Frailty as a Predictor of Acute Kidney Injury in Hospitalized Elderly Patients: A Single Center, Retrospective Cohort Study

National clinical and financial outcomes associated with acute kidney injury following esophagectomy for cancer

BACKGROUND

Esophagectomy is a complex oncologic operation associated with high rates of postoperative complications. While respiratory and septic complications have been well-defined, the implications of acute kidney injury (AKI) remain unclear. Using a nationally representative database, we aimed to characterize the association of AKI with mortality, resource use, and 30-day readmission.

METHODS

All adults undergoing elective esophagectomy with a diagnosis of esophageal or gastric cancer were identified in the 2010-2019 Nationwide Readmissions Database. Study cohorts were stratified based on presence of AKI. Multivariable regressions and Royston-Parmar survival analysis were used to evaluate the independent association between AKI and outcomes of interest.

RESULTS

Of an estimated 40,438 patients, 3,210 (7.9%) developed AKI. Over the 10-year study period, the incidence of AKI increased from 6.4% to 9.7%. Prior radiation/chemotherapy and minimally invasive operations were associated with reduced odds of AKI, whereas public insurance coverage and concurrent infectious and respiratory complications had greater risk of AKI. After risk adjustment, AKI remained independently associated with greater odds of in-hospital mortality (AOR: 4.59, 95% CI: 3.62-5.83) and had significantly increased attributable costs ($112,000 vs $54,000) and length of stay (25.7 vs 13.3 days) compared to patients without AKI. Furthermore, AKI demonstrated significantly increased hazard of 30-day readmission (hazard ratio: 1.16, 95% CI: 1.01-1.32).

CONCLUSIONS

AKI after esophagectomy is associated with greater risk of mortality, hospitalization costs, and 30-day readmission. Given the significant adverse consequences of AKI, careful perioperative management to mitigate this complication may improve quality of esophageal surgical care at the national level.

Acute Kidney Injury After Pulmonary Thromboendarterectomy: Associated Factors and Impact

BACKGROUND

Acute kidney injury (AKI) is a common complication after pulmonary thromboendarterectomy (PTE) that has been shown to be associated with worse outcomes. Our study assesses factors associated with the development of postoperative AKI after PTE and its impact on clinical outcomes.

METHODS

We retrospectively analyzed 247 patients who underwent PTE at our institution between June 2009 and December 2020. Baseline characteristics, risk factors, and outcomes were compared between patients with and without postoperative AKI. The primary endpoint was development of postoperative AKI using the Kidney Disease Improving Global Outcomes definition, and secondary endpoints were length of hospital stay, hospital mortality, and 5-year mortality.

RESULTS

The overall incidence of postoperative AKI in our study population was 49%. One hundred twenty-three patients (50.8%) did not develop AKI postoperatively, 87 patients (35.9%) developed stage 1 AKI postoperatively, 21 patients (8.7%) developed stage 2 AKI postoperatively, and 11 (4.5%) developed stage 3 AKI postoperatively. Patients who developed AKI postoperatively had longer hospital stays, higher in-hospital mortality rates, and higher 5-year mortality rates than patients who did not develop postoperative AKI. Higher body mass index, older age, low preoperative hemoglobin, low ejection fraction, and low creatinine were shown to be associated with postoperative AKI development.

CONCLUSIONS

Patients who developed AKI after PTE had worse mortality and morbidity. Clinicians should have a lower threshold for suspecting AKI and consider implementing Kidney Disease Improving Global Outcomes-based AKI prevention bundles for patients with factors associated with development of AKI.

Predictors and outcomes of acute kidney injury after bariatric surgery: analysis of the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program data registry

BACKGROUND

Acute kidney injury (AKI) after surgery increases long-term risk of kidney dysfunction. The major risk factor for AKI after bariatric surgery is having preoperative renal insufficiency. Little is known about the outcomes and risk factors for developing AKI in patients undergoing bariatric surgery with normal renal function.

OBJECTIVE

We aimed to describe factors that may increase risk of AKI after primary bariatric surgery in patients without history of kidney disease.

SETTING

Academic hospital, United States.

METHODS

We performed a retrospective analysis of the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program data registry for patients aged ≥18 years undergoing laparoscopic sleeve gastrectomy and laparoscopic Roux-en-Y gastric bypass (LRYGB) from 2015 to 2019. Patients with diagnosis of chronic kidney disease were excluded. The primary outcome was incidence of AKI. Secondary outcomes included 30-day complications, readmissions, reoperations, and mortality. Univariate and multivariate analyses were performed to identify differences between patients with and without AKI.

RESULTS

A total of 747,926 patients were included in our analysis (laparoscopic sleeve gastrectomy = 73.1%, LRYGB = 26.8%). Mean age was 44.40 ± 11.94 years, with female predominance (79.7%). AKI occurred in 446 patients (.05%). Patients with postoperative AKI had higher rates of complications, readmissions, reoperations, and mortality. Significant predictors of AKI were male sex, history of venous thromboembolism, hypertension, limitation for ambulation, and LRYGB. High albumin levels and White race were protective factors.

CONCLUSIONS

New-onset AKI was associated with adverse 30-day outcomes in patients undergoing bariatric surgery. Male sex, venous thromboembolism, hypertension, limited ambulation, and LRYGB were independent predictors of AKI. Prospective studies are needed to better describe these results.

Prediction of worsening postoperative renal function in older candidates to elective cardiac surgery: Choosing the best eGFR formula may not be enough

BACKGROUND

Though renal impairment is highly prevalent in older patients and influence post-operative outcomes in cardiac surgery; its prognostic relevance is debated and not fully assessed by surgical risk scores.

OBJECTIVE

We investigated the predictive role of estimated glomerular filtration rate formulas for in-hospital worsening renal function (WRF) after cardiac surgery.

METHODS

We prospectively enrolled in single-center cohort study, patients aged ≥ 75 years candidate to elective cardiac surgery. Four creatinine-based equations were used to calculate estimated glomerular filtration rate (eGFR) formulas: Cockroft-Gault, Modification of Diet in Renal Disease, Chronic Kidney Disease Epidemiology, and Berlin Initiative Study 1 formulas. Each patient underwent geriatric and clinical evaluation before surgery with calculation of the Society of Thoracic Surgeons scores. In-hospital WRF was defined as a composite of an increase in SCr ≥0.5 mg/dl or the occurrence of grade III KDIGO acute kidney injury. The association between each eGFR equation, alone and in models including clinical variables, and WRF was analyzed using logistic regressions and ROC analysis.

