Weight loss prior to lung transplantation is associated with improved survival

Impact of waitlist weight change on outcomes in heart transplant recipients: a UNOS database analysis

BACKGROUND

While the effect of pre-transplant weight on patient outcomes following heart transplantation (HTx) has previously been studied, data regarding the impact of dynamic weight change prior to HTx are extremely limited.

OBJECTIVES

We sought to elucidate the interaction between HTx listing weight and weight change while waitlisted, and explore how that interaction impacts post-HTx survival in a continuous manner.

METHODS

Adult patients listed for HTx from 1987 to 2020 were identified from UNOS database. Three-dimensional restricted cubic spline analysis explored post-HTx survival relative to both changes in BMI/weight and BMI at time of HTx listing. Continuous predictor variables were analyzed with Cox proportional hazards method.

RESULTS

9,628 included patients underwent HTx. Median recipient age was 55 [IQR 46-62] years, and 21% were females. 53% of patients lost while 47% gained weight on the waitlist. Median BMI (27.6 kg/m2 [24.3-31.3] vs. 27.4 kg/m2 [24.2-30.9], paired p < 0.001) and weight (84.8 kg [73.0-98.0] kg vs. 84.4 kg [72.6-96.6], p < 0.001) were similar at listing and transplant. One-year survival was 89.3%. Weight loss over 3 BMI points or 10 kg was associated with higher hazard of death irrespective of listing BMI. In non-obese patients, some weight gain (1-4 BMI points or 5-15 kg) was associated with improved survival. In cachectic patients (BMI < 18.5), failure to gain weight was associated with worse survival.

CONCLUSIONS

Impact of weight change varies depending on listing BMI. While a survival benefit is seen in non-obese patients who gain some weight, significant weight loss is associated with poorer survival.

Recipient selection for lung transplantation: perspective in decision-making

BACKGROUND

To determine the conditions that prevented transplant in patients referred to our center due to end-stage lung disease.

STUDY DESIGN

Descriptive study.

PLACE AND DURATION OF THE STUDY

Department of lung transplant clinic, Koşuyolu High Specialization Education and Research Hospital, Istanbul, Turkey, from December 2017 to January 2022.

METHODS

Patients with end-stage lung disease referred to our clinic were retrospectively evaluated with regard to reasons for exclusion, diagnosis, and demographic data. The Karnofsky Performance Status scoring scale was used to measure the functional status of the patients.

RESULTS

A total of 311 patients were evaluated during the study period. The mean age was 44.2 (range 4-73) years. There were 207 (66.6%) male patients. The most common indications were idiopathic interstitial pneumonia in 104 (33.4%) patients, chronic obstructive pulmonary disease in 53 (17%) patients, bronchiectasis in 49 (15.7%) patients, and cystic fibrosis in 28 (9%) patients. Of the patients, 106 (34%) were not appropriate candidates for a lung transplant. The most common reasons for refusal were preventable situations such as activity limitation and poor performance in 53 (50%) patients, weight in 49 (46.2%) patients, and smoking in 10 (9.4%) patients.

CONCLUSION

Impaired performance status was the most common cause of lung transplant exclusion. Weight and smoking were preventable causes of exclusion. Implementing pulmonary rehabilitation in very few patients was the most important handicap. It is believed that providing optimal treatment with a multidisciplinary approach and timely referral to transplant centers will significantly reduce the reasons for exclusion. Key message What is already known on this topic?  Referring lung transplant candidates to clinics at the earliest stage is essential for assessing their condition and exploring treatment options. What this study adds?  Factors like smoking, obesity, and muscle loss can hinder the transplantation process; thus, timely interventions are crucial. The primary reason for excluding candidates from lung transplantation is the decline in performance status. How this study might affect research, practice or policy?  Programs focused on smoking cessation, weight management, and muscle strengthening can play a vital role in enhancing patients' health before transplantation. It is imperative to expand and enhance the accessibility of pulmonary rehabilitation programs.

Lung transplantation for interstitial lung disease

Interstitial lung diseases (ILDs) are now the most common indication for lung transplant internationally. Given that many lung transplant candidates with idiopathic pulmonary fibrosis are older, referral to a pulmonary rehabilitation programme is important to help mitigate the adverse outcomes associated with frailty. Despite this increase many patients with ILD who would potentially benefit from lung transplant are either not referred or referred too late. Particularly relevant in ILD which may have prominent extra-pulmonary manifestations is a multidisciplinary assessment of comorbidities which may impact on post lung transplant outcomes. Particular challenges in lung transplant for ILD are increasing age, comorbidities, donor lung sizing and the risk-benefit balance of single versus bilateral lung transplant. Evidence is continuing to evolve for lung transplant in rarer ILDs, including surfactant protein associated ILD and TERT mutations. Unfortunately, the number of potential lung transplant recipients exceeds available donor organs and some patients will die without transplant. Palliative care is an important aspect of managing patients on an active lung transplant list to help optimise physical and psychological symptoms associated with uncertainty on an active lung transplant list.

The impact of time from ILD diagnosis to referral to the transplant center on the probability of inclusion in the transplant waiting list

BACKGROUND

Lung transplant is a therapeutic option for patients with progressive interstitial lung disease (ILD).

