Pre-Kidney Transplant Lower Extremity Impairment and Post-Kidney Transplant Mortality

Performance in a Balance Test and Prediction of All-Cause Mortality in Community-Dwelling Elderly Ambulatory Individuals: A Systematic Review and Meta-analysis

Objective: This systematic review and meta-analysis was performed to evaluate the association between an inability to perform a static balance test and mortality in community-dwelling older ambulatory individuals. Methods: PubMed, Embase, and Scopus were searched for relevant cohort studies. Hazard ratios (HR) were pooled (random-effect model). Meta-regression was performed with independent demographic variables (PROSPERO ID: CRD42022381137). Results: A total of 11,713 articles were screened and 15 were included. An inability to perform a static balance test was significantly associated with a higher risk of mortality irrespective of whether confounding variables were considered [HR, 1.14 (95% CI: 1.07-1.21); p < .001; i2, 87.96% (p < .01)] or not [HR, 1.11 (95% CI: 1.03-1.20); p = .01; i2, 95.28% (p < .01)] (both moderate GRADE evidence). Also, this association was correlated with progressive age. Conclusion: An inability to successfully complete a static balance test was significantly associated with a higher risk of mortality among community-dwelling older ambulatory individuals.

Age Is Just a Number for Older Kidney Transplant Patients

The rise in the mean age of the global population has led to an increase in older kidney transplant (KT) patients. This demographic shift, coupled with the ongoing organ shortage, requires a nuanced understanding of which older adults are most suitable for KT. Recognizing the increased heterogeneity among older adults and the limitations of solely relying on chronological age, there is a need to explore alternative aging metrics beyond chronological age. In this review, we discuss the impact of older age on access to KT and postoperative outcomes. Emphasizing the need for a comprehensive evaluation that extends beyond chronological age, we explore alternative aging metrics such as frailty, sarcopenia, and cognitive function, underscoring their potential role in enhancing the KT evaluation process. Most importantly, we aim to contribute to the ongoing discourse, fostering an optimized approach to KT for the rapidly growing population of older adults.

Perioperative Considerations in Older Kidney and Liver Transplant Recipients: A Review

With the growth of the older adult population, the number of older adults waitlisted for and undergoing kidney and liver transplantation has increased. Transplantation is an important and definitive treatment for this population. We present a contemporary review of the unique preoperative, intraoperative, and postoperative issues that patients older than 65 y face when they undergo kidney or liver transplantation. We focus on geriatric syndromes that are common in older patients listed for kidney or liver transplantation including frailty, sarcopenia, and cognitive dysfunction; discuss important considerations for older transplant recipients, which may impact preoperative risk stratification; and describe unique challenges in intraoperative and postoperative management for older patients. Intraoperative challenges in the older adult include using evidence-based best anesthetic practices, maintaining adequate perfusion pressure, and using minimally invasive surgical techniques. Postoperative concerns include controlling acute postoperative pain; preventing cardiovascular complications and delirium; optimizing immunosuppression; preventing perioperative kidney injury; and avoiding nephrotoxicity and rehabilitation. Future studies are needed throughout the perioperative period to identify interventions that will improve patients' preoperative physiologic status, prevent postoperative medical complications, and improve medical and patient-centered outcomes in this vulnerable patient population.

Latest advances in frailty in kidney transplantation: A narrative review

Frailty is a clinical syndrome that is characterised by decline in multiple systems with associated decreased physiological reserve and ability to respond to stressor events. It is associated with greater healthcare burden. It is common in patients with end-stage renal disease (ESRD). Kidney transplantation is considered the optimal form of renal replacement therapy for suitable patients with ESRD. However, surgery and immunosuppression are physiological stresses that can disproportionately affect frail individuals. Frailty is emerging as a potentially important risk factor in patients waitlisted for kidney transplantation. Most of the published research to date in this area comes from a single transplant centre in the USA. Frailty, as measured using the Physical Frailty Phenotype (FP), is prevalent in waitlisted patients and has been associated with early hospital re-admission, prolonged length of stay, delayed graft function and increased mortality after kidney transplantation. However, although kidney transplantation is a substantial physiological stress to a patient's reserve, by restoring kidney function, kidney transplantation has also been shown to improve a patient's frailty status. The FP is the most studied tool in patients waitlisted for transplantation, but it has not been able to distinguish those whose frailty is improved by kidney transplantation. In summary, there remain significant gaps in knowledge and uncertainties as to how to effectively use existing frailty measures to inform decision-making around kidney transplantation. Further research is needed to address these important gaps in the literature.

Narrative Review: Clinical Implications and Assessment of Frailty in Patients With Advanced CKD

Frailty is a multidimensional clinical syndrome characterized by low physical activity, reduced strength, accumulation of multiorgan deficits, decreased physiological reserve, and vulnerability to stressors. Frailty has key social, psychological, and cognitive implications. Frailty is accelerated by uremia, leading to a high prevalence of frailty in patients with advanced chronic kidney disease (CKD) and end-stage kidney disease (ESKD) as well as contributing to adverse outcomes in this patient population. Frailty assessment is not routine in patients with CKD; however, a number of validated clinical assessment tools can assist in prognostication. Frailty assessment in nephrology populations supports shared decision-making and advanced communication and should inform key medical transitions. Frailty screening and interventions in CKD or ESKD are a developing research priority with a rapidly expanding literature base.

Comprehensive geriatric assessment predicts listing for kidney transplant in patients with end-stage renal disease: a retrospective cohort study

BACKGROUND

Comprehensive geriatric assessment (CGA) involves a formal broad approach to assess frailty and creating a plan for management. However, the impact of CGA and its components on listing for kidney transplant in older adults has not been investigated.

METHODS

We performed a single-center retrospective study of patients with end-stage renal disease who underwent CGA during kidney transplant candidacy evaluation between 2017 and 2021. All patients ≥ 65 years old and those under 65 with any team member concern for frailty were referred for CGA, which included measurements of healthcare utilization, comorbidities, social support, short physical performance battery, Montreal Cognitive Assessment (MoCA), and Physical Frailty Phenotype (FPP), and estimate of surgical risk by the geriatrician.

RESULTS

Two hundred and thirty patients underwent baseline CGA evaluation; 58.7% (135) had high CGA ("Excellent" or "Good" rating for transplant candidacy) and 41.3% (95) had low CGA ratings ("Borderline," "Fair," or "Poor"). High CGA rating (OR 8.46; p < 0.05), greater number of CGA visits (OR 4.93; p = 0.05), younger age (OR 0.88; p < 0.05), higher MoCA scores (OR 1.17; p < 0.05), and high physical activity (OR 4.41; p < 0.05) were all associated with listing on transplant waitlist.

CONCLUSIONS

The CGA is a useful, comprehensive tool to help select older adults for kidney transplantation. Further study is needed to better understand the predictive value of CGA in predicting post-operative outcomes.

Physical Frailty Predicts Outcomes in Patients Undergoing Evaluation for Kidney Transplantation

INTRODUCTION

An increasing number of older patients are undergoing evaluation for kidney transplantation; however, older patients experience increased rates of complications compared with younger patients, leading to the study of frailty assessments. Although many centers have evaluated the Fried Frailty Phenotype (FFP), less is known about the ability of the Short Performance Physical Battery (SPPB) to predict outcomes.

METHODS

Frailty assessment by FFP and SPPB was introduced into routine outpatient evaluation for patients aged 55 years and older referred for transplantation. Transplant rate, length of stay, readmission up to 3 months posttransplant, and death were reviewed. Patients were evaluated in an initial cohort followed by a validation cohort by FFP and SPPB. Multivariate analysis correcting for demographic characteristics was applied.

RESULTS

Patient cohorts reflected the racial and ethnic diversity of our population, including approximately 40% Hispanic patients. The first cohort of 514 patients demonstrated a significant association between frailty as measured by SPPB and transplantation (odds ratio [OR], 2.27; 95% CI, 1.38-3.83; p = .002). The second cohort of 1408 patients validated the association between frailty measured by SPPB and transplantation (OR, 2.81; 95% CI, 1.83-4.48; p < .001). In addition, there was a significant association between nonfrail status measured by SPPB and death (OR, 0.16; 95% CI, 0.04-0.62; p = .006).

CONCLUSIONS

Frailty assessment is a potentially useful approach for the assessment of transplant candidates. Our real-world study examined the performance of 2 methods of frailty evaluation methods in a diverse population, demonstrating that SPPB but not FFP was predictive of clinical outcomes. Incorporation of frailty assessments into transplant evaluation may improve risk stratification and optimize outcomes for older patients.

