Quantity and quality of antigravity muscles in patients undergoing living-donor lobar lung transplantation: 1-year longitudinal analysis using chest computed tomography images

Effects of sarcopenia on postoperative recovery in elderly patients after cardiac surgery with cardiopulmonary bypass

BACKGROUND

Few studies have assessed sarcopenia identified by erector spinae muscle (ESM) using thoracic computed tomography (CT) before cardiac surgery. We aimed to explore the relationship between sarcopenia evaluated via ESM and poor outcomes following cardiac surgery with cardiopulmonary bypass (CPB) in elderly patients.

METHODS

268 patients older than 65 years who underwent cardiac surgery with CPB at our institution in 2020 were included in the retrospective, single center, cohort study. Preoperative chest CT scans were used to measure the cross-sectional areas of the ESM (ESMCSA), which were then adjusted for body surface area (BSA) to determine the muscle mass index. Patients were categorized into sarcopenia and non-sarcopenia groups based on ESMCSA/BSA scores, and their short- and long-term clinical outcomes were compared.

RESULTS

The ESMCSA/BSA detected sarcopenia in 51.1% of patients. Patients with sarcopenia had significantly extended durations of stay in both the intensive care unit and the hospital compared to those without sarcopenia. Furthermore, the incidence of major adverse events was significantly higher in the sarcopenia group compared to the non-sarcopenia group (15.3% vs. 32.1%, P < 0.001). Furthermore, multivariate logistic regression analysis demonstrated that sarcopenia (OR 2.457, 95% CI 1.178-5.126, P = 0.017) independently predicted the risk of postoperative complications after adjusting for gender, preoperative nutritional status, serum albumin, estimated glomerular filtration rate, creatinine, white blood cell count, lymphocytes, type of surgery, surgical time, and aortic cross-clamp time. Kaplan-Meier survival analysis revealed a statistically significant difference in overall mortality between groups (log-rank P = 0.011). The Cox proportional hazards model identified preoperative sarcopenia as an independent risk factor for long-term mortality (HR, 2.132; 95% CI 1.144-3.972, P = 0.017).

CONCLUSION

Our study identified preoperative sarcopenia, assessed via ESM muscle mass on chest CT, as an independent predictor of postoperative complications and long-term overall mortality in elderly cardiac surgery patients with CPB.

Antigravity muscle density on computed tomography and health-related independence in normal weight patients with chronic obstructive pulmonary disease

BACKGROUND

Low body mass index (BMI) is a prognostic factor, and skeletal muscle adiposity may affect mortality irrespective of BMI in patients with chronic obstructive pulmonary disease (COPD). However, the association between muscle adiposity and healthy life expectancy in normal-weight patients remains unestablished.

OBJECTIVE

To examine whether lower chest computed tomography (CT)-assessed erector spinae muscle density (ESMD), which represents antigravity muscle adiposity, is associated with subsequent loss of health-related independence in normal-weight patients with COPD.

METHODS

The ESMD lower limit of normal (LLN) was determined in 194 healthy subjects undergoing lung cancer screening CT. In a prospective cohort of patients with COPD undergoing baseline inspiratory/expiratory CT, the onset of loss of health-related independence, requiring long-term nursing facility or home nursing/medical care, was recorded over 5 years.

RESULTS

Smokers with COPD (n = 199) were divided into 4 groups on the basis of BMI and the ESMD-LLN: underweight (n = 22), normal-weight with (n = 40) and without (n = 81) low ESMD, and overweight (n = 56). Greater airway wall thickening was associated with BMI-independent low ESMD. A multivariable Cox proportional hazards model including only normal-weight patients with COPD (n = 121) indicated that low ESMD was independently associated with a higher loss-of-independence rate after adjusting for FEV1, COPD assessment test score, and a smaller cross-sectional area of erector spinae muscles (hazard ratio [95% confidence interval] = 3.21 [1.30-7.89]).

CONCLUSION

Low antigravity muscle density could reflect airway wall thickening and shorten healthy life expectancy in normal-weight patients with COPD.