OBJECTIVES

The objective of this study was to determine whether time from ILD diagnosis to referral to a transplant center influences the probability of being included in the transplant waiting list.

METHODS

We performed a retrospective cohort study including all ILD patients evaluated as lung transplantation (LT) candidates at a lung transplant center between 01/01/2017 and 31/12/2022. The primary endpoint was the probability of being included in the lung transplant waiting list according to the time elapsed from diagnosis to referral to the transplant center.

RESULTS

A total of 843 lung transplant requests were received, of which 367 (43.5%) were associated with ILD. Thirteen patients were excluded because they did not attend the first visit, whereas another 11 were excluded because some information was missing. As a result, our final sample was composed of 343 patients. The median time from diagnosis to referral was 29.4 (10.9 - 61.1) months. The overall probability of inclusion in the waiting list was 29.7%. By time from diagnosis to referral, the probability of inclusion in the waiting list was 48.1% for the patients referred 〈 6 months from diagnosis; 27.5% for patients referred 6 to 24 months from diagnosis; and 25.8% for patients referred 〉 24 months from diagnosis (p = 0.007).

CONCLUSIONS

Early referral to a lung transplant center seemed to increase the probability of being included in the lung transplant waiting list. Further research is needed in this topic.

Diaphragm and Lung Transplantation

Mutual interactions between the diaphragm and lung transplantation (LTx) are known to exist. Before LTx, many factors can exert notable impact on the diaphragmatic function, such as the underlying respiratory disease, the comorbidities, and the chronic treatments of the patient. In the post-LTx setting, even the surgical procedure itself can cause a stressful trauma to the diaphragm, potentially leading to morphological and functional alterations. Conversely, the diaphragm can significantly influence various aspects of the LTx process, ranging from graft-to-chest cavity size matching to the long-term postoperative respiratory performance of the recipient. Despite this, there are still no standard criteria for evaluating, defining, and managing diaphragmatic dysfunction in the context of LTx to date. This deficiency hampers the accurate assessment of those factors which affect the diaphragm and its reciprocal influence on LTx outcomes. The objective of this narrative review is to delve into the complex role the diaphragm plays in the different stages of LTx and into the modifications of this muscle following surgery.

Weight loss with GLP-1 analogues in preparation for transplantation

This case describes a woman in her 20s with a 6-month history of progressive exertional dyspnoea and cough. Examination revealed hypoxia on room air, sinus tachycardia, finger clubbing and bibasal inspiratory crackles. Inflammatory markers were mildly elevated and empirical antimicrobial therapy was commenced. A multidisciplinary discussion consensus diagnosis of acute interstitial pneumonitis was made based on the findings of high-resolution CT of the chest, macrophage predominant bronchoalveolar lavage cell differential and surgical lung biopsy. There was clinical and radiological deterioration despite glucocorticoids and antifibrotic therapy. A body mass index of 37.5 kg/m2 precluded her from lung transplant assessment and consideration. Following consultation with the weight management service, she was commenced on glucagon-like peptide 1 (GLP-1) analogue therapy. She had a remarkable response within 6 months, was listed for lung transplantation, and within 18 months of her initial presentation, a double lung transplantation was performed.

Successful Anesthetic Management for Obese Patients with Interstitial Lung Disease Undergoing Laparoscopic Sleeve Gastrectomy: A Bridge to Improved Lung Transplant Eligibility

BACKGROUND Patients with obesity with interstitial lung diseases (ILD) are encouraged to lose weight, as it improves lung function and lung transplant eligibility. As exercise tolerance in these patients is low and weight gain is a common adverse effect of corticosteroids, bariatric surgery can be an effective method for the management of obesity in this patient group. However, perioperative complications in such high-risk patients remain a concern. Therefore, we aimed to demonstrate successful anesthetic management for obese patients with ILD, which may be practically utilized to reduce perioperative pulmonary complications and improve outcomes. CASE REPORT Our case report presents a 42-year-old man with ILD who underwent laparoscopic sleeve gastrectomy (LSG). Preoperative studies revealed severe restrictive disease, right ventricular overload with assessed intermediate risk of pulmonary hypertension, and heart failure, with preserved left ventricle fraction but with poor exercise tolerance. Patient had opioid-free anesthesia (OFA) and postoperative multimodal analgesia. Following a 24-h stay in the Post-Anesthesia Care Unit, the patient was transferred to the ward and ultimately discharged home 2 days thereafter. At the 1-year follow-up, the patient reduced his weight by 40 kg and reported a significant improvement in physical capacity. CONCLUSIONS Our record demonstrates that OFA can be successfully used in high-risk patients with ILD undergoing LSG. In a period of a year, the patient improved so much that he no longer required lung transplantation, which may encourage clinicians to provide bariatric surgery using the OFA technique in the population of patients with obesity and severe respiratory illness.

Optimizing the prelung transplant candidate

PURPOSE OF REVIEW

Lung transplant outcomes are impacted by multiple modifiable risk factors. Candidate deterioration on the wait list remains problematic. Innovative technology and strategies to identify and impact pretransplant morbidity have improved short- and long-term outcomes. We focus our review on recent advances in pretransplant recipient assessment and optimization.

