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 cm /m pre-transplantation, 7.5±2.9 cm /m at 6 months, and 7.6±2.7 cm /m 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.