Impact of the quantity and quality of erector spinae muscles on the short-term prognosis of elderly patients with aspiration pneumonia in Japan

BACKGROUND

Whether muscle mass and muscle quality affect the prognosis of elderly patients with aspiration pneumonia is unclear. This study aimed to evaluate the relationship between erector spinae muscle mass and muscle quality on the 30-day prognosis of elderly patients with aspiration pneumonia.

METHODS

Two hundred fifty-eight patients who were diagnosed with aspiration pneumonia and admitted to Sanuki Municipal Hospital for pulmonary rehabilitation intervention were included. The cross-sectional area (ESMCSA/BSA) and CT values (ESMCT) of the erector spinae muscles at the 12th thoracic vertebra were measured on chest CT images to represent muscle mass and quality, respectively. The primary outcome was defined as 30-day survival.

RESULTS

Twenty-six patients died within 30 days after hospitalization. The ESMCSA/BSA ratio was significantly greater in the survival group than in the nonsurvival group (p = 0.001). The cutoff values for 30-day survival were calculated as follows: the ESMCSA/BSA was 11.046 cm2/m2 in male patients and 9.600 cm2/m2 in female patients; the ESMCT was 26.85 HU in male patients and 8.00 HU in female patients. A higher ESMCSA/BSA significantly improved 30-day survival, while ESMCT did not show a significant difference. Cox proportional hazards regression analysis revealed that the ESMCSA/BSA was independently associated with 30-day short-term prognosis (hazard ratio 0.34, p = 0.034).

CONCLUSION

The short-term prognosis of elderly patients with aspiration pneumonia may be more strongly influenced by muscle mass than by the muscle quality of the erector spinae muscles.

Perioperative changes in radiographic density in erector spinae muscle and mortality after lung transplantation

RATIONALE

The radiographic density of the erector spinae muscle (ESM) is often decreased early after lung transplantation (LTx). The prognostic impact of this change has not been elucidated.

OBJECTIVE

To investigate whether the decrease in the radiographic density of ESMs early after LTx is associated with a poor prognosis.

METHODS

This study is a single center retrospective cohort study. Routine follow-up chest computed tomography scan data just before and 12 weeks after LTx were retrospectively retrieved for adult patients who underwent primary LTx at Kyoto University Hospital. The radiographic density of ESM was quantitatively evaluated as the mean attenuation of the ESM (ESMct), and the impact of the decreased ESMct during the 12 weeks after LTx on overall survival (OS) was examined by Cox proportional hazard regression.

RESULTS

A total of 151 recipients (94 cadaveric LTx, 57 living-donor lobar LTx) were included in this study. The median duration of postoperative observation was 4.4 years, during which time 39 recipients (26%) died. Decreased postoperative ESMct was significantly associated with poor OS (HR, 1.64; 95% CI, 1.14-2.35, P = 0.008 per 1 Z score decrease) in the multivariate model adjusted for age, sex, episodes of acute rejection, and preoperative ESMct. Similar results were obtained when the subjects were limited to those with cadaveric LTx.

CONCLUSION

A decreased perioperative ESMct was strongly associated with a poor prognosis after LTx in addition to low preoperative ESMct. Maintaining postoperative muscle radiographic density, which reflects muscle quality, may be important for a better prognosis after LTx.