Measurement properties of performance-based measures to assess physical function in chronic kidney disease: recommendations from a COSMIN systematic review

Background

There is wide heterogeneity in physical function tests available for clinical and research use, hindering our ability to synthesize evidence. The aim of this review was to identify and evaluate physical function measures that could be recommended for standardized use in chronic kidney disease (CKD).

Methods

MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, CINAHL, Scopus and Web of Science were searched from inception to March 2022, identifying studies that evaluated a clinimetric property (validity, reliability, measurement error and/or responsiveness) of an objectively measured performance-based physical function outcomes using the COnsensus-based Standards for the selection of health Measurement Instruments (COSMIN) methodology and Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) based recommendations. Studies with individuals of all ages and of any stage of CKD were included.

Results

In total, 50 studies with 21 315 participants were included. Clinimetric properties were reported for 22 different physical function tests. The short physical performance battery (SPPB), Timed-up-and-go (TUG) test and Sit-to-stand tests (STS-5 and STS-60) had favorable properties to support their use in CKD and should be integrated into routine use. However, the majority of studies were conducted in the hemodialysis population, and very few provided information regarding validity or reliability.

Conclusion

The SPPB demonstrated the highest quality of evidence for reliability, measurement error and construct validity amongst transplant, CKD and dialysis patients. This review is an important step towards standardizing a core outcome set of tools to measure physical function in research and clinical settings for the CKD population.

Examining the safety and effectiveness of a 4-week supervised exercise intervention in the treatment of frailty in patients with chronic kidney disease

Background

The optimal duration of antifrailty interventions and how best to deliver them to patients with chronic kidney disease (CKD) is unknown. The aim of this study was to examine the safety, feasibility and preliminary efficacy of a 4-week supervised exercise intervention on frailty in patients with CKD.

Methods

We conducted a prospective feasibility study involving patients with ≥stage 3 CKD (1 patient with stage 3 CKD, 7 patients with stage 4 CKD and 17 patients with stage 5 CKD) who were either frail or prefrail according to the physical frailty phenotype and/or had a Short Physical Performance Battery (SPPB) score ≤10. The exercise intervention consisted of two supervised outpatient sessions per week for 4 weeks (eight total sessions). Frailty and other study measures were assessed at baseline and after 4 weeks of exercise.

Results

Of the 34 participants who completed the baseline assessment and were included in the analyses, 25 (73.5%) completed the 4-week assessment. Overall, 64.0% of patients were on dialysis and 64.0% had diabetes mellitus. After 4 weeks of exercise, frailty prevalence, total SPPB scores and energy/fatigue scores improved. No adverse study-related outcomes were reported.

Conclusions

The 4 weeks of supervised exercise was safe, was associated with an excellent completion rate and improved frailty parameters in CKD patients with CKD. This study provides important preliminary data for a future larger prospective randomized study.

Clinical Trialgov

registration: NCT03535584.

Frailty and prognosis of patients with kidney transplantation: a meta-analysis

BACKGROUND

The prevalence of frailty among candidates and recipients of kidney transplantation (KT) is well-established, yet the impact of frailty on clinical outcomes following KT remains uncertain. To address this knowledge gap, we conducted a systematic meta-analysis to comprehensively assess the aforementioned relationship.

METHODS

The present study conducted a comprehensive search of PubMed, Embase, and Cochrane Library databases to identify relevant observational studies that compared mortality risk and other clinical outcomes of KT recipients with and without frailty. Two authors independently conducted data collection, literature searching, and statistical analysis. The results were synthesized using a heterogeneity-incorporating random-effects model.

RESULTS

In this meta-analysis, 6279 patients from 13 cohort studies were included, and 1435 patients (22.9%) were with frailty before KT. There were higher mortality rates among frail patients at admission, compared to those without frailty (risk ratio [RR]: 1.97, 95% confidence interval [CI]: 1.57 to 2.47, p < 0.001; I2 = 19%). Subgroup analysis suggested the association between frailty and high mortality risk after KT was consistent in studies of frailty assessed via Physical Frailty Phenotype or other methods, and in studies of follow-up duration < or ≥ 5 years. In addition, frailty was associated with higher incidence of delayed graft function (RR: 1.78, 95% CI: 1.21 to 2.61, p = 0.003; I2 = 0%), postoperative complications (RR: 1.88, 95% CI: 1.15 to 3.08, p = 0.01; I2 = 0%), and longer hospitalization (RR: 1.55, 95% CI: 1.22 to 1.97, p < 0.001; I2 = 0%).

CONCLUSION

Following KT, frail patients are at higher risks for all-cause mortality, delayed graft function, postoperative complications, and longer hospital stays.

Use of frailty assessment instruments in nephrology populations: a scoping review

BACKGROUND

Frailty is a clinical syndrome of accelerated aging associated with adverse outcomes. Frailty is prevalent among patients with chronic kidney disease but is infrequently assessed in clinical settings, due to lack of consensus regarding frailty definitions and diagnostic tools. This study aimed to review the practice of frailty assessment in nephrology populations and evaluate the context and timing of frailty assessment.

METHODS

The search included published reports of frailty assessment in patients with chronic kidney disease, undergoing dialysis or in receipt of a kidney transplant, published between January 2000 and November 2021. Medline, CINAHL, Embase, PsychINFO, PubMed and Cochrane Library databases were examined. A total of 164 articles were included for review.

RESULTS

We found that studies were most frequently set within developed nations. Overall, 161 studies were frailty assessments conducted as part of an observational study design, and 3 within an interventional study. Studies favoured assessment of participants with chronic kidney disease (CKD) and transplant candidates. A total of 40 different frailty metrics were used. The most frequently utilised tool was the Fried frailty phenotype. Frailty prevalence varied across populations and research settings from 2.8% among participants with CKD to 82% among patients undergoing haemodialysis. Studies of frailty in conservatively managed populations were infrequent (N = 4). We verified that frailty predicts higher rates of adverse patient outcomes. There is sufficient literature to justify future meta-analyses.

CONCLUSIONS

There is increasing recognition of frailty in nephrology populations and the value of assessment in informing prognostication and decision-making during transitions in care. The Fried frailty phenotype is the most frequently utilised assessment, reflecting the feasibility of incorporating objective measures of frailty and vulnerability into nephrology clinical assessment. Further research examining frailty in low and middle income countries as well as first nations people is required. Future work should focus on interventional strategies exploring frailty rehabilitation.

Frailty in kidney transplant candidates and recipients: pathogenesis and intervention strategies

ABSTRACT

With the rapid aging of the global population posing a serious problem, frailty, a non-specific state that reflects physiological senescence rather than aging in time, has become more widely addressed by researchers in various medical fields. A high prevalence of frailty is found among kidney transplant (KT) candidates and recipients. Therefore, their frailty has become a research hotspot in the field of transplantation. However, current studies mainly focus on the cross-sectional survey of the incidence of frailty among KT candidates and recipients and the relationship between frailty and transplantation. Research on the pathogenesis and intervention is scattered, and relevant review literature is scarce. Exploring the pathogenesis of frailty in KT candidates and recipients and determining effective intervention measures may reduce waiting list mortality and improve the long-term quality of life of KT recipients. Therefore, this review explains the pathogenesis and intervention measures for frailty in KT candidates and recipients to provide a reference for the formulation of effective intervention strategies.

Frailty assessment as part of transplant listing: yes, no or maybe?

Frailty, characterized by a decreased physiological reserve and an increased vulnerability to stressors, is common among kidney transplant (KT) candidates and recipients. In this review, we present and summarize the key arguments for and against the assessment of frailty as part of KT evaluation. The key arguments for including frailty were: (i) sheer prevalence and far-reaching consequences of frailty on KT, and (ii) the ability to conduct a more holistic and objective evaluation of candidates, removing the inaccuracy associated with 'eye-ball' assessments of transplant fitness. The key argument against were: (i) lack of agreement on the definition of frailty and which tools should be used in renal populations, (ii) a lack of clarity on how, by whom and how often frailty assessments should be performed, and (iii) a poor understanding of how acute stressors affect frailty. However, it is the overwhelming opinion that the time has come for frailty assessments to be incorporated into KT listing. Although ongoing areas of uncertainty exist and further evidence development is needed, the well-established impact of frailty on clinical and experiential outcomes, the invaluable information obtained from frailty assessments, and the potential for intervention outweigh these limitations. Proactive and early identification of frailty allows for individualized and improved risk assessment, communication and optimization of candidates.

