Direct Oral Anticoagulants: An Updated Systematic Review of Their Clinical Pharmacology and Clinical Effectiveness and Safety in Patients With Nonvalvular Atrial Fibrillation

Direct oral anticoagulants have been an increasingly used class of drugs in the setting of nonvalvular atrial fibrillation, defying vitamin K antagonists' monopoly when it comes to anticoagulation due to its several limitations. Direct oral anticoagulants (DOACs) have entered the market as a noninferior and safer option in comparison with vitamin K antagonists, as their respective phase III clinical trials proved. The aim of this article was to update and summarize data on their clinical pharmacology and to review real-world data to know their comparative effectiveness and safety. We performed a systematic review using PubMed, Google Scholar, Embase, and Web of Science as search engines. Regarding pharmacodynamics, there were no substantial changes reported from their original profile. There were many advances in the knowledge about clinical pharmacokinetics of DOACs that have had a direct impact on their clinical use, mainly related to drug-drug interactions. In a real-world setting, DOACs have shown to be noninferior in preventing thromboembolic events compared to vitamin K antagonists. In regards to safety, DOACs have shown a lower bleeding risk relative to warfarin. Comparison between DOACs has demonstrated rivaroxaban to have the highest bleeding risk. Overall, the evidence gathered showed few changes from the original data presented in phase III clinical trials, concluding that their real-world use coincides greatly with them.

Real-world Comparisons of Direct Oral Anticoagulants for Stroke Prevention in Asian Patients with Non-valvular Atrial Fibrillation: a Systematic Review and Meta-analysis

BACKGROUND

Whether four direct oral anticoagulants (DOACs) are superior to warfarin among Asians with non-valvular atrial fibrillation (NVAF) remains unclear in the real-world setting.

METHODS

We searched PubMed and Medline + Journals@Ovid + EMBASE from September 17, 2009 to May 4, 2019 to perform a systematic review and meta-analysis of all observational real-world studies comparing four DOACs with warfarin specifically focused on Asian patients with NVAF.

RESULTS

From the original 212 results retrieved, 18 studies were included in the meta-analysis. Overall, DOACs were associated with lower risks of thromboembolism (hazard ratio; [95% confidence interval], 0.70; [0.63-0.78]), acute myocardial infarction (0.67; [0.57-0.79]), all-cause mortality (0.62; [0.56-0.69]), major bleeding (0.59; [0.50-0.69]), intracranial hemorrhage (0.50; [0.40-0.62]), gastrointestinal bleeding (0.66; [0.46-0.95]), and any bleeding (0.82; [0.73-0.92]) than warfarin. There was statistic heterogeneity between DOACs for the risks of thromboembolism (P interaction = 0.03) and acute myocardial infarction (P interaction = 0.007) when compared to warfarin. However, all DOACs showed lower risks of thromboembolism and acute myocardial infarction than warfarin when pooling studies that compared individual DOAC with warfarin. With regard to the other outcomes when compared to warfarin, there was no statistical heterogeneity between DOACs. In addition, the effectiveness and safety of four DOACs versus warfarin persisted in the subgroups of either standard-dose or low-dose DOACs.

CONCLUSIONS

The meta-analysis shows that the DOACs had greater effectiveness and safety compared to warfarin in real-world practice for stroke prevention, among Asian patients with NVAF.