Cardiac magnetic resonance assessment of right ventricular remodeling after anthracycline therapy.

There are limited data on the effects of anthracyclines on right ventricular (RV) structure, function, and tissue characteristics. The goal of this study was to investigate the effects of anthracyclines on the RV using cardiac magnetic resonance (CMR). This was a post-hoc analysis of a prospective study of 27 breast cancer (BC) patients (51.8 ± 8.9 years) using CMR prior, and up to 3-times after anthracyclines (240 mg/m2) to measure RV volumes and mass, RV extracellular volume (ECV) and cardiomyocyte mass (CM). Before anthracyclines, LVEF (69.4 ± 3.6%) and RVEF (55.6 ± 9%) were normal. The median follow-up after anthracyclines was 399 days (IQR 310-517). The RVEF reached its nadir (46.3 ± 6.8%) after 9-months (P < 0.001). RV mass-index and RV CM decreased to 13 ± 2.8 g/m2 and 8.13 ± 2 g/m2, respectively, at 16-months after anthracyclines. The RV ECV expanded from 0.26 ± 0.07 by 0.14 (53%) to 0.40 ± 0.1 (P < 0.001). The RV ECV expansion correlated with a decrease in RV mass-index (r = -0.46; P < 0.001) and the increase in CK-MB. An RV ESV index at baseline above its median predicted an increased risk of LV dysfunction post-anthracyclines. In BC patients treated with anthracyclines, RV atrophy, systolic dysfunction, and a parallel increase of diffuse interstitial fibrosis indicate a cardiotoxic response on a similar scale as previously seen in the systemic left ventricle.