Frailty in lung transplantation: a systematic review

Frailty in lung transplant recipients is associated with anemia and telomere dysfunction but independent of epigenetic age

Frailty is a syndrome of vulnerability to stressors linked to worse outcomes pre- and post-lung transplantation. However, the biological basis of this association is unknown. Biological correlates of aging include epigenetic reprograming, chronic inflammation, telomere dysfunction, and anemia. We hypothesized that these aging-associated biological processes would be associated with frailty in lung transplant recipients. In a nested case-control study, we compared 43 lung transplant recipients who were frail pre- and post-transplant with 43 non-frail matched controls. We quantified peripheral blood leukocyte epigenetic aging (Horvath) and longevity (GrimAge) clocks, telomere length, cytokine profiles, and hemoglobin before transplant. Epigenetic clocks were correlated with age but not frailty. However, we observed hypermethylation of multiple gene pathways, including hedgehog signaling and angiogenesis, and an associated decreased levels of plasma cytokines in frail recipients. Frailty was also associated with telomere dysfunction and anemia. Overall, telomere dysfunction and anemia of chronic disease were most linked to frailty in this cohort, while epigenetic aging and chronic inflammation were not. Understanding the heterogeneity of aging syndromes my help target interventions in frail lung transplant recipients.

Fueling the success of transplantation through nutrition: recent insights into nutritional interventions, their interplay with gut microbiota and cellular mechanisms

PURPOSE OF REVIEW

The role of nutrition in organ health including solid organ transplantation is broadly accepted, but robust data on nutritional regimens remains scarce calling for further investigation of specific dietary approaches at the different stages of organ transplantation. This review gives an update on the latest insights into nutritional interventions highlighting the potential of specific dietary regimens prior to transplantation aiming for organ protection and the interplay between dietary intake and gut microbiota.

RECENT FINDINGS

Nutrition holds the potential to optimize patients' health prior to and after surgery, it may enhance patients' ability to cope with the procedure-associated stress and it may accelerate their recovery from surgery. Nutrition helps to reduce morbidity and mortality in addition to preserve graft function. In the case of living organ donation, dietary preconditioning strategies promise novel approaches to limit ischemic organ damage during transplantation and to identify the underlying molecular mechanisms of diet-induced organ protection. Functioning gut microbiota are required to limit systemic inflammation and to generate protective metabolites such as short-chain fatty acids or hydrogen sulfide.

SUMMARY

Nutritional intervention is a promising therapeutic concept including the pre- and rehabilitation stage in order to improve the recipients' outcome after solid organ transplantation.

[Relationship between frailty and functional status in lung transplant candidates]

INTRODUCTION

Lung transplant (LT) is one of the therapeutic options for patients with terminal respiratory diseases. It is highly important to incorporate the functional status and frailty assessment into the selection process of candidates for LT.

OBJECTIVES

Identify the prevalence of frailty in the LT waiting list. Study the relationship between frailty, functional status, Lung Allocation Score (LAS) and muscular dysfunction.

METHODOLOGY

Descriptive transversal study of patients on the waiting list for LT.

POPULATION

74 patients with chronic respiratory diseases assessed by the lung transplant committee and accepted to be transplanted in a university hospital in Barcelona. The outcome variables were frailty status was evaluate for SPPB test, functional capacity was evaluate for the six-minute walking test (6MWT) and muscular dysfunction. The results were analyzed with the statistical package STATA 12.

RESULTS

Sample of 48 men and 26 women, with a median age of 56.55 years (SD 10.87. The prevalence of frailty assessed with the SPPB was 33.8% (8.1% are in frailty and 25.7% are in a state of pre-frailty). There is a relationship between the SPPB, 6MWT and maximal inspiratory pressure, but not with others force values. There is a relationship between the risk of frailty (scores below 9 in SPPB) and the meters walked in 6 but not with the LAS.

CONCLUSIONS

The risk of frailty in patients with terminal chronic respiratory diseases is high. Frailty is related with functional capacity, but not with LAS.