RESULTS

WRF occurred in 69 patients (19.8%), and the predictors of WRF were previous acute myocardial infarction, hypertension, 4-mt gait speed performance, and preoperative eGFR, irrespective of the equation used. With all equations, inclusion of these additional variables in the logistic regression models improved the prediction of WRF (AUCs 0.798-0.810).

CONCLUSIONS

An accurate assessment of renal function and of physical performance should be incorporated into cardiac surgery risk scores to improve prediction of in-hospital WRF and, hence, risk stratification in older adults undergoing elective cardiac surgery.

Advances of perioperative acute kidney injury in elderly patients undergoing non-cardiac surgery

The risk of developing perioperative acute kidney injury (AKI) in elderly patients increases with age. The combined involvement of aging kidneys, coexisting multiple underlying chronic diseases, and increased exposure to potential renal stressors and nephrotoxic drugs or invasive procedures constitute susceptibility factors for AKI in elderly patients. The perioperative AKI in elderly patients undergoing noncardiac surgery has its own specific population characteristics, so it is necessary to further explore the characteristics of AKI in elderly patients in terms of epidemiology, clinical diagnosis, risk factors, and preventive and curative measures to provide meaningful clinical advice to improve prognosis, accelerate recovery, and reduce medical burden in elderly patients. Since AKI has the fastest-growing incidence in older patients and is associated with a worse prognosis, early detection, early diagnosis, and prevention of AKI are important for elderly patients in the perioperative period. Large, multicenter, randomized controlled clinical studies in elderly non-cardiac surgery patients with AKI can be conducted in the future, with the aim of providing the evidence to reduce of the incidence of AKI and to improve the prognosis of patients.

Is It Time to Integrate Frailty Assessment in Onconephrology?

Simple Summary

There are an increasing number of older people living with kidney cancer and/or cancer and kidney disease worldwide, sparking a wider discussion on the impact of frailty and the clinical significance of conducting frailty assessments for this patient population. We provide an update on the current evidence related to frailty assessment in onconephrology and identify areas where further research efforts are anticipated to address knowledge gaps within this topic.

Abstract

Onconephrology has emerged as a novel sub-specialty of nephrology dedicated to the intersection between the kidney and cancer. This intersection is broad and includes a number of important areas of focus, including concurrent chronic kidney disease (CKD) and cancer, acute kidney complications of cancer, and cancer-treatment-induced nephrotoxicity. The importance of onconephrology is even more evident when considering the global growth in the population of older adults, many of whom are living with some degree of frailty. Furthermore, a considerable proportion of older adults have CKD (some of whom eventually progress to kidney failure) and are at high risk of developing solid tumour and hematologic malignancies. Specific to kidney disease, the association between frailty status and kidney disease has been explored in depth, and tools to capture frailty can be used to guide the management and prognostication of older adults living with kidney failure. Whilst there is emerging data regarding the assessment and impact of frailty in onconephrology, there remains a relative paucity of knowledge within this topic. In this article, we evaluate the definition and operationalization of frailty and discuss the significance of frailty within onconephrology. We review evidence on current approaches to assessing frailty in onconephrology and discuss potential developments and future directions regarding the utilization of frailty in this patient population. A greater awareness of the intersections and interactions between frailty and onconephrology and further efforts to integrate frailty assessment in onconephrology to optimize the delivery of realistic and goal-directed management strategies for patients is needed.

Poor nutritional status and frailty associated with acute kidney injury after cardiac surgery: A retrospective observational study

BACKGROUND

Acute kidney injury (AKI) is a major determinant of short- and long-term morbidity and mortality following cardiac surgery. The present study examines the effect of preoperative nutritional status and frailty on this significant adverse event.

METHODS

The data of 455 patients who underwent on-pump coronary artery bypass grafting (CABG) were analyzed retrospectively. Demographic data were recorded, and intraoperative and postoperative parameters, frailty score, geriatric nutritional risk index (GNRI), and prognostic nutritional index (PNI) were calculated. Risk factors for AKI within 7 postoperative days were investigated in accordance with the kidney disease improving global outcomes classification.

RESULTS

Preoperative urea and creatinine values were significantly higher (p = .006 vs. p = .006), while hemoglobin, hematocrit, and estimated glomerular filtration rate values were significantly lower (p = .011, p = .008 vs. p = .006) in the AKI group than no AKI group. In the intraoperative period, the cardiopulmonary bypass time was longer in the AKI group (p = .031), and the need for dopamine, steradine, and red blood cells transfusion was greater (p = .026, p = .038 vs. p = .015) than no AKI group. The number of patients with a frailty score of 1-3 was significantly higher in the AKI group (p = .042). Similarly, the GNRI and PNI values, indicating nutritional status, were higher in the AKI group (p = .047 vs. p = .024). The independent risk factors for AKI were a GNRI of <91, the intraoperative need for dobutamine, preoperative serum creatinine of >1.3, and hemoglobin of <10 (p < .05).

CONCLUSIONS

Malnutrition and frailty are strongly associated with AKI after CABG. Clinicians can effectively predict the risk of AKI through an evaluation of frailty and nutritional scores, which can be easily calculated in the preoperative period.

Incidence, severity, risk factors and outcomes of acute kidney injury in older adults: systematic review and meta-analysis

OBJECTIVES

Old age was identified as a strong risk factor for acute kidney injury (AKI). Our objectives were to provide estimates of AKI, risk factors and outcomes in patients ≥ 75 years for whom data are scarce.

METHODS

Observational studies and randomized controlled trials between 2005 and 2021 with patients of mean or median age ≥ 75 years, reporting AKI according to current definitions. Data on AKI incidence, risk factors and mortality were analyzed separately in unselected (UC) and acute heart failure (AHF) cohorts.

RESULTS

Twenty-six observational studies and 4 randomized controlled trials with 51,111 UC and 25,414 AHF patients were included. Ages averaged 79.4 and 79.8 years, respectively. Pooled risk ratios (RRs) of AKI rates were 26.29% (95% confidence intervals (CI) 13.20-41.97) (UC) and 24.21% (95% CI 20.03-28.65) (AHF). In both cohorts, AKI was associated with decreased estimated glomerular filtration rate at baseline, chronic kidney disease (UC: RR 1.80 (95% CI 1.15-2.80), AHF: RR 1.51 (95% CI 1.26-1.95) and hypertension (UC: RR 1.30 (95% CI 1.09-1.56), AHF: RR 1.07 (95% CI 1.05-1.09). RRs of AKI in patients on renin-angiotensin-inhibitors were 0.87 (95% CI 0.78-0.97) and 0.88 (95% CI 0.78-0.98) in UC and AHF, respectively. AKI was consistently associated with increased risk of in-hospital mortality (UC: RR 3.15 (95% CI 2.28-4.35), AHF: RR 4.28 (95% CI 2.53-7.24).

