A single centre experience of low dose direct oral anticoagulants (DOAC) after unprovoked venous thromboembolism (VTE)

Abstract

2 trials report effective secondary prevention with low dose apixaban or rivaroxaban after the initial treatment period for VTE (Agnelli 2013 & Weitz 2017). This is a retrospective service evaluation of low dose DOAC over 1 year in patients with unprovoked VTE. Methods: At 3 months post PE or proximal DVT, patients are assessed for VTE and bleeding risk factors. Patients with unprovoked VTE (without chronic thromboembolic pulmonary hypertension, high risk inherited thrombophilia or antiphospholipid syndrome & Results: 212 patients continued DOAC as extended thromboprophylaxis; 79 (37%) with standard dose and 133 (63%) with low dose. Of the patients that continued with low dose DOAC, there was 1 VTE recurrence in 137.4 patient years follow-up; a recurrence rate of 0.7/100 patient years (95% CI 0.0 – 4.0). There were no major bleeds or deaths (95% CI 0.0 – 2.7/100 patient years). Conclusion: At our centre, 63% of patients are treated with low dose DOAC and an average follow-up of more than a year showed low VTE recurrence and major bleeding rates. Larger trials are awaited