Risk factors and survival outcomes in children with early cardiotoxicity after allogeneic hematopoietic stem cell transplantation.

Cardiotoxicity in children is a potentially fatal complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT); therefore, early identification of risk factors can improve patient prognosis. However, there are few data on the clinical characteristics of early-stage cardiotoxicity in children after allo-HSCT. We conducted a retrospective single-center study of pediatric patients who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) between January 2016 and December 2022 at the Children's Hospital Affiliated with Chongqing Medical University to evaluate the clinical characteristics of early cardiac events (ECEs) after allo-HSCT and their impact on survival outcomes. We enrolled 444 patients who underwent allo-HSCT-304 males (68%) and 140 females (32%)-with a median age of 3.3 years (1.8-6.5 years) at transplantation. We found that 73 patients (16.4%) had ECEs after allo-HSCT. The ECEs included valvular disease (n = 46), pericardial effusion (n = 38), arrhythmia (n = 9), heart failure (n = 16), and dilated cardiomyopathy (n = 1). Female sex, age ≥ 6 years, body mass index (BMI) < 16 kg/m and HLA-type mismatches were risk factors for ECEs. We designed a stratified cardiac risk score that included these risk factors, and the higher the score was, the greater the cumulative incidence of ECEs. The occurrence of an ECE was closely associated with a lower overall survival (OS) rate and greater nonrelapse mortality (NRM). In addition, stratified analysis based on the number of combined ECEs showed that the greater the number of combined ECEs was, the more significant the negative impact on OS rates.