RECENT FINDINGS

Advancements in recipient management have focused on risk factor identification for adverse outcomes and the development of a lung transplant specific frailty assessment. Early surgical correction of gastroesophageal reflux disease (GERD), including the use of partial fundoplication in the setting of esophageal dysmotility, leads to improvements in graft function/longevity. New evidence supports expanding criteria for extracorporeal life support as a bridge to transplant.

SUMMARY

Candidate optimization requires early intervention to limit functional deterioration potentially contributing to adverse outcomes. Frailty can be identified with a transplant specific frailty assessment, and positively impacted with dedicated rehabilitation. Pretransplant frailty is reversible following transplant and should be considered in the context of overall fitness at the time of candidate selection. Invasive support modes including extracorporeal membrane oxygenation (ECMO) are appropriate to preserve strength and mobility, with awake, ambulatory ECMO preferred. The deleterious effect of GERD on graft function can be managed with early fundoplication over medical management alone.

Body mass index percentage and survival in pediatric patients listed for lung transplantation: A modern-era multi-institutional analysis

BACKGROUND

Prior studies suggest that being underweight by body mass index percentiles (BMI%) or thinness grade did not affect post-transplant survival in pediatric lung transplant (LTx) recipients regardless of cystic fibrosis (CF) or non-CF diagnosis. Graft and overall survival from the time of listing was instead evaluated based on listing BMI%, the current standard of practice for BMI definitions in pediatrics, to ascertain the impact of a "severely low" subcategory.

METHODS

The UNOS registry was queried for children listed for LTx (aged 2 to <18 years) from January 1986 to March 2020. BMI% at listing and transplant were calculated per CDC guidelines according to age in years, sex, and reported BMI%. Patients were divided by listing BMI%: severely low (<3rd), low (3-<5th), normal (5-<85th), overweight (85-<95th), and obese (≥95th). Kaplan-Meier curves were generated to assess differences in overall survival since listing based on BMI% classes. Cox proportional-hazards models were developed to assess risk factors for overall and graft survival, including listing BMI%, transplant listing era (≥2005), and listing age, by reporting hazard ratios (HR).

RESULTS

Listing BMI% was calculable for 1,876 patients. The proportion of patients with CF differed significantly between BMI% groups (p < 0.001). Patients listed with a non-CF diagnosis comprised 34% of those in the severely low category, and 88% of those listed with an obese BMI%. Compared to patients with a normal listing BMI%, the cohort with severely low BMI% had worse overall survival regardless of LTx (p = 0.009) and graft survival (p = 0.034). Compared to patients with a low BMI%, those with a severely low BMI% had significantly poorer graft survival as well (p = 0.040). Mean graft survival was not significantly different between groups that remained at listing BMI% vs those that improved in category despite an overall small sample size. Independent predictors of poorer survival from the time of listing include severely low vs low-normal BMI% (HR = 1.20) and listing age (HR = 1.02).

CONCLUSION

The proportion of children listed at severely low BMI% has steadily decreased with time, yet pediatric LTx candidates listed with a severely low BMI% had poorer graft and overall survival compared to those of normal BMI%. Severely low listing BMI% was an independent prognostic factor for higher mortality risk from the time of placement on the waitlist. BMI% may be a modifiable target for improving survival regardless of transplantation.

Body mass Index does not impact long-term survival of patients with idiopathic pulmonary fibrosis undergoing lung transplantation

Objective

We investigated the impact of body mass index (BMI) on post-operative outcomes and survival of patients with interstitial pulmonary fibrosis (IPF) undergoing lung transplantation.

Methods

We retrospectively reviewed 222 patients with IPF that underwent lung transplant (LT) at our institution from 2005 to 2019. Recipients were divided in 4 groups: group-1 consisted of underweight patients (BMI ≤18.5 kg/m2), group-2 of normal weight patients (BMI 18.5-25 kg/m2), group-3 of over-weight patients (BMI 25-29.9 kg/m2) and group-4 of obese patients (BMI ≥30 kg/m2).

Results

Group-1 consisted of 13 (6%) patients, group-2 of 67 (30%) patients, group-3 of 79 (36%) patients, group-4 consisted of 63 (28%) patients. Median BMI for group-1 was 17 [interquartile range (IQR): 17, 18], for group-2 was 23 (22, 24), for group-3 was 29 (28, 29.5) and group-4 was 32 (31, 33). Patients in group-1 were significantly younger (p < 0.01). Single LT comprised the majority of operation type in group-2 to group-4 and it was significantly higher than group 1 (p < 0.01). Median follow-up time was 39 months (13-76). A total of 79 (35.5%) patients died by the end of study. Overall, five deaths occurred in group-1, 17 in group-2, 33 in group-3, and 24 in group-4. Kaplan-Meier analysis showed that mortality was not statistically significant between the groups (p = 0.24). Cox-regression analysis was used to assess other possible risk factors that could influence the effect of BMI on mortality, including transplant type (single, double), lung allocation score, and age, diabetes and creatinine levels at surgery. None of these factors were shown to affect patient mortality (p > 0.05). Overall reasons for death included graft failure (24%), infection (23%), respiratory failure (14%), and malignancy (13%).

Conclusions

Body mass index does not impact long-term survival of patients with IPF undergoing lung transplantation.