Frailty and Age-Associated Assessments Associated with Chronic Kidney Disease and Transplantation Outcomes

Background. Frailty is often defined as a decrease in physiological reserve and has been shown to be correlated with adverse health outcomes and mortality in the general population. This condition is highly prevalent in the chronic kidney disease (CKD) patient population as well as in kidney transplant (KT) recipients. Other age-associated changes include sarcopenia, nutrition, cognition, and depression. In assessing the contributions of these components to patient outcomes and their prevalence in the CKD and KT patient population, it can be determined how such variables may be associated with frailty and the extent to which they may impact the adverse outcomes an individual may experience. Objectives. We sought to perform a systematic literature review to review published data on frailty and associated age-associated syndromes in CKD and KT patients. Results. Over 80 references pertinent to frailty, sarcopenia, nutrition, cognition, or depression in patients with CKD or KT were identified. Systematic review was performed to evaluate the data supporting the use of the following approaches: Fried Frailty, Short Physical Performance Battery, Frailty Index, Sarcopenia Index, CT scan quantification of muscle mass, health-related quality of life, and assessment tools for nutrition, cognition, and depression. Conclusion. This report represents a comprehensive review of previously published research articles on this topic. The intersectionality between all these components in contributing to the patient’s clinical status suggests a need for a multifaceted approach to developing comprehensive care and treatment for the CKD and KT population to improve outcomes before and after transplantation.

Factors associated with frailty in kidney transplant recipients: A cross-sectional study

BACKGROUND

Frailty is prevalent in kidney transplant recipients and associated with multiple health care challenges. The association between frailty and outcomes has been extensively studied in kidney transplant recipients, but the status of frailty and its associated factors are not well studied, hindering efforts to develop strategies to improve care and reduce frailty.

OBJECTIVES

To identify the factors that are associated with frailty in kidney transplant recipients comprehensively.

DESIGN AND PARTICIPANTS

The associated factors of frailty were explored by a cross-sectional study of 185 kidney transplant recipients.

MEASUREMENTS

Data were collected using the general information questionnaire, the Charlson comorbidity index, the Pittsburgh Sleep Quality Index, the Hospital Anxiety and Depression Scale, the Connor-Davidson Resilience Scale, the Perceived Social Support Scale and the Tilburg Frailty Indicator. Data were analyzed using the multiple linear regression analysis.

RESULTS

A total of 75 (40.5%) kidney transplant recipients were assessed as frail by Chinese TFI. Age (β = 0.228), time post-transplant (β = 0.055), sleep quality (β = 0.224) and psychological resilience (β = -0.038) entered the final multiple regression equation and accounted for 41.8% of the total frailty variation (R²  = 0.418, F = 21.31, p < 0.05).

CONCLUSIONS

Frailty was common among kidney transplant recipients. Old age, long time after transplantation, poor sleep quality and low psychological resilience were main associated factors for frailty. Integrated care interventions are therefore needed for this vulnerable population to prevent or delay frailty.

Comprehensive review: Frailty in pancreas transplant candidates and recipients

Well-selected patients with kidney disease and diabetes mellitus who undergo simultaneous kidney-pancreas transplantation often experience dramatic improvements in quality of life and long-term survival compared to those who remain on medical therapy. Over the past several years the importance of frailty in the pancreas transplant candidate and recipient populations has grown. More patients with advanced age have entered the waitlist, and complications from prolonged diabetes, even in younger patients, have created increased evidence of risk for frailty. Given these concerns, and the broad challenges facing pancreas transplantation volumes overall, we generated this review to help establish the impact and implications. We summarize the interplay of immunological factors, aging, environmental factors, diabetes mellitus, and chronic kidney disease that put these patients at risk for frailty. We discuss its measurement and recommend a combination of two instruments (both well-validated and one entirely objective). We describe the outcomes for patients before and after pancreas transplantation who may have frailty, and what interventions can be taken to mitigate its effects. Broader investigation into frailty in the pancreas transplant population is needed to better understand how to select patients for pancreas transplantation and to how manage its consequences thereafter.

Evaluation of Frailty Measures and Short-term Outcomes After Lung Transplantation

BACKGROUND

Frailty, measured as a single construct, is associated variably with poor outcomes before and after lung transplantation. The usefulness of a comprehensive frailty assessment before transplantation is unknown.

RESEARCH QUESTION

How are multiple frailty constructs, including phenotypic and cumulative deficit models, muscle mass, exercise tolerance, and social vulnerabilities, measured before transplantation, associated with short-term outcomes after lung transplantation?

STUDY DESIGN AND METHODS

We conducted a retrospective cohort study of 515 lung recipients who underwent frailty assessments before transplantation, including the short physical performance battery (SPPB), transplant-specific frailty index (FI), 6-min walk distance (6MWD), thoracic sarcopenia, and social vulnerability indexes. We tested the association between frailty measures before transplantation and outcomes after transplantation using logistic regression to model 1-year survival and zero-inflated negative binomial regression to model hospital-free days (HFDs) in the first 90 days after transplantation. Adjustment covariates included age, sex, native lung disease, transplantation type, lung allocation score, BMI, and primary graft dysfunction.

RESULTS

Before transplantation, 51.3% of patients were frail by FI (FI ≥ 0.25) and no patients were frail by SPPB. In multivariate adjusted models that also included FI, SPPB, and 6MWD, greater frailty by FI, but not SPPB, was associated with fewer HFDs (-0.006 per 0.01 unit worsening; 95% CI, -0.01 to -0.002 per 0.01 unit worsening) among discharged patients. Greater SPPB deficits were associated with decreased odds of 1-year survival (OR, 0.51 per 1 unit worsening; 95% CI, 0.28-0.93 per 1 unit worsening). Correlation among frailty measurements overall was poor. No association was found between thoracic sarcopenia, 6MWD, or social vulnerability assessments and short-term outcomes after lung transplantation.

INTERPRETATION

Both phenotypic and cumulative deficit models measured before transplantation are associated with short-term outcomes after lung transplantation. Cumulative deficit measures of frailty may be more relevant in the first 90 days after transplantation, whereas phenotypic frailty may have a stronger association with 1-year survival.

Relationship of Exercise Capacity, Physical Function, and Frailty Measures With Clinical Outcomes and Healthcare Utilization in Lung Transplantation: A Scoping Review

Measures of exercise capacity, frailty, and physical function are commonly used in lung transplant candidates and recipients to evaluate their physical limitations and the effects of exercise training and to select candidates for transplantation. It is unclear how these measures are related to clinical outcomes and healthcare utilization before and after lung transplantation. The purpose of this scoping review was to describe how measures of exercise capacity, physical function, and frailty are related to pre- and posttransplant outcomes.

Frailty in end stage renal disease: Current perspectives

Frailty is common in end stage renal disease (ESRD) and is a marker of poor outcomes. Its prevalence increases as chronic kidney disease (CKD) progresses. There are different measurement tools available to assess frailty in ESRD. The pathogenesis of frailty in ESRD is multifactorial including uraemia and dialysis related factors. In this current review, we discuss the importance of frailty, its pathogenesis, screening methods, prognostic implications and management strategies in context of ESRD.

Short physical performance battery as a predictor of mortality in community-dwelling older adults: a longitudinal study in the Brazilian Amazon region

Background

The Short Physical Performance Battery (SPPB) is an instrument for assessing physical performance widely used in research among the elderly in multiple settings. We did not find Brazilian longitudinal studies that aimed to analyze the predictive capacity and accuracy of the SPPB among community-dwelling older adults and no systematic reviews were found on the accuracy of the SPPB in predicting mortality in community- dwelling older adults. This study aimed to analyze the capacity and accuracy of the SPPB for predicting mortality in community-dwelling older adults, as well as to determine cut-off points for men and women.

Method

Longitudinal observational study conducted with 411 (70.1 ± 7.25 years) community-dwelling older adults, between 2017 and 2020 (37.7 ± 6.24 months). Physical performance was evaluated using the SPPB and information on the all-cause mortality rate was also recorded. Multivariate Cox regression analyses and curves were performed using the Kaplan-Meier method. Receiver Operating Characteristic (ROC) curves were constructed, with the parameters of area under the ROC curve (AUC) to determine cutoff points for discriminating mortality, considering a significance level of 5% (p < 0.05) and 95% confidence interval (CI) 95%.

