Direct oral anticoagulants versus vitamin K antagonists in antiphospholipid syndrome: A meta-analysis

Background: Anticoagulant treatment is recommended in patients with thrombosis and antiphospholipid syndrome (APS). Conflicting results have been reported on the role of direct oral anticoagulants (DOACs) in these patients. We performed a meta-analysis of randomized controlled trials (RCTs) focused on this issue. Methods: We searched MEDLINE and EMBASE for RCTs comparing DOACs and vitamin K antagonists (VKAs) for secondary thromboprophylaxis in patients with thrombotic APS. The primary objective was to assess the efficacy of DOACs compared to VKAs to prevent recurrence of thromboembolic events. Risk difference (RD) was reported as weighted RD according to Mantel-Haenszel random-effect method. Results: Three RCTs (426 patients) were included, all comparing rivaroxaban with VKAs. The proportion of recurrences (either arterial or venous) was higher among rivaroxaban patients when compared with those receiving VKAs (9.5% vs 2.8%; RD 6%, 95% CI, -0.05 – 0.18, p=0.29), although non-statistically significant. In patients with an arterial index event, thromboembolic recurrences were more frequent in those treated with rivaroxaban compared to those treated with VKAs (25% vs 6.2%; RD 19%, 95% CI, 0.04 – 0.33; p =0.01; I2 49%). In triple aPL positive patients, rivaroxaban showed higher rates of thromboembolic recurrences compared with VKAs (12% vs 3%; RD 9%, 95% CI, 0.02 – 0.15; p= 0.01; I2 13%). Non-statistically significant differences were observed in major bleeding events or mortality. Conclusions: The use of rivaroxaban in APS patients is associated with an increased rate of thromboembolic recurrences compared to VKAs, at least in those with arterial index event or triple aPL positivity.