RecruitingClinical trialPrehabilitation Program to Improve Cardiac Reserve in High-Risk Patients Undergoing Hematopoietic Stem Cell TransplantationTo assess the feasibility and preliminary effectiveness of a Cardio-Oncology Prehabilitation program in patients at high-risk of developing Cardiovascular (CV) events in improving Cardiorespiratory fitness (CRF) and reducing acute CV complications in Hematopoietic stem cell transplant (HSCT) recipients.