The association between renal recovery after acute kidney injury and long-term mortality after transcatheter aortic valve replacement

Trajectory of AKI and hospital mortality among patients with COVID-19

BACKGROUND

Acute kidney injury (AKI) in COVID-19 patients is associated with poor prognosis. Characterization of AKI by timing and trajectory and early prediction of AKI progression is required for better preventive management and the prediction of patient outcomes.

METHODS

A total of 858 patients who were hospitalized due to coronavirus disease 2019 (COVID-19) were retrospectively enrolled from December 2020 to August 2021. The occurrence of AKI was evaluated throughout hospitalization. The hazard ratios (HRs) of mortality outcomes according to the trajectory of AKI were measured using Cox regression models after adjustment for multiple variables.

RESULTS

Among 858 patients, 226 (26.3%) presented AKI at admission, and 44 (5.1%) developed AKI during hospitalization. Patients with AKI at admission or hospital-acquired AKI had a higher risk of mortality than those without AKI, with HRs of 9.87 (2.81-34.67) and 13.74 (3.57-52.84), respectively. Of 226 patients with AKI at admission, 104 (46.0%) recovered within 48 hr, 83 (36.7%) had AKI beyond 48 hr and recovered in 7 days, and 39 (17.3%) showed no recovery from AKI on Day 7. Delayed recovery and persistent AKI were significantly associated with an increased risk of mortality, with HRs of 4.39 (1.06-18.24) and 24.33 (7.10-83.36), respectively.

CONCLUSIONS

The onset and progression of AKI was significantly associated with in-hospital mortality in patients with COVID-19. A thorough observation of the recovery trajectory of early AKI after infection is necessary.

Anticipation of recovery of native renal function and liberation from renal replacement therapy in critically ill patients with severe acute kidney injury

Background

Renal replacement therapy (RRT) is used to manage critically ill patients with severe acute kidney injury (AKI-D), and it is undoubtedly life-sustaining for most patients. However, the prolonged unnecessary use of these techniques may be harmful. At present, no consensus guidelines provide specific recommendations for clinicians on when (optimal timing of discontinuation) and how (liberation or weaning) to stop RRT in intensive care unit (ICU) patients with recovering native kidney function.

Methods and results

Numerous variables such as clinical parameters, classical surrogate markers for glomerular filtration rate, novel biomarkers of kidney function and damage, and new imaging techniques in AKI-D have been described to predict successful discontinuation of RRT. Most available studies are limited by study design, heterogeneity of variable assessment and thresholds of biomarkers, and lack of prospective validation. At present, the decision on discontinuation of RRT in ICU patients is based on three clinical scenarios: (a) intrinsic kidney function (defined as spontaneous urine output > 500 ml/24 h, timed creatinine clearance > 15 to 20 ml/min) has adequately improved to match the demands and continued RRT is no longer consistent with goals of care (transition to intermittent RRT); (b) the acute illness that prompted RRT has improved; (c) the clinical practice of switching haemodynamic stable patients with persistent AKI-D from continuous RRTs to intermittent RRTs is variable, but de-escalation of RRT (frequency, dose) may facilitate mobilization and discharge of ICU patients.

Conclusions

The predictive ability of novel kidney biomarkers, surrogate markers of kidney function, and direct measurements of kidney function should be evaluated in future studies.

Development of mortality prediction model in the elderly hospitalized AKI patients

Acute kidney injury (AKI) correlates with increased health-care costs and poor outcomes in older adults. However, there is no good scoring system to predict mortality within 30-day, 1-year after AKI in older adults. We performed a retrospective analysis screening data of 53,944 hospitalized elderly patients (age > 65 years) from multi-centers in China. 944 patients with AKI (acute kidney disease) were included and followed up for 1 year. Multivariable regression analysis was used for developing scoring models in the test group (a randomly 70% of all the patients). The established models have been verified in the validation group (a randomly 30% of all the patients). Model 1 that consisted of the risk factors for death within 30 days after AKI had accurate discrimination (The area under the receiver operating characteristic curves, AUROC: 0.90 (95% CI 0.875–0.932)) in the test group, and performed well in the validation groups (AUROC: 0.907 (95% CI 0.865–0.949)). The scoring formula of all-cause death within 1 year (model 2) is a seven-variable model including AKI type, solid tumor, renal replacement therapy, acute myocardial infarction, mechanical ventilation, the number of organ failures, and proteinuria. The area under the receiver operating characteristic (AUROC) curves of model 2 was > 0.80 both in the test and validation groups. Our newly established risk models can well predict the risk of all-cause death in older hospitalized AKI patients within 30 days or 1 year.

