Direct oral anticoagulant use and thrombus detection in patients with chronic thromboembolic pulmonary hypertension referred for pulmonary thromboendarterectomy

Background: Patients with chronic thromboembolic pulmonary hypertension (CTEPH) should be on lifelong, effective anticoagulant therapy. The safety and efficacy of direct oral anticoagulant (DOAC) in CTEPH is unknown. Aim: To evaluate the trend of DOAC usage and correlation with subacute thrombus detection at time of pulmonary thromboendarterectomy. Methods: We performed a retrospective analysis of 405 consecutive pulmonary thromboendarterectomy (PTE) cases at the University of California, San Diego from July 2015 through July 2017. The PTE specimen were reviewed for the presence of acute or subacute thrombotic material removed at the time of PTE. Results: Of 405 consecutive PTE cases, 239 (59.0%) presented on either oral vitamin-K antagonist or chronic injectable therapy; 166 patients (41%) were anticoagulated with DOACs. There were no significant differences in baseline characteristics between DOAC and non-DOAC groups. Evidence of acute or subacute thrombi was observed in 16 (6.7%) within the non-DOAC group versus 22 (13.3%) in the DOAC group. The odds ratio (OR) of DOACs usage and evidence of recent thrombosis was 2.34 (95% CI, 1.09-5.01, p=0.028) after adjusting for age, gender, race, BMI, and history of antiphospholipid antibody syndrome. Conclusions: CTEPH patients referred for PTE while on DOAC therapy were twice as likely to have associated acute or subacute thrombi removed at the time of surgery compared with those on conventional anticoagulant therapies. This raises questions of safety and efficacy of DOACs in the chronic treatment of CTEPH. A formal study of DOACs in the management of CTEPH is indicated.