Subclinical Myocardial Remodelling after Hematopoietic Stem Cell Transplantation: Insights from Cardiac Magnetic Resonance Study

Abstract Introduction Hematopoietic stem cell transplantation (HSCT) is an effective treatment option for haematological malignancies (HM), although it involves potentially cardiotoxic therapies. Cardiotoxicity is currently defined mainly by reduction in left ventricular ejection fraction (LVEF) and/or global longitudinal strain (GLS), which may occur after earlier subclinical myocardial changes have already developed [1]. While transthoracic echocardiography is the first-line modality, its sensitivity for early subclinical myocardial changes may be limited. Cardiac magnetic resonance (CMR) enables more comprehensive assessment of ventricular function, deformation and geometry, yet data on CMR-detected subclinical myocardial remodelling after HSCT remains limited [2]. Purpose To evaluate subclinical myocardial remodelling before and one year after HSCT using CMR-derived functional, deformation and geometric parameters. Methods Thirty-nine patients with HM undergoing HSCT were prospectively enrolled. CMR was performed before HSCT and at one-year follow-up using a 3T scanner. Left ventricular (LV) and right ventricular (RV) volumes, systolic function longitudinal and circumferential strain, ventricular geometry and mitral valve-LV (MV-LV) coupling parameters were assessed. Statistical analysis was performed using IBM SPSS 29.0. Paired comparisons between baseline and one-year follow-up were performed, with correlation and subgroup analyses based on baseline values, sex and age. The study protocol was approved by our Regional Biomedical Research Ethics Committee. Results The study population had a median age of 61 years (range 18-74). Of the 39 patients included, 21 were men (53.8%) and 18 were women (46.2%). LVEF, LV geometry, volumes, GLS and circumferential strain did not change significantly. MV-LV coupling analysis demonstrated an increase in MV end-systolic area (p=0.015) and a greater systolic circumferential strain dispersion at the mitral level (p=0.021). Overall mitral annular circumferential strain remained unchanged, but patients with worse baseline values exhibited significantly greater deterioration (p=0.033), indicating heterogeneous MV-LV coupling response. RV remodelling was characterized by a deterioration in RV GLS (p=0.023) and an increase in RV ESL (p=0.039), with basal diameter changes affecting patients with smaller baseline values (p=0.005). Changes in mitral annular circumferential strain correlated with changes in RV GLS (ρ=0.727, p<0.001). Increasing age was associated with greater LV GLS deterioration over time (ρ=0.54, p<0.001). Conclusions Despite preserved ventricular volumes and global systolic function, CMR revealed early and heterogeneous subclinical myocardial remodelling one year after HSCT, involving MV-LV coupling and RV function. These findings suggest selective vulnerability of myocardial mechanics not detected by conventional functional parameters.