste da dose de insulina foi baseado em medições de glicose no sangue arterial não diluído, em intervalos de uma hora por meio de um sistema de monitoramento de glicose e beta-cetona no sangue. Resultados A incidência de LRA foi de 53,7% (KDIGO estágios 1, 2 ou 3). Não houve diferença significante entre os grupos quanto ao desfecho primário (p=0,294). Entretanto, observou-se maior frequência de recuperação da função renal (p=0,010), na alta da UTI (p=0,028) e alta hospitalar (p=0,048) entre os pacientes submetidos ao controle glicêmico convencional. A utilização do controle glicêmico intensivo esteve associada com maior tempo de permanência na UTI (p=0,031). O número de episódios de hipoglicemia foi semelhante nos dois grupos (1,6 ± 0,9 vs. 1,3 ± 0,6, p=0,731), demonstrando a segurança das estratégias utilizadas. Conclusão Não se observou o impacto do controle glicêmico intensivo na redução da incidência de lesão renal aguda. Em contrapartida, os pacientes tratados no GC apresentaram maior frequência de recuperação da função renal.

TAVR-present, future, and challenges in developing countries

Transcatheter aortic valve replacement (TAVR) has become a well-established therapy for inoperable and high-risk patients of Aortic Stenosis in most of the part of the world. The technological advancements in the hemodynamic performance and design of valve prosthesis and also the data provided by various trials regarding the safety and efficacy of TAVR have widened the scope of TAVR in intermediate and low-risk groups also. The main focus of this review is to discuss the feasibility of TAVR in developing countries. Along with this review, it also gives a detailed outlook of the pros and cons of TAVR along with insight into the future of TAVR and its adoption into the low-risk group.

In-hospital outcomes of transcatheter versus surgical aortic valve replacement for nonagenarians

OBJECTIVES

To compare the in-hospital outcomes of transcatheter aortic valve replacement (TAVR) versus surgical aortic valve replacement (SAVR) in nonagenarians.

BACKGROUND

Data comparing the outcomes of TAVR versus SAVR in nonagenarians are limited.

METHODS

Using the National Inpatient Sample years 2012-2014, hospitalization data were retrieved for subjects aged ≥90 years who underwent TAVR or SAVR for severe aortic stenosis. The incidence of in-hospital mortality and peri-procedural outcomes were compared using unadjusted, multivariate logistic regression, and propensity score matched analyses.

RESULTS

The final cohort included 6,680 records of nonagenarians undergoing aortic valve replacement, among which 5,840 (87.4%) underwent TAVR. There was no difference in the incidence of in-hospital mortality between both groups in the unadjusted (5.8% versus 6.0% P = 0.95), multivariate (odds ratio [OR] 0.78, 95% confidence interval [CI] 0.35-1.74), and propensity score matched (OR 1.07, 95% CI 0.75-1.51) analyses. In the propensity-matched analysis, TAVR was associated with a lower incidence of acute kidney injury (OR 0.58, 95% CI 0.47-0.72), post-operative blood transfusion (OR 0.51, 95% CI 0.43-0.61), a higher likelihood of discharge to home (OR 4.71, 95% 3.44-5.06), and a similar incidence of pacemaker placement (OR 1.16, 95% 0.89-1.53) and stroke (OR 1.34, 0.90-1.99).

CONCLUSIONS

In this nationwide analysis, TAVR was associated with an overall similar incidence of in-hospital mortality and less morbidity compared with SAVR. These findings suggest that TAVR is effective and safe in nonagenarians.

Acute kidney injury post-transcatheter aortic valve replacement

Transcatheter aortic valve replacement (TAVR) is a treatment option in high-risk patients with severe aortic stenosis who are not surgical candidates. In light of emerging evidence, it is being increasingly performed even in intermediate-risk patients in recent years. Patients who develop acute kidney injury (AKI) following TAVR are known to have worse outcomes. The objective of this concise review was to identify the prevalence and the impact of AKI following TAVR on patient outcomes by including the most recent literature in our search. After a thorough search on MEDLINE, Google Scholar, and PubMed, we included all literature relevant to AKI following TAVR. We found that AKI was caused by a variety of reasons, such as hemodynamic instability during rapid pacing, blood transfusion, periprocedural embolization, and use of contrast medium, to name a few. In patients who developed AKI following TAVR, 30-day and 1-year mortality were increased. Further, in these patients, length and cost of hospital stay were increased as well. Preventive measures such as optimal periprocedural hydration, careful contrast use, and techniques to prevent embolization during device implantation have been tried with limited success. Given that TAVR is expected to be increasingly performed, this review aimed to summarize the rapidly expanding currently available literature in an effort to reduce procedural complications and thereby improve patient outcomes.

Pros and cons of transcatheter aortic valve implantation (TAVI)

Transcatheter aortic valve implantation (TAVI) or replacement (TAVR) was recently approved by the FDA for intermediate risk patients with severe aortic stenosis (AS). This technique was already worldwide adopted for inoperable and high-risk patients. Improved device technology, imaging analysis and operator expertise has reduced the initial worrisome higher complications rate associated with TAVR, making it comparable to surgical aortic valve replacement (SAVR). However, many answers need to be addressed before adoption in lower risk patients. This paper highlights the pros and cons of TAVI based mostly on randomized clinical trials involving the two device platforms approved in the United States. We focused our analysis on metrics that will play a key role in expanding TAVR indication in healthier individuals. We review the significance and gave a perspective on paravalvular leak (PVL), valve performance, valve durability, leaflet thrombosis, stroke and pacemaker requirement.