To study the usefulness and comparison of myocardial strain imaging by 2D and 3D echocardiography for early detection of cardiotoxicity in patients undergoing cardiotoxic chemotherapy

BACKGROUND: Chemotherapy-induced cardiotoxicity constitutes subclinical myocardial dysfunction, arrhythmias, pericarditis, coronary vasospasm, and significant symptomatic heart failure. Anthracyclines pose higher risk for long-term cardiac dysfunction, with increased incidences of morbidity and mortality. Hence, early detection of chemotherapy-induced cardiac dysfunction may prompt an earlier treatment modification. AIM: To evaluate global, longitudinal, radial, and circumferential strain changes in adult patients undergoing anthracycline chemotherapy along with the usefulness of three-dimensional (3D) echocardiography as the new modality over two-dimensional (2D) echocardiography. METHODS: This was a single centre, prospective, observational study that included asymptomatic patients free from any cardiac signs and symptoms attributable to heart failure, who underwent potentially cardiotoxic chemotherapy for malignancy from December 2017 to November 2018 at a tertiary care centre in India. Baseline demographics were recorded, and 2D and 3D echocardiography was performed at baseline and after completion of four cycles of chemotherapy. RESULTS: All the 55 patients received a cumulative dose of doxorubicin of less than 550 mg/m(2). Follow-up period from the beginning of doxorubicin therapy was 108 ± 14 days. 9 patients were excluded from the study due to poor 3D images, so data analysis was done only for 46 patients. In 2D echocardiography, only global longitudinal strain (GLS) was observed to be significantly reduced (Δ18.33%; P < 0.001). 2D ejection fraction (EF) did not show significant change (Δ0.67%; P = 0.176), while by 3D echo, EF reduced significantly (Δ3.55%; P < 0.001). 3D global longitudinal (Δ29.19%; P < 0.001), circumferential (Δ30.65%; P < 0.001), area (Δ21.61%; P < 0.001), and radial (Δ29.66%; P < 0.001) strains were observed to be significantly reduced at follow-up. CONCLUSION: Myocardial dysfunction induced by cardiotoxic chemotherapy can be detected earlier by using 2D GLS, 3D volumetric analysis, and 3D strain analysis by calculating global, longitudinal, radial, and circumferential strain changes. 3D echocardiographic assessment seems to be more accurate in picking out small changes in left ventricular functions, but at the cost of slightly poor image quality as compared to the 2D echocardiography. These newer techniques could potentially improve the ability for early detection of subclinical abnormalities of LV function in patients undergoing cardiotoxic chemotherapy and thus early initiation of treatment could be possible.