Use of direct anticoagulants in chronic thromboembolic pulmonary hypertension: An anatomopathological study of endarterectomy material

OBJETIVE: Chronic thromboembolic pulmonary hypertension (CTEPH) is a potentially curable cause of pulmonary hypertension, characterized by persistent organized thrombi and micro vasculopathy leading to increased pulmonary vascular resistance and right heart failure. Pulmonary endarterectomy (PEA) remains the treatment of choice for operable patients. Although vitamin K antagonists (VKAs) are traditionally used for lifelong anticoagulation, direct oral anticoagulants (DOACs) have gained popularity despite limited evidence supporting their use in CTEPH. Histopathological assessment may provide new insights into anticoagulation effectiveness. This study aimed to evaluate the presence of recent thrombi in PEA specimens from patients using DOACs versus VKAs and to correlate these findings with surgical and hemodynamic outcomes. METHODS: Retrospective cohort study included 115 patients with CTEPH who underwent PEA at a national referral center for the treatment of CTEPH between 2018 and 2023. Patients were categorized based on anticoagulant type (DOAC or VKA). All surgical specimens underwent histopathological evaluation. Pre- and postoperative hemodynamic and clinical data were analyzed. Statistical comparisons were performed using appropriate parametric and non-parametric tests. RESULTS: Recent thrombi were identified in 26.2 % of patients on DOACs and 9.2 % of those on VKAs (p < 0.05). Despite the higher prevalence of thrombi in the DOAC group, no significant differences were observed in extracorporeal circulation time, cardiac arrest duration, or postoperative hemodynamic parameters between groups. Microscopic evaluation proved to be more sensitive than macroscopic analysis for detecting thrombi. CONCLUSION: Our findings demonstrate the presence of recent thrombi in patients with CTEPH undergoing PEA. This observation raises questions regarding the use of DOACs in patients with CTEPH.