CONCLUSION

AKI is frequent in patients ≥ 75 years. While reduced renal function at baseline, CKD and hypertension were associated with AKI development, renin-angiotensin-inhibitors may be protective. Older AKI patients showed higher short-term mortality rates.

Association Between the Severity of Early Acute Kidney Injury and Subsequent in-Hospital Complications and 90-Day Mortality in Geriatric Patients Receiving Invasive Mechanical Ventilation

Purpose

Acute kidney injury (AKI) in elderly patients is associated with higher hospital mortality. However, the relationship between AKI and peri-intubation complications is unclear.

Methods

This retrospective, observational, multicenter cohort study enrolled 3271 consecutive elderly patients (≥75 years) who received invasive mechanical ventilation (MV) in four medical centers of Chinese PLA General Hospital from 2008 to 2020. AKI was diagnosed according to the 2012 KDIGO criteria by an absolute increase in serum creatinine of ≥26.5 µmol/L within the first 48 hours of MV. We recorded subsequent in-hospital complications, including incident gastrointestinal bleeding, new-onset electrolyte imbalances, severe hypoxemia, hypoalbuminemia, cardiovascular instability and all-cause 90-day mortality.

Results

A total of 1292 patients were included in the final evaluation, with 29.1% presenting AKI (stage 1: 31.4%, stage 2: 35.1%, stage 3: 33.5%). Multiple regression analyses show that more advanced AKI increased the risk of MAP <65 mmHg (stage 1: OR=1.833, P=0.002; stage 2: OR= 4.653, P<0.001; stage 3: OR=4.834, P<0.001) and SBP <90 mmHg (stage 1: OR=1.644, P=0.014; stage 2: OR=3.701, P<0.001; stage 3: OR=5.750, P<0.001), a new need for or requiring an increased dose of vasopressors (stage 1: OR=1.623, P=0.014; stage 2: OR=3.250, P<0.001; stage 3: OR=12.132, P<0.001), gastrointestinal bleeding (stage 1: OR=1.102, P=0.669; stage 2: OR=1.471, P=0.060; stage 3: OR=2.377, P<0.001), severe hypoxia (stage 1: OR=1.213, P=0.399; stage 2: OR=1.449, P=0.077; stage 3: OR=2.214, P<0.001) and all-cause 90-day mortality (stage 1: OR =0.935; P=0.741; stage 2: OR=1.888; P=0.001; stage 3: OR=12.584; P<0.001).

Conclusion

Our study suggests that the presence of AKI within the first 48 hours of MV in geriatric patients is associated with a higher risk for postintubation complications and 90-day mortality. Moreover, the risk of complications was greater for patients with more severe AKI.

Application of Machine Learning Algorithms to Predict Acute Kidney Injury in Elderly Orthopedic Postoperative Patients

Objective

There has been a worldwide increment in acute kidney injury (AKI) incidence among elderly orthopedic operative patients. The AKI prediction model provides patients’ early detection a possibility at risk of AKI; most of the AKI prediction models derive, however, from the cardiothoracic operation. The purpose of this study is to predict the risk of AKI in elderly patients after orthopedic surgery based on machine learning algorithm models.

Methods

We organized a retrospective study being comprised of 1000 patients with postoperative AKI undergoing orthopedic surgery from September 2016, to June, 2021. They were divided into training (80%;n=799) and test (20%;n=201) sets.We utilized nine machine learning (ML) algorithms and used intraoperative information and preoperative clinical features to acquire models to predict AKI. The performance of the model was evaluated according to the area under the receiver operating characteristic (AUC), sensitivity, specificity and accuracy. Select the optimal model and establish the nomogram to make the prediction model visualization. The concordance statistic (C-statistic) and calibration curve were used to discriminate and calibrate the nomogram respectively.

Results

In predicting AKI, nine ML algorithms posted AUC of 0.656–1.000 in the training cohort, with the randomforest standing out and AUC of 0.674–0.821 in the test cohort, with the logistic regression model standing out. Thus, we applied the logistic regression model to establish nomogram. The nomogram was comprised of ten variables: age, body mass index, American Society of Anesthesiologists, hypoproteinemia, hypertension, diabetes, anemia, duration of low mean arterial pressure, mean arterial pressure, transfusion.The calibration curves showed good agreement between prediction and observation in both the training and test sets.

Conclusion

By including intraoperative and preoperative risk factors, ML algorithm can predict AKI and logistic regression model performing the best. Our prediction model and nomogram that are based on this ML algorithm can help lead decision-making for strategies to inhibit AKI over the perioperative duration.

Relationship between Braden Scale scores and acute kidney injury among patients with acute coronary syndrome: a multicentre retrospective cohort study

OBJECTIVES

To evaluate the impact of pressure ulcer events assessed by the Braden Scale (BS) on acute kidney injury (AKI) in patients with acute coronary syndrome (ACS).

DESIGN

A multicentre retrospective cohort study.

SETTING

Chest pain centres from seven tertiary hospitals in China.

PARTICIPANTS

We analysed 3185 patients with ACS from the Retrospective Evaluation of Acute Chest Pain study. The patients were divided into three groups (B1, B2 and B3) according to their BS scores (≤12 vs 13-14 vs ≥15, respectively) at admission.

OUTCOME MEASURES

AKI was defined according to the criteria of the 2012 Kidney Disease: Improving Global Outcomes. Multivariate logistic analysis was used to evaluate the relationship between the BS score and AKI.

RESULTS

There were 461 patients (14.5%) with ACS who had the complication of AKI. Patients with a lower score on the BS had a higher incidence of AKI (p<0.001). Multivariate logistic regression analysis showed that adjusted ORs of the BS score for AKI were 2.242 (B1 vs B3: 95% CI: 1.643 to 3.060, p<0.001) and 1.566 (B2 vs B3: 95% CI: 1.186 to 2.069, p=0.002). The receiver operating characteristic curve analysis showed that the area under the curve of the BS score was 0.719 (95% CI: 0.702 to 0.736; p<0.001) for AKI.

CONCLUSIONS

The BS score was independently associated with AKI. It may be a useful tool to identify those who may benefit from further prediction and prevention of AKI in patients with ACS.

TRAIL REGISTRATION NUMBER

ChiCTR1900024657 (http://www.chictr.org.cn/). The satge rekates to results.