Association between mid-term worsening renal function and mortality after transcatheter aortic valve replacement in patients with chronic kidney disease

INTRODUCTION

Chronic kidney disease (CKD), acute kidney injury (AKI) and worsening renal function at 30 days after transcatheter aortic valve replacement (TAVR) portend poor outcomes. We sought to evaluate the association between worsening renal function at 3-6 months and mortality among patients with baseline renal dysfunction undergoing TAVR.

METHODS

This is a retrospective study of patients with glomerular filtration rate (GFR) < 60 ml/min undergoing TAVR between June 2011 and March 2019 at the Regional Cardiac Catheterization Lab at Kaiser Permanente Los Angeles. Worsening renal function at 3-6 months post-TAVR was defined as: increase in serum creatinine >1.5 times compared to baseline, absolute increase of ≥0.3 mg/dl, or initiation of dialysis.

RESULTS

Of 683 patients reviewed, 176 were included in the analysis (median age 84 [IQR 79-88] years, 56% female). Of these, 27 (15.3%) had worsening renal function. AKI post-TAVR (OR 2.9, 95% CI 1.1-7.4, p = .03) and transfusion of ≥4 units red blood cells (OR 8.4, 95% CI 1.2-59, p = .03) were independent predictors of worsening renal function. Worsening renal function increased risk for mortality (HR 2.2, 95% CI 1.17-4.27, p = .015) at a median follow-up of 691 days. Those with improved/stable function with baseline GFR < 60 ml/min had comparable mortality risk to those with baseline GFR ≥ 60 ml/min (18% vs. 16.5%; HR 1.1, 95% CI 0.72-1.75, p = .62).

CONCLUSION

Among patients with baseline renal dysfunction, only 15% developed worsening renal function at 3-6 months after TAVR, which was associated with increased mortality. Predictors for worsening renal function include AKI and blood transfusions. Preventative measures peri-procedurally and continued monitoring post-discharge are warranted to improve outcomes.

Assessment of Kidney Function After Transcatheter Aortic Valve Replacement

Background:

Transcatheter aortic valve replacement (TAVR), although associated with an increased risk for acute kidney injury (AKI), may also result in improvement in renal function.

Objective:

The aim of this study is to evaluate the magnitude of kidney function improvement (KFI) after TAVR and to assess its significance on long-term mortality.

Design:

This is a prospective single center study.

Setting:

The study was conducted in cardiology department, interventional unit, in a tertiary hospital.

Patients:

The cohort included 1321 patients who underwent TAVR.

Measurements:

Serum creatinine level was measured at baseline, before the procedure, and over the next 7 days or until discharge.

Methods:

Kidney function improvement was defined as the mirror image of AKI, a reduction in pre-procedural to post-procedural minimal creatinine of more than 0.3 mg/dL, or a ratio of post-procedural minimal creatinine to pre-procedural creatinine of less than 0.66, up to 7 days after the procedure. Patients were categorized and compared for clinical endpoints according to post-procedural renal function change into 3 groups: KFI, AKI, or preserved kidney function (PKF). The primary endpoint was long-term all-cause mortality.

Results:

The incidence of KFI was 5%. In 55 out of 66 patients patients, the improvement in kidney function was minor and of unclear clinical significance. Acute kidney injury occurred in 19.1%. Estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m² was a predictor of KFI after multivariable analysis (odds ratio = 0.93 to develop KFI; confidence interval [95% CI]: 0.91-0.95, P < .001). Patients in the KFI group had a higher Society of Thoracic Surgery (STS) score than other groups. Mortality rate did not differ between KFI group and PKF group (43.9% in KFI group and 33.8% in PKF group) but was significantly higher in the AKI group (60.7%, P < .001).