Rehabilitation interventions to modify physical frailty in adults before lung transplantation: a systematic review protocol

INTRODUCTION

Lung transplantation is the gold-standard treatment for end-stage lung disease for a small group of patients meeting strict acceptance criteria after optimal medical management has failed. Physical frailty is prevalent in lung transplant candidates and has been linked to worse outcomes both on the waiting list and postoperatively. Exercise has been proven to be beneficial in optimising exercise capacity and quality of life in lung transplant candidates, but its impact on physical frailty is unknown. This review aims to assess the effectiveness of exercise interventions in modifying physical frailty for adults awaiting lung transplantation.

METHODS AND ANALYSIS

This protocol was prospectively registered on the PROSPERO database. We will search four databases plus trial registries to identify primary studies of adult candidates for lung transplantation undertaking exercise interventions and assessing outcomes pertaining to physical frailty. Studies must include at least 10 participants. Article screening will be performed by two researchers independently at each stage. Extraction will be performed by one reviewer and checked by a second. The risk of bias in studies will be assessed by two independent reviewers using tools appropriate for the research design of each study; where appropriate, we will use Cochrane Risk of Bias 2 or ROBINS-I. At each stage of the review process, discrepancies will be resolved through a consensus or consultation with a third reviewer. Meta-analyses of frailty outcomes will be performed if possible and appropriate as will prespecified subgroup and sensitivity analyses. Where we are unable to perform meta-analysis, we will conduct narrative synthesis following Synthesis without Meta-analysis guidance. The review will be reported using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist.

ETHICS AND DISSEMINATION

No ethical issues are predicted due to the nature of this study. Dissemination will occur via conference abstracts, professional networks, peer-reviewed journals and patient support groups.

PROSPERO REGISTRATION NUMBER

CRD42022363730.

European Respiratory Society statement on frailty in adults with chronic lung disease

Frailty is a complex, multidimensional syndrome characterised by a loss of physiological reserves that increases a person's susceptibility to adverse health outcomes. Most knowledge regarding frailty originates from geriatric medicine; however, awareness of its importance as a treatable trait for people with chronic respiratory disease (including asthma, COPD and interstitial lung disease) is emerging. A clearer understanding of frailty and its impact in chronic respiratory disease is a prerequisite to optimise clinical management in the future. This unmet need underpins the rationale for undertaking the present work. This European Respiratory Society statement synthesises current evidence and clinical insights from international experts and people affected by chronic respiratory conditions regarding frailty in adults with chronic respiratory disease. The scope includes coverage of frailty within international respiratory guidelines, prevalence and risk factors, review of clinical management options (including comprehensive geriatric care, rehabilitation, nutrition, pharmacological and psychological therapies) and identification of evidence gaps to inform future priority areas of research. Frailty is underrepresented in international respiratory guidelines, despite being common and related to increased hospitalisation and mortality. Validated screening instruments can detect frailty to prompt comprehensive assessment and personalised clinical management. Clinical trials targeting people with chronic respiratory disease and frailty are needed.

Old Age and Frailty in Deceased Organ Transplantation and Allocation-A Plea for Geriatric Assessment and Prehabilitation

Due to demographic ageing and medical progress, the number and proportion of older organ donors and recipients is increasing. At the same time, the medical and ethical significance of ageing and old age for organ transplantation needs clarification. Advanced age is associated with the frailty syndrome that has a negative impact on the success of organ transplantation. However, there is emerging evidence that frailty can be modified by suitable prehabilitation measures. Against this backdrop, we argue that decision making about access to the transplant waiting list and the allocation of donor organs should integrate geriatric expertise in order to assess and manage frailty and impairments in functional capacity. Prehabilitation should be implemented as a new strategy for pre-operative conditioning of older risk patients' functional capacity. From an ethical point of view, advanced chronological age per se should not preclude the indication for organ transplantation and the allocation of donor organs.

