Background: Role of vitamin K antagonist (VKA) or Direct Oral anticoagulation (DOAC) for non-valvular atrial fibrillation has widely been discussed. But the literature on anticoagulation therapy for patients with valvular atrial fibrillation (VAF) is limited. Aim of this meta-analysis was to evaluate the outcomes (stroke-vascular events and intracranial bleeding) following DOAC and VKA amongst patients with VAF.
Methods: A systematic review and meta-analysis were performed using PRISMA guidelines and MOOSE protocol to evaluate the outcomes of patients with valvular atrial fibrillation following OAC vs. VKA. We included clinical trials and observational studies published in the last 10 years. Review Manager 5.4 was used to evaluate the collected data on stroke-vascular events and intracranial bleeding following DOAC and VKA amongst VAF patients to find out risk ratio and 95% confidence interval. Forest plots were obtained using random effects models. Heterogeneity was assessed by using the I2 statistic.
Results: A total of 15,215 patients [NOAC (8,732) and VKA (6483)] were pooled. In a meta-analysis of 8 studies, incidence of stroke-vascular events was 3.4% with higher incidence following VKA (3.9%) compared with OAC (3.1%). We found 24% risk reduction (pooled RR: 0.76, 95%CI: 0.64-0.90, p=0.002) by OAC in comparison with VKA with 0% interstudy variability (I2 =0%, p for I2 =0.49, Chi2 =6.43, Tau2=0). A total of 6 studies provided Intracranial bleeding, a total of 14862 participants were pooled in our analysis. The incidence of Intracranial bleeding was 0.96% (143/14862). We found 57% risk reduction after DOAC treatment compared to VKA. The pooled risk ratio was 0.43 (95% CI: 0.24-0.77, p=< 0.05) with heterogeneity analysis showing no statistical variation with in the studies (I2 =55%, p for I2 =0.05, Chi2 =11.03, Tau2=0.25).
Conclusions: Compared to vitamin K antagonists, oral anticoagulation drugs found to have less risk of stroke-vascular events and intracranial bleeding.