Oncologists’ knowledge, clinical practices, barriers and facilitators of cardio-oncology guideline-concordant care.

e24011 Background: Cancer and cardiovascular (CV) disease are leading global causes of morbidity and mortality, with rising CV complications across all cancer types.The 2022 European Society of Cardiology (ESC) Cardio-Oncology guidelines provide several (over 150 of 272) class 1 recommendations for cardio-oncology care. We evaluated knowledge and practice of the class 1 recommendations pertinent to oncology practice. Methods: A cross-sectional questionnaire, hosted on REDCap, was distributed to Canadian oncology providers from November 2025-January 2026. It tested knowledge of class 1 recommendations (4 general questions and additional questions by prescribed therapy), awareness of ESC guidelines, and perceived barriers to clinical uptake. Data were analysed descriptively, with associations between responses and respondent characteristics explored descriptively and using logistic regression. Results: Sixty-three respondents completed the survey. Most practiced in academic settings (75.8%) and devoted ≥50% of time to clinical work (88.7%). Almost half of respondents were within the first 10 years of practice (42.8%) and reported moderate to high exposure to cardio-oncology (44%). Forty percent (19/47) got 3 or 4 correct answers out of 4 general knowledge questions. Over half (63.3%) identified the correct tool to calculate baseline CV risk, while fewer correctly identified high baseline CV toxicity risk scenarios (38.8%) or appropriate cardio-oncology referral indications (39.6%). Less than 50% of anthracycline prescribers correctly identified the correct timing for post-treatment echocardiography. Over 70% of immune checkpoint inhibitor prescribers were unaware of recommended baseline CV assessment. In contrast, > 90% of HER2-therapy prescribers correctly identified management of symptomatic LVEF < 50% and nearly all CAR-T prescribers correctly identified the recommended baseline CV assessment. Male sex at birth was quantitatively but not statistically correlated with correctly answering knowledge questions (OR 2.6, 95%CI 0.73-9.26, p = 0.14) but greater exposure to cardio-oncology (regular involvement and/or an academic interest in cardio-oncology) and years in practice were not. Three quarters of respondents reported rarely or never consulting ESC guidelines. Key barriers included guideline length, time constraints, and limited access to cardio-oncology services. Simplified guidelines geared to oncologists, workflow prompts, and timely access to investigations and cardio-oncology specialists were perceived to facilitate guideline concordant care. Conclusions: Oncology providers are well positioned to identify individuals at CV risk at all treatment phases, yet have low knowledge and report barriers to implementation of oncology-specific ESC guidelines. Implementation strategies should be identified and evaluated to improve this gap.