Introduction:

Anticoagulant therapy is prescribed in nearly half of patients with Pulmonary Arterial Hypertension (PAH) and is the cornerstone of treatment for chronic thromboembolic pulmonary hypertension (CTEPH). The tolerability of long-term anticoagulant therapy in these populations is unclear.

Method:

We report the interim results of a prospective multicenter study (NCT02800941) evaluating the risk of major bleeding (according to ISTH) during one year, under oral anticoagulant therapy in patients with PAH or CTEPH.

Results:

Among the 203 included patients (88 PAH, 115 CTEPH), 152 (75%) received vitamin-K antagonist and 51 (25%) direct oral anticoagulants (34 apixaban and 17 rivaroxaban), as initial anticoagulant therapy (table). Four patients received concomitant antiplatelet therapy (table 1).

Major bleeding was notified in 22 patients (11.22%; 95%CI [7.21-15.92]), with 12 (14%) occurring in PAH patients and 10 (9%) in CTEPH patients. Ten patients died, including 2 from fatal bleeding. Follow-up is still ongoing for 16 patients.

Conclusion:

Our interim analysis indicates a high risk of major bleeding, including fatal bleeding. Risk factors for bleeding will be analyzed in the full set of data, once complete follow-up and independent adjudication of the events are available.