Body Mass Index and Cause-Specific Mortality after Lung Transplantation in the United States

Rationale: Low and high body mass index (BMI) are associated with increased mortality after lung transplantation. Why extremes of BMI might increase risk of death is unknown. Objectives: To estimate the association of extremes of BMI with causes of death after transplantation. Methods: We performed a retrospective study of the United Network for Organ Sharing database, including 26,721 adults who underwent lung transplantation in the United States between May 4, 2005, and December 2, 2020. We mapped 76 reported causes of death into 16 distinct groups. We estimated cause-specific hazards for death from each cause using Cox models. Results: Relative to a subject with a BMI of 24 kg/m2, a subject with a BMI of 16 kg/m2 had 38% (hazard ratio [HR], 1.38; 95% confidence interval [95% CI], 0.99-1.90), 82% (HR, 1.82; 95% CI, 1.34-2.46), and 62% (HR, 1.62; 95% CI, 1.18-2.22) increased hazards of death from acute respiratory failure, chronic lung allograft dysfunction (CLAD), and infection, respectively, and a subject with a BMI of 36 kg/m2 had 44% (HR, 1.44; 95% CI, 0.97-2.12), 42% (HR, 1.42; 95% CI, 0.93-2.15), and 185% (HR, 2.85; 95% CI, 1.28-6.33) increased hazards of death from acute respiratory failure, CLAD, and primary graft dysfunction, respectively. Conclusions: Low BMI is associated with increased risk of death from infection, acute respiratory failure, and CLAD after lung transplantation, whereas high BMI is associated with increased risk of death from primary graft dysfunction, acute respiratory failure, and CLAD.

Listing Dilemmas: Age, Frailty, Weight, Preexisting Cancers, and Systemic Diseases

Selection of lung transplant candidates is an evolving field that pushes the boundaries of what is considered the norm. Given the continually changing demographics of the typical lung transplant recipient as well as the growing list of risk factors that predispose patients to poor posttransplant outcomes, we explore the dilemmas in lung transplant candidate selections pertaining to older age, frailty, low and high body mass index, preexisting cancers, and systemic autoimmune rheumatic diseases.

The Lung Allocation Score and Other Available Models Lack Predictive Accuracy for Post-Lung Transplant Survival

BACKGROUND

Improved predictive models are needed in lung transplantation in the setting of a proposed allocation system that incorporates longer-term post-transplant survival in the United States. Allocation systems require accurate mortality predictions to justly allocate organs.

METHODS

Utilizing the United Network for Organ Sharing database (2005-2017), we fit models to predict 1-year mortality based on the Lung Allocation Score (LAS), the Chan, et al, 2019 model, a novel "clinician" model (a priori clinician selection of pre-transplant covariates), and two machine learning models (Least Absolute Shrinkage and Selection Operator; LASSO and Random Forests) for predicting 1-year and 3-year post-transplant mortality. We compared predictive accuracy among models. We evaluated the calibration of models by comparing average predicted probability vs observed outcome per decile. We repeated analyses fit for 3-year mortality, disease category, including donor covariates, and LAS era.

RESULTS

The area under the cure for all models was low, ranging from 0.55 to 0.62. All exhibited reasonable negative predictive values (0.87-0.90), but the positive predictive value for was poor (all <0.25). Evaluating LAS calibration found 1-year post-transplant estimates consistently overestimated risk of mortality, with greater differences in higher deciles. LASSO, Random Forests, and clinician models showed no improvement when evaluated by disease category or with the addition of donor covariates and performed worse for 3-year outcomes.

CONCLUSIONS

The LAS overestimated patients' risk of post-transplant death, thus underestimating transplant benefit in the sickest candidates. Novel models based on pre-transplant recipient covariates failed to improve prediction. There should be wariness in post-transplant survival predictions from available models.

Consensus document for the selection of lung transplant candidates: An update from the International Society for Heart and Lung Transplantation

Tens of thousands of patients with advanced lung diseases may be eligible to be considered as potential candidates for lung transplant around the world each year. The timing of referral, evaluation, determination of candidacy, and listing of candidates continues to pose challenges and even ethical dilemmas. To address these challenges, the International Society for Heart and Lung Transplantation appointed an international group of members to review the literature, to consider recent advances in the management of advanced lung diseases, and to update prior consensus documents on the selection of lung transplant candidates. The purpose of this updated consensus document is to assist providers throughout the world who are caring for patients with pulmonary disease to identify potential candidates for lung transplant, to optimize the timing of the referral of these patients to lung transplant centers, and to provide transplant centers with a framework for evaluating and selecting candidates. In addition to addressing general considerations and providing disease specific recommendations for referral and listing, this updated consensus document includes an ethical framework, a recognition of the variability in acceptance of risk between transplant centers, and establishes a system to account for how a combination of risk factors may be taken into consideration in candidate selection for lung transplantation.

