Sarcopenia is Distinct from Physical Frailty and Significantly Associated with Length of Stay after Transplantation

Abstract

<h3>Purpose</h3> Our previous studies demonstrated an association between physical frailty by Fried frailty phenotype (FFP) with waitlist death and length of stay (LOS) after lung transplantation. We sought to evaluate the predictive ability of sarcopenia in patients undergoing evaluation for lung transplantation. <h3>Methods</h3> We identified 68 patients, ages 60-71, who had frailty evaluation by FFP or short performance physical battery (SPPB) with chest CT available for review during transplant evaluation. Using the software Osirix (Pixmeo, Switzerland), we determined the total area (in cm2) and average attenuation (in HU) of the right and left pectoralis muscle at the level of one slice above the aortic arch (<b>Figure</b>). Pectoralis was chosen as it resulted in more reproduceable measurements compared with intercostal muscles. <h3>Results</h3> Sarcopenia, as measured by either total pectoral area or average attenuation, was not significantly associated with patient age or physical frailty by FFP or SPPB. Sarcopenia was not associated with death on the waiting list or death in the first year after transplantation. Notably, however, patients with less sarcopenia were more likely to be transplanted (p= 0.022), a clinical outcome that was not associated with age, sex, or physical frailty. For patients who underwent transplantation during the period of study (n= 46), both lower total pectoral area and average attenuation were significantly associated with increased LOS after transplantation (p=0.002 and p=0.034, respectively). <h3>Conclusion</h3> Sarcopenia represents an attractive avenue for patient assessment, where chest CT evaluation is part of routine evaluation. No association was seen between physical frailty and sarcopenia, although both measures were predictive of clinical outcomes. This suggests the possibility of applying multiple assessments for patient risk stratification. Future studies are needed to determine the impact of optimizing nutrition and physical therapy in waitlisted patients.