Decision making for oral anticoagulants in atrial fibrillation: the ATA-AF study

Abstract

Background: Oral anticoagulants offer the best long-term protection against ischemic stroke in patients with atrial fibrillation (AF). However, vitamin K antagonists (VKA) are cumbersome to use and their prescription is far from guidelines recommendations. We report the results of a large survey on the attitudes of prescription of VKA in patients with AF.

Methods: 7148 patients were enrolled by 196 Internal Medicine (MED) and 164 Cardiology (CARD) centers, and VKA specifically analyzed. Thrombotic and hemorrhagic risks were evaluated by means of CHADS2 and CHA2DS2VASc scores, and a study-specific bleeding score (modified HAS-BLED).

Results: 63.9% of non-valvular patients had a CHADS2 score≥2 (MED: 75.3%-CARD: 53.1%), and 28.4% a bleeding score≥3 (41.9% MED-15.8% CARD). VKA were prescribed in 55.5% of non-valvular patients (46.3% MED and 64.2% CARD), in 81% of high-risk valvular patients and in 58.8% of the overall study population. Among patients at high risk of bleeding (score≥3), VKA were prescribed in 26.9% of subjects, while, in the subgroup at high risk of thrombosis (CHADS2 Score<2), these were prescribed in 54.4%. Age≥75, paroxysmal AF, cognitive impairment, need for assistance, CHADS2<2 and bleeding score≥3 were independent predictors of non-use of VKA.

Conclusions: Oral anticoagulants are more frequently used in CARD than in MED, plausibly due to greater complexity of MED patients. Stratification of thrombotic and hemorrhagic risk significantly drives the choice for VKA. However the fraction of patients in whom prescription or non-prescription is based on other individual characteristics is not negligible.