Results

Older adults with very low and low physical performance in the SPPB, showed higher risks of mortality (HR = 9.67; 95% CI [1.20-77.65]; HR = 4.06; 95% CI [1.09-15.01]), respectively. In the subtest's analysis, older adults with low performance in the balance (HR = 0.54; 95% CI [0.36-0.81]) and gait speed tests (HR = 0.50; 95% CI [0.33-0.76]) showed greater risks of dying. The same was reproduced for categories in each test (participants that scored 2 points in the balance test had an HR = 5.86; 95% CI [1.84-18.61] and 2 points in the gait speed test, HR = 5.07; 95% CI [1.76-14.58]. The cutoff point ≤ 9 in the SPPB set the discriminator criterion for mortality in older people of both sexes.

Conclusions

The SPPB, as well as the balance and gait speed subtests were predictors of mortality, and the SPPB is accurate in predicting mortality among community-dwelling older adults.

Effects of Artificial Intelligence-Derived Body Composition on Kidney Graft and Patient Survival in the Eurotransplant Senior Program

The Eurotransplant Senior Program allocates kidneys to elderly transplant patients. The aim of this retrospective study is to investigate the use of computed tomography (CT) body composition using artificial intelligence (AI)-based tissue segmentation to predict patient and kidney transplant survival. Body composition at the third lumbar vertebra level was analyzed in 42 kidney transplant recipients. Cox regression analysis of 1-year, 3-year and 5-year patient survival, 1-year, 3-year and 5-year censored kidney transplant survival, and 1-year, 3-year and 5-year uncensored kidney transplant survival was performed. First, the body mass index (BMI), psoas muscle index (PMI), skeletal muscle index (SMI), visceral adipose tissue (VAT), and subcutaneous adipose tissue (SAT) served as independent variates. Second, the cut-off values for sarcopenia and obesity served as independent variates. The 1-year uncensored and censored kidney transplant survival was influenced by reduced PMI (p = 0.02 and p = 0.03, respectively) and reduced SMI (p = 0.01 and p = 0.03, respectively); 3-year uncensored kidney transplant survival was influenced by increased VAT (p = 0.04); and 3-year censored kidney transplant survival was influenced by reduced SMI (p = 0.05). Additionally, sarcopenia influenced 1-year uncensored kidney transplant survival (p = 0.05), whereas obesity influenced 3-year and 5-year uncensored kidney transplant survival. In summary, AI-based body composition analysis may aid in predicting short- and long-term kidney transplant survival.

Long-Term Trajectories of Frailty and Its Components After Kidney Transplantation

BACKGROUND

Frailty is common and associated with poor outcomes among kidney transplant (KT) recipients. While frailty improves in the first 3 months post-KT with restored kidney function, longer-term trajectories are likely to plateau/decline due to aging and other stressors (eg, immunosuppression). We evaluated longer-term post-KT trajectories of the physical frailty phenotype (PFP) and its components in adult patients at 2 centers.

METHODS

PFP components were measured at admission, 1, 3, 6 months, 1 year, and annually thereafter post-KT. We used adjusted mixed-effects models to describe repeated measures of continuous components (weight, gait speed, grip strength, activity) and generalized estimating equations to quantify longitudinal, binomial response patterns (PFP; exhaustion).

RESULTS

Among 1 336 recipients (mean age = 53) followed for a median of 1.9 years (interquartile range [IQR] = 0.1-3.2), likelihood of frailty declined in the first 2.5 years post-KT (adjusted odds ratio [aOR] = 0.96, 95% confidence interval [CI]: 0.95, 0.98), but increased after 2.5 years post-KT (aOR = 1.03, 95% CI: 1.00, 1.05). In the first 2.5 years post-KT, recipients demonstrated increases in weight (0.4 lbs/month, 95% CI: 0.3, 0.5), grip strength (0.2 kg/month, 95% CI: 0.1, 0.2), and activity (23.9 kcal/month, 95% CI: 17.5, 30.2); gait speed remained stable (-0.01 s/month, 95% CI: 0.01, 0.003). Additionally, likelihood of becoming exhausted declined post-KT (OR = 0.99, 95% CI: 0.98, 1.00). After 2.5 years post-KT, recipients demonstrated decreased grip strength (-0.07 kg/month, 95% CI: -0.12, -0.01) and activity (-20 kcal/month, 95% CI: -32.3, -8.2); they had stable weight (-0.003 lbs/month, 95% CI: -0.17, 0.16), gait speed (-0.003 s/month, 95% CI: -0.02, 0.01), and likelihood of becoming exhausted (OR = 1.01, 95% CI: 0.99, 1.02).

CONCLUSION

Despite frailty improvements in the first 2.5 years, recipients' frailty worsened after 2.5 years post-KT. Specifically, they experienced gains in strength, activity, and exhaustion in the first 2.5 years post-KT, but declined in strength and activity after 2.5 years post-KT while experiencing persistent slowness. Clinicians should consider monitoring recipients for worsening frailty after 2.5 years despite shorter-term improvements.

Transplant centers that assess frailty as part of clinical practice have better outcomes

BACKGROUND

Frailty predicts adverse post-kidney transplant (KT) outcomes, yet the impact of frailty assessment on center-level outcomes remains unclear. We sought to test whether transplant centers assessing frailty as part of clinical practice have better pre- and post-KT outcomes in all adult patients (≥18 years) and older patients (≥65 years).

METHODS

In a survey of US transplant centers (11/2017-4/2018), 132 (response rate = 65.3%) centers reported their frailty assessment practices (frequency and specific tool) at KT evaluation and admission. Assessment frequency was categorized as never, sometime, and always; type of assessment tool was categorized as none, validated (for post-KT risk prediction), and any other tool. Center characteristics and clinical outcomes for adult patients during 2017-2019 were gleaned from the transplant national registry (Scientific Registry of Transplant Recipients). Poisson regression was used to estimate incidence rate ratios (IRRs) of waitlist outcomes (waitlist mortality, transplantation) in candidates and IRRs of post-KT outcomes (all-cause mortality, death-censored graft loss) in recipients by frailty assessment frequency. We also estimated IRRs of waitlist outcomes by type of assessment tool at evaluation. All models were adjusted for case mix and center characteristics.

RESULTS

Assessing frailty at evaluation was associated with lower waitlist mortality rate (always IRR = 0.91,95%CI:0.84-0.99; sometimes = 0.89,95%CI:0.83-0.96) and KT rate (always = 0.94,95%CI:0.91-0.97; sometimes = 0.88,95%CI:0.85-0.90); the associations with waitlist mortality rate (always = 0.86,95%CI:0.74-0.99; sometimes = 0.83,95%CI:0.73-0.94) and KT rate (always = 0.82,95%CI:0.77-0.88; sometimes = 0.92,95%CI:0.87-0.98) were stronger in older patients. Furthermore, using validated (IRR = 0.90,95%CI:0.88-0.92) or any other tool (IRR = 0.90,95%CI:0.87-0.93) at evaluation was associated lower KT rate, while only using a validated tool was associated with lower waitlist mortality rate (IRR = 0.89,95%CI:0.83-0.96), especially in older patients (IRR = 0.82,95%CI:0.72-0.93). At admission for KT, always assessing frailty was associated with a lower graft loss rate (IRR = 0.71,95%CI:0.54-0.92) but not with mortality (IRR = 0.93,95%CI:0.76-1.13).

CONCLUSIONS

Assessing frailty at evaluation is associated with lower KT rate, while only using a validated frailty assessment tool is associated with better survival, particularly in older candidates. Centers always assessing frailty at admission are likely to have better graft survival rates. Transplant centers may utilize validated frailty assessment tools to secure KT access for appropriate candidates and to better allocate health care resources for patients identified as frail, particularly for older patients.

Change in Physical Activity and Function in Patients with Baseline Advanced Nondialysis CKD

BACKGROUND AND OBJECTIVES

Although progressive decline in physical activity and function are common in individuals with worsening CKD, little is known about the effect of dialysis initiation on physical activity. We assessed for any association of progression to dialysis in people with advanced CKD with temporal rates of change in physical activity and function.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Canadian Frailty Observation and Interventions Trial (CanFIT) participants with an eGFR of <30 ml/min per 1.73 m² were included. Outcomes included change in physical activity level, measured using the Physical Activity Scale for the Elderly, and physical function, measured using the chair stand, 4-m gait speed, and grip strength tests. Generalized linear regression models were conducted to determine whether dialysis initiation was associated with greater decline in physical activity or function.

RESULTS

Of 386 individuals, 162 progressed to dialysis. Both assessments were completed by 98% of individuals for the Physical Activity Scale for the Elderly, 86% for the chair stand test, 84% for the gait speed test, and 91% for the grip strength test. Median (interquartile range) interassessment follow-up was 427 (357-578) days for the "stable advanced CKD" group and 606 (428-1000) days for the "progressed to dialysis" group. Self-reported physical activity and gait speed significantly declined in both groups. Mean (SD) chair stand time increased from 20.8 (17.1) to 24.0 (21.0) seconds among patients with stable advanced CKD, and from 18.5 (15.4) to 27.4 (22.2) seconds among those who progressed to dialysis (adjusted difference in change, 5.2 seconds; 95% confidence interval, 0.8 to 9.7 seconds; P=0.02).