Critical oxygen delivery threshold during cardiopulmonary bypass in older cardiac surgery patients with increased frailty risk

OBJECTIVES

Older patients have a higher cardiac surgery-associated acute kidney injury (CSA-AKI) related mortality. Low oxygen delivery (DO2) during cardiopulmonary bypass (CPB) is a risk factor for CSA-AKI, but critical DO2 thresholds for older patients are unknown. This study investigated critical DO2 thresholds for CSA-AKI in patients ≥70 years undergoing on-pump cardiac surgery.

METHODS

Patients were enrolled from July 2015 until August 2017. CPB data from 432 patients were collected, and DO2 values were calculated per minute. The primary outcome was CSA-AKI. The association between DO2 and CSA-AKI was analysed with multivariable regression analysis. Multiple DO2 thresholds were analysed. The association between CSA-AKI and the area below the DO2 thresholds (DO2 deficit) was evaluated, as was the association between frailty and CSA-AKI.

RESULTS

CSA-AKI occurred in 63 (14.6%) patients. Mean and nadir (lowest) DO2 values were lower in patients with CSA-AKI (283 vs 312 ml/min/m2; P-value <0.001 and 238 vs 270 ml/min/m2; P-value <0.001, respectively). The adjusted relative risk for CSA-AKI was 1.006 [99% confidence interval (CI) 1.001-1.012] per ml/min/m2 nadir DO2 decrease. The critical DO2 threshold was 270 ml/min/m2 [adjusted relative risk 2.06 (99% CI 1.33-2.80)]. The DO2 deficit below 270 ml/min/m2 was associated with CSA-AKI [adjusted relative risk 2.84 (99% CI 1.87-3.81)]. No association between frailty and CSA-AKI was found (P = 0.82).

CONCLUSIONS

Low DO2 increased the risk for CSA-AKI in older patients who had cardiac surgery. A critical DO2 threshold of 270 ml/min/m2 was applicable for frail and non-frail patients. The efficacy of a DO2 >270 ml/min/m2 to reduce CSA-AKI in older patients needs further evaluation.

Exploration of the Relationship Among Key Risk Factors of Acute Kidney Injury for Elderly Patients Considering Covid-19

Background: Previous systematic reviews and meta-analyses supported the relationship between frailty and risk of acute kidney injury (AKI) in elderly patients. However, few studies evaluated proactive management to wear down AKI risk in such frail populations.

Purpose: To understand how AKI risk factors might influence each other and to identify the source factors for clinical decision aids.

Methods: This study uses the decision-making trial and evaluation laboratory (DEMATEL) method to establish influential network-relationship diagrams (INRDs) to form the AKI risk assessment model for the elderly.

Results: Based on the DEMATEL approach, the results of INRD identified the six key risk factors: comorbidity, malignancy, diabetes, creatinine, estimated glomerular filtration rate, and nutritional assessment. (The statistical significance confidence is 98.423%, which is higher than 95%; the gap error is 1.577%, which is lower than 5%). After considering COVID-19 as an additional risk factor in comorbidity, the INRD revealed a similar influential relationship among the essential aspects.

Conclusion: While evaluating the geriatric population, physicians need to pay attention to patients' comorbidities and nutritional assessment; also, they should note patients' creatinine values and glomerular filtration rate. Physicians could establish a preliminary observation index and then design a series of preventive guidelines to reduce the incidence of AKI risk for the elderly.

Serum Sodium Levels Predict Mortality in Elderly Acute Kidney Injury Patients: A Retrospective Observational Study

Purpose

We examined the relationship between different levels of serum sodium and mortality among elderly patients with acute kidney injury (AKI).

Methods

We retrospectively enrolled elderly patients from Chinese PLA General Hospital from 2007, to 2018. All-cause mortality was examined according to eight predefined sodium levels: <130.0 mmol/L, 130.0–134.9 mmol/L, 135.0–137.9 mmol/L, 138.0–141.9 mmol/L, 142.0–144.9 mmol/L, 145.0–147.9 mmol/L, 148.0–151.9 mmol/L, and ≥152.0 mmol/L. We estimated the risk of all-cause mortality using a multivariable adjusted Cox analysis, with a normal sodium level of 135.0–137.9 mmol/L as a reference.

Results

In total, 744 patients were suitable for the final evaluation. After 90 days, the mortality rates in the eight strata were 36.1, 27.8, 19.6, 24.4, 30.7, 48.6, 52.8, and 57.7%, respectively. In the multivariable adjusted analysis, patients with sodium levels <130.0 mmol/L (HR: 2.247; 95% CI: 1.117–4.521), from 142.0 to 144.9 mmol/L (HR: 1.964; 95% CI: 1.100–3.508), from 145.0 to 147.9 mmol/L (HR: 2.942; 95% CI: 1.693–5.114), from 148.0 to 151.9 mmol/L (HR: 3.455; 95% CI: 2.009–5.944), and ≥152.0 mmol/L (HR: 3.587; 95% CI: 2.151–5.983) had an increased risk of all-cause mortality. After 1 year, the mortality rates in the eight strata were 58.3, 47.8, 33.7, 38.9, 45.5, 64.3, 69.4, and 78.4%, respectively. Patients with sodium levels <130.0 mmol/L (HR: 1.944; 95% CI: 1.125–3.360), from 142.0 to 144.9 mmol/L (HR: 1.681; 95% CI: 1.062–2.660), from 145.0 to 147.9 mmol/L (HR: 2.631; 95% CI: 1.683–4.112), from 148.0 to 151.9 mmol/L (HR: 2.411; 95% CI: 1.552–3.744), and ≥152.0 mmol/L (HR: 3.037; 95% CI: 2.021–4.563) had an increased risk of all-cause mortality.

Conclusion

Sodium levels outside the interval of 130.0–141.9 mmol/L were associated with increased risks of 90-day mortality and 1-year mortality in elderly AKI patients.

Clinical Knowledge Supported Acute Kidney Injury (AKI) Risk Assessment Model for Elderly Patients

From the clinical viewpoint, the statistical approach is still the cornerstone for exploring many diseases. This study was conducted to explore the risk factors related to acute kidney injury (AKI) for elderly patients using the multiple criteria decision-making (MCDM) approach. Ten nephrologists from a teaching hospital in Taipei took part in forming the AKI risk assessment model. The key findings are: (1) Comorbidity and Laboratory Values would influence Comprehensive Geriatric Assessment; (2) Frailty is the highest influential AKI risk factor for elderly patients; and (3) Elderly patients could enhance their daily activities and nutrition to improve frailty and lower AKI risk. Furthermore, we illustrate how to apply MCDM methods to retrieve clinical experience from seasoned doctors, which may serve as a knowledge-based system to support clinical prognoses. In conclusion, this study has shed light on integrating multiple research approaches to assist medical decision-making in clinical practice.

