Preoperative Sarcopenia Assessment Using Pectoralis Muscle Mass Indicated Poor Mid-term Cardiac Surgery Prognosis

Background: Many studies have defined sarcopenia based on psoas muscle mass using abdominal computed tomography (CT). We hypothesized that sarcopenia can be assessed by measuring pectoralis muscle mass on chest CT and aimed to examine its relationship with the postoperative prognosis of cardiac surgery. Methods: This retrospective study included 189 patients who underwent cardiac surgery via median sternotomy between July 2020 and June 2022. We excluded patients <70 years old, urgent/emergent cases, no chest CT within 90 days before surgery, and cases in which evaluation of the pectoralis muscle was impossible with CT. The pectoralis muscle area (PMA) was measured using a preoperative chest CT. The sarcopenia cut-off value was defined as the lowest sex-specific tertile in PMA at the level of the 4th thoracic vertebrae. Results: Eighty patients were included. The lower tertile were classified as the sarcopenia group (SG) (n = 26) and the rest as the non-sarcopenia group (NSG) (n = 54). In the SG, 1-year survival was significantly worse than that in NSG (NSG: 92.7% vs. SG: 54.9%, p < 0.0001). In the multivariate model, sarcopenia was an independent risk factor for mid-term all-cause death (hazard ratio, 4.89; 95% confidence interval: 1.14–21.0, p = 0.033). Conclusion: Preoperative sarcopenia defined using PMA was associated with poor mid-term survival after elective cardiac surgery via median sternotomy. The pectoralis muscle mass observed through a chest CT could be used for preoperative risk scoring in older patients undergoing cardiac surgery.