Severe underweight decreases the survival rate in adult lung transplantation

Impact of changes in skeletal muscle mass and quality during the waiting time on outcomes of lung transplantation

INTRODUCTION

The association of changes in skeletal muscle mass and quality during the waiting time with outcomes of lung transplantation (LT) remains unclear. We aimed to examine the association of changes in skeletal muscle mass and quality during the waiting time, as well as preoperative skeletal muscle mass and quality, with outcomes of LT.

METHODS

This study included individuals who underwent LT from brain-dead donors. Skeletal muscle mass (cm2 /m2 ) and quality (mean Hounsfield units [HU]) of the erector spinae muscle at the 12th thoracic level were evaluated using computed tomography. Preoperative skeletal muscle mass and quality, and their changes during the waiting time were calculated. We evaluated the associations among mechanical ventilation (MV) duration, intensive care unit (ICU) length of stay (LOS), hospital LOS, 6-minute walk distance at discharge, and 5-year survival after LT.

RESULTS

This study included 98 patients. The median waiting time was 594.5 days (interquartile range [IQR], 355.0-913.0). The median changes in skeletal muscle mass and quality were -4.4% (IQR, -13.3-3.1) and -2.9% (IQR, -16.0-4.1), respectively. Severe low skeletal muscle mass at LT was associated with prolonged ICU LOS (B = 8.46, 95% confidence interval [CI]: .51-16.42) and hospital LOS (B = 36.00, 95% CI: 3.23-68.78). Pronounced decrease in skeletal muscle mass during the waiting time was associated with prolonged MV duration (B = 7.85, 95% CI: .89-14.81) and ICU LOS (B = 7.97, 95% CI: .83-15.10).

CONCLUSION

Maintaining or increasing skeletal muscle mass during the waiting time would be beneficial to improve the short-term outcomes of LT.

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.

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.

The outcome of lung transplantation for end-stage pulmonary diseases with pulmonary hypertension: a single-center experience

BACKGROUND

Lung transplantation is a treatment for end-stage lung disease. The optimal transplant strategy for patients with end-stage lung disease complicated by pulmonary hypertension (PH) is controversial. The aim of this study is to review this experience and analyze the outcomes of lung transplantation for PH.

METHODS

This retrospective study collected data on patients with PH undergoing lung transplantation between March 2016 and December 2019 at a single center in China. The perioperative features and short- and medium-term outcomes between single-lung transplantation (SLT) and double-lung transplantation (DLT) were compared. Kaplan-Meier methods were used to analyze overall survival across a variety of transplantation procedures, age, mean pulmonary artery pressure (mPAP), body mass index (BMI), and indications of transplantation.

RESULTS

A total of 63 patients with PH were finally included in the analysis. The mean age, mean BMI, and mPAP were 56.37 years, 19.56 kg/m², and 35.4 mmHg respectively. The overall 1-, 2-, and 3-year survival was 70%, 63%, and 60%, respectively. Five (7.94%) patients died within 30 days after surgery and nine patients (14.3%) died from infection during the followed-up period. There were no significant differences in the short- and medium-term survival outcomes of SLT and DLT, but postoperative pulmonary function was better in DLT. Patients older than 60 years of age had worse survival (P=0.01).

CONCLUSIONS

The short- and medium-term survival outcomes between SLT and DLT are similar in selected patients with PH. DLT provides better pulmonary function. Patients older than 60 years are associated with worse survival.

Elexacaftor/Tezacaftor/Ivacaftor as a Bridge to Lung Retransplant in a Recipient With Cystic Fibrosis

The triple-combination cystic fibrosis transmembrane conductance regulator modulator elexacaftor/- tezacaftor/ivacaftor is known to improve lung function and have extrapulmonary benefits in people with cystic fibrosis. However, there is limited evidence for its use in patients with cystic fibrosis after lung transplant, where the donor lung expresses normal levels of the cystic fibrosis transmembrane conductance regulator. We describe the use of elexacaftor/tezacaftor/ivacaftor as a bridge to potential lung retransplant in a 37-year-old man with cystic fibrosis and chronic lung allograft dysfunction. Although forced expiratory volume in 1 second did not improve, the patient had decreased sputum volume, no pulmonary exacerbations of cystic fibrosis, and no longer required continuous antibiotic therapy. Pancreatic function, revised Cystic Fibrosis Questionnaire scores, sinus symptoms, weight, and corticosteroid dependence significantly improved. There were no reported side effects attributable to elexacaftor/tezacaftor/ivacaftor. However, the patient exhibited declined renal function, which had been initially attributed to lability in cyclosporin levels but which were corrected after lithotripsy for renal calculi. Triple-combination modulators of the cystic fibrosis transmembrane conductance regulator may offer benefits to carefully selected individuals awaiting retransplant, balanced against the risk of worsened immunosuppressant level control.