Frailty and emergency department utilisation in adults with systemic lupus erythematosus ≤65 years of age: an administrative claims data analysis of Medicaid beneficiaries

OBJECTIVE

Frailty is a risk factor for adverse health in adults with SLE, including those <65 years. Emergency department (ED) utilisation is high in adults with SLE, but to our knowledge, whether frailty is associated with ED use is unknown. In a large administrative claims dataset, we assessed risk of ED utilisation among frail adults with SLE ≤65 years of age relative to non-frail adults ≤65 years of age with SLE.

METHODS

Using the MarketScan Medicaid subset from 2011 to 2015, we identified beneficiaries 18-65 years with SLE (≥3 SLE International Classification of Diseases, Ninth Revision codes ≥30 days apart). Comparators without a systemic rheumatic disease (SRD) were matched 4:1 on age and gender. Frailty status in 2011 was determined using two claims-based frailty indices (CFIs). We compared risk of recurrent ED utilisation among frail and non-frail beneficiaries with SLE using an extension of the Cox proportional hazard model for recurrent events data.

RESULTS

Of 2262 beneficiaries with SLE and 9048 non-SRD comparators, 28.8% and 11.6% were frail, respectively, according to both CFIs. Compared with non-frail beneficiaries with SLE, frail beneficiaries with SLE had significantly higher hazard of recurrent ED use (HR 1.75, 95% CI 1.48 to 2.08).

CONCLUSION

Frailty increased hazard of recurrent ED visits in frail adults ≤65 years of age with SLE relative to comparable non-frail adults with SLE. Frailty is a potential target for efforts to improve quality of care in SLE.

Development of the Lung Transplant Frailty Scale (LT-FS)

BACKGROUND

Existing measures of frailty developed in community dwelling older adults may misclassify frailty in lung transplant candidates. We aimed to develop a novel frailty scale for lung transplantation with improved performance characteristics.

METHODS

We measured the short physical performance battery (SPPB), fried frailty phenotype (FFP), Body Composition, and serum Biomarkers representative of putative frailty mechanisms. We applied a 4-step established approach (identify frailty domain variable bivariate associations with the outcome of waitlist delisting or death; build models sequentially incorporating variables from each frailty domain cluster; retain variables that improved model performance ability by c-statistic or AIC) to develop 3 candidate "Lung Transplant Frailty Scale (LT-FS)" measures: 1 incorporating readily available clinical data; 1 adding muscle mass, and 1 adding muscle mass and research-grade Biomarkers. We compared construct and predictive validity of LT-FS models to the SPPB and FFP by ANOVA, ANCOVA, and Cox proportional-hazard modeling.

RESULTS

In 342 lung transplant candidates, LT-FS models exhibited superior construct and predictive validity compared to the SPPB and FFP. The addition of muscle mass and Biomarkers improved model performance. Frailty by all measures was associated with waitlist disability, poorer HRQL, and waitlist delisting/death. LT-FS models exhibited stronger associations with waitlist delisting/death than SPPB or FFP (C-statistic range: 0.73-0.78 vs. 0.57 and 0.55 for SPPB and FFP, respectively). Compared to SPPB and FFP, LT-FS models were generally more strongly associated with delisting/death and improved delisting/death net reclassification, with greater improvements with increasing LT-FS model complexity (range: 0.11-0.34). For example, LT-FS-Body Composition hazard ratio for delisting/death: 6.0 (95%CI: 2.5, 14.2), SPPB HR: 2.5 (95%CI: 1.1, 5.8), FFP HR: 4.3 (95%CI: 1.8, 10.1). Pre-transplant LT-FS frailty, but not SPPB or FFP, was associated with mortality after transplant.

CONCLUSIONS

The LT-FS is a disease-specific physical frailty measure with face and construct validity that has superior predictive validity over established measures.

Lung transplantation outcomes in underweight recipients: A single center experience

Background

Current guidelines recommend a body mass index (BMI) of 16 kg/m² as the minimum threshold for lung transplantation, despite mixed evidence on outcomes in underweight patients. The current study aimed to describe survival outcomes of underweight patients who underwent lung transplantation at a single center.

Methods

This retrospective observational study included adult lung transplant recipients who underwent transplantation for the first time between March 2010 and March 2022 at King Faisal Specialist Hospital and Research Center and excluded patients with obesity. We defined an underweight status as a BMI <17 kg/m².

