Core Muscle Size Predicts Postoperative Outcome in Lung Transplant Candidates

Abstract

Background: Careful patient selection is the prerequisite to raise transplant benefit. In lung transplant (LT) candidates, the effect of body mass index (BMI) on postoperative outcome remains controversial, possibly due to the inaccuracy of BMI in discriminating between fat and muscle mass. We therefore hypothesized that assessment of body composition by muscle mass measures is more accurate than by BMI regarding postoperative outcome.

Methods: All LT recipients from 2011 to 2014 were included and retrospectively analyzed. Lean psoas area (LPA) was assessed from pretransplant computed tomography scans, and associations with postoperative outcomes were investigated.

Results: Included were 103 consecutive LT recipients with a mean pre-LT BMI of 22.0 ± 4.0 kg/m(2) and a mean LPA of 22.3 ± 8.3 cm(2). LPA was inversely associated with length of mechanical ventilation (p = 0.03), requirement of tracheostomy (p = 0.035), and length of stay in the intensive care unit (p = 0.02), while controlling for underlying disease, BMI, sex, age, and procedure; in contrast, BMI was not (p = 0.25, p = 0.54, and p = 0.42, respectively.). Multiple regression analysis revealed that the 6-minute walk distance at the end of pulmonary rehabilitation was significantly associated with LPA (p = 0.02).

Conclusions: LPA can easily be assessed in LT candidates as part of pretransplant evaluation and was significantly associated with short-term outcome, whereas BMI was not. Assessment of LPA may provide additional information on body composition beyond BMI. However, the clinical utility has to be further evaluated.