Weight loss for critical care patient to improve lung transplantation candidacy: A case report

A 47-year-old male with morbid obesity and progressive pulmonary fibrosis was admitted to the intensive care unit (ICU) with worsening hypoxia and nocturnal ventilator dependence. Due to a significant oxygen requirement, the patient could only safely remain in an acute care setting. Unfortunately, he was not eligible for lung transplantation due to having obesity, a relative contraindication to lung transplantation due to potential for post transplantation complications and increased mortality. Therefore, we treated the patient with a modified very low calorie diet (MVLCD) to achieve weight loss. He had successful, sustained weight loss over a period of seven weeks and reached a target weight that made him eligible for transplantation. He subsequently underwent successful bilateral lung transplantation. The patient had improved metabolic parameters and no side effects attributable to the reduced calorie diet. This report shows that in patients with end stage lung disease and a poor prognosis without transplantation, inpatient weight loss is safe and may allow for potentially lifesaving lung transplantation.

Obesity, transplantation, and bariatric surgery: An evolving solution for a growing epidemic

The increasing obesity epidemic has major implications in the realm of transplantation. Patients with obesity face barriers in access to transplant and unique challenges in perioperative and postoperative outcomes. Because of comorbidities associated with obesity, along with the underlying end-stage organ disease leading to transplant candidacy, these patients may not even be referred for transplant evaluation, much less be waitlisted or actually undergo transplant. However, the use of bariatric surgery in this population can help optimize the transplant candidacy of patients with obesity and end-stage organ disease and improve perioperative and postoperative outcomes. We review the impact of obesity on kidney, liver, and cardiothoracic transplant candidates and recipients and explore potential interventions to address obesity in these populations.

Need for tracheostomy after lung transplant predicts decreased mid- and long-term survival

BACKGROUND

Tracheostomy is an important adjunct for lung transplant patients requiring prolonged ventilation. We explored the effects of post-transplant tracheostomy on survival and bronchiolitis obliterans syndrome after lung transplant.

METHODS

A retrospective, single center analysis was performed on all lung transplant recipients during the Lung Allocation Score (LAS) era. Risk factors for post-transplant tracheostomy or death within 30 days were assessed. Kaplan-Meier estimates and Cox proportional hazards models were used to examine the association between tracheostomy within 30 days after transplant and survival at 1 and 3 years. A total of 403 patients underwent single or bilateral lung transplant between May 2005 and February 2016 with complete data for 352 cases, and 35 patients (9.9%) underwent tracheostomy or died (N = 10, 2.8%) within 30 days.

RESULTS

In adjusted analyses, primary graft dysfunction grade 3 (PGD3) was associated with a composite end point of tracheostomy or death within 30 days (HR 3.11 (1.69, 5.71), P-value < .001). Tracheostomy within 30 days was associated with decreased survival at 1(HR 4.25 [1.75, 10.35] P-value = .001) and 3 years (HR 2.74 [1.30, 5.76], P-value = .008), as well as decreased bronchiolitis obliterans (BOS)-free survival at 1 (HR 1.87 [1.02, 3.41] P-value = .042) and 3 years (HR 2.15 [1.33, 3.5], P-value = .002).

CONCLUSION

Post-transplant tracheostomy is a marker for advanced lung allograft dysfunction with significant reduction in long-term overall and BOS-free survival.

Optimizing Nutrition Assessment to Create Better Outcomes in Lung Transplant Recipients: A Review of Current Practices

Lung transplantation offers patients with end-stage lung disease an opportunity for a better quality of life, but with limited organ availability it is paramount that selected patients have the best opportunity for successful outcomes. Nutrition plays a central role in post-surgical outcomes and, historically, body mass index (BMI) has been used as the de facto method of assessing a lung transplant candidate’s nutritional status. Here, we review the historical origins of BMI in lung transplantation, summarize the current BMI literature, and review studies of alternative/complementary body composition assessment tools, including lean psoas area, creatinine-height index, leptin, and dual x-ray absorptiometry. These body composition measures quantify lean body mass versus fat mass and may provide a more comprehensive analysis of a patient’s nutritional state than BMI alone.

Trends, Determinants, and Impact on Survival of Post-Lung Transplant Weight Changes: A Single-center Longitudinal Retrospective Study

BACKGROUND

Weight gain is commonly seen in lung transplant (LTx) recipients. Although previous studies have focused on weight changes at fixed time periods and relatively early after transplant, trends over time and long-term weight evolution have not been described in this population. The study objectives were to document weight changes up to 15 years post-LTx and assess the predictors of post-LTx weight changes and their associations with mortality.

METHODS

Retrospective cohort study of LTx recipients between January 1, 2000, and November 30, 2016 (n = 502). Absolute weight changes from transplant were calculated at fixed time periods (6 mo, 1, 2, 5, 10, and 15 y), and continuous trends over time were generated. Predictors of weight changes and their association with mortality were assessed using linear and Cox regression analysis.

RESULTS

LTx recipients experienced a gradual increase in weight, resulting from the combination of multiple weight trajectories. Interstitial lung disease diagnosis negatively predicted post-LTx weight changes at all time points, whereas transplant body mass index categories were significant predictors at earlier time points. Patients with a weight gain of >10% at 5 years had a better survival (hazard ratio [HR], 0.36; 95% confidence interval [CI], 0.20-0.66), whereas a 10% weight loss at earlier time points was associated with worse survival (1 y: HR, 2.04; 95% CI, 1.22-3.41 and 2 y: HR, 2.37; 95% CI, 1.22-4.58).