CONCLUSIONS

Patients with advanced CKD experience progressive declines in physical activity and function. Transition to dialysis is associated with accelerated decline in physical function, as measured by the chair stand test.

The clinical application of frailty in nephrology and transplantation

PURPOSE OF REVIEW

Clinicians treating end-stage kidney disease (ESKD) and kidney transplant patients face unique challenges in their care because of the high burden of frailty in these patients. Frailty has gained significant attention by medical and surgical specialties for risk stratification in the past decades. This review highlights the importance of measuring frailty in kidney transplant candidates and recipients.

RECENT FINDINGS

Emerging data support that frailty is present even at younger ages among patients undergoing dialysis, transplant evaluation, or transplantation. It is estimated that 18.8% of younger (18-64 years) candidates, 25.2% of older (≥65 years) candidates, 14.3% of younger recipients, and 20.8% of older recipients are frail. Additionally, frailty is dynamic and subject to change pretransplantation and posttransplantation. Although many patients and clinicians are aware of the importance of measuring frailty, further studies addressing the need for interventions to reduce frailty burden are needed.

SUMMARY

Frailty is independently associated with many adverse outcomes in ESKD and kidney transplant populations. Given the growing number of ESKD and kidney transplant patients, it is pivotal to expand the utility of frailty measurement in clinical practice, recognize the burden of frailty, and identify appropriate interventions to mitigate the adverse effects of frailty.

Short Physical Performance Battery as a Measure of Physical Performance and Mortality Predictor in Older Adults: A Comprehensive Literature Review

The association between the Short Physical Performance Battery (SPPB) score and several adverse health outcomes, including mortality, has been reported in the scientific literature. We conducted a comprehensive literature review of studies on the relationship between SPPB and mortality. The current paper synthesizes the characteristics and main findings of longitudinal studies available in the literature that investigated the role of the SPPB in predicting mortality in older adults. The studies (n = 40) are from North America, South America, Europe, and Asia; the majority (n = 16) were conducted with community-dwelling older adults and reported an association between lower SPPB scores and a higher risk of mortality, and between higher SPPB scores and higher survival. Nevertheless, few studies have analyzed the accuracy of the instrument to predict mortality. The only study that established cut-off points was conducted with older adults discharged from an acute care hospital. Although an SPPB score lower than 10 seems to predict all-cause mortality, further studies showing cut-off points in specific settings and loco-regional specificities are still necessary.

Association of physical function and performance with peak VO2 in elderly patients with end stage kidney disease

BACKGROUND

Physical function is impaired in end stage renal disease (ESRD). Various instruments have been used to assess the functional capabilities and health status of patients with ESRD, but it is not known which has the best association with peak VO₂.

AIMS

To assess the association between functional measures in ESRD.

METHODS

Thirty nine elderly ESRD patients were evaluated with commonly used functional, health status, and quality of life measures, including maximal cardiopulmonary exercise testing (CPET), 6-min walk (6MWT), sit-to-stand test (STS), Veterans Specific Activity Questionnaire (VSAQ), upper and lower body strength, pulmonary function tests, and body composition determined by dual X-ray absorptiometry. The association between performance on these functional tools, clinical variables, and exercise test responses was assessed, and a non-exercise test multivariate model was developed to predict peak VO₂.

RESULTS

Peak VO₂ was modestly related to VSAQ score (r = 0.59, p < 0.01), indices of upper and lower body strength (r = 0.45, p < 0.01 for both), and FEV₁ (r = 0.51, p < 0.01). Functional and quality of life questionnaires were generally poorly related to one another and to peak VO₂. In a multivariate model, 6MWT performance, forced expiratory volume in 1 s (FEV₁), and VSAQ score were the best predictors of peak VO₂, yielding a multiple R = 0.82, accounting for 67% of the variance in peak VO₂.

CONCLUSION

Exercise capacity can be reasonably estimated using non-exercise test variables in patients with ESRD, including a symptom questionnaire (VSAQ), 6MWT and FEV₁.

CLINICAL TRIAL INFORMATION

ClinicalTrials.gov identifier: NCT01990495. Registered Nov 21, 2013.

Changes in Functional Status Among Kidney Transplant Recipients: Data From the Scientific Registry of Transplant Recipients

BACKGROUND

With stressors of dialysis prekidney transplantation (KT) and restoration of kidney function post-KT, it is likely that KT recipients experience a decline in functional status while on the waitlist and improvements post-KT.

METHODS

We leveraged 224 832 KT recipients from the national registry (SRTR, February 1990-May 2019) with measured Karnofsky Performance Status (KPS, 0%-100%) at listing, KT admission, and post-KT. We quantified the change in KPS from listing to KT using generalized linear models. We described post-KT KPS trajectories using adjusted mixed-effects models and tested whether those trajectories differed by age, sex, race, and diabetes status using a Wald test among all KT recipients. We then quantified risk adverse post-KT outcomes (mortality and all-cause graft loss [ACGL]) by preoperative KPS and time-varying KPS.

RESULTS

Mean KPS declined from listing (83.7%) to admission (78.9%) (mean = 4.76%, 95% confidence interval [CI]: -4.82, -4.70). After adjustment, mean KPS improved post-KT (slope = 0.89%/y, 95% CI: 0.87, 0.91); younger, female, non-Black, and diabetic recipients experienced greater post-KT improvements (Pinteractions < 0.001). Lower KPS (per 10% decrease) at admission was associated with greater mortality (adjusted hazard ratio [aHR] = 1.11, 95% CI: 1.10, 1.11) and ACGL (aHR = 1.08, 95% CI: 1.08, 1.09) risk. Lower post-KT KPS (per 10% decrease; time-varying) were more strongly associated with mortality (aHR = 1.93, 95% CI: 1.92, 1.94) and ACGL (aHR = 1.84, 95% CI: 1.83, 1.85).

CONCLUSIONS

Functional status declines pre-KT and improves post-KT in the national registry. Despite post-KT improvements, poorer functional status at KT and post-KT are associated with greater mortality and ACGL risk. Because of its dynamic nature, clinicians should repeatedly screen for lower functional status pre-KT to refer vulnerable patients to prehabilitation in hopes of reducing risk of adverse post-KT outcomes.

Pretransplant Comprehensive Geriatric Assessment in Older Patients with Advanced Chronic Kidney Disease

BACKGROUND

In older patients with advanced chronic kidney disease (CKD), the decision of kidney transplantation (KT) is a challenge for nephrologists. The use of comprehensive geriatric assessment (CGA) is increasingly gaining interest into the process of decision-making about treatment modality choice for CKD. The aim of this study was to assess the prevalence of geriatric impairment and frailty in older dialysis and nondialysis patients with advanced CKD using a pretransplant CGA model and to identify geriatric impairments influencing the geriatricians' recommendations for KT.

METHODS

An observational study was conducted with retrospective data from July 2017 to January 2020. Patients aged ≥65 years with advanced CKD, treated or not with dialysis, and referred by the nephrologist were included in the study. The CGA assessed comorbidity burden, cognition, mood, nutritional status, (instrumental) activities of daily living, physical function, frailty, and polypharmacy. Geriatric impairments influencing the geriatricians' recommendations for KT were identified using univariate and multivariate logistic regressions.

RESULTS

156 patients were included (74.2 ± 3.5 years and 62.2% on dialysis). Geriatric conditions were highly prevalent in both dialysis and nondialysis groups. The rate of geriatric impairments was higher in dialysis patients regarding comorbidity burden, symptoms of depression, physical function, autonomy, and frailty. Geriatrician's recommendations for KT were as follows: favorable (79.5%) versus not favorable or multidisciplinary discussion needed with nephrologists (20.5%). Dependence for Instrumental Activities of Daily Living (IADL) (odds ratio [OR] = 3.01 and 95% confidence interval [CI] = 1.30-7.31), physical functions (OR = 2.91 and 95% CI = 1.08-7.87), and frailty (OR = 2.66 and 95% CI = 1.07-6.65) were found to be independent geriatric impairments influencing geriatrician's recommendations for KT.

CONCLUSIONS

Understanding the burden of geriatric impairment provides an opportunity to direct KT decision-making and to guide interventions to prevent functional decline and preserve quality of life.