Results

Forty-eight of the 202 lung transplant recipients were underweight at the time of surgery. The underweight patients had similar lengths of hospital (p = 0.53) and intensive care unit (p = 0.81) stays compared to other patients. Thirty-three percent of underweight patients had died within 5-year follow-up, compared to 34% of patients who were not underweight. There was no significant difference in mortality risk between underweight patients and patients with normal BMIs in our multivariable Cox regression model (adjusted HR 1.57, 95%CI: 0.77-3.20, p = 0.21). Exploratory analyses revealed that a pre-transplant BMI <13 kg/m² was associated with a trend towards increased 5-year mortality (adjusted HR 4.00, 95%CI: 0.87-18.35, p = 0.07).

Conclusions

Our findings suggest that patients with BMIs of 13-17 kg/m² may be candidates for lung transplantation. Large multi-center cohort studies are needed to confirm the lower BMI limit for safely transplanting patients.

Prehabilitation in Adult Solid Organ Transplant Candidates

Purpose of Review

To highlight the importance of biological age in the context of prehabilitation and to present relevant research regarding prehabilitation prior to solid organ transplantation.

Recent Findings

Studies on the effect of prehabilitation have been performed in kidney-, lung-, liver-, and heart transplant patient populations. Prior to kidney transplantation, exercise interventions have been shown to improve cardiopulmonary- and physical fitness and result in a decreased length of hospital stay postoperatively. Among lung transplant candidates, various methods of prehabilitation have been studied including home-based, outpatient and in-patient programs, consisting of physical training, psychological support, education, and nutritional interventions. Overall, prehabilitation seems to improve or maintain quality of life and exercise capacity in this patient population. Patients undergoing liver transplantation seem to benefit from prehabilitation as well. Not only does it seem safe and feasible, but significant improvements in aerobic and functional capacity have also been found. Regarding heart transplant candidates, both inpatient and outpatient, supervised prehabilitation programs show promising results with improvements in exercise capacities and quality of life.

Summary

Prehabilitation is an effective and safe intervention for improving functional outcomes of solid organ transplant patients. Future studies should evaluate whether prehabilitation translates into improved pre- and post-transplant clinical outcomes.

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.

The Intersection of Aging and Lung Transplantation: its Impact on Transplant Evaluation, Outcomes, and Clinical Care

Purpose

Older adults (age ≥ 65 years) are the fastest growing age group undergoing lung transplantation. Further, international consensus document for the selection of lung transplant candidates no longer suggest a fixed upper age limit. Although carefully selected older adults can derive great benefit, understanding which older adults will do well after transplant with improved survival and health-related qualiy of life is key to informed decision-making. Herein, we review the epidemiology of aging in lung transplantation and its impact on outcomes, highlight selected physiological measures that may be informative when evaluating and managing older lung transplant patients, and identify directions for future research.

Recent Findings

In general, listing and transplanting older, sicker patients has contributed to worse clinical outcomes and greater healthcare use. Emerging evidence suggest that measures of physiological age, such as frailty, body composition, and neurocognitive and psychosocial function, may better identify risk for poor transplant outcomes than chronlogical age.

Summary

The evidence base to inform transplant decision-making and improvements in care for older adults is small but growing. Multipronged efforts at the intersection of aging and lung transplantation are needed to improve the clinical and patient centered outcomes for this large and growing cohort of patients. Future research should focus on identifying novel and ideally modifiable risk factors for poor outcomes specific to older adults, better approaches to measuring physiological aging (e.g., frailty, body composition, neurocognitive and psychosocial function), and the underlying mechanisms of physiological aging. Finally, interventions that can improve clinical and patient centered outcomes for older adults are needed.

Frailty in Lung Transplantation: Candidate Assessment and Optimization

The concept of frailty has gained considerable interest in clinical solid-organ transplantation over the past decade. Frailty as a phenotypic construct to describe a patient's risk from biologic stresses has an impact on posttransplant survival. There is keen interest in characterizing frailty in lung transplantation, both to determine which patients are suitable candidates for listing and also to prepare for their care in the aftermath of lung transplantation. Here, we review the current status of research on frailty in lung transplant candidates and recipients. This review will highlight areas of uncertainty for frailty in clinical lung transplantation that are likely to impact the state-of-the-art in the field for the next decade.

