Rationale, design and baseline characteristics of the cardio-oncology registry (CARE) study: a prospective, observational study of cardiotoxic effects during breast cancer therapy

Background Anthracycline and Human Epidermal Growth Factor Receptor 2 (HER2) targeted therapy may induce cancer therapy-related cardiac dysfunction (CTRCD). Current guidelines recommend risk stratification using the Heart Failure Association–International Cardio-Oncology Society (HFA-ICOS) risk assessment tool. However, data on the incidence of CTRCD in contemporary breast cancer populations treated according to current standard-of-care regimens remain limited. Moreover, the actual cardiovascular risk associated with the HFA-ICOS risk categories in breast cancer treatment remains uncertain. Real-world evaluation of whether this consensus-based stratification appropriately separates patients according to subsequent CTRCD risk has been highlighted as a key research priority. Purpose Overall, the study aims to determine the incidence of CTRCD and to evaluate cardiovascular risk stratification using the HFA-ICOS tool and its association with subsequent CTRCD. Methods CARE is a prospective observational study including women scheduled for (neo)adjuvant anthracycline therapy and/or HER2-targeted therapy. Echocardiography, using standard and novel echocardiographic parameters, and circulating cardiac biomarkers were assessed at baseline (visit 1), after completion of scheduled therapy (visit 2), and 12 months after completion of scheduled therapy (visit 3). Participants were categorized into three treatment regimen groups: 1) Anthracycline therapy only, 2) HER2-targeted therapy only, and 3) HER2-targeted therapy sequentially to anthracyclines (Figure 1). The primary outcome is incidence of CTRCD. Secondary outcomes include HFA-ICOS risk stratification in relation to subsequent CTRCD. Results In total, 515 women (median age (Q1,Q3): 53 (45,64) years) were included. Overall, 335 (63%) participants received anthracycline therapy only, 100 (15%) received HER2-targeted therapy only, and 80 (19%) received anthracycline therapy followed by HER2-targeted therapy. Baseline cardiovascular risk factors included hypertension in 20%, current smoking in 13%, diabetes in 7%, and a history of heart disease in 7.6%, while 3.5% had received previous anti-cancer treatment (Table 1). Conclusion The CARE study is a large prospective observational cardio-oncology study evaluating the incidence of CTRCD after contemporary breast cancer therapy regimens. With systematic echocardiographic and biomarker assessment, the study will provide important insights into the incidence of CTRCD, the performance of the HFA-ICOS risk stratification tool and follow-up strategies in routine cardio-oncology care.