P3117Usefulness of cardiac magnetic resonance imaging for early detection of subclinical chemotherapy-related cardiac dysfunction in cancer patients

Abstract Background Long-term prognosis of cancer patients has been improved along with the progress in chemotherapies. However, chemotherapy-related cardiac dysfunction (CTRCD) is emerging as a serious adverse effect as it worsens patients' outcome and quality of life. Thus, early detection of subclinical CTRCD is an important emerging issue in the management of cancer patients. Cardiac magnetic resonance (CMR) utilizes parametric mapping approach and strain analysis to provide detailed information about cardiac tissue and diastolic cardiac function. Purpose We examined whether the novel CMR imaging techniques are useful for early detection of CTRCD. Methods and results We performed both retrospective and prospective studies. (1) Retrospective study: We retrospectively enrolled 52 cancer patients (mean age 55.6±13 yrs., M/F=14/38) who had been treated with anthracyclines. We examined the usefulness of CMR for quantitative assessment of myocardial fibrosis caused by chemotherapies. We found that native T1 value was significantly prolonged in cancer patients compared with healthy controls (N=10) (1,279±56 vs. 1,240±34 msec, P=0.036). (2) Prospective study: A total of 99 consecutive female patients with breast cancer treated with chemotherapies were enrolled in this study from August 2017 to January 2019. To evaluate CTRCD in those patients, we performed CMR (at baseline and/or 6 months) and biomarkers analysis for cardiac troponin T (cTnT) and BNP at baseline and every 3 months during chemotherapies. In the 99 patients, 52 (mean age 53.0±12.7 yrs.) completed cardiac assessment at 6 months, and 6 (12%) developed CTRCD defined as a reduction in left ventricular ejection fraction (LVEF) >10% from baseline and below 53% without symptoms. In patients with CTRCD (CTRCD group, N=6), as compared with those without it (non-CTRCD group, N=46), native T1 value was significantly prolonged after chemotherapies (1,303±32 vs. 1,322±22 msec at 6 months, P=0.03). Plasma cTnT levels at 3 months were also significantly higher in the CTRCD group compared with the non-CTRCD group [0.022 (IQR 0.015–0.026) vs. 0.01 (0.006–0.014) ng/mL, P=0.024], whereas there was no difference in BNP values. In the 52 patients, 28 (mean age 56.3±12.3 yrs.) underwent CMR both before and 6 months after chemotherapies. In those patients, LVEF and global radial strain were significantly decreased at 6 months from baseline (LVEF, from 70.5±4.6 to 66.0±7.1%; global radial strain, from 70.0±22.5 to 61.1±22.6%, respectively, both P<0.05). In patients with elevated cTnT levels at 3 months, as compared with those without it, LVEF and extracellular volume fraction (ECV) at 6 months were significantly worse (LVEF, 59.0±6.0 vs. 62.7±2.6%, P=0.042; ECV, 32.3±2.9 vs. 30.2±2.3%, P=0.049, respectively). Conclusions These results indicate that novel CMR imaging techniques are useful for early detection of CTRCD among cancer patients treated with chemotherapies.