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.

背景：因心血管疾病等需接受抗凝治疗的患者数量持续上升，即便在免疫性血小板减少症（immune thrombocytopenia, ITP）患者群体中亦是如此。但目前尚缺乏针对此类人群的详细指南与相关研究。在免疫性血小板减少症相关临床试验中，服用抗凝药物的患者通常会被排除；而抗凝治疗相关研究也往往会排除血小板减少症患者。本研究的主要目标是阐明临床日常实践中影响免疫性血小板减少症患者抗凝治疗决策的各类因素。
方法：本研究通过开展问卷调查，探究免疫性血小板减少症患者抗凝治疗的优选管理方案。问卷设置了常见的患者临床场景，并收集了影响是否启动抗凝治疗决策的相关因素。
结果：本研究共调查了德国、奥地利与瑞士的235名同行。其中210名受访者为血液科专科医师，13名接受过止血学高级培训。约半数参与者（110/210；55%）每月接诊5~10例免疫性血小板减少症患者。针对免疫性血小板减少症患者的抗血栓治疗推荐血小板阈值整体较为一致。多数受访者表示，在多数临床场景下，抗凝治疗的最低血小板计数阈值为50×10^9/L。但受访者之间的个体临床实践模式存在较大差异。患者的社会心理状态对治疗决策具有重要影响。
结论：为免疫性血小板减少症患者制定抗凝治疗方案仍颇具挑战。本研究的问卷调查结果展现了临床医师在管理免疫性血小板减少症患者抗凝治疗时的多元视角。当血小板计数＞50×10^9/L时，抗凝治疗被认为是安全的。而对于血小板计数更低的患者，出血倾向、合并症以及社会心理状态等其他影响因素则成为决策关键。本研究结果凸显了平衡临床判断、制定循证指南，以及与患者充分沟通以优化治疗策略的重要性。