Background: Guidelines recommend oral anticoagulant (OAC) therapy to prevent stroke and systemic embolism for atrial fibrillation (AF) patients at high thromboembolic risk (CHA2DS2-VASc score ≥2). Approximately 30–40% of eligible patients do not receive OAC therapy. The reasons for guideline non-adherence are unclear.
Purpose: To identify patient characteristics associated with non-use of OAC for AF.
Methods: The Global Anticoagulant Registry in the FIELD (GARFIELD-AF) registry is a prospective multicentre study of patients with newly diagnosed AF and ≥1 additional risk factors for stroke. We analysed GARFIELD-AF data for patient characteristics associated with non-use of OAC for patients with CHA2DS2-VASc score ≥2 using logistic regression. The rates per 100 person-years (%/y) of all-cause mortality, cardiovascular mortality, stroke or systemic embolism (SSE) and major bleeding were also compared between patients receiving and those not receiving OAC. P-values less than 0.05 were considered statistically significant. To explore patient characteristics that influence decision-making, we distributed a web-based survey to physicians treating AF in Belgium, Canada, France, and Portugal.
Results: In GARFIELD-AF 42,471 (82.9%) had a CHA2DS2-VASc score ≥2 and 12,884 (30.3%) of them did not receive OAC therapy. Use of antiplatelet therapy (OR 15.0, 95% CI 14.1–15.8) and a history of bleeding (OR 2.52, 95% CI 2.18–2.92) were the strongest predictors of withholding OAC. Patients without OAC had an increased incidence of all-cause mortality (5.3 vs. 3.9%/y, p<0.001) and cardiovascular mortality (1.8 vs. 1.4%/y, p<0.001) and SSE (1.6 vs. 1.1%/y, p<0.001). Table 1 shows the most frequently reported characteristics leading to a preference to withhold OAC among 266 survey respondents.
Conclusions: Antiplatelet therapy and history of bleeding were the strongest predictors of OAC non-use in AF patients with CHA2DS2-VASc score ≥2 in the GARFIELD-AF registry. Major/critical site bleeding and cirrhosis may also influence non-use of OAC by some physicians. Guideline-based treatment with OAC was associated with better outcomes. Understanding decision-making may improve OAC prescription rates and outcomes in AF.