Abstract Background Cancer therapy related cardiac dysfunction (CTRCD) is a significant side effect of several chemotherapies, targeted agents, and immunotherapies integral to treatment. Anthracyclines are an example of a commonly used chemotherapy drug class that can cause irreversible early and late onset heart failure. CTRCD often leads to dose reductions and treatment delays or cessation, limiting treatment success and contributing to increased mortality and life-long morbidity in oncology survivors. In Australia, there are currently no multi-centre, longitudinal studies examining CTRCD in adult oncology patients. Trial design The Australian Cardiology-Oncology Registry (ACOR) is a prospective observational non-interventional study involving 14 sites across Australia. Patient information is obtained from hospital medical records and de-identified upon entry into the registry. Patient demographics, medical history, cancer diagnosis, treatment, cardiac evaluations, and the management of demonstrated CTRCD are recorded. Data is collected at baseline (prior to treatment), and then at six-monthly intervals thereafter. Additionally, patients who develop anthracycline-induced cardiotoxicity (ACT) will be asked to participate in the biobanking study, which will involve a one-off 12mL peripheral blood draw that will be processed at an external site for whole genome exome sequencing and the development of pluripotent derived stem cell cardiomyocytes. Eligibility criteria Inclusion Criteria • Adult oncology patients (>18+ years of age) treated with cardiotoxic therapies within the last 5-years Exclusion Criteria • Diagnosis of Trisomy 21 • Patients being treated with palliative intent Specific aims Chris O’Brien Lifehouse aims to use the ACOR to explore the epidemiology, clinical presentation, and management of CTRCD amongst adult oncology patients receiving cardiotoxic therapies. In addition, a biobanking sub-study will attempt to identify gene polymorphisms predisposing individuals to developing ACT. It is hoped that such longitudinal data collection can lead to the introduction of an ACT susceptibility genetic screening test allowing for the inclusion of patient risk stratification prior to anthracycline exposure in routine cancer treatment. Statistical methods Descriptive statistics will be used for variables for quantitative analysis. Kaplan Meier analyses will be used for survival curves, freedom from cardiac failure since enrolment and freedom from arrhythmia since enrolment. An annual report will be produced. Present accrual and target accrual At the time of submission, 224 adult oncology patients have been recruited to the ACOR via Chris O’Brien Lifehouse with the opening of the biobanking sub-study currently in progress. The ACOR anticipates with full registered site capacity to capture 600 patients annually. Citation Format: Jocelyn Finney, Ben Felmingham, Sanjeev Kumar, Alina Mahmood, Lisa Horvath, David Celermajer, Rachel Conyers. Using the Australian Cardio-Oncology Registry to study long-term cancer therapy related cardiac dysfunction in adult oncology patients – The Chris O’Brien Lifehouse experience [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-20-06.