CONCLUSIONS

Post-LTx weight changes display various trajectories, are predicted to some extent by individual and LTx-related factors, and have a negative or positive impact on survival depending on the time post-LTx. These results may lead to a better individualization of weight management after transplant.

Pre-transplant weight loss and clinical outcomes after lung transplantation

BACKGROUND

Patients with greater adiposity before lung transplantation are at an increased risk for worse post-transplant outcomes. Few studies have addressed whether pre-transplant weight loss mitigates this risk. In this study we examined the association between pre-transplant weight loss and post-transplant clinical outcomes.

METHODS

We conducted a retrospective cohort study of patients who received a lung transplant at the Duke University Hospital from May 1, 2005 to April 30, 2015. The sample included adult transplant recipients with restrictive, obstructive, and vascular diseases. Cox proportional hazards models were used to examine mortality and chronic lung allograft dysfunction (CLAD)-free survival, and negative binomial regression analyses were used to examine length of stay (LOS). Weight loss was assessed from change in body mass index (BMI).

RESULTS

The cohort consisted of 810 patients. Initially, 403 (50%) were overweight and 109 (13%) were obese by BMI criteria. Greater pre-transplant weight loss was associated with dose-response improvements in survival (hazard ratio [HR] 0.83 [0.72 to 0.97], p = 0.018), with modest (0% to 3%, HR 0.91), moderate (7% to 10%, HR 0.83), and high (>15%, HR 0.71) levels of weight loss conferring longer survival, independent of initial weight (p = 0.533 for interaction). Weight loss was also associated with improved CLAD-free survival (HR 0.84 [0.71 to 0.99], p = 0.034) and shorter LOS (b = ‒0.17, p < 0.001).

CONCLUSIONS

Weight loss before transplantation was associated with improved short- and long-term clinical outcomes, independent of initial weight. Survival improved proportionally to percentage of weight lost. The mechanisms by which weight loss improve clinical outcomes warrant further exploration.

The Impact of Waiting List BMI Changes on the Short-term Outcomes of Lung Transplantation

BACKGROUND

Obesity and underweight are associated with a higher postlung transplantation (LTx) mortality. This study aims to assess the impact of the changes in body mass index (BMI) during the waiting period for LTx on early postoperative outcomes.

METHODS

Medical records of 502 consecutive cases of LTx performed at our institution between 1999 and 2015 were reviewed. Patients were stratified per change in BMI category between pre-LTx assessment (candidate BMI) and transplant BMI as follows: A-candidate BMI, less than 18.5 or 18.5 to 29.9 and transplant BMI, less than 18.5; B-candidate BMI, less than 18.5 and transplant BMI, 18.5 to 29.9; C-candidate BMI, 18.5 to 29.9 and transplant BMI, 18.5 to 29.9; D-candidate BMI, 30 or greater and transplant BMI, 18.5 to 29.9; and E-candidate BMI, 30 or greater or 18.5 to 29.9 and transplant BMI, 30 or greater. Our primary outcome was in-hospital mortality and secondary outcomes were length of mechanical ventilation, intensive care unit length of stay (LOS), hospital LOS and postoperative complications.

RESULTS

BMI variation during the waiting time was common, as 1/3 of patients experienced a change in BMI category. Length of mechanical ventilation (21 days vs 9 days; P = 0.018), intensive care unit LOS (26 days vs 15 days; P = 0.035), and rates of surgical complications (76% vs 44%; P = 0.018) were significantly worse in patients of group E versus group D. Obese candidates who failed to decrease BMI less than 30 by transplant exhibited an increased risk of postoperative mortality (odds ratio, 2.62; 95% confidence interval, 1.01-6.48) compared with patients in group C. Pre-LTx BMI evolution had no impact on postoperative morbidity and mortality in underweight patients.

CONCLUSIONS

Our results suggest that obese candidates with an unfavorable pretransplant BMI evolution are at greater risk of worse post-LTx outcomes.

Nutritional Requirements of Lung Transplant Recipients: Challenges and Considerations

An optimal nutritional status is associated with better post-transplant outcomes and survival. Post-lung transplant nutrition management is however particularly challenging as lung recipients represent a very heterogeneous group of patients in terms of age, underlying diseases, weight status and presence of comorbidities. Furthermore, the post-transplant period encompasses several stages characterized by physiological and pathophysiological changes that affect nutritional status of patients and necessitate tailored nutrition management. We provide an overview of the current state of knowledge regarding nutritional requirements in the post-lung transplant period from the immediate post-operative phase to long-term follow-up. In the immediate post-transplantation phase, the high doses of immunosuppressants and corticosteroids, the goal of maintaining hemodynamic stability, the presence of a catabolic state, and the wound healing process increase nutritional demands and lead to metabolic perturbations that necessitate nutritional interventions. As time from transplantation increases, complications such as obesity, osteoporosis, cancer, diabetes, and kidney disease, may develop and require adjustments to nutrition management. Until specific nutritional guidelines for lung recipients are elaborated, recommendations regarding nutrient requirements are formulated to provide guidance for clinicians caring for these patients. Finally, the management of recipients with special considerations is also briefly addressed.

