Do Patients with Atrial Fibrillation and a History of Ischemic Stroke Overuse Reduced Doses of NOACs?-Results of the Polish Atrial Fibrillation (POL-AF) Registry

Background: The aim of our study was to assess if patients with AF (atrial fibrillation) and a history of ischemic stroke (IS) excessively receive reduced doses of NOACs (non-vitamin K antagonist oral anticoagulants). Methods: The Polish AF (POL-AF) registry is a prospective, observational, multicenter study, including patients with AF from 10 cardiology hospital centers. In this study we focused on patients with IS in their past. Results: Among 3999 patients enrolled in the POL-AF registry, 479 (12%) had a previous history of IS. Compared to patients without IS history, post-stroke subjects had a higher CHA(2)DS(2)-VASc score (median score 7 vs. 4, p < 0.05). Of these subjects, 439 (92%) had anticoagulation therapy, 83 (18.9%) were treated with a vitamin K antagonist (VKA), 135 (30.8%) with rivaroxaban, 112 (25.5%) with dabigatran, and 109 (24.8%) with apixaban. There were a significant number of patients after IS with reduced doses of NOACs (48.9% for rivaroxaban, 45.5% for dabigatran, and 36.7% for apixaban). In many cases, patients were prescribed reduced doses of NOACs without any indication for reduction (28.8% of rivaroxaban use, 56.9% of dabigatran use, and 60.0% of apixaban use-out of reduced dosage groups, p = 0.06). Conclusions: A significant proportion of AF patients received reduced doses of NOAC after ischemic stroke in a sizeable number of cases, without indication for dose reduction.