Background: Oral anticoagulant (OAC) therapy is prescribed in approximately 40% of patients with atrial fibrillation (AF) and low thromboembolic risk (CHA2DS2-VASc score 0 [male] or 1 [female]). Guidelines recommend against OAC therapy in such patients because the annual thromboembolic risk (<1%) is outweighed by bleeding.
Purpose: To identify patient characteristics and reasons for clinicians to prescribe OAC therapy in AF despite a low thromboembolic risk.
Methods: Patient characteristics associated with OAC prescription were assessed in the subgroup with a low CHA2DS2-VASc score from the GARFIELD-AF registry. All-cause mortality, ischemic stroke or systemic embolism, and major bleeding were compared according to OAC status. Next, a diverse group of clinicians involved in AF care were questioned through a web-based survey. Items included factors, not included in the CHA2DS2-VASc score, that may influence prescription of OAC therapy in AF.
Results: In the GARFIELD-AF registry (n=52,014), 2,123 patients had a low CHA2DS2-VASc score. OAC therapy was prescribed in 950 (45%). Permanent [OR (95%) = 2.32 (1.52–3.56)] or persistent AF [OR (95%) = 3.08 (2.17–4.38)] and increasing age <65 years [OR (95%) = 1.34 (1.20–1.50)] demonstrated a significant increase in odds for OAC use, while concomitant antiplatelet therapy [OR (95%) = 0.083 (0.065–0.105)] and female gender [OR (95%) = 0.714 (0.561–0.907)] showed a significant decrease in odds. Crude event rates were low for those with as well as without OAC therapy: all-cause mortality (14 versus 20), ischemic stroke or systemic embolism (6 versus 5), and major bleeding (4 versus 3). When clinicians (n=229) were questioned about decision-making regarding OAC therapy for AF patients with low thromboembolic risk, an enlarged left atrium or spontaneous echo contrast was the most frequently cited reason (reach: 59.8%). Adding cardioversion or ablation procedures, rheumatic heart disease, and subjective fear of stroke by the patient increased the reach to 83.8% (Table 1).
Conclusions: There is a discrepancy between patient characteristics predicting OAC use in AF patients with a low CHA2DS2-VASc score and factors reported by clinicians influencing their decision-making.