Predictive value of chart-based frailty evaluation for lung transplant candidates

Frailty, defined as a state of decreased physiologic reserve, has been correlated with poorer outcomes after hospitalization or surgery. Studies in lung transplant patients have associated frailty with an increased risk of post-transplant mortality; however, a unified approach is lacking. The identification of frail patients can help clinicians pre-emptively target modifiable risk factors and may facilitate risk stratification. The Frailty Risk Score (FRS) is a chart review-based approach based on eight symptoms and four laboratory biomarkers. We applied this method in a retrospective study to investigate its utility in predicting post-transplant lung outcomes. Eighty-four lung transplant recipients were evaluated, including 51 older (≥ 60) and 33 younger (< 60) patients. Median FRS score was 3.9, with 63 categorized as frail (75%) and 21 as non-frail (25%), using a previously published cut-off of ≥3 to define frailty. A high FRS was associated with readmission in the first year after transplantation and with the number of readmissions. There was also an association between FRS score and death (p = .047). FRS may be a viable tool in the assessment of lung transplant candidates. Frail patients may benefit from earlier referral and targeted therapy prior to transplant, as well as close post-transplant follow-up.

Selection Criteria for Lung Transplantation: Controversies and New Developments

Lung transplantation is an accepted therapeutic option for end-stage lung diseases. The imbalance between limited availability and vast need of donor organs necessitates careful selection of recipient candidates, ensuring the best possible utilization of the scarce resource of organs. Nonetheless, possible lung transplant candidates who could experience a meaningful improvement in survival and quality of life should not be excluded solely based on the complexity of their case. In this review, controversial issues or difficult limitations for lung transplantation, and new developments in recipient selection criteria, are discussed, which may help broaden recipient eligibility for lung transplantation without compromising long-term outcomes.

Risk factors for mortality in lung transplant recipients aged ≥65 years: A retrospective cohort study of 5,815 patients in the scientific registry of transplant recipients

BACKGROUND

Lung transplantation is increasingly performed in recipients aged ≥65 years. However, the risk factors for mortality specific to this population have not been well studied. In lung transplant recipients aged ≥65 years, we sought to determine post-transplant survival and clinical factors associated with post-transplant mortality.

METHODS

We investigated 5,815 adult lung transplants recipients aged ≥65 years in the Scientific Registry of Transplant Recipients. Mortality was defined as a composite of recipient death or retransplantation. The Kaplan-Meier method was used to estimate the median time to mortality. Univariable and multivariable Cox proportional hazards regression models were used to examine the association between time to mortality and 23 donor, recipient, or center characteristics.

RESULTS

Median survival in lung transplant recipients aged ≥65 years was 4.41 years (95% CI: 4.21-4.60 years) and significantly worsened by increasing age strata. In the multivariable model, increasing recipient age strata, creatinine level, bilirubin level, hospitalization at the time of transplantation, single lung transplant operation, steroid use at the time of transplantation, donor diabetes, and cytomegalovirus mismatch were independently associated with increased mortality.

CONCLUSIONS

Among the 8 risk factors we identified, 5 factors are readily available, which can be used to optimize post-transplant survival by informing risk during candidate selection of patients aged ≥65 years. Furthermore, bilateral lung transplantation may confer improved survival in comparison with single lung transplantation. Our results support that after careful consideration of risk factors, lung transplantation can provide life-extending benefits in individuals aged ≥65 years.

The Year in Cardiothoracic Transplantation Anesthesia: Selected Highlights from 2019

The highlights in cardiothoracic transplantation focus on the recent research pertaining to heart and lung transplantation, including expansion of the donor pool, the optimization of donors and recipients, the use of mechanical support, the perioperative and long-term outcomes in these patient populations, and the use of transthoracic echocardiography to diagnose rejection.