Sarcopenia of the Psoas Muscles is Associated with Poor Outcomes Following Lung Transplantation.

BACKGROUND: Sarcopenia, a known component of frailty, defined by diminished cross-sectional area of the psoas muscles, is associated with poor outcomes after a range of surgical procedures. However, little is known of the relationship between sarcopenia of the psoas muscles (SPM) and long-term mortality, decline in pulmonary function, and graft failure after lung transplantation.

METHODS: We reviewed patients who underwent primary lung transplantation at our institution from 2011 to 2014. Cross-sectional areas of the psoas muscles at the L4 vertebral level were measured using preoperative computed tomography (CT). Gender-based cutoff values for sarcopenia were generated and validated. The primary outcomes were one-, two-, and three-year all-cause mortality, FEV1 values, and graft function. Adjusted logistic regression and survival analysis was used to analyze outcomes.

RESULTS: 95 patients were included in this study. 39 (41.1%) patients were considered sarcopenic. SPM was significantly associated with short- and mid-term mortality on multivariate analysis (1-year [OR: 8.7, p=0.017], 2-year [OR: 12.7, p<0.01], 3-year [OR: 13.4, p<0.01]). Survival analysis showed significantly decreased survival in sarcopenic patients at three-years (35.9% vs 76.8%, p<0.01). SPM is also associated with decreased FEV1 (Coeff: -17.3, p=0.03). Adjusted Cox analysis showed an increased hazard for all-cause mortality (HR: 5.8, p<0.01) and graft failure (HR: 14.7, p<0.01) in sarcopenic patients.

CONCLUSIONS: This study demonstrates a significant association between SPM and mortality, pulmonary function, and graft failure in patients receiving a lung transplant. Determining SPM preoperatively may be a useful component of frailty assessment and a predictor of survival in this patient population.