Low skeletal muscle mass defined by thoracic CT as a prognostic marker in acute pulmonary embolism

Sarcopenia defined as low skeletal muscle mass (LSMM) is associated with several clinically relevant factors in people who are critically ill. The aim of the present study was to analyze the role of LSMM derived from thoracic computed tomography (CT) for prediction of mortality and prognosis of acute pulmonary embolism (PE).

The clinical database of our department was retrospectively screened for patients with acute PE between 2013 and 2017. Overall, 234 patients were included in the analysis. LSMM was assessed on axial slides at the thoracic vertebra 5 (Th5) level of contrast-enhanced pulmonary angiography thoracic CT. The skeletal muscle index (SMI) was calculated by adjusting the muscle area to height. All-cause 30-d mortality was used as a primary outcome.

Overall, 64 participants (27.4% of the sample) died. SMI was slightly higher for survivors than non-survivors (57.7 ± 11.9 versus 55.6 ± 14.3 cm²/m²; P = 0.07). SMI was associated with 30-d mortality in univariate as well as multivariate analysis (respective hazard ratios and 95% CI: 1.06, 1.03-1.09; 1.08, 1.04-1.11).

SMI at Th5 derived from thoracic CT has a relevant effect on 30-d mortality in people with acute PE and should be included in the clinical routine.