SARCOPENIA AND MORTALITY AFTER HEART TRANSPLANTATION

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Psoas muscle area (PMA) is a validated indicator of frailty and sarcopenia that can be easily measured on abdominal computed tomography (CT) scans. There has yet to be a study examining the prognostic impact of sarcopenia in patients undergoing cardiac transplantation. In this retrospective study, pre- and post-operative CT scans were retrieved for adult patients transplanted between 2000-2015 and followed at the Heart Transplant Clinic of the McGill University Health Centre. PMA was measured on axial images at the level of the L4 vertebrae using the CoreSlicer software. Outcomes of interest were ascertained by chart review and included long-term mortality and in-hospital major adverse postoperative events (MAPE; defined as mortality, prolonged intubation, stroke, dialysis, mediastinitis, or reoperation). Out of 157 patients transplanted, 82 patients had at least one abdominal CT scan over an average follow-up of 3 years. The median PMA was 24.7 cm2 (IQR 20.9, 30.0) in men, 16.6 cm2 (IQR 14.9, 19.1) in women, and decreased by 8-11% from the first to the last available CT scan. Patients with smaller PMA, defined as less than the sex-stratified median, had a four-fold increase in MAPE (OR 4.28; 95% CI 1.18, 15.46) and a trend towards a three-fold increase in long-term mortality (HR 3.12; 95% CI 0.96, 10.20). Adjusting for age, sex, BMI, and cardiomyopathy etiology, every 1 cm2 increase in PMA was found to be significantly associated with a 17% reduction in MAPE (OR 0.83; 95% CI 0.72, 0.96) and a 9% reduction in long-term mortality (HR 0.91; 95%CI 0.83-0.99). Sarcopenia as defined by PMA is associated with a higher risk of mortality and major morbidity after cardiac transplantation. Further studies are needed to define the longitudinal progression of sarcopenia in this population and test the value of muscle-building interventions such as exercise and protein supplementation to improve short- and long-term outcomes.