Determinants of pre-transplantation pectoralis muscle area (PMA) and post-transplantation change in PMA in lung transplant recipients

BackgroundThis study aimed to determine predictors of pectoralis muscle area (PMA) and assess change in PMA following lung transplantation and its relationship to outcomes. MethodsA 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. ResultsPMI decreased post-transplantation (8.12.8cm(2)/m(2) pre-transplantation, 7.5 +/- 2.9cm(2)/m(2) at 6months, and 7.6 +/- 2.7cm(2)/m(2) at 12months, P<.05). Chronic obstructive pulmonary disease (COPD) and interstitial lung disease (ILD) were predictors of pre-transplant PMI (=-2.3, P=.001 for COPD; =2.1, P<.001 for ILD) and percent change in PMI at 12months post-transplantation relative to baseline (=19.2, P=.04 for COPD; =-20.1, P=.01 for ILD). Patients in the highest quartile for PMI change at 12months had fewer ventilator days compared with patients in the other quartiles (P=.03). ConclusionsUnderlying 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.