Preoperative Cardiovascular Assessment of the Renal Transplant Recipient: A Narrative Review

Patients with end-stage kidney disease (ESKD) have a high prevalence of cardiovascular disease; it is the leading cause of death in these patients and the optimisation of their cardiovascular health may improve their post-transplant outcomes. Patients awaiting renal transplant often spend significant amounts of time on the waiting list allowing for the assessment and optimisation of their cardiovascular system. Coronary artery disease (CAD) is commonly seen in these patients and we explore the possible functional and anatomical investigations that can help assess and manage CAD in renal transplant candidates. We also discuss other aspects of cardiovascular assessment and management including arrhythmias, impaired ventricular function, valvular disease, lifestyle and pulmonary arterial hypertension. We hope that this review can form a basis for centres hoping to implement an enhanced recovery after surgery (ERAS) protocol for renal transplantation.

Frailty and Kidney Transplantation: A Systematic Review and Meta-analysis

Frailty is a multidimensional condition and is the result of the body's age-associated decline in physical, cognitive, physiological, and immune reserves. The aim of this systematic review is to assess the quality of evidence of the included studies, determine the prevalence of frailty among kidney transplant candidates, and evaluate the relationship between frailty and associated patient characteristics and outcomes after kidney transplantation.

METHODS

A systematic search was performed for relevant literature on frailty and kidney transplantation. This was followed by a meta-analysis for patient characteristics and outcomes reported by a minimum of 2 studies including mean age, gender, mean body mass index, type of kidney transplantation, dialysis, previous kidney transplantation, comorbidities, hypertension, race, preemptive kidney transplantation, delayed graft function, and length of stay.

RESULTS

A total of 18 studies were included in the systematic review and 14 of those studies were suitable for meta-analysis. The overall pooled prevalence of frailty before transplantation was estimated at 17.1% (95% confidence interval [CI], 15.4-18.7). Frailty was significantly associated with higher age (mean difference, 3.6; 95% CI, 1.4-5.9), lower rate of preemptive transplantation (relative risk, 0.60; 95% CI, 0.4-0.9), longer duration of delayed graft function (relative risk, 1.80; 95% CI, 1.1-3.0), and length of stay longer than 2 wk (odds ratio, 1.64; 95% CI, 1.2-2.3).

CONCLUSIONS

One in 6 kidney transplant recipients is frail before transplantation. The presence of frailty is associated with lower rates of preemptive transplantation, older recipient age, higher rates of delayed graft function, and longer length of stay. Future research is required to explore the association of frailty with other adverse outcomes after kidney transplantation and the effects of intervention programs to improve the different frailty domains.

Frailty and kidney transplant candidates

Frailty is a concept that has been mainly developed in geriatrics and it came from the need of identifying subjects at risk to develop complications when they faced a stressful event. Frail patients have higher risk of mortality, poor outcomes and disability, and this is independent from their age or comorbidities. Chronic kidney disease patients present with high prevalence of frailty, especially those who are in renal replacement therapy. Frail or pre-frail patients on the kidney transplant waiting list represent 20-30%, and these patients are proven to have poorer results after the transplant, which is a stressful event itself. Tools for frailty assessment, both scales or indexes, may be useful to identify which subjects might be at risk for complications after transplant, and this is necessary to adapt our clinical practice and minimize morbidity. The most used frailty scale in kidney patients is Fried scale, which is based in five phenotypic items. Besides that, knowing frail population allows potential interventions such as prehabilitation while the patient is waiting for the kidney transplant, which the aim of improving their vulnerability prior to transplant and, therefore, optimizing results after transplant. More studies are needed amongst kidney patients to improve and prevent frailty.

Measuring frailty in younger populations: a rapid review of evidence

OBJECTIVES

Frailty is typically assessed in older populations. Identifying frailty in adults aged under 60 years may also have value, if it supports the delivery of timely care. We sought to identify how frailty is measured in younger populations, including evidence of the impact on patient outcomes and care.

DESIGN

A rapid review of primary studies was conducted.

DATA SOURCES

Four databases, three sources of grey literature and reference lists of systematic reviews were searched in March 2020.

ELIGIBILITY CRITERIA

Eligible studies measured frailty in populations aged under 60 years using experimental or observational designs, published after 2000 in English.

DATA EXTRACTION AND SYNTHESIS

Records were screened against review criteria. Study data were extracted with 20% of records checked for accuracy by a second researcher. Data were synthesised using a narrative approach.

RESULTS

We identified 268 studies that measured frailty in samples that included people aged under 60 years. Of these, 85 studies reported evidence about measure validity. No measures were identified that were designed and validated to identify frailty exclusively in younger groups. However, in populations that included people aged over and under 60 years, cumulative deficit frailty indices, phenotype measures, the FRAIL Scale, the Liver Frailty Index and the Short Physical Performance Battery all demonstrated predictive validity for mortality and/or hospital admission. Evidence of criterion validity was rare. The extent to which measures possess validity across the younger adult age (18-59 years) spectrum was unclear. There was no evidence about the impact of measuring frailty in younger populations on patient outcomes and care.

CONCLUSIONS

Limited evidence suggests that frailty measures have predictive validity in younger populations. Further research is needed to clarify the validity of measures across the adult age spectrum, and explore the utility of measuring frailty in younger groups.

Cumulative Deficits Frailty Index Predicts Outcomes for Solid Organ Transplant Candidates

Supplemental Digital Content is available in the text.

Despite comprehensive multidisciplinary candidacy assessments to determine appropriateness for solid organ transplantation, limitations persist in identifying candidates at risk of adverse outcomes. Frailty measures may help inform candidacy evaluation. Our main objective was to create a solid organ transplant frailty index (FI), using the cumulative deficits model, from data routinely collected during candidacy assessments. Secondary objectives included creating a social vulnerability index (SVI) from assessment data and evaluating associations between the FI and assessment, waitlist, and posttransplant outcomes.

Physical Function in Kidney Transplantation: Current Knowledge and Future Directions

Purpose of review

Low physical function (PF) is common among individuals with end-stage kidney disease. In this review, we explore data on the impacts of PF on access to kidney transplantation (KT) and KT outcomes. We also discuss the latest interventions to improve PF in pre- and post-KT settings.

Recent Findings

Many US KT programs measure PF or related constructs when assessing KT candidacy. Although carefully selected KT candidates with low PF can benefit from KT with respect to survival and quality of life, low PF decreases the likelihood of being listed for KT and increases the risk of adverse post-KT outcomes. Recent trials suggest that exercise is a promising strategy to improve PF among KT candidates and recipients.

Summary

PF is a potentially modifiable risk factor for adverse pre- and post-KT outcomes. Research is needed to determine the ideal PF metric for use in KT evaluations and interventions to improve PF.

[Frailty and kidney transplant candidates]

Frailty is a concept that has been mainly developed in geriatrics and it came from the need of identifying subjects at risk to develop complications when they faced a stressful event. Frail patients have higher risk of mortality, poor outcomes and disability, and this is independent from their age or comorbidities. Chronic kidney disease patients present with high prevalence of frailty, especially those who are in renal replacement therapy. Frail or pre-frail patients on the kidney transplant waiting list represent 20-30%, and these patients are proven to have poorer results after the transplant, which is a stressful event itself. Tools for frailty assessment, both scales or indexes, may be useful to identify which subjects might be at risk for complications after transplant, and this is necessary to adapt our clinical practice and minimize morbidity. The most used frailty scale in kidney patients is Fried scale, which is based in five phenotypic items. Besides that, knowing frail population allows potential interventions such as prehabilitation while the patient is waiting for the kidney transplant, which the aim of improving their vulnerability prior to transplant and, therefore, optimizing results after transplant. More studies are needed amongst kidney patients to improve and prevent frailty.

Toward telemedicine-compatible physical functioning assessments in kidney transplant candidates

Frailty is associated with adverse kidney transplant outcomes and can be assessed by subjective and objective metrics. There is increasing recognition of the value of metrics obtainable remotely. We compared the self‐reported SF‐36 physical functioning subscale score (SF‐36 PF) with in‐person physical performance tests (6‐min walk and sit‐to‐stand) in a prospective cohort of kidney transplant candidates. We assessed each metric's ability to predict time to the composite outcome of waitlist removal or death, censoring at transplant. We built time‐dependent receiver operating characteristic curves and calculated the area under the curve [AUC(t)] at 1 year, using bootstrapping for internal validation. In 199 patients followed for a median of 346 days, 41 reached the composite endpoint. Lower SF‐36 PF scores were associated with higher risk of waitlist removal/death, with every 10‐point decrease corresponding to a 16% increase in risk. All models showed an AUC(t) of 0.83–0.84 that did not contract substantially after internal validation. Among kidney transplant candidates, SF‐36 PF, obtainable remotely, can help to stratify the risk of waitlist removal or death, and may be used as a screening tool for poor physical functioning in ongoing candidate evaluation, particularly where travel, increasing patient volume, or other restrictions challenge in‐person assessment.

