# Thoracic sarcopenia as a comorbidity-independent predictor of length of stay in congenital cardiac surgery

## TL;DR

This study shows that low thoracic muscle volume is linked to longer hospital stays and higher mortality in children undergoing congenital heart surgery.

## Contribution

Thoracic sarcopenia is identified as a comorbidity-independent predictor in congenital cardiac surgery outcomes.

## Key findings

- Low thoracic skeletal muscle volume correlates with longer hospital length of stay.
- Patients with reduced TSMV had higher hospital mortality rates.
- Higher TSMV predicts shorter hospital stays in multivariable analysis.

## Abstract

Thoracic sarcopenia, as shown by reduced thoracic skeletal muscle volume (TSMV) on imaging, predicts adverse outcomes after surgery in other patient populations. We sought to ascertain whether a decrease in the thoracic muscle volume serves as a prognostic indicator for postoperative morbidity and mortality in patients undergoing surgery for congenital cardiac anomalies.

All consecutive patients who underwent an index congenital cardiac operation were retrospectively analyzed. Chest cross-sectional imaging within 6 months preoperatively was identified. The TSMV was calculated at the T6 to T10 thoracic vertebrae level. Patients were stratified into high and low muscle groups using the median of muscle cross-sectional volume.

101 patients were included. Those with low TSMV were more likely to be less than one year old, had lower body weight, and had more preoperative comorbidities than those with high thoracic muscle volume. In univariate analysis, patients with low TSMV had a longer hospital length of stay (LOS) (10 vs. 7 days, p = 0.01) and more risk of hospital mortality (10.2% vs. 0%, p = 0.024). In the multivariable models, low thoracic volume showed no clear association with overall complications, cardiopulmonary complications, or intubation duration. Higher TSMV did predict a shorter LOS (MD per 10,000 mm3 increase: −70.7 days, CI −12.7 – −1.4, P = 0.01).

Our findings indicate that thoracic sarcopenia holds an association with LOS and mortality in patients undergoing surgery for congenital cardiac anomalies. As such, thoracic sarcopenia merits consideration as a potential risk factor in the preoperative assessment of patients presenting for congenital cardiac surgical interventions.