Allogeneic hematopoietic stem cell transplantation (HSCT) represents a major therapeutic strategy for malignant hematologic diseases, with the number of procedures steadily increasing in France each year. Conditioning and maintenance regimens carry a risk of both short- and long-term cardiotoxicity, leading to serious cardiovascular events including acute coronary syndrome (ACS), cardiac dysfunction, arrhythmias, pulmonary hypertension, and pericardial effusion. The pathophysiology of cardiotoxicity in HSCT patients remains poorly understood.

It is therefore crucial to investigate underlying mechanisms and identify predictive factors of cardiotoxicity in order to provide appropriate cardiological follow-up and management. Current European Society of Cardiology guidelines recommend routine monitoring of HSCT patients with echocardiography and cardiac biomarkers (NT-proBNP, troponin), although these recommendations are based on small-scale studies. The cardiodepressor factor DPP3 has shown promising results in cardio-oncology, with a causal role in anthracycline-induced cardiac dysfunction. Its role in HSCT-related cardiotoxicity requires further evaluation.

This multicenter study of HSCT recipients will be a valuable resource, enabling a better understanding of the pathophysiology of cardiotoxicity and prognosis. It will highlight imaging (echocardiography, calcium score, supra-aortic Doppler), electrocardiographic, and biological markers (including DPP3) associated with prognosis.

Inclusion Criteria:

• Age ≥ 15 years
• Informed about the study and without objection to participation (or with consent from legal guardians)
• Undergoing allogeneic HSCT

Exclusion Criteria:

• Patient not followed up at the participating center
• Pregnant or breastfeeding women
• Patient not affiliated with social security
• Patient under guardianship, curatorship, or legal protection

All consecutive patients hospitalized for HSCT in the participating centers, meeting eligibility criteria, will be included.