Vitamin K antagonist control in patients with atrial fibrillation in Asia compared with other regions of the world: Real-world data from the GARFIELD-AF registry

OBJECTIVE: To compare the distribution of international normalized ratios (INRs) in patients receiving vitamin K antagonist (VKA) for newly diagnosed atrial fibrillation in Eastern and Southeastern Asia and in other regions of the world (ORW) represented in the ongoing, global observational study GARFIELD-AF. METHODS AND RESULTS: 3621 and 13,541 patients were recruited prospectively in 2010-2013 from Asia and ORW, respectively. At baseline, excluding patients with unknown antithrombotic treatment, 1356 (37.8%) in Asia and 7081 (53.3%) in ORW received VKA (±antiplatelets). INR readings during 1-year follow-up were analyzed for VKA-treated patients with ≥3 measurements (878 [64.7%] patients in Asia, 4452 [62.9%] in ORW). VKA-treated patients in Asia were younger than those in ORW (mean 67.1 vs 71.3years), with a lower CHA₂DS₂-VASc score (3.0 vs 3.5), but a similar HAS-BLED score (1.3 vs 1.4). Mean INR was lower in Asia than in ORW (2.0 vs 2.4). The proportion of time in the therapeutic range, defined using the multinational target of 2.0-3.0, was substantially lower in Asia (31.1% vs 54.1%). In Asia and ORW, 59.3% and 28.2% of INRs were <2, and 9.6% and 17.7% were >3, respectively. The same trend was found in different age groups (<65, 65-74, ≥75years). CONCLUSION: GARFIELD-AF data demonstrate a difference in the distribution of INRs in patients from Asia versus other regions under current real-world practice. Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362.