Direct oral anticoagulants: key considerations for use to prevent stroke in patients with nonvalvular atrial fibrillation

Abstract

Atrial fibrillation (AF) is the most common cardiac arrhythmia worldwide. Strokes that occur as a complication of AF are usually more severe and associated with a higher disability or morbidity and mortality rate compared with non-AF-related strokes. The risk of stroke in AF is dependent on several risk factors; AF itself acts as an independent risk factor for stroke. The combination of effective anticoagulation therapy, risk stratification (based on stroke risk scores, such as CHADS2 and CHA2DS2-VASc), and recommendations provided by guidelines is essential for decreasing the risk of stroke in patients with AF. Although effective in preventing the occurrence of stroke, vitamin K antagonists (VKAs; eg, warfarin) are associated with several limitations. Therefore, direct oral anticoagulants, such as apixaban, dabigatran etexilate, edoxaban, and rivaroxaban, have emerged as an alternative to the VKAs for stroke prevention in patients with nonvalvular AF. Compared with the VKAs, these agents have more favorable pharmacological characteristics and, unlike the VKAs, they are given at fixed doses without the need for routine coagulation monitoring. It remains important that physicians use these direct oral anticoagulants responsibly to ensure optimal safety and effectiveness. This article provides an overview of the existing data on the direct oral anticoagulants, focusing on management protocols for aiding physicians to optimize anticoagulant therapy in patients with nonvalvular AF, particularly in special patient populations (eg, those with renal impairment) and other specific clinical situations.

Ischemic stroke due to carbon monoxide intoxication: Two case reports

“…[5] Atrial fibrillation (AF) is the most common cardiac arrhythmia in the world and is an independent risk factor for stroke. [7] However, since our cases had normal sinus rhythm in their ECGs, we considered that the clinical findings were manifested not because of an embolic event due to AF but due to the mechanism mentioned above, which was created by CO.…”

Re-Initiation of Dabigatran and Direct Factor Xa Antagonists After a Major Bleed

“…A further consideration when re-initiating OAC therapy is the time to onset of action, which is much faster for DOACs than for warfarin (0.5–4 hours vs 36–72 hours, respectively). 69 …”

Stroke Prevention in Atrial Fibrillation

“…The study RE-LY (Randomized Evaluation of Long-Term Anticoagulation Therapy) showed not only non-inferiority but it has provided evidence on superior efficacy for thromboembolic episodes compared to warfarin, and similar rates (3.11% vs. 3.36% with dabigatran) of preventing hemorrhagic events with 150 mg dose dabigatran (110 mg regimen was more effective in reducing bleeding risks of 2.71% vs. 3.36% with warfarin, but had similar effect on stroke prevention as warfarin treatment). The reliability of RE-LY is characterized by the fact that it also draws attention to adverse effects, such as dyspepsia and higher rates of gastrointestinal hemorrhage and myocardial infarction (0.81%) [34][35][36][37][38][39][40][41][42].…”

“…The study population of this trial had a higher stroke risk than the patient group of the RE-LY trial with warfarin patients spending only in 55% of the time in the therapeutic range of INR. The meta-analysis of the available studies revealed that the incidence of myocardial infarction is significantly less during rivaroxaban treatment [34][35][36][37][38][39][40][41]43].…”

“…Apixaban was compared to acetylsalicylic acid in a patient group with the CHADS 2 score [2]. The trial was stopped after 1.1 years due to the significant superiority of apixaban, decreasing ischemic events by 55% but with no differences in preventing intracerebral and other major hemorrhagic events [34][35][36][37][38][39][40][41]44,45].…”