Rapid cardiac MRI protocol for cardiac assessment in paediatric and young adult patients undergoing haematopoietic stem cell transplant: a feasibility study

Imaging of pediatric hematopoietic stem cell transplant recipients: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper

Imaging in hematopoietic stem cell transplantation patients is not targeted at evaluating the transplant per se. Rather, imaging is largely confined to evaluating peri-procedural and post-procedural complications. Alternatively, imaging may be performed to establish a baseline study for comparison should the patient develop certain post-procedural complications. This article looks to describe the various imaging modalities available with recommendations for which imaging study should be performed in specific complications. We also provide select imaging protocols for different indications and modalities for the purpose of establishing a set minimal standard for imaging in these complex patients.

Cardiovascular Complications in Hematopoietic Stem Cell Transplanted Patients

Hematopoietic stem cell transplantation (HSCT) is the only curative treatment for many patients suffering from hematologic malignancies, solid tumors, inborn errors of metabolism or genetic disorders. Despite decades of successful HSCT, clinical outcomes are still far from satisfactory due to treatment-related complications, including graft-versus-host disease (GvHD) and cardiovascular complications (CVC). CVC may affect patients in the acute period post-HSCT; however, the occurrence is far higher among long-term survivors. Induction treatment using cardiotoxic treatments, e.g., anthracyclines and radiotherapy, conditioning regimens containing cyclophosphamide, and post-HSCT comorbidities, including GvHD, are factors contributing to CVC. Cardiac function evaluation prior to and post-transplantation is an important strategy for choosing the proper conditioning regimen, HSCT protocol and post-HSCT supportive care. Cardiac systolic function evaluation by echocardiography, in addition to serum cardiac biomarkers, such as troponins and brain natriuretic peptides, is recommended as a routine follow-up for HSCT patients. Angiotensin-converting enzyme inhibitors, angiotensin-II-receptor blockers, and beta-blockers, which are mostly used for the treatment of chemotherapy-induced cardiotoxicity, might be used as treatments for HSCT-related CVC. In summary, the present review reveals the urgent need for further investigations concerning HSCT-related CVC both at the preclinical and clinical levels due to the lack of knowledge about CVC and its underlying mechanisms.

Cardiac complications associated with hematopoietic stem-cell transplantation

Advances in chemotherapy and supportive therapy have resulted in improved clinical outcomes in patients with hematological malignancies undergoing hematopoietic stem-cell transplantation (HSCT). However, the association between HSCT and early- and late-onset cardiotoxicity remains controversial as these cardiac complications, including acute heart failure and arrhythmia, such as atrial fibrillation, can occasionally be lethal. Although the overall pathophysiology has not been elucidated, initial/salvage chemotherapy before HSCT, such as anthracycline-combined regimens, conditioning regimens, thoracic radiotherapy, and pre-existing personal risk factors, could be associated with an increased risk of cardiac events. Routine monitoring of cardiac function using global longitudinal strain or left ventricular ejection fraction in echocardiogram and serum biomarkers could be an option to detect early changes in cardiac status before irreversible cardiac complications develop. While beta-blockers and angiotensin-converting enzyme inhibitors are commonly used for cardioprotection, their clinical benefit has not been fully established in HSCT-associated cardiotoxicity. In the future, genetic analysis to reveal individual vulnerability to cardiotoxicity and prospective trials assessing the clinical benefit of early interventions, including novel agents such as angiotensin receptor-neprilysin inhibitor, are warranted. Collaboration between oncologists and cardiologists is crucial to establishing a strategy to prevent cardiac complications.