Cancer management has undergone major advances over the past 30 years. Several anticancer therapies are now highly effective, allowing many cancers to become chronic diseases through sequential lines of treatment. However, these therapies may be associated with severe cardiovascular adverse events.

It is therefore essential to better understand the factors that determine, for a given patient and a given anticancer therapy, the occurrence of cardiovascular toxicity, and ideally to predict which patients are at highest risk.

The 2022 ESC Cardio-Oncology Guidelines strongly recommend risk stratification prior to the initiation of cardiotoxic anticancer therapies. Current recommendations suggest the use of risk scores known as "HFA-ICOS" scores. However:

Not all cardiotoxic anticancer therapies currently have an associated risk score; Existing scores are derived from small retrospective or prospective cohorts (typically fewer than 100 patients), and most have not undergone rigorous validation, leaving considerable room for improvement.

The EU-CARTOX-SCORES protocol aims to develop new prediction scores for cardiotoxicity occurring within the first year after initiation of cardiotoxic anticancer therapies. This protocol is innovative through the integration of artificial intelligence and/or machine learning approaches alongside conventional statistical methods. These models will be interfaced with a dedicated cardio-oncology digital platform (CardioOncoPilot), currently being deployed across the European Union, ensuring standardized and high-quality data collection within routine clinical care.

This is a prospective, multicenter, observational study designed as a European cardio-oncology registry, involving all European cardiologists using the platform in routine practice. The inclusion period will last 3 years, with a 12-month follow-up for each patient. At the time of data extraction, all available cases recorded in the CardioOncoPilot platform will be analyzed.

Overall, it is anticipated that between 1,000 and 5,000 patients across Europe will be included by the end of 2027. These patients will be managed in cardio-oncology clinics as part of routine care during treatment with cardiotoxic anticancer therapies, with follow-up conducted at the same center throughout the study.

The primary endpoint will be the occurrence of cardiotoxicity as defined by the 2022 ESC Guidelines. Additionally, the performance of newly developed prediction models will be compared with existing HFA-ICOS risk scores (when available) in the same patient population.

Patients will be followed according to routine clinical practice and in accordance with the 2022 ESC Cardio-Oncology Guidelines, which recommend both a baseline pre-treatment assessment and a follow-up evaluation at 1 year, regardless of the type of cardiotoxic therapy.

Patient management will not be modified by the study. This research will consist solely of secondary use of data collected during routine care.

We anticipate that this study will significantly improve prognostic risk stratification tools in patients treated with cardiotoxic anticancer therapies, thereby enhancing identification of those at highest risk of clinically relevant cardiovascular adverse events during follow-up.

This project will be conducted in collaboration with the ESC Council of Cardio-Oncology, chaired by Prof. Teresa Lopez-Fernandez, ensuring optimal dissemination through appropriate scientific channels. The developed scores will be shared with the scientific community, particularly the European Society of Cardiology (ESC), with the aim of informing future guideline updates.

Inclusion Criteria:

• Age ≥ 18 years
• Diagnosis of cancer
• Planned cardio-oncology follow-up as part of pre-treatment assessment prior to cardiotoxic anticancer therapy, as defined in the 2022 ESC Cardio-Oncology Guidelines

Exclusion Criteria:

• Patients for whom 12-month follow-up is planned to be conducted outside the center that performed the baseline pre-treatment evaluation

All consecutive patients seen in a cardio-oncology outpatient clinic at one of the participating centers during the inclusion period (June 2026 to December 2029) will be eligible for inclusion in the study.