Cardiovascular complications after contemporary allogeneic haematopoietic stem cell transplantation
M Murati, M Vito, F Vanni, A Grasso Granchietti, M Vannini, G Coltro, A Pasquini, C Nozzoli, S CaciolliAbstract
Background
Advances in conditioning regimens, supportive care, and patient selection have expanded the use of allogeneic haematopoietic stem cell transplantation (HSCT) to older and more clinically complex patients. While cardiovascular complications are increasingly recognised as relevant contributors to early post-HSCT morbidity and mortality, contemporary real-world data describing their incidence, timing, clinical phenotype, and prognostic impact remain limited, particularly in the context of modern transplant strategies.
Purpose
To characterise the incidence, temporal distribution, and clinical phenotype of cardiovascular complications following allogeneic HSCT in a contemporary real-world cohort, and to assess their association with short- and long-term outcomes.
Methods
We performed a single-centre retrospective cohort study including 488 adults (299 male) who underwent allogeneic HSCT between 2013 and 2025 (mean age 47.6 years); risk was stratified using HCT-CI. Cardiovascular events were classified as early (≤100 days) or late (>100 days). Outcomes included 100-day mortality, overall survival, and cardiovascular mortality. Events analysed were ventricular dysfunction, atrial fibrillation, pericardial effusion, stroke, and myocardial infarction. Analyses were mainly descriptive; group comparisons used chi-square or Fisher’s exact tests. Overall survival was estimated by Kaplan–Meier and compared by log-rank test. All analyses were exploratory.
Results
Early cardiovascular (CV) events occurred in 211 patients (42.3%), mostly pericardial effusion and atrial fibrillation (34.4%), followed by acute cardiac dysfunction (5.7%), stroke (3.1%), and myocardial infarction (1.4%). Traditional CV risk factors were infrequent and not associated with early events, suggesting a treatment- and inflammation-related pathophysiology. Patients with early CV events had higher 100-day mortality than those without (21.4% vs 13.8%, p=0.04), particularly with acute cardiac dysfunction (35.9%, p=0.003). Kaplan–Meier analysis showed reduced overall survival in patients with early CV complications (log-rank p=0.02), driven by excess mortality within 100 days; survival curves were parallel thereafter. During long-term follow-up, CV events and CV mortality were rare (3.1% and 0.2%).
Conclusions
In the contemporary allogeneic HSCT setting, cardiovascular complications are relatively common early after transplant, marking a period of heightened vulnerability with increased short-term mortality. These largely non-atherosclerotic events appear to have limited impact on long-term cardiovascular burden in carefully selected survivors; our findings support a model of early, non-cumulative risk, emphasising the need for focused surveillance and preventive strategies during the initial post-transplant period.Overall survival by early CV events Early mortality (≤100 days) by HSCT year