An overview of frailty in kidney transplantation: measurement, management and future considerations

The construct of frailty was first developed in gerontology to help identify older adults with increased vulnerability when confronted with a health stressor. This article is a review of studies in which frailty has been applied to pre- and post-kidney transplantation (KT) populations. Although KT is the optimal treatment for end-stage kidney disease (ESKD), KT candidates often must overcome numerous health challenges associated with ESKD before receiving KT. After KT, the impacts of surgery and immunosuppression represent additional health stressors that disproportionately impact individuals with frailty. Frailty metrics could improve the ability to identify KT candidates and recipients at risk for adverse health outcomes and those who could potentially benefit from interventions to improve their frail status. The Physical Frailty Phenotype (PFP) is the most commonly used frailty metric in ESKD research, and KT recipients who are frail at KT (~20% of recipients) are twice as likely to die as nonfrail recipients. In addition to the PFP, many other metrics are currently used to assess pre- and post-KT vulnerability in research and clinical practice, underscoring the need for a disease-specific frailty metric that can be used to monitor KT candidates and recipients. Although frailty is an independent risk factor for post-transplant adverse outcomes, it is not factored into the current transplant program risk-adjustment equations. Future studies are needed to explore pre- and post-KT interventions to improve or prevent frailty.

Frailty and the Kidney Transplant Wait List: Protocol for a Multicenter Prospective Study

Background:

Understanding how frailty affects patients listed for transplantation has been identified as a priority research need. Frailty may be associated with a high risk of death or wait-list withdrawal, but this has not been evaluated in a large multicenter cohort of Canadian wait-listed patients.

Objective:

The primary objective is to evaluate whether frailty is associated with death or permanent withdrawal from the transplant wait list. Secondary objectives include assessing whether frailty is associated with hospitalization, quality of life, and the probability of being accepted to the wait list.

Design:

Prospective cohort study.

Setting:

Seven sites with established renal transplant programs that evaluate patients for the kidney transplant wait list.

Patients:

Individuals who are being considered for the kidney transplant wait list.

Measurements:

We will assess frailty using the Fried Phenotype, a frailty index, the Short Physical Performance Battery, and the Clinical Frailty Scale at the time of listing for transplantation. We will also assess frailty at the time of referral to the wait list and annually after listing in a subgroup of patients.

Methods:

The primary outcome of the composite of time to death or permanent wait-list withdrawal will be compared between patients who are frail and those who are not frail and will account for the competing risks of deceased and live donor transplantation. Secondary outcomes will include number of hospitalizations and length of stay, and in a subset, changes in frailty severity over time, change in quality of life, and the probability of being listed. Recruitment of 1165 patients will provide >80% power to identify a relative hazard of ≥1.7 comparing patients who are frail to those who are not frail for the primary outcome (2-sided α = .05), whereas a more conservative recruitment target of 624 patients will provide >80% power to identify a relative hazard of ≥2.0.

Results:

Through December 2019, 665 assessments of frailty (inclusive of those for the primary outcome and all secondary outcomes including repeated measures) have been completed.

Limitations:

There may be variation across sites in the processes of referral and listing for transplantation that will require consideration in the analysis and results.

Conclusions:

This study will provide a detailed understanding of the association between frailty and outcomes for wait-listed patients. Understanding this association is necessary before routinely measuring frailty as part of the wait-list eligibility assessment and prior to ascertaining the need for interventions that may modify frailty.

Trial Registration:

Not applicable as this is a protocol for a prospective observational study.

Poor Outcomes in Kidney Transplant Candidates and Recipients With History of Falls

BACKGROUND

Falls occur in 28% of hemodialysis patients and increase the risk of physical impairment, morbidity, and mortality. Therefore, it is likely that kidney transplantation (KT) candidates with recurrent falls are less likely to access KT and more likely to experience adverse post-KT outcomes.

METHODS

We used a 2-center cohort study of KT candidates (n = 3666) and recipients (n = 770) (January 2009 to January 2018). Among candidates, we estimated time to listing, waitlist mortality, and transplant rate by recurrent falls (≥2 falls) before evaluation using adjusted regression. Among KT recipients, we estimated risk of mortality, graft loss, and length of stay by recurrent falls before KT using adjusted regression.

RESULTS

Candidates with recurrent falls (6.5%) had a lower chance of listing (adjusted hazard ratio [aHR] = 0.68, 95% confidence interval [CI], 0.56-0.83) but not transplant rate; waitlist mortality was 31-fold (95% CI, 11.33-85.93) higher in the first year and gradually decreased over time. Recipients with recurrent falls (5.1%) were at increased risk of mortality (aHR = 51.43, 95% CI, 16.00-165.43) and graft loss (aHR = 33.57, 95% CI, 11.25-100.21) in the first year, which declined over time, and a longer length of stay (adjusted relative ratio [aRR] = 1.13, 95% CI, 1.03-1.25). In summary, 6.5% of KT candidates and 5.1% of recipients experienced recurrent falls which were associated with adverse pre- and post-KT outcomes.

CONCLUSIONS

While recurrent falls were relatively rare in KT candidates and recipients, they were associated with adverse outcomes. Transplant centers should consider employing fall prevention strategies for high-risk candidates as part of comprehensive prehabilitation.

Protocolized exercise improves frailty parameters and lower extremity impairment: A promising prehabilitation strategy for kidney transplant candidates

BACKGROUND

Frailty and decreased functional status are risk factors for adverse kidney transplant (KT) outcomes. Our objective was to examine the efficacy of an exercise intervention on frailty and decreased functional status in a cohort of patients with advanced chronic kidney disease (CKD).

METHODS

We conducted a prospective study involving 21 adults with ≥stage 4 CKD who were (a) frail or pre-frail by Fried phenotype and/or (b) had lower extremity impairment [short physical performance battery score ≤10]. The intervention consisted of two supervised outpatient exercise sessions per week for 8 weeks.

RESULTS

Among our cohort, median participant age was 62 years (interquartile range, 53-67) and 85.7% had been evaluated for KT. Following the study, participants reported satisfaction with the intervention and multiple frailty parameters improved significantly, including fatigue, physical activity, walking time, and grip strength. Lower extremity impairment also improved (90.5%-61.9%, P = .03). No study-related adverse events occurred.

CONCLUSIONS

Preliminary data from this study suggest that a supervised, outpatient exercise intervention is safe, acceptable, feasible, and associated with improved frailty parameters, and lower extremity function, in patients with advanced CKD. Further studies are needed to confirm these findings and determine whether this prehabilitation strategy improves KT outcomes.

Kidney transplant outcomes in recipients with visual, hearing, physical and walking impairments: a prospective cohort study

BACKGROUND

Disability in general has been associated with poor outcomes in kidney transplant (KT) recipients. However, disability can be derived from various components, specifically visual, hearing, physical and walking impairments. Different impairments may compromise the patient through different mechanisms and might impact different aspects of KT outcomes.

METHODS

In our prospective cohort study (June 2013-June 2017), 465 recipients reported hearing, visual, physical and walking impairments before KT. We used hybrid registry-augmented Cox regression, adjusting for confounders using the US KT population (Scientific Registry of Transplant Recipients, N = 66 891), to assess the independent association between impairments and post-KT outcomes [death-censored graft failure (DCGF) and mortality].

RESULTS

In our cohort of 465 recipients, 31.6% reported one or more impairments (hearing 9.3%, visual 16.6%, physical 9.1%, walking 12.1%). Visual impairment was associated with a 3.36-fold [95% confidence interval (CI) 1.17-9.65] higher DCGF risk, however, hearing [2.77 (95% CI 0.78-9.82)], physical [0.67 (95% CI 0.08-3.35)] and walking [0.50 (95% CI 0.06-3.89)] impairments were not. Walking impairment was associated with a 3.13-fold (95% CI 1.32-7.48) higher mortality risk, however, visual [1.20 (95% CI 0.48-2.98)], hearing [1.01 (95% CI 0.29-3.47)] and physical [1.16 (95% CI 0.34-3.94)] impairments were not.

