Antithrombotic therapy after cardiac valve surgery: prospective real-world data of Class II guidelines application and outcomes from the EURObservational Research Programme Valvular Heart Disease II survey.

Background: Antithrombotic therapy (AT) after cardiac valve surgery is complex, with guidelines often relying on limited evidence. Objectives: This study examines real-world adherence to the European Society of Cardiology Class II, level C recommendations for AT in valve surgery, as well as the 6-month impact of AT on patient outcomes. Methods: This prospective, observational subanalysis of the European Society of Cardiology EURObservational Research Programme Valvular Heart Disease II survey included 6 substudies examining different valve interventions and AT regimens. Patient demographics, clinical characteristics, and 6-month outcomes were compared between groups receiving the recommended AT and those who did not. Results: Guideline adherence varied widely (39.5%-81.1%) across substudies. Factors influencing AT decisions included cardiovascular risk factors, atrial fibrillation, and prior percutaneous coronary intervention. In unadjusted analyses of 3 substudies, 6-month all-cause mortality was significantly higher in patients not receiving the recommended AT. However, no significant differences were observed in thromboembolic events, bleeding, or other complications between AT and non-AT groups across all substudies at 6 months. Conclusion: This analysis reveals potential mortality benefits associated with guideline-recommended AT in some patient groups. However, the observational nature of the study limits causal inferences, emphasizing the importance of further prospective research to optimize AT strategies and improve patient outcomes in this complex clinical setting, particularly as new AT and valve types emerge.