Introduction
Non-Hodgkin’s lymphoma includes a variety of tumors originating from lymphoid tissues. With an estimated 500,000 new cases in 2018, non-Hodgkin’s lymphoma accounts for approximately 3% of all cancer cases worldwide[1]. There is growing evidence that patients with cancer are at substantially increased risk of developing cardiovascular adverse event [2]. The reasons behind this observation are thought to be multifactorial, including the common risk factors between cancer and cardiovascular disease and the cardiovascular toxic effects of antineoplastic drugs[3, 4]. Even when impaired LVEF was diagnosed immediately after anthracycline therapy, 36% of patients failed to regain normal LV function despite therapeutic interventions[5]. Research into more sensitive markers of subclinical cardiac dysfunction or myocardial injury remains imminent.
Left ventricular ejection fraction (LVEF) has long been considered a key criterion for evaluating cardiotoxicity[6]. Left ventricular global longitudinal strain (GLS) has been shown to detect cardiac dysfunction earlier than LVEF and is an important predictor of chemotherapy-induced cardiotoxicity in patients with preserved LVEFs[7, 8]. LVEF and GLS are recognized as criteria for assessing cardiac function and monitoring chemotherapy-induced cardiotoxicity in most patients with heart disease and as per guidelines[9]. However, few data are available on right ventricular (RV) function in cancer survivors, especially in long-term cancer survivors. It is possible that measurements of RV function are more predictive of mortality than measures of left ventricular function in many cardiac diseases, e.g. late post-myocardial infarction, and chronic heart failure[10-12]. After treatment with anthracyclines, 27% of childhood cancer survivors had impaired right ventricular ejection fraction as assessed by cardiac magnetic resonance imaging[13]. However, the availability of cardiac magnetic resonance imaging (CMR) is limited in many areas, and echocardiography is the method of choice for screening cardiac toxicity after cancer treatment. Three-dimensional transthoracic echocardiography (3DTTE) has the advantage of full-volume acquisition of the entire right ventricle and can overcome the technical and clinical limitations of 2D transthoracic echocardiography[14]. The accuracy of 3D TTE in measuring RV volume and RVEF against CMR has been confirmed in recent studies, and it has been documented that RV volume measured by 3D TTE correlates well with the corresponding values obtained by CMR by using new RV analysis software[15-17]. Our previous study showed that subclinical changes in RV function and size by 3DE-derived RV volume occurred after the anthracycline-based chemotherapy[18]. However, the value of right ventricular function in predicting cardiovascular events in patients treated with anthracyclines remains to be investigated. Identifying patients at high risk for heart failure and cardiac death is particularly important in patients at high risk for clinical events, such as those with hematologic malignancies.
The purpose of this study was to assess the value of 3D echo right ventricular function measured during chemotherapy in identifying cardiovascular events in patients with hematologic malignancies treated with anthracyclines.