Prognostic value of pre-transplant mean pulmonary arterial pressure in lung transplant recipients: a single-institution experience

Background

Currently, lung transplantation (LTX) is considered to be a curative treatment option in patients with end-stage lung disease. Although pulmonary hypertension (PH), confirmed by cardiac catheterization, is a prognostic factor in patients undergoing LTX, the prognostic value of PH in Asian lung transplant recipients remains uncertain. In this study, we aimed to determine whether PH before LTX may serve as a prognostic factor for survival in Asian patients.

Methods

The medical records of 50 patients [male, 27; female, 23; mean age, 51.0 (41.0-60.0) years], who received preoperative right heart catheterization (RHC) and echocardiography before single or double LTX at Severance Hospital between January 2010 and December 2014, were reviewed. The relationship between 1-year survival after LTX and PH [mean pulmonary arterial pressure (mPAP) ≥25 mmHg at rest] was evaluated.

Results

The mean right ventricular systolic pressure and mPAP were 48.5 (22.8) and 30.0 (24.0-40.0) mmHg. Of the 50 patients, 17 (34.0%) died within a year after LTX. The 1-year survival rate among patients with mPAP ≥25 mmHg (58.8%) was lower than the survival rate among patients with mPAP <25 mmHg (87.5%). Pre-transplantation mPAP of ≥25 mmHg was associated with post-transplantation survival [hazard ratio (HR), 4.832; 95% confidence interval (CI), 1.080-21.608, P=0.039]. The presence of preoperative PH was also associated with an increased risk of postoperative complications.

Conclusions

Confirmation of PH via preoperative cardiac catheterization was associated with the prognosis of the patient after LTX. Clinicians should consider the necessity for early transplantation surgery before the mPAP reaches ≥25 mmHg.

An educational initiative to improve the team-based care of patients with idiopathic pulmonary fibrosis

A successful initiative to improve best care practice in IPF supported by electronic medical record changes http://ow.ly/ORxi30hBEmy.

The sarcopenia index: A novel measure of muscle mass in lung transplant candidates

BACKGROUND

Frailty, including low muscle mass, is an emerging risk factor for poor outcomes after lung transplant. The sarcopenia index (SI)-(serum creatinine value/cystatin C value) × 100-is a novel blood test to approximate muscle mass. We sought to validate SI among lung transplant patients.

METHODS

We retrospectively identified adult lung transplant recipients from 2000 through 2012 at our institution who underwent computed tomography within 1 year before transplant and had preserved blood samples. Creatinine and cystatin C values were measured using the samples and used to calculate SI. Muscle mass was estimated by computed tomographic measurement of skeletal muscle cross-sectional surface area (SA) at the L1 to L3 vertebral levels. Correlation between SI and SA was evaluated.

RESULTS

Of 28 patients meeting eligibility criteria, most were white (96%) and men (54%). Median (interquartile range) body mass index, SI, and SA were 25.9 (22-30) kg/m² , 106 (91-119), and 157 (113-195) cm2, respectively. The Pearson correlation coefficient between SI and SA was significant at L2 (0.43; P = .02) and L3 (0.41; P = .03).

CONCLUSION

Sarcopenia index is a potentially objective measure for estimating muscle mass that is noninvasive and less expensive. Sarcopenia index could be considered in lung transplant candidate selection following prospective validation in larger cohorts.

Primary Graft Dysfunction After Lung Transplantation

Primary graft dysfunction is a form of acute injury after lung transplantation that is associated with significant short- and long-term morbidity and mortality. Multiple mechanisms contribute to the pathogenesis of primary graft dysfunction, including ischemia reperfusion injury, epithelial cell death, endothelial cell dysfunction, innate immune activation, oxidative stress, and release of inflammatory cytokines and chemokines. This article reviews the epidemiology, pathogenesis, risk factors, prevention, and treatment of primary graft dysfunction.

Association of body mass index with lung transplantation survival in the United States following implementation of the lung allocation score

BACKGROUND

The association of body mass index (BMI) with survival after lung transplantation remains controversial, owing to conflicting evidence in the literature. Previous reports have used traditional BMI categories, included patients who underwent transplantation before implementation of the lung allocation score (LAS), or were limited by single-center experiences. Here we evaluated the association of individual BMI units with short-term and long-term mortality in a large national database following implementation of the LAS.

METHODS

The Scientific Registry of Transplant Recipients database was used to collect data for 17,233 adult lung transplantations performed between May 2005 and June 2016. The primary outcome was all-cause mortality at 90 days and 1 year posttransplantation. Logistic regression modeling was used to independently predict mortality per BMI unit, adjusting for donor and recipient factors.

RESULTS

BMI was an independent predictor of mortality at both 90 days and 1 year. At 90 days, a BMI of 25 was associated with the lowest predicted probability of death (0.053; 95% confidence interval [CI], 0.047-0.049), with increased odds of mortality at BMI ≤20 and ≥28. At 1 year, a BMI of 26 was associated with the lowest predicted probability of death (0.12; 95% CI, 0.11-0.13), with increased odds of mortality at BMI ≤24 and ≥28.

CONCLUSIONS

Each individual BMI unit has a quantifiable effect on posttransplantation survival, and the patterns of effect do not fit into the predefined BMI categories. The mortality risk associated with BMI should be considered by transplant centers when making listing decisions and by regulatory bodies for estimating expected outcomes.

