Long-term prognostic significance of cardiovascular complications following hematopoietic stem cell transplantation: a prospective regional cohort analysis

Background Hematopoietic stem cell transplantation (HSCT) has established itself as a cornerstone therapeutic intervention for a broad spectrum of hematologic malignancies. However, despite improvements in procedural safety, cardiovascular (CV) adverse events remain a substantial concern, contributing significantly to both treatment-related morbidity and overall mortality in this population. This regional registry was established to quantify the incidence of such cardiovascular complications and to evaluate their specific influence on patient survival during the follow-up period. Methods This prospective, regional observational cohort study consecutively enrolled adult patients undergoing either autologous or allogeneic HSCT between 2019 and 2025. Each participant was subjected to a standardized cardiac screening protocol designed for early detection of toxicity, including 12-lead electrocardiograms (ECGs), comprehensive transthoracic echocardiography, and the longitudinal assessment of cardiac biomarkers. These evaluations were performed at the baseline prior to transplantation, and subsequently at the 2-month, 6-month, and semi-annual intervals throughout the post-transplant period. The primary clinical outcomes included new-onset systolic dysfunction, venous thromboembolic events (encompassing both deep vein thrombosis and pulmonary embolism), cerebrovascular accidents (stroke), various cardiac arrhythmias, pericarditis, and acute hypertensive crises. Results 147 patients, with a mean age of 56±13 years, were followed for a median of 2.6 years (1.1-5.1 years). The prevalence of significant cardiovascular risk factors was relatively low, with only 17% of the participants having a documented history of prior cardiovascular events. Nevertheless, 39% of the entire cohort experienced at least one cardiovascular-related adverse event during the study's duration. Detailed clinical monitoring identified 12 cases of VTE/PE, 8 instances of atrial fibrillation, 7 cases of heart failure or cardiogenic shock, and 5 cases each of peripheral vascular disease and hypertensive crises (Figure 1). Notably, a majority of these complications (68%) manifested within the first six months following the transplant. The occurrence of any cardiovascular adverse event was linked to a more than twofold increase in all-cause mortality, which rose from 12% in unaffected patients to 29% in those with complications (Figure 2; p=0.003). Conclusions Cardiovascular complications are remarkably prevalent among recipients of HSCT and can affect a wide range of patients, including those who are young and lack baseline comorbidities. The development of a cardiovascular event is a negative prognostic indicator for overall survival. Because two thirds of these events occurs within the initial six months post-transplantation, it is critical to improve early cardiac surveillance to improve long-term patient outcomes.Figure 1Figure 2