Differences in anticoagulant therapy prescription in patients with paroxysmal versus persistent atrial fibrillation

Background: Patients with paroxysmal and persistent atrial fibrillation experience a similar risk of thromboembolism. Therefore, consensus guidelines recommend anticoagulant therapy in those at risk for thromboembolism irrespective of atrial fibrillation classification. We sought to examine whether there are differences in rates of appropriate oral anticoagulant treatment among patients with paroxysmal vs persistent atrial fibrillation in real-world cardiology practices.

Methods: We studied 71,316 outpatients with atrial fibrillation and intermediate to high thromboembolic risk (CHADS2 score ≥2) enrolled in the American College of Cardiology PINNACLE Registry between 2008 and 2012. Using hierarchical modified Poisson regression models adjusted for patient characteristics, we examined whether anticoagulant treatment rates differed between patients with paroxysmal vs persistent atrial fibrillation.

Results: The majority of outpatients (78.4%, n = 55,905) had paroxysmal atrial fibrillation. In both unadjusted and multivariable adjusted analyses, patients with paroxysmal atrial fibrillation were less frequently prescribed oral anticoagulant therapy than those with persistent atrial fibrillation (50.3% vs 64.2%; adjusted risk ratio [RR] 0.74; 95% confidence interval [CI], 0.72-0.76). Instead, patients with paroxysmal atrial fibrillation were prescribed more frequently only antiplatelet therapy (35.1% vs 25.0%; adjusted RR 1.77; 95% CI, 1.69-1.86) or neither antiplatelet nor anticoagulant therapy (14.6% vs 10.8%; adjusted RR 1.35; 95% CI, 1.26-1.44; P < .0001 for differences across all 3 comparisons).

Conclusions: In a large, real-world cardiac outpatient population, patients with paroxysmal atrial fibrillation with a moderate to high risk of stroke were less likely to be prescribed appropriate oral anticoagulant therapy and more likely to be prescribed less effective or no therapy for thromboembolism prevention.