Severity of frailty as a significant predictor of mortality for hemodialysis patients: a prospective study in China

Background: Frailty is known to be highly prevalent in older hemodialysis (HD) patients. We studied the prevalence of frailty and its associated factors in Chinese HD patients. We further studied if frailty could predict survival in HD patients. Methods: This is a prospective study involving patients receiving maintenance HD in the dialysis center of Xuanwu Hospital, Beijing. Study subjects were enrolled from October to December, 2017 and followed up for two years. Demographic data, comorbidities and biological parameters were collected. Frailty was assessed using the Fried frailty phenotype at baseline. Cox regression analysis was performed to identify the relationship between frailty and mortality in HD patients. Kaplan-Meier was plotted using the cutoff value obtained by ROC curve to evaluate survival rates in different frailty status. Results: Total of 208 HD patients were enrolled with a mean age of 60.5±12.7 years. According to the frailty criteria, at baseline the prevalence of robust, pre-frail and frail in HD patients was 28.7%, 45.9%, and 25.4%, respectively. The two-year all-cause mortality was 18.8% (39/207) and underlying causes of death included coronary artery disease (CAD), cerebrovascular disease (CVD), hyperkalemia, severe infection, malignant tumor and others. Survival curve showed the patients with frailty score ≥4 to have significantly shorter survival time as compared to patients with frailty score ≤ 3. Frailty predicted two-year mortality when frailty score ≥4 with a sensitivity of 70% and a specificity of 83.67% with an AUC of 0.819. Frailty score was positively associated with age and ratio of ultrafiltration volume to dry weight, while negatively associated with levels of serum albumin, uric acid and diastolic blood pressure after HD. Conclusions: Our results confirm frailty to be very common among HD patients and severity of frailty was a significant predictor of mortality for HD patients. Factors such as age, malnutrition and low blood pressure are the factors to be associated with frailty. Interdialytic weight gain inducing excessive ultrafiltration volume is an important risk factor.

Clinical features, risk factors, and clinical burden of acute kidney injury in older adults

Background: Few epidemiologic studies on acute kidney injury (AKI) have focused on the older adult population. This study investigated the clinical features, risk factors, and clinical burden in this population. Methods: A retrospective observational study was performed with the clinical data of inpatients at Guangdong Geriatrics Institute from 1 August 2012, to 31 December 2016. AKI was classified into community-acquired AKI (CA-AKI) and hospital-acquired AKI (HA-AKI), and the risk factors for AKI were ranked by weight. The relationships between AKI and adverse outcomes during hospitalization were analyzed using univariate and multivariate logistic regression. Results: In total, 6126 patients were enrolled, and 1704 patients developed AKI (27.8%): 6.3% had CA-AKI, and 21.5% had HA-AKI. In total, 1425 (23.3%), 202 (3.3%), and 77 (1.3%) patients had stage 1, 2 and 3 AKI, respectively. Age, dementia, moderate/severe renal disease, moderate/severe liver disease, metastatic solid tumor, female sex, congestive heart failure, chronic pulmonary disease, diabetes mellitus with chronic complications, non-metastatic tumor and lymphoma were independent risk factors for HA-AKI. The first five were also independent risk factors for CA-AKI. After multiple adjustment, AKI was associated with intensive care admission (CA-AKI: OR 5.688, 95% CI 3.122-10.361; HA-AKI: OR 4.704, 95% CI 3.023-7.298) and in-hospital mortality (CA-AKI: OR 5.073, 95% CI 2.447-10.517; HA-AKI: OR 13.198, 95% CI 8.133-21.419). Conclusion: AKI occurs in >25% of older adults in the geriatric ward. In addition to traditional risk factors, dementia and tumors were risk factors for AKI in older adults. AKI is closely related to a poor prognosis.

Impact of Dexmedetomidine Infusion on Postoperative Acute Kidney Injury in Elderly Patients Undergoing Major Joint Replacement: A Retrospective Cohort Study

Purpose

Postoperative acute kidney injury (AKI) is a frequent complication in elderly patients that increases morbidity and mortality. Approximately 1.7 million people die from AKI worldwide every year. Dexmedetomidine (Dex) is often used as an adjunct to multimodal analgesia. Our study investigated whether Dex could safely decrease the incidence of AKI in elderly patients undergoing major joint replacement.

Methods

A single-center retrospective study was conducted in patients aged >65 years undergoing major joint replacement. Propensity score–matching analysis was used, and a total of 1,006 patients were matched successfully. The primary outcome was the incidence of postoperative AKI. Secondary outcomes included perioperative adverse complications, opioid consumption, time to extubation, and length of hospital stay.

Results

Among the 1,006 patients included, postoperative AKI occurred in 9.3% (n=94). The Dex group (perioperative Dex infusion) had lower incidence of postoperative AKI than the control group (7.2% vs 11.5%, P=0.017). Compared with the control group, the Dex group had less opioid consumption (P<0.05), reduced time to extubation (P=0.004), and shorter length of hospital stay (P=0.001). The Dex group also showed higher incidence of bradycardia (20.1% vs 15.1%, P=0.038). There were no differences in intraoperative hypotension (19.5% vs 17.5%), postoperative nausea and vomiting (4.2% vs 5.4%), time in PACU (45.0±6.4 vs 45.5±6.2 minutes), or rate of ICU admission (9.7% vs 11.1%) between the Dex group and control group (All P>0.05).

Conclusion

This retrospective study showed Dex infusion in elderly patients undergoing major joint replacement was associated with lower incidence of postoperative AKI, less opioid consumption, and shorter extubation time and hospital stay. However, the Dex group had higher incidence of bradycardia. We found no statistical differences in other perioperative adverse complications between the groups.

Exogenous biological renal support ameliorates renal pathology after ischemia reperfusion injury in elderly mice

We established an exogenous biological renal support model through the generation of parabiotic mice. At 72 hours after ischemia reperfusion injury (IRI), the aged mice that received exogenous biological renal support showed significantly higher levels of renal cell proliferation and dedifferentiation, lower levels of renal tubular injury, improved renal function, and a lower mortality than those that did not receive exogenous biological renal support. Using the Quantibody Mouse Cytokine Antibody Array, we found that aged IRI mice that received exogenous biological renal support had an up-regulation of multiple inflammatory related cytokines compared to the group that did not receive exogenous biological renal support. We suggest that the exogenous biological renal support might promote renal tubular epithelial cell proliferation and dedifferentiation and improve the prognosis of aged IRI mice. Exogenous biological renal support may play an important role in the amelioration of renal IRI by regulating the expression of multiple cytokines.

