The evolving challenge of evaluating older renal transplant candidates

Frailty and solid-organ transplant candidates: a scoping review

BACKGROUND

There is currently no consensus as to a standardized tool for frailty measurement in any patient population. In the solid-organ transplantation population, routinely identifying and quantifying frailty in potential transplant candidates would support patients and the multidisciplinary team to make well-informed, individualized, management decisions. The aim of this scoping review was to synthesise the literature regarding frailty measurement in solid-organ transplant (SOT) candidates.

METHODS

A search of four databases (Cochrane, Pubmed, EMBASE and CINAHL) yielded 3124 studies. 101 studies (including heart, kidney, liver, and lung transplant candidate populations) met the inclusion criteria.

RESULTS

We found that studies used a wide range of frailty tools (N = 22), including four 'established' frailty tools. The most commonly used tools were the Fried Frailty Phenotype and the Liver Frailty Index. Frailty prevalence estimates for this middle-aged, predominantly male, population varied between 2.7% and 100%. In the SOT candidate population, frailty was found to be associated with a range of adverse outcomes, with most evidence for increased mortality (including post-transplant and wait-list mortality), post-operative complications and prolonged hospitalisation. There is currently insufficient data to compare the predictive validity of frailty tools in the SOT population.

CONCLUSION

Overall, there is great variability in the approach to frailty measurement in this population. Preferably, a validated frailty measurement tool would be incorporated into SOT eligibility assessments internationally with a view to facilitating comparisons between patient sub-groups and national and international transplant services with the ultimate goal of improved patient care.

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.

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.

Relationship between pre-transplant physical function and outcomes after kidney transplant

BACKGROUND

Performance-based measures of physical function predict morbidity following non-transplant surgery. Study objectives were to determine whether physical function predicts outcomes after kidney transplant and assess how physical function changes post-transplant.

METHODS

We conducted a prospective study involving living donor kidney transplants recipients at our center from May 2012 to February 2014. Physical function was measured using the Short Physical Performance Battery (SPPB [balance, chair stands, gait speed]) and grip strength testing. Initial length of stay (LOS), 30- day rehospitalizations, allograft function, and quality of life (QOL) were assessed.

RESULTS

The majority of the 140 patients in our cohort had excellent pre-transplant physical function. In general, balance scores were more predictive of post-transplant outcomes than the SPPB. Decreased pre-transplant balance was independently associated with longer LOS and increased rehospitalizations but not with post-transplant QOL; 35% of patients experienced a clinically meaningful (≥ 1.0 m/s) improvement in gait speed 4 months post-transplant.

CONCLUSIONS

Decreased physical function may be associated with longer LOS and rehospitalizations following kidney transplant. Further studies are needed to confirm this association. The lack of relationship between pre-transplant gait speed and outcomes in our cohort may represent a ceiling effect. More comprehensive measures, including balance testing, may be required for risk stratification.

The Kidney Transplant Evaluation Process in the Elderly: Reasons for Being Turned down and Opportunities to Improve Cost-Effectiveness in a Single Center

Background. The kidney transplant evaluation process for older candidates is complex due to the presence of multiple comorbid conditions. Methods. We retrospectively reviewed patients ≥60 years referred to our center for kidney transplantation over a 3-year period. Variables were collected to identify reasons for patients being turned down and to determine the number of unnecessary tests performed. Statistical analysis was performed to estimate the association between clinical predictors and listing status. Results. 345 patients were included in the statistical analysis. 31.6% of patients were turned down: 44% due to coronary artery disease (CAD), peripheral vascular disease (PVD), or both. After adjustment for patient demographics and comorbid conditions, history of CAD, PVD, or both (OR = 1.75, 95% CI (1.20, 2.56), p = 0.004), chronic obstructive pulmonary disease (OR = 8.75, 95% CI (2.81, 27.20), p = 0.0002), and cancer (OR 2.59, 95% CI (1.18, 5.67), p = 0.02) were associated with a higher risk of being turned down. 14.8% of patients underwent unnecessary basic testing and 9.6% underwent unnecessary supplementary testing with the charges over a 3-year period estimated at $304,337. Conclusion. A significant number of older candidates are deemed unacceptable for kidney transplantation with primary reasons cited as CAD and PVD. The overall burden of unnecessary testing is substantial and potentially avoidable.

Kidney Transplantation Among the Elderly: Challenges and Opportunities to Improve Outcomes

Elderly patients (>65 years old) represent the fastest growing population among the ESRD patients and those awaiting kidney transplantation. There is ample evidence to suggest that kidney transplant in the elderly population offers the best chance of survival and improves health-related quality of life compared to remaining on dialysis. Although all these emerging facts are encouraging, this population brings with them complex medical problems including frailty, cognitive impairment, and multiple comorbidities. These issues can be barriers to transplantation and threaten the well-being of the patients after transplantation. Furthermore, aging results in changes to the immune system and affects the pharmacokinetics of immunosuppressants. All these changes can increase risk of complications such as infections and malignancy. Because death with a functioning graft is a common cause of graft loss, the new kidney allocation system has been implemented in an attempt to maximize allograft utilization and minimize unrealized graft years. This may result in longer wait-times for the elderly. In this review, we will highlight the barriers to kidney transplant, characterize transplant-related issues in the elderly, and propose alternative strategies under the new allocation system.