Respiratory sarcopenia: A position paper by four professional organizations

We defined respiratory sarcopenia as a coexistence of respiratory muscle weakness and decreased respiratory muscle mass. Although respiratory muscle function is indispensable for life support, its evaluation has not been included in the regular assessment of respiratory function or adequately evaluated in clinical practice. Considering this situation, we prepared a position paper outlining basic knowledge, diagnostic and assessment methods, mechanisms, involvement in respiratory diseases, intervention and treatment methods, and future perspectives on respiratory sarcopenia, and summarized the current consensus on respiratory sarcopenia. Respiratory sarcopenia is diagnosed when respiratory muscle weakness and decreased respiratory muscle mass are observed. If respiratory muscle mass is difficult to measure, we can use appendicular skeletal muscle mass as a surrogate. Probable respiratory sarcopenia is defined when respiratory muscle weakness and decreased appendicular skeletal muscle mass are observed. If only respiratory muscle strength is decreased without a decrease in respiratory function, the patient is diagnosed with possible respiratory sarcopenia. Respiratory muscle strength is assessed using maximum inspiratory pressure and maximum expiratory pressure. Ultrasonography and computed tomography are commonly used to assess respiratory muscle mass; however, there are insufficient data to propose the cutoff values for defining decreased respiratory muscle mass. It was jointly prepared by the representative authors and authorized by the Japanese Society for Respiratory Care and Rehabilitation, Japanese Association on Sarcopenia and Frailty, Japanese Society of Respiratory Physical Therapy and Japanese Association of Rehabilitation Nutrition. Geriatr Gerontol Int 2023; 23: 5-15.

Impact of inspiratory muscle strength on exercise capacity after lung transplantation

BACKGROUND AND PURPOSE

Though inspiratory muscle strength is essential for patients with respiratory disease, it is unclear whether the recovery of inspiratory muscle strength contributes to an exemplary achievement of exercise tolerance after lung transplantation (LTx). We aimed to elucidate the inspiratory muscle strength affects the recovery of exercise capacity after LTx.

METHODS

Recipients who underwent LTx between June 2017 and September 2018 were enrolled, and 6-min walking distance (6MWD), quadriceps force, inspiratory muscle strength (maximal inspiratory pressure [MIP]), and spirometry were evaluated at 3, 6, and 12 months after LTx. The relationships between inspiratory muscle strength and changes in physical performance were analyzed.

RESULTS

Nineteen recipients (mean age: 44.8 years, male: 32%) who completed all follow-ups were analyzed. At 3 months after LTx, mean MIP (88.4% predicted) and vital capacity (60.9% predicted), quadriceps force (QF; 2.1 N*m/kg), and 6MWD (504 m) were lower than normal values. After LTx, 6MWD significantly improved up to 12 months. From 3 to 6 months after LTx, changes in MIP were significantly associated with increases in 6MWD by univariate (r = 0.55, p = 0.02) and multivariate (β = 0.59, p = 0.01) regression analyses, whereas changes of QF in place of MIP were significantly associated with the recoveries of 6MWD from 6 to 12 months.

DISCUSSION

Improvements in MIP may impact the recovery of exercise capacity in the early phase after LTx. Factors that determine the improvement in exercise capacity following LTx may vary with postoperative time.

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.

Physical function after lung transplantation for late-onset noninfectious pulmonary complications after allogeneic hematopoietic stem cell transplantation

PURPOSE

Late-onset noninfectious pulmonary complications (LONIPCs) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) are fatal, and lung transplantation is the only curative treatment. Although lung transplantation for LONIPCs may confer good survival rates, it is unclear whether or how impaired physical functioning is restored. Thus, this study aimed to investigate the long-term course and associated changes in physical functions after lung transplantation in patients with LONIPCs after allo-HSCT.

METHODS

This prospective cohort study enrolled 15 patients who received lung transplantation for LONIPCs after allo-HSCT between 2012 and 2018. Dyspnea scores, performance status, physical function, and exercise tolerance were assessed before lung transplantation and up to 2 years after transplantation.

RESULTS

Two years after lung transplantation, the dyspnea scores and performance status improved, but did not recover completely. Physical function was assessed using the knee extensor strength (KES) and 6-min walk test (6MWT); the results were poor until 3 months after transplantation but improved over 2 years. The 6MWT distance showed improvement to a nearly healthy level (562.7 m). Recovery of exercise tolerance was associated with recovery in % vital capacity (%VC; r=0.5) and KES (r=0.4) from 3 months to 2 years after lung transplantation. Furthermore, a flat thorax, which is a characteristic of patients with LONIPCs, affected the %VC at 2 years after transplantation (r=0.8).

CONCLUSION

Lung transplantation for LONIPCs may restore impaired physical function. A multifaceted rehabilitation program should be considered, especially to improve muscle weakness and pulmonary function.