International trends in clinical characteristics and oral anticoagulation treatment for patients with atrial fibrillation: Results from the GARFIELD-AF, ORBIT-AF I, and ORBIT-AF II registries

Atrial fibrillation (AF) is the most common cardiac arrhythmia in the world. We aimed to provide comprehensive data on international patterns of AF stroke prevention treatment. METHODS: Demographics, comorbidities, and stroke risk of the patients in the GARFIELD-AF (n=51,270), ORBIT-AF I (n=10,132), and ORBIT-AF II (n=11,602) registries were compared (overall N=73,004 from 35 countries). Stroke prevention therapies were assessed among patients with new-onset AF (≤6 weeks). RESULTS: Patients from GARFIELD-AF were less likely to be white (63% vs 89% for ORBIT-AF I and 86% for ORBIT-AF II) or have coronary artery disease (19% vs 36% and 27%), but had similar stroke risk (85% CHA₂DS₂-VASc ≥2 vs 91% and 85%) and lower bleeding risk (11% with HAS-BLED ≥3 vs 24% and 15%). Oral anticoagulant use was 46% and 57% for patients with a CHA₂DS₂-VASc=0 and 69% and 87% for CHA₂DS₂-VASc ≥2 in GARFIELD-AF and ORBIT-AF II, respectively, but with substantial geographic heterogeneity in use of oral anticoagulant (range: 31%-93% [GARFIELD-AF] and 66%-100% [ORBIT-AF II]). Among patients with new-onset AF, non-vitamin K antagonist oral anticoagulant use increased over time to 43% in 2016 for GARFIELD-AF and 71% for ORBIT-AF II, whereas use of antiplatelet monotherapy decreased from 36% to 17% (GARFIELD-AF) and 18% to 8% (ORBIT-AF I and II). CONCLUSIONS: Among new-onset AF patients, non-vitamin K antagonist oral anticoagulant use has increased and antiplatelet monotherapy has decreased. However, anticoagulation is used frequently in low-risk patients and inconsistently in those at high risk of stroke. Significant geographic variability in anticoagulation persists and represents an opportunity for improvement.