Low-dose direct oral anticoagulants for secondary prevention in patients at high risk for recurrence due to history of recurrent venous thromboembolic events or severe thrombophilia: a retrospective analysis of the Italian Survey on anTicoagulated pAtients RegisTry 2

Abstract

Background: Long-term anticoagulation is recommended in patients with venous thromboembolism (VTE) deemed at high risk for recurrence (HRR). Limited information is available on patients with recurrent VTE and/or severe thrombophilia. In addition, these patients were not included in studies evaluating long-term treatment with low doses of direct oral anticoagulants (DOACs).

Objectives: The aims of our study were to (1) record the drugs and dosages used in HRR patients, and (2) to record adverse events occurring during follow-up.

Methods: Among 2520 VTE patients enrolled in the Survey on anTicoagulated pAtients RegisTry 2, we retrospectively analyzed the management of patients with a history of recurrent VTE and/or severe thrombophilia (HRR patients).

Results: A total of 487 HRR patients were analyzed. Anticoagulants were stopped in 11 of 487 patients (2.3%), full-dose DOACs were continued in 176 patients (36.1%), and 311 patients (63.9%) were shifted to low-dose DOACs (61.4% with apixaban 2.5 mg twice a day and 38.6% with rivaroxaban 10 mg once a day) after a median time of 1.3 years (range, 0.5-20.2 years). During follow-up, no adverse events were recorded in patients who stopped treatment. Among patients who continued treatment, 10 had recurrent VTE (rate, 0.4 × 100 patient-years) and 19 had bleeding (rate, 0.9 × 100 patient-years). The risk of recurrent VTE was similar between patients on full-dose and low-dose anticoagulation. Patients on full-dose anticoagulation had a trend toward a higher bleeding risk (relative risk, 2.2; 95% CI, 0.7-9.0).

Conclusion: HRR patients with a history of unprovoked recurrent VTE and/or patients with severe thrombophilia treated with long-term low-dose DOACs showed a low risk for recurrence and bleeding events.

Keywords: bleeding risk; low-dose direct oral anticoagulants; venous thromboembolism; venous thromboembolism recurrence.