Changing Landscape for Stroke Prevention in Atrial Fibrillation

Study Questions:

How have the characteristics of atrial fibrillation (AF) patients changed since the introduction of nonvitamin K antagonist oral anticoagulants (NOACs) in 2011?


The authors compared AF disease characteristics and antithrombotic medications for patients enrolled in the GLORIA-AF’s first two registry phases. Phase I included patients treated before the introduction of NOACs, while phase II began in each participating country once dabigatran was first approved and continued through 2014. Cross-sectional data were collected at baseline for adult patients with a CHA2DS2-VASc score ≥1 and newly diagnosed nonvalvular AF.


In both phase I and II, 45.5% of patients were female, with a median age of 71 years (interquartile range, 64-78). Patients were enrolled from Europe (47.1%), North America (22.5%), Asia (20.3%), Latin America (6.0%), and the Middle East/Africa (4.0%). A CHA2DS2-VASc score ≥2 was present in 86.1% of patients. Overall, 79.9% of patients received oral anticoagulants, 47.6% were treated with a NOAC, 32.3% with a vitamin K antagonist (VKA), 12.1% with antiplatelet agents, and 7.8% with no antithrombotic therapy. Use of oral anticoagulation increased from 64.0% in phase I to 80.0% in phase II. Use of aspirin or no antithrombotic therapy declined from 41.7% and 20.2% in phase I, to 12.1% and 7.8% in phase II, respectively. During phase II, use of NOACs was more common than VKAs in Europe (52.3% vs. 37.8%, respectively) and in North America (52.1% vs. 26.2%, respectively). NOAC and VKA use was similar in Asia (27.7% and 27.5%, respectively). Antiplatelet therapy was most common in Asia (25.0%), followed by North America (14.0%). No antithrombotic therapy was common in Asia (19.8%).


The authors concluded that NOACs have been widely adopted for stroke prevention in newly diagnosed nonvalvular AF patients. They also concluded that undertreatment was common in both North America and Asia.


This global snapshot of antithrombotic therapy for newly diagnosed AF patients demonstrates important trends. Most importantly, undertreatment (no therapy or use of antiplatelet therapy only) has declined since 2011. However, undertreatment remains an important issue in North American and Asia, likely reflecting the difference in use of aspirin for intermediate stroke-risk patients between the American College of Cardiology/American Heart Association and European Society of Cardiology AF guidelines during that time. This study also highlights the important role of NOACs for stroke prevention, now being used in nearly 50% of new AF patients. However, a significant proportion of new AF patients are electing to use VKAs, a sure sign that warfarin will continue to have an important role for stroke prevention in AF for years to come.

Clinical Topics: Anticoagulation Management, Arrhythmias and Clinical EP, Prevention, Anticoagulation Management and Atrial Fibrillation, Implantable Devices, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias

Keywords: Anticoagulants, Arrhythmias, Cardiac, Aspirin, Atrial Fibrillation, Fibrinolytic Agents, Platelet Aggregation Inhibitors, Primary Prevention, Stroke, Vitamin K, Warfarin

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