Cardiac arrhythmias are common causes of cardiac related morbidity and mortality. If the heart does not properly beat in a normal rhythm, there can be many issues in terms of clotting and possible venous thromboembolisms. Atrial fibrillation is the most common cause of cardiac arrhythmias. It is the number one cause of cardiac related stroke. When the blood in the heart is not properly and efficiently ejected, there can be stasis and pooling of the blood in the heart. This can lead to a clot forming in the atria of the heart. When this clot becomes dislodged, it can travel to the brain and block the blood flow to the brain. In order to prevent the formation of clots in the atria of the heart, people with atrial fibrillation are placed on anticoagulants. This will thin the blood and decrease the risk of a stroke. Typically, people with atrial fibrillation are placed on either warfarin or a direct-acting oral anticoagulant (DOAC). Warfarin is a burdensome drug for patients to be on life-long. It requires therapeutic drug monitoring, and there are many interactions with foods, medications, and supplements. Any small change in a patient’s lifestyle can have drastic effects on their INR level.(1) Edoxaban is a direct factor Xa inhibitor, and does not have any therapeutic monitoring required. It has not, however, been compared to warfarin for the treatment of atrial fibrillation after a transcatheter aortic-valve replacement (TAVR).
In a multicenter, prospective, randomized, open-label trial comparing edoxaban versus vitamin K, over 21,000 patients were enrolled. The primary endpoint was a stroke or some kind of systemic embolism. Patients who were enrolled in the study had moderate or severe risk atrial fibrillation. The rate of the primary endpoint in the warfarin arm was 1.50%, while the rate of the primary endpoint for the edoxaban arm was 1.13%. Although these percentages might not look much different, this number could still save lives. The dose of the edoxaban that was effective was a high dose of 60 mg and the lower dose of 30 mg. Edoxaban was shown to be non-inferior to warfarin. Edoxaban also offers convenience and lack of monitoring as compared to warfarin. Edoxaban also showed to reduce major bleeding events, all cause cardiovascular death, and a composite of strokes, systemic embolism, or death from any cardiovascular cause. These results are significant in terms of the safety and efficacy of an anticoagulant regimen. For patients on anticoagulants, the biggest risk is the risk of bleeding. Both warfarin and edoxaban are reversible anticoagulants. The risk associated with edoxaban is lower than warfarin, and might be a more appropriate therapy for patients with a high fall and bleeding risk. (2)
When evaluating two treatment options, it is important to consider patient specific parameters. Patients with renal impairment have a dose adjustment with edoxaban. This might be specifically relevant for patients with concomitant kidney disease. Patients who are unable to present for follow-up INR visits are more likely to be initiated on some other kind of anticoagulant, such as edoxaban. It is essential to have multiple options for patients, as every patient has different needs. This trial shows that edoxaban is another tool for patients with atrial fibrillation.