Racial and Ethnic Disparities in Graft and Recipient Survival in Elderly Kidney Transplant Recipients

OBJECTIVES

To investigate racial and ethnic differences in graft and recipient survival in elderly kidney transplant recipients.

DESIGN

Retrospective cohort.

SETTING

First-time, kidney-only transplant recipients aged 60 and older of age at transplantation transplanted between July 1996 and October 2010 (N = 44,013).

PARTICIPANTS

United Network for Organ Sharing (UNOS) database.

MEASUREMENTS

Time to graft failure and death obtained from the UNOS database and linkage to the Social Security Death Index. Neighborhood poverty from 2000 U.S. Census geographic data.

RESULTS

Of the 44,013 recipients in the sample, 20% were black, 63% non-Hispanic white, 11% Hispanic, 5% Asian, and the rest "other racial groups." In adjusted Cox models, blacks were more likely than whites to experience graft failure (hazard ratio (HR) = 1.23, 95% confidence interval (CI) = 1.15-1.32), whereas Hispanics (HR = 0.77, 95% CI = 0.70-0.85) and Asians (HR = 0.70, 95% CI = 0.61-0.81) were less likely to experience graft failure. Blacks (HR = 0.84, 95% CI = 0.80-0.88), Hispanics (HR = 0.68, 95% CI = 0.64-0.72), and Asians (HR = 0.62, 95% CI = 0.57-0.68) were less likely than whites to die after renal transplantation.

CONCLUSION

Elderly blacks are at greater risk of graft failure than white transplant recipients but survive longer after transplantation. Asians have the highest recipient and graft survival, followed by Hispanics. Further studies are needed to assess additional factors affecting graft and recipient survival in elderly adults and to investigate outcomes such as quality of life.

Access to renal transplantation for the elderly in the face of new allocation policy: a review of contemporary perspectives on "older" issues

The benefits of renal transplantation have been demonstrated to extend to the elderly. As a result, more seniors have been placed on the kidney transplant wait list and have received renal allografts in recent years. In June 2013 significant amendments to deceased donor kidney allocation policy were approved to be instituted in 2014 with the goal of increasing overall life years and graft years achieved compared to the current system. Going forward, it is conceivable that transplant centers may perceive a need to adjust practice patterns and modify evaluation and listing criteria for the elderly as the proportion of kidneys distributed to this segment of the wait list would potentially decrease under the new system, further increasing wait times. This review examines contemporary perspectives on access to transplantation for seniors and pertinent issues for this subgroup such as wait time, comorbidity, and evaluation and listing practices. Potential approaches to improve the evaluation of elderly patients being considered for transplant and to increase availability of expanded criteria donor (or higher kidney donor profile index) and living donor organ transplant opportunities while maintaining acceptable outcomes for seniors are explored.

The accuracy of positron emission tomography in the detection of posttransplant lymphoproliferative disorder

We investigated sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 18F-fluorodeoxyglucose-positron emission tomography in 170 cases with suspected or biopsy-proven posttransplant lymphoproliferative disorder. All solid organ and hematopoietic stem cell transplant recipients who underwent an 18F-fluorodeoxyglucose-positron emission tomography scan between 2003 and 2010 in our center for the indication posttransplant lymphoproliferative disorder, were retrospectively reviewed and results were compared with tissue biopsy whenever possible. One hundred and seventy positron emission tomography scans in 150 patients were eligible for evaluation. In 45 cases, the patient had a biopsy-confirmed posttransplant lymphoproliferative disorder before positron emission tomography scanning and positron emission tomography was performed for staging purposes. In the remaining 125 cases, positron emission tomography was performed to differentiate between posttransplant lymphoproliferative disorder and other diseases. 18F-fluorodeoxyglucose-uptake was quantitatively expressed by calculation of maximum and mean standardized uptake value in the most intense lesion or, in the absence of attenuation corrected positron emission tomography scans, by comparing uptake in target lesion to liver and mediastinal uptake. We found an overall sensitivity of 89%, specificity of 89%, positive predictive value of 91% and negative predictive value of 87% for posttransplant lymphoproliferative disorder detection by 18F-fluorodeoxyglucose-positron emission tomography. In a subanalysis of the 125 scans performed for differentiating posttransplant lymphoproliferative disorder from other diseases, sensitivity, specificity, positive predictive value and negative predictive value were 90%, 89%, 85% and 93%, respectively. 18F-fluorodeoxyglucose-uptake in posttransplant lymphoproliferative disorder was generally high with a median mean and maximum standardized uptake value of 9.0 (range 2.0-18.6) and 17.4 (range 2.6-26.4). Posttransplant lymphoproliferative disorder often had an atypical presentation on positron emission tomography with high incidence of extranodal involvement. In conclusion, from these data, we can conclude that 18F-fluorodeoxyglucose-positron emission tomography is highly sensitive for detecting posttransplant lymphoproliferative disorder and has an excellent ability to differentiate posttransplant lymphoproliferative disorder from non-malignant diseases.

