Safety of Post-Transplant Cyclophosphamide-Based Prophylaxis in AML Patients with Pre-Existing Cardiac Morbidity Undergoing Allogeneic Hematopoietic Cell Transplantation

Abstract

Background: Post-transplant cyclophosphamide (PTCy) is a standard graft-versus-host disease (GVHD) prophylaxis in allogeneic hematopoietic cell transplantation (allo-HCT). While effective, concerns remain about cyclophosphamide-related cardiotoxicity, especially in patients with pre-existing cardiac morbidity, a population often underrepresented in clinical trials. Objectives: To assess the incidence and outcomes of early (ECE, ≤100 days) and late (LCE, >100 days) cardiac events in acute myeloid leukemia (AML) patients with and without baseline cardiac morbidity undergoing allo-HCT with PTCy. Study Design: Retrospective multicenter study by the Grupo Español de Trasplante Hematopoyético y Terapia Celular (GETH-TC) including 461 AML patients (62 with cardiac morbidity) transplanted between 2012 and 2022. Cardiac morbidity was defined by documented cardiac disease or left ventricular ejection fraction < 45%. Cumulative incidence, overall survival (OS), and non-relapse mortality (NRM) were analyzed using competing risks models and adjusted with propensity score matching (PSM) and inverse probability weighting (IPW). Results: Cardiac events occurred in 13.2% of patients: 11% vs. 7% ECE (p = 0.93) and 8% vs. 5.3% LCE (p = 0.85) in those with vs. without cardiac morbidity. Most ECEs were arrhythmias or heart failure. Adjusted analyses confirmed no significant differences in CE incidence, OS, or NRM between groups. Two-year OS was 69% vs. 70% (p = 0.50); NRM was 18% vs. 17% (p = 0.20). ECE was associated with higher mortality in both groups. Conclusions: PTCy is feasible in AML patients with pre-existing cardiac morbidity when combined with comprehensive cardiovascular evaluation and cardio-oncology follow-up, supporting its safe use in broader patient populations with appropriate cardiologic support.