Validation of the HFA-ICOS cardio-oncology cardiovascular risk calculator in an Australian cancer cohort receiving anthracyclines and HER2 targeted therapies

Background Cancer patients are at risk of developing cancer treatment related cardiovascular toxicity (CTR-CVT). Cardiac surveillance during cancer treatment provides an opportunity for early diagnosis and management to ensure optimal cardiac and cancer outcomes. The appropriate modality and frequency of cardiac surveillance and use of primary cardioprotection depends on individual risk assessment, but the optimal means of assessing risk remains undetermined. Whilst there has been increasing clinical use of the HFA-ICOS Cardio-Oncology Cardiovascular Risk Calculator (1), it has yet to be validated in an Australian cancer cohort. Purpose The aim of this study was to validate the accuracy of the HFA-ICOS Cardio-Oncology Cardiovascular Risk Calculator (1) in an Australian cancer population receiving anthracyclines and HER2-targeted therapies. Methods Retrospective data analysis of consecutive patients initiated on either anthracyclines or HER2 targeted therapy between 1 January 2022 and 31 December 2023 at a quaternary cancer referral centre was performed. The risk of CTR-CVT according to the HFA-ICOS Cardio-Oncology Cardiovascular Risk Calculator (1) prior to initiating cancer treatment was calculated. The incidence of CTR-CVT within the first 24 months of receiving cancer treatment was recorded. Results 157 patients were included in this analysis. The mean age was 59.01 ± 15.38 years; 30.6% (48/157) were male. 42.7% (67/157) had breast cancer, 22.9% (36/157) had lymphoma, and 34.4% had other cancer subtypes. 61.8% (97/157) received anthracyclines and 38.2% (60/157) received HER2 targeted therapies. Using the HFA-ICOS Cardio-Oncology Risk Calculator, 49.0% (77/157) were assessed as low-risk, 33.8% (53/157) as moderate risk, 13.4% (21/157) as high risk, and 3.8% (6/157) as very high risk. 38 cardiovascular events (CVEs) were recorded in 34 patients; the incidence of CTR-CVT was 21.7%. This incidence was 14.3% (11/77) in the low-risk, 25.9% (14/54) in the medium-risk, 30.0% (6/20) in the high-risk, and 50.0% (3/6) in the very high-risk groups respectively. Conclusions The HFA-ICOS Cardio-Oncology Risk Calculator provides accurate CTR-CVT risk stratification in an Australian cancer cohort receiving anthracyclines and HER2 targeted therapies, with increasing cardiotoxicity rates corresponding to increasing risk categories. This validates its utility as a tool to guide cancer treatment, primary cardioprotective measures, and cardiac surveillance decision-making. However, the real-world incidence of CTR-CVT is higher than that estimated by the Risk Calculator, and further work will be needed to improve the precision and accuracy of risk estimation.