Renal replacement therapy in the elderly population

ESRD has become an important problem for elderly patients. The segment of the ESRD population age 65 years or older has grown considerably, and this growth is expected to accelerate in coming years. Nephrologists caring for the elderly with advanced kidney disease will encounter patients with comorbid conditions common in younger patients, as well as physical, psychological, and social challenges that occur with increased frequency in the aging population. These challenging factors must be addressed to help inform decisions regarding the option to initiate dialysis, the choice of dialysis modality, whether to pursue kidney transplantation, and end-of-life care. This article will highlight some common problems encountered by elderly patients with ESRD and review data on the clinical outcomes of elderly patients treated with different modalities of dialysis, outcomes of kidney transplantation in the elderly, and nondialytic management of CKD stage 5.

Age and the associations of living donor and expanded criteria donor kidneys with kidney transplant outcomes

BACKGROUND

Recent studies show a survival advantage with kidney transplant in elderly patients compared with those on dialysis therapy.

STUDY DESIGN

In our present study, we examined and compared the association of expanded criteria donor (ECD) kidney and living kidney donation with the outcome of kidney transplant across different ages, including elderly recipients.

SETTING & PARTICIPANTS

Using the Scientific Registry of Transplant Recipients, we identified 145,470 adult kidney transplant patients. Mortality and death-censored transplant failure risks were estimated by Cox proportional regression analyses during follow-up with a median of 3.9 years.

PREDICTORS

ECD kidney and living kidney donation and age compared with others.

OUTCOMES

Mortality and death-censored transplant failure risk.

RESULTS

Patients were aged 45 ± 16 years and included 40% women and 19% patients with diabetes. Compared with transplant recipients 55 to younger than 65 years, the fully adjusted death-censored transplant failure risk was higher in patients 75 years and older (HR, 1.30; 95% CI, 1.09-1.56), 35 to younger than 55 years (HR, 1.13; 95% CI, 1.08-1.17), and 18 to younger than 35 years (HR, 1.64; 95% CI, 1.57-1.71). Compared with non-ECD kidneys, ECD kidneys were significant predictors of mortality in nonelderly patients (18-<35 years: HR, 1.46 [95% CI, 1.19-1.77]; 35-<55 years: HR, 1.23 [95% CI, 1.14-1.32]; and 55-<65 years: HR, 1.26 [95% CI, 1.15-1.38]) and patients 65 to younger than 70 years (HR, 1.20; 95% CI, 1.05-1.36), but not in other groups of elderly patients (HRs of 1.12 [95% CI, 0.93-1.36] for 70-<75 years and 1.04 [95% CI, 0.74-1.47] for ≥75 years). Similar results were found for risk of transplant loss. Compared with deceased donor kidneys, a living donor kidney was associated with better survival in all age groups and lower transplant loss risk in patients younger than 70 years.

LIMITATIONS

Unmeasured confounders cannot be adjusted for.

CONCLUSIONS

For deceased donors, ECD kidneys are not associated with increased mortality or transplant failure in recipients older than 70 years. For all types of donors, the persistent association between living donor kidneys and lower all-cause mortality across all ages suggests that, if possible, elderly patients gain longevity from living donor kidney transplant.

Age, exclusion criteria, and generalizability of randomized trials enrolling kidney transplant recipients

BACKGROUND

The proportion of elderly (≥65 years) kidney transplant recipients (KTRs) doubled in the United States from 1999 to 2008. Given higher mortality, more medication side effects, and less rejection among elderly KTRs, optimal care of these patients may require tailored decisions about transplant therapeutics. It is unknown whether participants in transplant clinical trials-which generate the best evidence for patient care-are representative of the aging population of KTRs.

METHODS

Using PubMed, we identified randomized trials involving KTRs from 1999 to 2008 and determined age-exclusion criteria and the mean age of participants. The mean age of these trial participants was compared with the mean age of the overall population of incident KTRs in the United States.

RESULTS

The 87,222 participants in 573 trials were significantly younger than the US KTR population (P<0.05). This age discrepancy worsened over the study period (during the years 2006 to 2008, the mean age was 45 years for trial participants versus 50 years for US KTRs, P<0.05). Thirty percent of trials had an exclusion criterion based on older age, and 16% excluded recipients aged 65 years or older. In multivariable regression, immunosuppression trials (P<0.01) and trials in higher impact journals (P=0.03) were more likely to exclude the elderly, but there was no significant difference in exclusion of elderly patients based on a trial's geographic location.

CONCLUSIONS

Trial participants are younger than KTRs in the United States and many trials exclude older patients. Transplant investigators should make strong efforts to recruit patients across the total age spectrum.