Tehran University of Medical Sciences The Research in Heart Yield and Translational Medicine (RHYTHM) 3115-7270 21 4 2026 07 19 297 304 Azin Alizadehasl MD, FACC, FASE, Professor of Cardiology, Echocardiologist, Cardio-Oncologist, Cardio-Oncology Research Center, Rajaie Cardiovascular Institute, Tehran, Iran. Mehran Gheshlaghi Student Research Committee, School of Medicine, Shahroud University of Medical Sciences, Shahroud, Iran Mahsa Masjedi Esfahani Radiology department , Shahid Rajaee heart center, Tehran, Iran Sina Sadati Student Research Committee, Kashan University of Medical Sciences, Kashan, Iran Hosein Sheibani Assistant Professor of Cardio-Oncology, Rajaie Cardiovascular Institute, Tehran, Iran Bahram Mohebbi Cardio-Oncology Research Center, Rajaie Cardiovascular Institute, Tehran, Iran. Farzaneh Ashrafi Cardio-Oncology Research Center, Rajaie Cardiovascular Institute, Tehran, Iran. Maryam Honardoost Cardio-Oncology Research Center, Rajaie Cardiovascular Institute, Tehran, Iran Mohammad Faranoush Cardio-Oncology Research Center, Rajaie Cardiovascular Institute, Tehran, Iran. Mohammad Sadegh Keshmiri Lung Transplant Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran. Seyedeh Fatemeh Hosseini Jebelli Assistant Professor of Cardio-Oncology, Rajaie Cardiovascular Institute, Tehran, Iran Leila Emadian Razavi Assistant Professor of Cardio-Oncology, Rajaie Cardiovascular Institute, Tehran, Iran 2026 02 21 2026 07 08 Background: Anthracycline-based chemotherapy is associated with cancer therapy–related cardiac dysfunction, primarily manifested by a decline in left ventricular ejection fraction (LVEF). Sarcopenia, characterized by reduced skeletal muscle mass and strength, shares mechanistic pathways with anthracycline cardiotoxicity, including mitochondrial dysfunction, oxidative stress, and systemic inflammation. We aimed to investigate the association between postchemotherapy sarcopenia and changes in cardiac function in a heterogeneous cohort of patients with cancer. Methods: In this single-center prospective observational study, 163 adult patients scheduled to receive anthracycline-containing chemotherapy were enrolled. Transthoracic echocardiography was performed before treatment and 3 months after completion, with assessment of LVEF using the biplane Simpson method and global longitudinal strain. Sarcopenia was assessed postchemotherapy using computed tomography–derived skeletal muscle index at the L3 level combined with handgrip strength. Cardiotoxicity was defined as a reduction in LVEF of 10% or more to below normal and/or new diastolic dysfunction. Multivariable logistic regression was used to evaluate independent associations. Results: Sarcopenia was identified in 46% of patients following chemotherapy. Significant differences in echocardiographic outcomes were observed between sarcopenic and nonsarcopenic groups (P<.05). Sarcopenia was strongly associated with cardiotoxicity, with logistic regression demonstrating robust predictive performance (Nagelkerke R²=0.485; P<.001). Patients with low muscle mass and strength exhibited markedly higher odds of cardiac dysfunction. Conclusion: Postchemotherapy sarcopenia is independently associated with anthracycline-induced cardiac dysfunction. Integrating CT-based muscle assessment and functional testing into cardio-oncology risk stratification may enhance early identification of vulnerable patients and guide cardioprotective strategies. https://jthc.tums.ac.ir/index.php/jthc/article/view/2436 https://jthc.tums.ac.ir/index.php/jthc/article/download/2436/1289