B64-35 Stuck Between a Rock and a Hard Place: Anticoagulation in a Patient With Chronic Thromboembolic Pulmonary Hypertension and Recurrent Bleeding

Abstract Chronic thromboembolic pulmonary hypertension (CTEPH) is estimated to occur in 1-5% of survivors of acute pulmonary embolism (PE). It is unclear why some patients with acute PE progress to CTEPH whereas others do not. The only potentially curative therapy that currently exists for CTEPH is pulmonary endarterectomy (PTE). Whether they undergo PTE or not, these patients typically remain on lifelong anticoagulation, either with warfarin or direct oral anticoagulants. Here we present a challenging case of CTEPH after PTE who ultimately developed intractable bleeding. A 34-year-old male with past medical history significant for tobacco use disorder and alcohol use disorder presented with a 2-week history of shortness of breath. He was found to have a bilateral pulmonary embolism with significant right heart strain and was discharged on apixaban. After discharge, he was seen in pulmonary clinic multiple times with ongoing dyspnea and was diagnosed with CTEPH (pulmonary artery systolic pressure of 51mmHg on echocardiogram). Workup for prothombotic disorders was limited with no significant results except JAK2 V617 positivity suggesting mild clonal hematopoiesis. Factor VIII levels were not checked. He subsequently underwent pulmonary endarterectomy. After PTE, he developed hemorrhagic pancreatitis with an associated retroperitoneal hematoma. He went several days without anticoagulation, and then started on a heparin drip. This was interrupted on several occasions, and he developed multiple acute thrombi, treated with an IVC filter. Ultimately, after a complicated hospital stay, he developed a new liver hematoma while on therapeutic enoxaparin. The patient eventually passed due to hemorrhagic shock secondary rupture of hepatic hematoma. There is data to suggest that CTEPH is associated with a prothrombotic state, characterized by upregulation of several coagulation factors (factor VIII, fibrinogen and thrombocytosis). There is also data to suggest that some testing we do to monitor anticoagulation (such as aPTT for heparin activity) is less accurate in post-PEA patients due to post-operative fibrinogen elevation. Despite encouraging data that shows improved outcomes in patients with normal pulmonary pressures after endarterectomy, the challenge of minimizing bleeding risk in these patients, with their tendency to clot remains. There are no formal guidelines on anticoagulation for CTEPH but most organizations (ERS, AHA and ASH) are in consensus that lifelong anticoagulation is necessary, irrespective of the results of coagulation studies. The pathogenesis of CTEPH is not fully established but this case highlights the importance of detailed workup for clotting abnormalities as well as the challenges of anticoagulation with recurrent bleeding. This abstract is funded by: None