Background: Left-ventricular (LV) global longitudinal strain (GLS) has been reported to be a robust and sensitive marker of chemotherapy-induced cardiac damage. Image quality is paramount for accurate GLS measurements. In real-world cardio-oncology settings, the incidence of suboptimal echocardiography quality and its significance in clinical decision-making have not been well investigated. This prospective study examined the incidence and impact of suboptimal echocardiographic image quality on detecting subtle myocardial damage by chemotherapy.
Methods: Seventy-seven consecutive patients with breast cancer (age, 52 ± 12 years, 76 women, 33 with left-sided breast cancer) were included in this study. Echocardiography was performed at 3-month intervals 1 year before and after chemotherapy initiation. We classified the image quality of each echocardiographic acquisition into three groups: optimal, suboptimal, or inadequate for speckle tracking.
Results: Among the 376 examinations obtained during the cardiac monitoring, the image quality in 194 (52%) was optimal, suboptimal in 159 (42%), and inadequate in 23 (6%). The interobserver reproducibility was 0.91 in the optimal and 0.21 in the suboptimal group. In contrast, the optimal group showed progressive impairment in both GLS (p = 0.001) and LV ejection fraction (LVEF) (p < 0.001) during follow-up, and the suboptimal group showed a progressive decrease in LVEF (p = 0.006), but not in GLS (p = 0.13). Left-sided mammotomy and/or reconstruction surgery and high body mass index were significant determinants of suboptimal image quality.
Conclusions: Even in cases of minor image quality impairment, the physician should assess GLS carefully to avoid errors in crucial clinical decision-making.
Keywords: Anthracycline; Cancer therapy-related cardiac dysfunction; Cardiotoxicity; Echocardiography; Global longitudinal strain.
© 2022. Japanese Society of Echocardiography.