Acute Kidney Injury Outcomes of Elderly and Nonelderly Patients in the Medical Intensive Care Unit of a University Hospital in a Developing Country

Background

Aging is associated with a high risk of acute kidney injury (AKI), and the elderly with AKI show a higher mortality rate than those without AKI. In this study, we compared AKI outcomes between elderly and nonelderly patients in a university hospital in a developing country.

Materials and Methods

This retrospective cohort study included patients with AKI who were admitted to the medical intensive care unit (ICU) between January 1, 2012, and December 31, 2017. The patients were divided into the elderly (eAKI; age ≥65 years; n = 158) and nonelderly (nAKI; n = 142) groups. Baseline characteristics, comorbidities, principle diagnosis, renal replacement therapy (RRT) requirement, hospital course, and in-hospital mortality were recorded. The primary outcome was in-hospital mortality.

Results

The eAKI group included more females, patients with higher Acute Physiology and Chronic Health Evaluation II scores, and patients with more comorbidities than the nAKI group. The etiology and staging of AKI were similar between the two groups. There were no significant differences in in-hospital mortality (p=0.338) and RRT requirement (p=0.802) between the two groups. After adjusting for covariates, the 28-day mortality rate was similar between the two groups (p=0.654), but the 28-day RRT requirement was higher in the eAKI group than in the nAKI group (p=0.042).

Conclusion

Elderly and nonelderly ICU patients showed similar survival outcomes of AKI, although the elderly were at a higher risk of requiring RRT.

Association of acute kidney injury with frailty in elderly population: a systematic review and meta-analysis

Aim: The objective of this study was to assess whether an elderly patient's frailty was associated with acute kidney injury (AKI) and to examine whether severe frailty group had an increased risk of AKI than mild-moderate group.Methods: We searched The Cochrane Library, PubMed, and EMBASE for relevant studies without language limitations before 1 March 2019 with a priori defined inclusion and exclusion criteria. Five population-based cohort studies were included for systematic review and meta-analysis.Results: Compared with the control group, the frailty group is significantly associated AKI (Odds Ratio = 2.05; 95% CI: 1.23-3.43). The moderate-severe frailty group has an increased risk of AKI than mild frailty group (Hazard Ratio = 2.87; 95% CI: 1.60-5.17.Conclusion: In conclusion, the available best evidence support an association between frailty and AKI among elder patients, thus relevant interventions should be taken among elderly under potential risk of AKI.

Continuous renal replacement therapy in elderly with acute kidney injury

The objective of this article is to raise awareness among physicians of the increasing incidence of acute kidney injury in the elderly population and the utility of continuous renal replacement therapy (CRRT) in its management. While CRRT is frequently applied in younger patients, its use in elderly patients is less frequent, for various reasons, including resistance to such an aggressive intervention from the family and the healthcare team. However, predictors of prognosis have been identified and some studies have concluded that advanced age is not associated with poor outcomes. Decisions regarding management are more complex when dealing with the elderly but like very other patient, the approach should be patient- centered.

Acute Kidney Injury Among Older Patients Undergoing Coronary Angiography for Acute Myocardial Infarction: The SILVER-AMI Study

BACKGROUND

Among older adults (age ≥75 years) hospitalized for acute myocardial infarction, acute kidney injury after coronary angiography is common. Aging-related conditions may independently predict acute kidney injury, but have not yet been analyzed in large acute myocardial infarction cohorts.

METHODS

We analyzed data from 2212 participants age ≥75 years in the Comprehensive Evaluation of Risk Factors in Older Patients with Acute Myocardial Infarction (SILVER-AMI) study who underwent coronary angiography. Acute kidney injury was defined using Kidney Disease Improving Global Outcomes (KDIGO) criteria (serum Cr increase ≥0.3 mg/dL from baseline or ≥1.5 times baseline). We analyzed the associations of traditional acute kidney injury risk factors and aging-related conditions (activities of daily living impairment, prior falls, cachexia, low physical activity) with acute kidney injury, and then performed logistic regression to identify independent predictors.

RESULTS

Participants' mean age was 81.3 years, 45.2% were female, and 9.5% were nonwhite; 421 (19.0%) experienced acute kidney injury. Comorbid diseases and aging-related conditions were both more common among individuals experiencing acute kidney injury. However, after multivariable adjustment, no aging-related conditions were retained. There were 11 risk factors in the final model; the strongest were heart failure on presentation (odds ratio [OR] 1.91; 95% confidence interval [CI], 1.41-2.59), body mass index [BMI] >30 (vs BMI 18-25: OR 1.75; 95% CI, 1.27-2.42), and nonwhite race (OR 1.65; 95% CI, 1.16-2.33). The final model achieved an area under the receiver operating characteristic curve of 0.72 and was well calibrated (Hosmer-Lemeshow P = .50). Acute kidney injury was independently associated with 6-month mortality (OR 1.98; 95% CI, 1.36-2.88) but not readmission (OR 1.26; 95% CI, 0.98-1.61).

CONCLUSIONS

Acute kidney injury is common among older adults with acute myocardial infarction undergoing coronary angiography. Predictors largely mirrored those in previous studies of younger individuals, which suggests that geriatric conditions mediate their influence through other risk factors.

Acute kidney injury is independently associated with mortality and resource use after emergency general surgery operations

INTRODUCTION

The incidence of severe perioperative renal dysfunction in high-acuity patients has not been well-explored at the national level. The present study aimed to evaluate the trends in the incidence of perioperative acute kidney injury and renal replacement therapy as well as associated mortality among patients undergoing an emergency general surgery operation.

METHODS

This was a retrospective cohort study using the National Inpatient Sample to identify all adult patients (>18 y) without chronic kidney disease who underwent an emergency general surgery procedure from 2008 to 2016. The study cohort was stratified based on presence of acute kidney injury and need for renal replacement therapy postoperatively. A multivariable logistic regression model was developed to predict the odds of mortality and composite morbidity. Nonparametric trend analyses of acute kidney injury and renal replacement therapy incidence and associated mortality were performed.

RESULTS

Of an estimated 5,862,657 patients who underwent an emergency general surgery procedure during the study period, 7.4% patients developed an acute kidney injury and 0.48% patients required renal replacement therapy. Overall, the incidence of acute kidney injury (5.3%-19.4%) and renal replacement therapy (0.43%-0.93%) increased (P < .0001) over the study period. Even without need for renal replacement therapy, acute kidney injury was associated with greater odds of mortality and composite morbidity (adjusted odds ratio 5.2, 95% confidence interval [CI] 5.1-5.3) and mortality (adjusted odds ratio = 2.20, 95% CI 2.3-2.4), as well as greater costs of hospitalization and duration of stay.