Erector spinae muscle radiographic density is associated with survival after lung transplantation

OBJECTIVE

The study objective was to verify whether low preoperative radiographic density of erector spinae muscles is associated with poor prognosis after lung transplantation.

METHODS

Preoperative chest computed tomography scans for patients who underwent deceased-donor lung transplantation between 2013 and 2019 at Kyoto University Hospital were retrospectively retrieved. The radiographic density of erector spinae muscles was quantitatively evaluated as the mean attenuation of erector spinae muscles, and low mean radiographic density of the erector spinae muscles was defined as a mean radiographic density of the erector spinae muscles value below the median value for all patients. Overall survival and chronic lung allograft dysfunction-free survival with high and low mean radiographic density of the erector spinae muscles were estimated using the Kaplan-Meier method and evaluated by the log-rank test, as well as by univariate and multivariate Cox proportional hazard analyses.

RESULTS

Of the 107 adult patients who underwent primary transplantation, 96 underwent at least 1 chest computed tomography scan within 24 hours before lung transplantation. The median mean radiographic density of the erector spinae muscles in these 96 patients was 49.2 Hounsfield units. A low mean radiographic density of the erector spinae muscles value was significantly associated with decreased overall survival (hazard ratio, 4.50; P = .030) and chronic lung allograft dysfunction-free survival (hazard ratio, 3.18; P = .028) in the multivariate analysis. Additionally, patients with preoperative steroid use and a low mean radiographic density of the erector spinae muscles value had a worse overall survival (P < .001) and chronic lung allograft dysfunction-free survival (P < .001) than patients with preoperative steroid use and a high mean radiographic density of the erector spinae muscles value and those without preoperative steroid use.

CONCLUSIONS

Low mean radiographic density of the erector spinae muscles was closely associated with a poor prognosis after lung transplantation. The prognosis was particularly poor in patients with preoperative steroid use and a low mean radiographic density of the erector spinae muscles. These results may be useful when considering the indications for lung transplantation or preoperative interventions. VIDEO ABSTRACT.

Lung Transplantation for Pleuroparenchymal Fibroelastosis

Pleuroparenchymal fibroelastosis (PPFE), a new disease entity associated with interstitial pneumonia, is characterized by fibrosis and elastosis involving the pleura and subpleural lung parenchyma, predominantly in the upper lobe. As the awareness of this disease entity has increased, many studies have revealed the prevalence and incidence, clinical and pathological characteristics, and disease course of PPFE. Patients with PPFE reportedly have several unique clinical characteristics—including an extremely low body mass index with a slender body and chest wall deformity, known as “flat chest”. As this disease progresses, shrinking of the lungs often causes life-threatening complications, such as pneumothorax, and associated air leak syndrome. Lung transplantation is considered the only effective treatment for patients with advanced PPFE; however, little is known about the influences of the characteristics of PPFE on the outcome of lung transplantation. This review focuses on the unique clinicopathologic characteristics of PPFE and associated outcomes of lung transplantation for these patients.

Physical Function Measured Prior to Lung Transplantation Is Associated With Posttransplant Patient Outcomes

INTRODUCTION

The primary objective of this study was to determine whether pretransplant physical function is correlated with posttransplantation outcomes.

METHODS

We performed a retrospective study of patients that participated in pretransplantation screening and subsequently underwent lung transplantation. Pretransplant variables of interest included demographics, muscle mass, body composition, physical function, and physical frailty. Correlation tests were performed to assess relationships with significance set at 0.05.

RESULTS

Twenty-five patients with a mean age of 57 ± 13 years (68% male) with pretransplant lung allocation score of 45 ± 14 were included. This cohort had a 3-year mortality rate of 32% (n = 8). Pretransplant 4-m gait speed was significantly related to performance on the Short Physical Performance Battery (r = 0.74, P = .02) and distance ambulated on the 6-minute walk test (r = 0.62, P = .07) at hospital discharge. Older age was associated with slower gait speed and worse performance on sit-to-stand testing at hospital discharge (r = -0.76, P = .01 and r = -0.75, P = .01, respectively). Statistically, only diagnosis of cystic fibrosis was associated with 3-year mortality.

DISCUSSION

Our study demonstrates that demographic, clinical, and physical function assessed prior to lung transplantation may be indicators of functional recovery.

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.