CONCLUSIONS

Impairments are common among KT recipients, yet only visual impairment and walking impairment are associated with adverse post-KT outcomes. Referring nephrologists and KT centers should identify recipients with visual and walking impairments who might benefit from targeted interventions pre-KT, additional supportive care and close post-KT monitoring.

Physical Performance Testing in Kidney Transplant Candidates at the Top of the Waitlist

RATIONALE & OBJECTIVE

Frailty and poor physical function are associated with adverse kidney transplant outcomes, but how to incorporate this knowledge into clinical practice is uncertain. We studied the association between measured physical performance and clinical outcomes among patients on kidney transplant waitlists.

STUDY DESIGN

Prospective observational cohort study.

SETTING & PARTICIPANTS

We studied consecutive patients evaluated in our Transplant Readiness Assessment Clinic, a top-of-the-waitlist management program, from May 2017 through December 2018 (N=305). We incorporated physical performance testing, including the 6-minute walk test (6MWT) and the sit-to-stand (STS) test, into routine clinical assessments.

EXPOSURES

6MWT and STS test results.

OUTCOMES

The primary outcome was time to adverse waitlist outcomes (removal from waitlist or death); secondary outcomes were time to transplantation and time to death.

ANALYTICAL APPROACH

We used linear regression to examine the relationship between clinical characteristics and physical performance test results. We used subdistribution hazards models to examine the association between physical performance test results and outcomes.

RESULTS

Median 6MWT and STS results were 393 (IQR, 305-455) m and 17 (IQR, 12-21) repetitions, respectively. Clinical characteristics and Estimated Post-Transplant Survival scores accounted for only 14% to 21% of the variance in 6MWT/STS results. Physical performance test results were associated with adverse waitlist outcomes (adjusted subdistribution hazard ratio [sHR] of 1.42 [95% CI, 1.30-1.56] per 50-m lower 6MWT test result and 1.53 [95% CI, 1.33-1.75] per 5-repetition lower STS test result) and with transplantation (adjusted sHR of 0.80 [95% CI, 0.72-0.88] per 50-m lower 6MWT test result and 0.80 [95% CI, 0.71-0.89] per 5-repetition lower STS test result). Addition of either STS or 6MWT to survival models containing clinical characteristics enhanced fit (likelihood ratio test P<0.001).

LIMITATIONS

Single-center observational study. Other measures of global health status (eg, Fried Frailty Index or Short Physical Performance Battery) were not examined.

CONCLUSIONS

Among waitlisted kidney transplant candidates with high kidney allocation scores, standardized and easily performed physical performance test results are associated with waitlist outcomes and contain information beyond what is currently routinely collected in clinical practice.

Postural balance, muscle strength, and history of falls in end-stage renal disease patients living with a kidney transplant: A cross-sectional study

BACKGROUND

End-stage renal disease patients living with a kidney transplant (KT) often present with frailty, functional disability, and mobility impairments that may result in a high risk of falls. Postural balance and muscle strength are implicated in the etiology of falls in the geriatric population, and both may be impaired in KT patients.

RESEARCH QUESTION

We conducted a cross-sectional investigation to estimate the prevalence of falls, as well as to explore the association between postural balance, muscle strength and history of falls in end-stage renal disease patients living with a KT.

METHODS

Fifty-nine prevalent KT patients (age = 53.2 ± 11 years) were enrolled in this cross-sectional study. Participants were classified as fallers/non-fallers and underwent an objectively-measured assessment of postural balance on a stabilometric platform in eyes open (EO), eyes closed (EC), and dual-task (DT) conditions. Center of pressure (CoP) variables were taken for the analysis. In addition, participants underwent isometric (IM) and isokinetic (IK) assessments of lower limb muscle strength on a multi-joint evaluation system.

RESULTS

Thirty-four percent of the study participants reported at least one fall in the previous 12 months. In logistic regression analysis, CoP velocity in EO (OR: 1.23, 95 % CI: 1.06-1.43, p = .007), and IK ankle dorsiflexion strength (OR: 0.87, 95 % CI: 0.77-0.99, p = .034) were independently associated with increased odds of falling.

SIGNIFICANCE

This cross-sectional study indicates that patients living with a KT presented with a prevalence of falls indicative of a high risk of falling. Postural balance and muscle strength are exercise-modifiable factors and further research is warranted to establish to what extent these measures may be implicated in the etiology of falling in this patient group.

Perceptions and Practices Regarding Frailty in Kidney Transplantation: Results of a National Survey

BACKGROUND

Given the potential utility of frailty, a clinical phenotype of decreased physiologic reserve and resistance to stressors, to predict postkidney transplant (KT) outcomes, we sought to understand the perceptions and practices regarding frailty measurement in US KT programs.

METHODS

Surveys were emailed to American Society of Transplantation Kidney/Pancreas Community of Practice members and 202 US transplant programs (November 2017 to April 2018). Program characteristics were gleaned from Scientific Registry of Transplant Recipients.

RESULTS

The 133 responding programs (response rate = 66%) represented 77% of adult KTs and 79% of adult KT candidates in the United States. Respondents considered frailty to be a useful concept in evaluating candidacy (99%) and endorsed a need to develop a frailty measurement specific to KT (92%). Frailty measurement was more common during candidacy evaluation (69%) than during KT admission (28%). Of the 202 programs, 38% performed frailty assessments in all candidates while 23% performed assessments only for older candidates. There was heterogeneity in the frailty assessment method; 18 different tools were utilized to measure frailty. The most common tool was a timed walk test (19%); 67% reported performing >1 tool. Among programs that measure frailty, 53% reported being less likely to list frail patients for KT.

CONCLUSIONS

Among US KT programs, frailty is recognized as a clinically relevant construct and is commonly measured at evaluation. However, there is considerable heterogeneity in the tools used to measure frailty. Efforts to identify optimal measurement of frailty using either an existing or a novel tool and subsequent standardization of its measurement and application across KT programs should be considered.

Physical Impairment and Access to Kidney Transplantation

BACKGROUND

The short physical performance battery (SPPB) test is an objective measurement of lower extremity function (walk speed, balance, chair stands). SPPB impairment is associated with longer length of stay and increased mortality in kidney transplant (KT) recipients. Furthermore, the SPPB test may represent an objective quantification of the "foot of the bed test" utilized by clinicians; therefore, impairment may translate with decreased access to KT.

METHODS

We studied 3255 participants (2009-2018) at 2 KT centers. SPPB impairment was defined as a score of ≤10. We estimated time to listing, waitlist mortality, and transplant rate by SPPB impairment status using Cox proportional hazards, competing risks, and Poisson regression.

RESULTS

The mean age was 54 years (SD = 14; range 18-89) and 54% had SPPB impairment. Impaired participants were less likely to be listed for KT (adjusted hazard ratio: 0.70, 95% CI: 0.64-0.77, P < 0.001). Also, once listed, impaired candidates had a 1.6-fold increased risk of waitlist mortality (adjusted subhazard ratio: 1.56, 95% CI: 1.18-2.06, P = 0.002). Furthermore, impaired candidates were transplanted 16% less frequently (adjusted incidence rate ratio: 0.84, 95% CI: 0.73-0.98, P = 0.02).

CONCLUSIONS

SPPB impairment was highly prevalent in KT candidates. Impaired candidates had decreased chance of listing, increased risk of waitlist mortality, and decreased rate of KT. Identification of robust KT candidates and improvement in lower extremity function are potential ways to improve survival on the waitlist and access to KT.

Role of Physical Performance Assessments and Need for a Standardized Protocol for Selection of Older Kidney Transplant Candidates

The older adult population (65 years or older) with advanced or end-stage kidney disease is steadily growing, but rates of transplantation within this cohort have not increased in a similar fashion. Physical deconditioning, resulting in poor post-transplantation outcomes, is a primary concern among older renal patients. The assessment of physical function often holds more weight in the selection process for older candidates, despite evidence showing benefits of transplantation to this vulnerable population. Although several frailty assessment tools are being used increasingly to assess functional status, there is no standardized selection process for older candidates based on these assessment results. Also, it is unknown if timely targeted physical therapy interventions in older patients result in significant improvement of functioning capacity, translating to higher listing and transplantation rates, and improved post-transplantation outcomes. It is therefore of upmost importance not only to incorporate an effective objective functional status assessment process into selection and waitlist evaluation protocols, but also to have targeted interventions in place to maintain and improve physical conditioning among older renal patients. This paper reviews the commonly utilized assessment tools, and their applicability to older patients with renal disease. We also propose the need for definitive selection and waitlist management guidelines to formulate a streamlined assessment of functional capacity and transplant eligibility, as well as a process to maintain functional status, thereby increasing the access of older patients to renal transplantation.