CONCLUSION

In this national study, we found that the incidence of acute kidney injury and renal replacement therapy after an emergency general surgery operation has increased. Both acute renal failure and hemodialysis were associated with much greater odds of morbidity and mortality. The apparent increase in the rate of acute kidney injury and renal replacement therapy warrant further investigation of mechanisms for monitoring and limiting the impact of organ malperfusion associated with emergency general surgery operations.

Predictores de progresión de enfermedad renal en el paciente anciano

El riñón del anciano experimenta cambios estructurales y funcionales, que lo convierte en más vulnerable para la enfermedad renal. La mayoría de ancianos con enfermedad renal crónica fallece antes de desarrollar progresión renal. Sin embargo, el principal grupo de pacientes incidentes de nefropatía terminal es el de personas mayores de 65 años, representando la diabetes mellitus y las causas vasculares sus principales etiologías. En esta revisión se analizan elementos renales (filtrado glomerular, proteinuria/albuminuria, potasio, fracaso renal agudo y diuréticos) y factores geriátricos (estado funcional, cognitivo y fragilidad) como predictores de progresión de enfermedad renal. La identificación de estos factores contribuirá a establecer estrategias de prevención renal y al pronóstico de la enfermedad en la toma decisiones.

Acute kidney injury among nonagenarians in Jordan: a retrospective case-control study

Background

Improvements in health care systems worldwide have had notable effects on the life expectancy of older individuals. As a result, nonagenarians are emerging as a separate age group with distinct health care needs. The aim of this study was to evaluate the incidence of acute kidney injury (AKI), the mortality rates, and length of in-hospital stay among nonagenarians.

Methods

This is a retrospective case–control chart review of patients of age 90 years and above who were admitted to hospital. Patients with Stage I, II, or III chronic kidney disease were included in the analysis. The incidence of AKI was determined using data from the Acute Kidney Injury Network (AKIN) classification. Primary outcome variables included length of in-hospital stay and mortality rates.

Results

Of the 253 patients who were included in the study, the mean age was 91.5 years, 61 of the patients (25.9%) developed AKI, and 41 patients (66.1%) were in Stage I AKI according to AKIN criteria. Fifty-seven patients died during the study period; 57.9% of those patients had AKI. Hospital stay was longer in patients with AKI with a mean length of stay of 8.1 days. Congestive heart failure, cancer, and use of non-steroidal anti-inflammatory drugs were the main risk factors for AKI among those patients.

Conclusion

AKI is common in nonagenarians. It was associated with increased length of hospital stays and increased risk for mortality.

Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study

BACKGROUND

Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery.

METHODS

This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation.

RESULTS

A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65).

DISCUSSION

Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability.

Is Frailty a Predictor of Outcomes in Elderly Inpatients with Acute Kidney Injury? A Prospective Cohort Study

BACKGROUND

Frailty and acute kidney injury are independently associated with an increased risk of morbidity and mortality. The degree of frailty can be assessed by the Clinical Frailty Score (CFS). This study assessed whether an individual's CFS was associated with acute kidney injury in acute elderly medical admissions and recorded the short-term outcomes.

METHODS

This was a single-center prospective observational cohort study. All patients aged ≥65 years admitted under an acute medical take over 12 nonconsecutive days were included. Patient demographics, comorbidities, baseline CFS, and renal status on admission were recorded. Outcomes of death, length of stay, and hospital re-attendance were assessed 2 weeks following admission.

RESULTS

Of 164 patients (77 males), 19% had acute kidney injury on admission and 22% were considered severely frail. Severe frailty was associated with acute kidney injury (P = .01) and death within 2 weeks (P = .01). Two-week mortality was highest among patients with both (36%).

CONCLUSION

The incidence of acute kidney injury in "severely frail" acutely unwell elderly patients is significantly higher and associated with an increased short-term mortality. The CFS may be useful in acute illness to guide clinical decisions in elderly patients.

Youthful systemic milieu alleviates renal ischemia-reperfusion injury in elderly mice

The incidence of acute kidney injury (AKI) is high in elderly people, and is difficult to prevent and treat. One of its major causes is renal ischemia-reperfusion injury (IRI). A young systemic environment may prevent the senescence of old organs. However, it is unknown whether a young milieu may reduce renal IRI in the elderly. To examine this question, bilateral renal IRI was induced in old (24 months) mice three weeks after parabiosis model establishment. At 24 hours after IRI, compared to old wild-type mice, the old mice with IRI had significantly damaged renal histology, decreased renal function, increased oxidative stress, inflammation, and apoptosis. However, there was no increase in autophagy. Compared to old mice with IRI, old-old parabiosis mice with IRI did not show differences in renal histological damage, oxidative stress, inflammation, apoptosis, or autophagy, but did exhibit improved renal function. Compared to the old-old parabiosis mice with IRI, the old mice with IRI in the young (12 week)-old parabiosis showed less renal histological injury and better renal function. Renal oxidative stress, inflammation, and apoptosis were significantly decreased, and autophagy was significantly increased. Thus, a youthful systemic milieu may decrease oxidative stress, inflammation, and apoptosis, and increase autophagy in old mice with IRI. These effects ameliorated IRI injuries in old mice. Our study provides new ideas for effectively preventing and treating AKI in the elderly.

Incidence and outcomes of acute kidney injury in octogenarians in Jordan

Objective

Improvements in the health care system, resulted in a greater number of geriatric patients diagnosed with acute kidney injury (AKI). We evaluated the incidence and outcome of AKI in octogenarians, as studies in the Middle-East region are few; moreover, treatment approaches, in addition to medical decisions, may require special consideration for advanced age to improve the outcomes.

Results

At King Abdullah II teaching and referral hospital, we recruited patients aged 80–90 years who were admitted to the medical floor between January 2010 and December 2013. Patients were followed-up for at least 1 year after discharge.850 patients were admitted during the study period. Of these, 135 were excluded from our analysis. The most common admission diagnoses were uncontrolled diabetes mellitus and acute coronary syndrome. AKI occurred in 216 patients (30.2%). Using the acute kidney injury network classification; stage 1, stage 2, and stage 3 disease were present in 59, 17.5, and 23.5% of patients, respectively. Of the 115 patients who died before discharge (16.1%), 87 (75.6%) had developed AKI. Hypertension, the use of angiotensin receptor blockers and non-steroidal anti-inflammatory drugs, heart failure, and exposure to radiologic contrast media were significant risk factors for AKI.

Is Frailty a Modifiable Risk Factor of Future Adverse Outcomes in Elderly Patients with Incident End-Stage Renal Disease?

