Safety and efficacy of oral factor-Xa inhibitors versus Vitamin K antagonist in patients with non-valvular atrial fibrillation: Meta-analysis of phase II and III randomized controlled trials.

Background: Aim of our study was to assess the safety and efficacy on factor-Xa inhibitors (FXIs) in patients with non-valvular atrial fibrillation (NVAF) as compared to Vitamin K antagonist (VKA).

Methods: Phase II and III randomized controlled trials that reported clinical safety and efficacy of FXI in patients with NVAF were identified from MEDLINE, Embase, and Cochrane Central Register of Controlled Trials through December 10, 2015. The primary safety outcome of our study was composite of stroke and systemic embolic event. Secondary outcomes studied were individual endpoints of primary safety outcome, major bleeding, clinically relevant non-major bleed (CRNMB), and all-cause mortality.

Results: We included 11 RCTs with a total of 59,164 participants, of which 34,231 patients received oral FXI and 24,933 patients were on VKA with a mean follow-up of 369days. There was a significant reduction in primary outcome with FXI compared to VKA, 1,112 (3.4%) versus 816 (3.6%) events, respectively (OR 0.82; 95% CI 0.68-0.99). Use of FXI significantly reduced major bleeding events compared to VKA, OR 0.74, 95% CI 0.58-0.96, test for heterogeneity (I(2)=74%). Incidence of CRNMB was not different between FXI and VKA groups, OR 0.84, 95% CI 0.68-1.04. There was a significant reduction in all-cause mortality in FXI group compared to VKA group, OR 0.88, 95% CI 0.83-0.94 with no significant heterogeneity.

Conclusion: Use of FXI was associated with a significant reduction in major bleeding events and all-cause mortality without increased risk of stroke or SEE compared to VKA.