Supplementary Material for: Managing antithrombotic treatment in Patients with Immune Thrombocytopenia

Introduction: The number of patients requiring anticoagulation, e.g., for cardiovascular diseases, is increasing, even in patients with immune thrombocytopenia (ITP). However, detailed guidelines and studies are lacking. In clinical trials in ITP, patients taking anticoagulants are usually excluded and patients with thrombocytopenia are often excluded from anticoagulation studies. Our main goal was to highlight factors influence anticoagulation decision-making in clinical routine. Methods: We conducted a survey to explore the preferred management of anticoagulation therapy in patients with ITP. It presented common patient scenarios and elicited factors influencing decisions regarding whether to initiate anticoagulation therapy. Results: We surveyed 235 colleagues in Germany, Austria, and Switzerland. A total of 210 respondents specialized in hematology; 13 had advanced training in hemostaseology. About half (110/210; 55%) of participants treat 5-10 patients with ITP per month. The recommended platelet thresholds for antithrombotic therapy were similar among patients with ITP. Most participants recommended a minimum platelet count of 50 × 109/L for anticoagulation therapy in most scenarios. However, there was great variability in individual practice patterns among the respondents. The psychosocial status of patients was important for decision making. Conclusion: Deciding on anticoagulation therapy in patients with ITP remains challenging. Our survey illustrated the diverse perspectives of medical professionals in managing anticoagulation therapy in ITP. A platelet count >50 × 109/L was considered safe. In patients with lower platelet counts, other influencing factors such as bleeding tendency, comorbidities, and psychosocial status become relevant. Our findings emphasize the importance of balanced clinical judgment, need for evidence-based guidelines, and open discussions with patients to optimize treatment strategies.