Limitations:

The following are the limitations: heterozygous definitions of KFI within different studies and a single center study. Although data were collected prospectively, analysis plan was defined after data collection.

Conclusions:

Improvement in kidney function following TAVR was not a common phenomenon in our cohort and did not reduce overall mortality rate.

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.

Diagnostics, Risk Factors, Treatment and Outcomes of Acute Kidney Injury in a New Paradigm

Acute kidney injury (AKI) is a common clinical condition among patients admitted in the hospitals. The condition is associated with both increased short-term and long-term mortality. With the development of a standardized definition for AKI and the acknowledgment of the impact of AKI on patient outcomes, there has been increased recognition of AKI. Two advances from past decades, the usage of computer decision support and the discovery of AKI biomarkers, have the ability to advance the diagnostic method to and further management of AKI. The increasingly widespread use of electronic health records across hospitals has substantially increased the amount of data available to investigators and has shown promise in advancing AKI research. In addition, progress in the finding and validation of different forms of biomarkers of AKI within diversified clinical environments and has provided information and insight on testing, etiology and further prognosis of AKI, leading to future of precision and personalized approach to AKI management. In this this article, we discussed the changing paradigms in AKI: from mechanisms to diagnostics, risk factors, and management of AKI.

Acute kidney injury in hospitalized children: consequences and outcomes

Over the past decade, the nephrology and critical care communities have adopted a consensus approach to diagnosing acute kidney injury (AKI) and, as a result, we have seen transformative changes in our understanding of pediatric AKI epidemiology. The data regarding outcomes among neonates and children who develop AKI have become far more robust and AKI has been clearly linked with an increased need for mechanical ventilation, longer inpatient stays, and higher mortality. Though AKI was historically thought to be self-limited, we now know that renal recovery is far from universal, particularly when AKI is severe; the absence of recovery from AKI also carries longitudinal prognostic implications. AKI survivors, especially those without full recovery, are at risk for chronic renal sequelae including proteinuria, hypertension, and chronic kidney disease. This review comprehensively describes AKI-related outcomes across the entire pediatric age spectrum, using the most rigorous studies to identify the independent effects of AKI events.

Acute Kidney Injury in Patients Undergoing Cardiac Transplantation: A Meta-Analysis

Background: Acute kidney injury (AKI) is a common complication following solid-organ transplantation. However, the epidemiology of AKI and mortality risk of AKI among patients undergoing cardiac transplantation is not uniformly described. We conducted this study to assess the incidence of AKI and mortality risk of AKI in adult patients after cardiac transplantation. Methods: A systematic review of EMBASE, MEDLINE, and Cochrane Databases was performed until June 2019 to identify studies evaluating the incidence of AKI (by standard AKI definitions), AKI requiring renal replacement therapy (RRT), and mortality risk of AKI in patients undergoing cardiac transplantation. Pooled AKI incidence and mortality risk from the included studies were consolidated by random-effects model. The protocol for this study is registered with PROSPERO (no. CRD42019134577). Results: 27 cohort studies with 137,201 patients undergoing cardiac transplantation were identified. Pooled estimated incidence of AKI and AKI requiring RRT was 47.1% (95% CI: 37.6-56.7%) and 11.8% (95% CI: 7.2-18.8%), respectively. The pooled ORs of hospital mortality and/or 90-day mortality among patients undergoing cardiac transplantation with AKI and AKI requiring RRT were 3.46 (95% CI, 2.40-4.97) and 13.05 (95% CI, 6.89-24.70), respectively. The pooled ORs of 1-year mortality among patients with AKI and AKI requiring RRT were 2.26 (95% CI, 1.56-3.26) and 3.89 (95% CI, 2.49-6.08), respectively. Conclusion: Among patients undergoing cardiac transplantation, the incidence of AKI and severe AKI requiring RRT are 47.1% and 11.8%, respectively. AKI post cardiac transplantation is associated with reduced short term and 1-year patient survival.