Little is known about the clinical significance of frailty and changes of frailty after dialysis initiation in elderly patients with end-stage renal disease (ESRD). We prospectively enrolled 46 elderly patients with incident ESRD at a dialysis center of a tertiary hospital between May 2013 and March 2015. Frailty was assessed by using a comprehensive geriatric assessment protocol and defined as a multidimensional frailty score of ≥ 10. The main outcome was the composite of all-cause death or cardiovascular hospitalization, as determined in June 2016. The median age of the 46 participants was 71.5 years, and 63.0% of them were men. During the median 17.7 months follow-up, the rate of composite outcome was 17.4%. In multivariate logistic regression analysis, after adjusting for age, sex, diabetes, body mass index (BMI), and time of predialytic nephrologic care, female sex, and increased BMI were associated with increased and decreased odds of frailty, respectively. In multivariate Cox proportional hazards analysis, after adjusting for age, sex, diabetes, BMI, and time of predialytic nephrologic care, frailty was significantly associated with the composite adverse outcome. In repeated frailty assessments, the multidimensional frailty score significantly improved 12 months after the initiation of dialysis, which largely relied on improved nutrition. Therefore, frailty needs to be assessed for risk stratification in elderly patients with incident ESRD.

Hypoalbuminemia at admission predicts the development of acute kidney injury in hospitalized patients: A retrospective cohort study

Background

Development of acute kidney injury (AKI) is common and is associated with poor outcomes. We aimed to determine whether hypoalbuminemia (HA) at admission could be a risk factor for the development of AKI and mortality in hospitalized patients.

Methods

We enrolled patients who were admitted to Seoul National University Bundang Hospital from January 2013 to December 2013. HA at admission was defined as a serum albumin level < 3.4 mg/dL measured within two days after admission. AKI was defined as an increase in the serum creatinine level by ≥0.3 mg/dL or ≥1.5 times of the baseline value during the hospital stay.

Results

A total of 19,472 patients were enrolled and divided into HA and normoalbuminemia (NA) groups at admission. The incidence of AKI was 10.7% (340/3179) in the HA group and 4.1% (662/16293) in the NA group (adjusted odds ratio [OR], 1.243; 95% confidence interval [CI], 1.069–1.445; P = 0.005). The hazard ratios for the 30-day, 90-day, and 1-year mortality were 1.873 (95% CI, 1.383–2.537; P < 0.001), 1.710 (95% CI, 1.410–2.072; P < 0.001), and 1.372 (95% CI, 1.214–1.551; P < 0.001), compared to the NA group. In patients with AKI, albumin replacement improved renal recovery (OR, 2.605; 95% CI, 1.450–4.681; P = 0.001). The mortality rate was not different according to albumin replacement.

Conclusions

HA is associated with the development of AKI and high mortality in hospitalized patients. Replacement of albumin after the development of AKI may contribute to renal recovery. Further clinical trials are warranted.

Association of frailty status with acute kidney injury and mortality after transcatheter aortic valve replacement: A systematic review and meta-analysis

Objective

Frailty is a common condition in patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR). The aim of this systematic review was to assess the impact of frailty status on acute kidney injury (AKI) and mortality after TAVR.

Methods

A systematic literature search was conducted using MEDLINE, EMBASE, and Cochrane databases from the inception through November 2016. The protocol for this study is registered with PROSPERO (International Prospective Register of Systematic Reviews; no. CRD42016052350). Studies that reported odds ratios, relative risks or hazard ratios comparing the risk of AKI after TAVR in frail vs. non-frail patients were included. Mortality risk was evaluated among the studies that reported AKI-related outcomes. Pooled risk ratios (RR) and 95% confidence interval (CI) were calculated using a random-effect, generic inverse variance method.

Results

Eight cohort studies with a total of 10,498 patients were identified and included in the meta-analysis. The pooled RR of AKI after TAVR among the frail patients was 1.19 (95% CI 0.97–1.46, I² = 0), compared with non-frail patients. When the meta-analysis was restricted only to studies with standardized AKI diagnosis according to Valve Academic Research Consortium (VARC)-2 criteria, the pooled RRs of AKI in frail patients was 1.16 (95% CI 0.91–1.47, I² = 0). Within the selected studies, frailty status was significantly associated with increased mortality (RR 2.01; 95% CI 1.44–2.80, I² = 58).

Conclusion

The findings from our study suggest no significant association between frailty status and AKI after TAVR. However, frailty status is associated with mortality after TAVR and may aid appropriate patient selection for TAVR.

Pre-Stage Acute Kidney Injury Can Predict Mortality and Medical Costs in Hospitalized Patients

The significance of minimal increases in serum creatinine below the levels indicative of the acute kidney injury (AKI) stage is not well established. We aimed to investigate the influence of pre-stage AKI (pre-AKI) on clinical outcomes. We enrolled a total of 21,261 patients who were admitted to the Seoul National University Bundang Hospital from January 1, 2013 to December 31, 2013. Pre-AKI was defined as a 25–50% increase in peak serum creatinine levels from baseline levels during the hospital stay. In total, 5.4% of the patients had pre-AKI during admission. The patients with pre-AKI were predominantly female (55.0%) and had a lower body weight and lower baseline levels of serum creatinine (0.63 ± 0.18 mg/dl) than the patients with AKI and the patients without AKI (P < 0.001). The patients with pre-AKI had a higher prevalence of diabetes mellitus (25.1%) and malignancy (32.6%). The adjusted hazard ratio of in-hospital mortality for pre-AKI was 2.112 [95% confidence interval (CI), 1.143 to 3.903]. In addition, patients with pre-AKI had an increased length of stay (7.7 ± 9.7 days in patients without AKI, 11.4 ± 11.4 days in patients with pre-AKI, P < 0.001) and increased medical costs (4,061 ± 4,318 USD in patients without AKI, 4,966 ± 5,099 USD in patients with pre-AKI, P < 0.001) during admission. The adjusted hazard ratio of all-cause mortality for pre-AKI during the follow-up period of 2.0 ± 0.6 years was 1.473 (95% CI, 1.228 to 1.684). Although the adjusted hazard ratio of pre-AKI for overall mortality was not significant among the patients admitted to the surgery department or who underwent surgery, pre-AKI was significantly associated with mortality among the non-surgical patients (adjusted HR 1.542 [95% CI, 1.330 to 1.787]) and the patients admitted to the medical department (adjusted HR 1.384 [95% CI, 1.153 to 1.662]). Pre-AKI is associated with increased mortality, longer hospital stay, and increased medical costs during admission. More attention should be paid to the clinical significance of pre-AKI.