Late cardiac effects of anthracycline-based therapy in childhood cancer survivors: a CMR study of cardiac strain and function.

Anthracycline-based therapies cause cancer therapy-related cardiac dysfunction (CTRCD) in childhood cancer survivors (CCS). This cross-sectional observational study aimed to assess the potential of cardiac strain, evaluated with cardiovascular magnetic resonance feature tracking (CMR-FT), as a marker of subclinical CTRCD in CCS treated with anthracyclines. We prospectively included 117 CCS examined approximately 12 years after treatment and retrospectively selected 79 age- and sex-matched controls. Cardiac strain was assessed with CMR-FT, including global longitudinal strain (GLS), global circumferential strain (GCS), global radial strain (GRS) for both ventricles, and longitudinal strain for both atria. CCS were further divided into CCS-low (< 250 mg/m2) and CCS-high (≥ 250 mg/m2) based on cumulative anthracycline dose. Compared to controls, CCS had lower but preserved left ventricular (LV) ejection fraction (EF), lower indexed LV myocardial mass, higher indexed end-diastolic and end-systolic LV volumes, and impaired LV strain parameters, which were further worsened in the CCS-high subgroup. In multivariable analysis, a higher cumulative dose was independently associated with reduced LVEF and worse LV circumferential and radial strain, after adjustment for age and sex. These findings suggest a dose-dependent effect on subclinical cardiac function. Incorporating CMR-FT strain assessment into the cardiac monitoring of CCS may help identify subclinical CTRCD in this population.