OC 01.5 - Anticoagulation Post-Pulmonary Endarterectomy: A retrospective cohort study

Background: Chronic thromboembolic pulmonary hypertension (CTEPH) is a devastating disease, but is treatable with pulmonary endarterectomy (PEA) and life-long anticoagulation (AC). Direct oral anticoagulants (DOACs) are largely replacing vitamin K antagonists (VKAs) as first line AC for many indications, but data is limited in the post-PEA setting.

Aims: To compare DOACs to VKAs in CTEPH post-PEA patients for recurrent VTE, composite major bleeding (MB) and clinically relevant non-major bleeding (CRNMB) (ISTH definitions), MB, CRNMB, overall mortality, and initiation of targeted pulmonary hypertension therapy (TPHT).

Methods: This was a REB approved single center, retrospective, cohort study of CTEPH patients who underwent PEA between Jan 2005 to February 2022 with long-term follow up at our institution. Patient identification and clinical data were obtained from an institutional CTEPH database, and the electronic patient chart. Patients were followed from post-PEA discharge to last known follow up, or until discontinuation of oral AC. Outcomes by AC group were calculated as events per 100 person-years and compared as rate ratios with 95% confidence intervals (CI) using the Mid-P exact test.

Results: The cohort included 336 individuals, of which 171 received DOACs and 195 received VKAs at some point, with total follow-up of 1095 patient years (Table 1). The mean age was 58.15 years, and 50% were female. There was a statistically significant higher rate of recurrent VTE with DOACs compared to VKAs (rate ratio 2.62 (95% CI 1.06 to 6.50)) (Table 2). There were no differences in composite MB and CRNMB, MB, CRNMB, death, or initiation of TPHT between the two groups.

Conclusion(s): Our study comparing DOACs to VKAs in CTEPH patients post-PEA found a higher rate of recurrent VTE on DOACs, but no difference in bleeding, initiation of TPHT or mortality. Further studies are needed to assess the safety and efficacy of DOACS in CTEPH.