Guideline-Adherent Antithrombotic Treatment Improves Outcomes in Patients With Atrial Fibrillation: Insights From the Community-Based Darlington Atrial Fibrillation Registry

Abstract

ObjectiveTo assess the influence of guideline-adherent vs nonadherent antithrombotic treatment (ATT) on stroke and mortality rates in an atrial fibrillation (AF) primary care population. Patients and MethodsWe used the Darlington Registry cohort, which included 105,000 patients from March 31, 2012, through March 31, 2013. Guideline adherence in ATT was assessed against 2014 National Institute for Health and Care Excellence guidelines, which recommend oral anticoagulation for stroke prevention as a default management unless a truly low risk of stroke (CHA2DS2-VASc=0 in men and 1 in women) is evident. ResultsOf 2259 patients with AF (2.15%), 36.1% were undertreated, 50.8% were guideline adherent, and 13.1% were overtreated. Oral anticoagulation was declined by 5.0% and contraindicated in 8.3%. Of 67 incident strokes (3.0%), 66 (98.5%) occurred in high-risk patients (CHA2DS2-VASc ≥2). For the high-risk cohort, 1-year stroke rates were 4.5% (95% CI, 3.2%-6.3%) for undertreatment, 1.9% (95% CI, 1.2%-2.9%) for guideline adherence, and 7.2% (95% CI, 4.4%-11.6%) for overtreatment; corresponding mortality rates were 16.1% (95% CI, 13.6%-19.0%), 8.0% (95% CI, 6.5%-9.8%), and 8.2% (95% CI, 5.2%-12.7%), respectively. On multivariable analysis, both undertreatment and overtreatment of high-risk patients were associated with significant increases in stroke rates (odds ratio [OR]=2.32; 95% CI, 1.30-3.14; P=.005 and OR=2.28; 95% CI, 1.12-4.63; P=.02, respectively). Undertreatment was also associated with a significant increase in all-cause mortality (OR=1.59; 95% CI, 1.14-2.21; P=.006). ConclusionOnly half of all eligible patients with AF are prescribed oral anticoagulation in accordance with guideline recommendations. Guideline-adherent ATT significantly reduces the risk of stroke and improves survival.