Usefulness of cardiac magnetic resonance for early detection of cancer therapeutics-related cardiac dysfunction in breast cancer patients

Background: Prognosis of breast cancer patients has been improved along with the progress in cancer therapies. However, cancer therapeutics-related cardiac dysfunction (CTRCD) has been an emerging issue. For early detection of CTRCD, we examined whether native T1 mapping and global longitudinal strain (GLS) using cardiac magnetic resonance (CMR) and biomarkers analysis are useful. Methods: We prospectively enrolled 83 consecutive chemotherapy-naïve female patients with breast cancer (mean age, 56 ± 13 yrs.) between 2017 and 2020. CTRCD was defined based on echocardiography as left ventricular ejection fraction (LVEF) below 53% at any follow-up period with LVEF>10% points decrease from baseline after chemotherapy. To evaluate cardiac function, CMR (at baseline and 6 months), 12‑lead ECG, echocardiography, and biomarkers (at baseline and every 3 months) were evaluated. Results: A total of 164 CMRs were performed in 83 patients. LVEF and GLS were significantly decreased after chemotherapy (LVEF, from 71.2 ± 4.4 to 67.6 ± 5.8%; GLS, from −27.9 ± 3.9 to −24.7 ± 3.5%, respectively, both P < 0.01). Native T1 value also significantly elevated after chemotherapy (from 1283 ± 36 to 1308 ± 39 msec, P < 0.01). Among the 83 patients, 7 (8.4%) developed CTRCD. Of note, native T1 value before chemotherapy was significantly higher in patients with CTRCD than in those without it (1352 ± 29 vs. 1278 ± 30 msec, P < 0.01). The multivariable logistic regression analysis revealed that native T1 value was an independent predictive factor for the development of CTRCD [OR 2.33; 95%CI 1.15–4.75, P = 0.02]. Conclusions: These results indicate that CMR is useful to detect chemotherapy-related myocardial damage and predict for the development of CTRCD in breast cancer patients.