Physical activity level significantly affects the survival of patients with end-stage lung disease on a waiting list for lung transplantation

PURPOSE

Our objective was to investigate the factors predicting the survival of patients on the waiting list for lung transplantation (LT) during the waiting period, with a special emphasis on the physical activity level.

METHODS

The study included 70 patients with end-stage pulmonary disease who were on the waiting list for LT at Kyoto University Hospital. We examined the association between the baseline characteristics, including the body mass index and body composition, serum albumin, serum C-reactive protein (CRP), steroid administration, physical activity level (calculated by the food frequency questionnaire) and survival during the waiting period using Kaplan-Meier curves and Cox proportional hazard regression models.

RESULTS

A physical activity level of ≤1.2 was correlated with significantly decreased survival (1-year survival: 68 vs. 90.9%, p = 0.0089), with a hazard ratio (HR) of 2.24 (95% confidence interval (CI) 1.22-4.19, p = 0.0001). Hypo-albumin (HR 2.024, 95% CI 1.339-6.009, p = 0.004), a high level of CRP (HR 2.551, CI 1.229-4.892, p = 0.02), and the administration of steroids (HR 2.258, CI 1.907-5.032, p = 0.024) were also significant predictors of survival.

CONCLUSIONS

Low levels of physical activity during the waiting period for LT led to decreased survival times among LT candidates.

Determinants of pre-transplantation pectoralis muscle area (PMA) and post-transplantation change in PMA in lung transplant recipients

BACKGROUND

This study aimed to determine predictors of pectoralis muscle area (PMA) and assess change in PMA following lung transplantation and its relationship to outcomes.

METHODS

A retrospective review of 88 lung transplant recipients at a single center was performed. PMA was determined on a single axial slice from chest computerized tomography. Pectoralis muscle index (PMI) was calculated from the PMA divided by the height squared.

RESULTS

PMI decreased post-transplantation (8.1±2.8 cm² /m² pre-transplantation, 7.5±2.9 cm² /m² at 6 months, and 7.6±2.7 cm² /m² at 12 months, P<.05). Chronic obstructive pulmonary disease (COPD) and interstitial lung disease (ILD) were predictors of pre-transplant PMI (β=-2.3, P=.001 for COPD; β=2.1, P<.001 for ILD) and percent change in PMI at 12 months post-transplantation relative to baseline (β=19.2, P=.04 for COPD; β=-20.1, P=.01 for ILD). Patients in the highest quartile for PMI change at 12 months had fewer ventilator days compared with patients in the other quartiles (P=.03).

CONCLUSIONS

Underlying diagnosis was a significant predictor of both pre-transplantation PMI and change in PMI post-transplantation. Further studies of PMI are needed to determine its clinical utility in predicting outcomes following lung transplantation.

Primary graft dysfunction: pathophysiology to guide new preventive therapies

INTRODUCTION

Primary graft dysfunction (PGD) is a common complication of lung transplantation characterized by acute pulmonary edema associated with bilateral pulmonary infiltrates and hypoxemia in the first 3 post-operative days. Development of PGD is a predictor of poor short- and long-term outcomes after lung transplantation, but there are currently limited tools to prevent its occurrence. Areas covered: Several potentially modifiable donor, recipient, and operative risk factors for PGD have been identified. In addition, basic and translational studies in animals and ex vivo lung perfusion systems have identified several biomarkers and mechanisms of injury in PGD. In this review, we outline the clinical and genetic risk factors for PGD and summarize experimental data exploring PGD mechanisms, with a focus on strategies to reduce PGD risk and on potential novel molecular targets for PGD prevention. Expert commentary: Because of the clinical importance of PGD, development of new therapies for prevention and treatment is critically important. Improved understanding of the pathophysiology of clinical PGD provides a framework to explore novel agents to prevent or reverse PGD. Ex vivo lung perfusion provides a new opportunity for rapid development of therapeutics that target this devastating complication of lung transplantation.

Pre-transplant wasting (as measured by muscle index) is a novel prognostic indicator in lung transplantation

BACKGROUND

Frailty in non-transplant populations increases morbidity and mortality. Muscle wasting is an important frailty characteristic. Low body mass index is used to measure wasting, but can over- or underestimate muscle mass. Computed tomography (CT) software can directly measure muscle mass. It is unknown if muscle wasting is important in lung transplantation.

AIM AND METHODS

The aim of this single-center, retrospective cohort study was to determine whether pre-transplant low muscle mass (as measured by CT using Slice-O-matic software at L2-L3 interspace) was associated with post-transplantation mortality, hospital and intensive care unit length of stay (LOS), duration of mechanical ventilation, or primary graft dysfunction. Lung transplant recipients from 2000 to 2012 with a CT scan less than six months prior to transplant were included. Univariate, multivariate, and Kaplan-Meier analyses were conducted.

RESULTS

Thirty-six patients were included. Those with low muscle index (lower 25th percentile) had a worse survival (hazard ratio = 3.83; 95% confidence interval 1.42-10.3; p = 0.007) and longer hospital LOS by an estimated 7.2 d (p = 0.01) when adjusted for age and sex as compared to those with higher muscle index.

CONCLUSION

Low muscle index at lung transplantation is associated with worse survival and increased hospital LOS.