Non Vitamin K Antagonist Oral Anticoagulants Versus Warfarin in Patients With Cancer and Atrial Fibrillation: A Systematic Review and Meta-Analysis

Background-Several studies have investigated the effect of non-vitamin K antagonist oral anticoagulants (NOACs) in atrial fibrillation (AF) patients with cancer, but the results remain controversial. Therefore, we conducted a meta-analysis to compare the efficacy and safety of NOACs versus warfarin in this population. Methods and Results-We systematically searched the PubMed and Embase databases until February 16, 2019 for studies comparing the effect of NOACs with warfarin in AF patients with cancer. Risk ratios (RRs) with 95% CIs were extracted and pooled by a random-effects model. Five studies involving 8908 NOACs and 12 440 warfarin users were included. There were no significant associations between cancer status and risks of stroke or systemic embolism, major bleeding, or death in AF patients. Compared with warfarin, NOACs were associated with decreased risks of stroke or systemic embolism (RR, 0.52; 95% CI, 0.28-0.99), venous thromboembolism (RR, 0.37, 95% CI, 0.22-0.63), and intracranial or gastrointestinal bleeding (RR, 0.65; 95% CI, 0.42-0.98) and with borderline significant reductions in ischemic stroke (RR, 0.63; 95% CI, 0.40-1.00) and major bleeding (RR, 0.73; 95% CI, 0.53-1.00). In addition, risks of efficacy and safety outcomes of NOACs versus warfarin were similar between AF patients with and without cancer. Conclusions-In patients with AF and cancer, compared with warfarin, NOACs had lower or similar rates of thromboembolic and bleeding events and posed a reduced risk of venous thromboembolism.