Prognostic Impact of Preoperative Osteosarcopenia Assessed by Computed Tomography in Patients Undergoing Cardiac Surgery

AIM: To investigate the prognostic significance of osteosarcopenia, as assessed by preoperative computed tomography (CT), in older patients undergoing cardiac surgery. METHODS: This single-center retrospective observational study included 221 consecutive patients aged ≥ 65 years who underwent cardiac surgery between November 2016 and August 2023. Sarcopenia was defined by the psoas muscle index at the third lumbar vertebral level, and osteopenia by bone mineral density at the first lumbar vertebral level on preoperative CT, with the lowest sex-specific quartile considered indicative of each condition. Osteosarcopenia was defined as the coexistence of both sarcopenia and osteopenia. The primary endpoint was a composite of all-cause mortality and unplanned readmission within 2 years after discharge. Prognostic factors were evaluated using multivariable Cox proportional hazards models. RESULTS: Of the 221 eligible patients, 184 were included in the final analysis (mean age 73.5 ± 5.3 years; 64.1% male). The primary endpoint occurred in 43 patients (23.4%). Event-free survival rates were 81.7% in the normal group, 75.9% in the sarcopenia-alone group, 72.4% in the osteopenia-alone group, and 50.0% in the osteosarcopenia group, with the osteosarcopenia group demonstrating the poorest prognosis (log-rank p = 0.015). In the multivariable analysis, osteosarcopenia remained independently associated with adverse outcomes after adjustment for multiple clinical covariates. CONCLUSIONS: Preoperative CT-defined osteosarcopenia was significantly associated with poorer postoperative outcomes in older patients undergoing cardiac surgery. Even after adjustment for clinical risk factors, osteosarcopenia persisted as an independent prognostic indicator, suggesting its potential utility for preoperative risk stratification.