Outcomes and Safety of Direct Oral Anticoagulants (DOACs) versus Vitamin K Antagonists (VKAs) amongst Patients with Valvular Heart Disease (VHD): A Systematic Review and Meta-Analysis

Background: Both valvular heart disease (VHD) and atrial fibrillation (AF) frequently coexist. AF is an important cause of arrhythmias with a definitive cardiovascular morbidity. The use of either vitamin K antagonists (VKAs/warfarin) or direct oral anticoagulants (DOACs) (also known as new oral anticoagulants (NOACs)) has been the mainstay for preventing stroke and systemic embolism in patients with VHD and/or AF, and this has been broadly discussed. However, there are limited studies on anticoagulation therapy for patients with valvular atrial fibrillation (VAF). The main aim of this meta-analysis was to evaluate the outcomes (stroke–vascular events and intracranial bleeding) following DOAC and VKA treatment amongst patients with VAF. Methods: We identified clinical trials and observational studies published in the last 10 years. A systematic review and a meta-analysis were performed to evaluate the outcomes of patients with valvular atrial fibrillation following DOAC vs. VKA treatment. Data evaluation was performed using Review Manager 5.4; the endpoints were stroke–vascular events and intracranial bleeding following DOAC and VKA treatment amongst VAF patients. Risk ratios (RR) were evaluated with 95% confidence intervals. Using random effects models, forest plots were obtained. Heterogeneity was assessed by using the I2 statistic. Results: Eight studies were included in this metanalysis, and a total of fifteen thousand two hundred and fifteen patients (DOAC (8732) and VKA (6483)) were pooled. We found a significant risk reduction in stroke–vascular events when using DOACs in comparison with using VKAs (pooled RR: 0.76; 95% CI: 0.64–0.90, p = 0.002). A total of 14862 patients (DOAC (8561) and VKA (6301)) were pooled from a total of six studies for intracranial bleeding. We found a significant risk reduction in terms of intracranial bleeding when using DOACs in comparison with using VKAs (pooled RR: 0.43; 95% CI: 0.24–0.77, p ≤ 0.05). Conclusions: When compared to VKAs, DOAC agents were found to have less risk of stroke–vascular events and intracranial bleeding. Further prospective studies are essential to establish the efficacy and safety of DOAC agents in patients with various subtypes of VAF.