Risk of post-transplant cyclophosphamide-related cardiotoxicity in allogeneic stem cell transplantation

European Heart Journal Supplements

3 August 2026

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Abstract

AbstractIntroduction

Although post-transplant cyclophosphamide (PT-Cy) is currently widely used to prevent graft-versus-host disease (GvHD) following allogeneic hematopoietic stem cell transplantation (alloHSCT), concerns remain regarding its cardiotoxicity.

Purpose

The aim was to investigate the association between early cardiotoxicity occurring within the first 100 days post-transplant and PT-Cy.

Methods

We conducted a monocentric retrospective observational study including all consecutive patients who underwent alloHSCT at our Hospital between July 2011 and July 2023. The primary endpoint was a composite of early cardiotoxicity, including cardiovascular death, heart failure (HF), myocarditis, pericardial disease, electrical disorders, and acute arterial events. A propensity-score matching was performed to balance characteristics between patients who received post-transplant PT-Cy and those who did not. Predictors of early cardiotoxicity were analyzed using Fine-and-Gray subdistribution hazard models.

Results

Among 1,381 patients, 143 (10%) experienced early cardiotoxicity within 100 days post-transplant. The most frequent events were HF (53%), electrical disorders (20%), and pericardial disease (19%). Age (sHR 1.01; 95% CI: 1.00-1.03; p=0.028), prior HF (sHR 2.02; 95% CI: 1.04-3.93; p=0.037), prior cancer therapy–related cardiac dysfunction (sHR 4.24; 95% CI: 2.05-8.78; p<0.001), hypertension (sHR 1.54; 95% CI: 1.00-2.36; p=0.047), and PT-Cy (sHR 1.62; 95% CI: 1.07-2.44; p=0.022) were independently associated with early cardiotoxicity. After 1:1 propensity score–matching, the administration of PT-Cy remained associated with cardiotoxicity (HR=2.00; 95% CI: 1.05-3.80; p=0.035).

Conclusions

The administration of PT-Cy was independently associated with an increased risk of early cardiotoxicity, particularly HF. These results underscore the need for early cardiovascular risk assessment and tailored surveillance, particularly in patients receiving PT-Cy.

Early cardiotoxicity

Hematologic outcomes