Anticoagulation and antiplatelet therapy in hereditary hemorrhagic telangiectasia: A scoping review

Introduction: Data describing safety and tolerability of anticoagulation and antiplatelet therapy in hereditary hemorrhagic telangiectasia (HHT), the second-most-common inherited bleeding disorder, is limited.Methods: We performed a scoping review, searching MEDLINE and EMBASE from inception to March 2023 for eligible studies reporting detailed clinical data describing antithrombotic use in HHT. Data extracted included study design, patient population, and characteristics and outcomes of antithrombotic therapy.Results: Of 625 unique manuscripts identified through database search, 77 were included: 64 case reports/case series describing 65 patients and 13 cohort studies. Data were extracted on a total of 466 patients with HHT, covering 587 episodes of antithrombotic therapy. The most common reasons for antithrombotic therapy were venous thromboembolism (VTE) (44.6 %), atrial arrhythmias (17.8 %) and stroke (10.5 %). anticoagulation was used in in 356 episodes (61.9 %), antiplatelet therapy in 140 episodes (24.3 %), and both together in 50 episodes (8.7 %). Complications of therapy included worsened HHT-associated bleeding (primarily epistaxis and gastrointestinal bleeding) in 198 antithrombotic treatment episodes (38.9 %) and premature antithrombotic therapy discontinuation in 142 episodes (28.9 %). Bleeding-directed therapy (local ablative therapy and systemic therapies) were employed to address worsening bleeding in 14.6 % of episodes. No specific complications of therapy were reported in 322 total antithrombotic events (58.4 %). Rates of bleeding (8.3 % to 80 %), therapy discontinuation (14.3 % to 57.1 %), and other complications ranged considerably from study to study. Conclusion: Current publications vary widely on the outcomes and tolerability of antithrombotics in HHT, but confirm the clinical challenge of adequate antithrombotic therapy in this population. More formal studies are needed to better guide optimal antithrombotic use in HHT.