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

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 its impact on survival outcome. 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/m2 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 had a significant negative effect on overall survival (OS) rates after allo-HSCT. In addition, stratified analysis based on the number of combined ECEs showed that the greater the number of combined ECEs, the more significant was the negative impact on OS rates.