Abstract Background: Due to the rising adverse cardiovascular effects of anthracyclines and trastuzumab in breast cancer, the early detection of cardiotoxicity is crucial. These drugs cause myocardial fibrosis and left ventricular (LV) dysfunction. Cardiac magnetic resonance imaging (CMR) with parametric mapping quantifies fibrosis and systolic function, aiming to correlate early mapping changes with LV dysfunction. Materials and Methods: We conducted a prospective, observational study, recruiting 16 patients receiving concurrent anthracycline and trastuzumab, and performed CMR, echocardiography, and serum troponin assessments at baseline, 2 months (4 cycles), and 4 months (8 cycles). Imaging included function and parametric mapping (native T1, T2, and extracellular volume) using Modified Look-Locker Inversion recovery sequences. Results: In human epidermal growth factor 2-positive patients, a subclinical decline in LV function (37%) was detected by echocardiography and CMR at 4 months. Right ventricular (RV) ejection fraction decreased significantly, with 18.75% of patients developing CMR-defined RV dysfunction, highlighting early and preferential RV involvement. Serum troponin T increased notably at 4 months. Some individual cases showed changes in parametric mapping and global longitudinal strain, but collective mapping values remained within the normal limits. Conclusion: Patients on combined anthracycline and trastuzumab had subclinical LV decline on echocardiography and CMR and prominent RV dysfunction on CMR at 4 months. However, parametric mapping values did not show notable changes, suggesting limited sensitivity for early fibrosis detection in this setting. Conventional imaging remains valuable for the early detection of cardiotoxicity, while parametric mapping may require further refinement. Troponin elevation supports its use as an adjunct biomarker. Larger, longer-term studies are needed to clarify the role of advanced imaging for early myocardial changes in this high-risk population.
Ninan et al. (Thu,) studied this question.