Differing attitudes in anticoagulation therapy in atrial fibrillation patients with and without coronary artery disease: results from the registry of atrial fibrillation to investigate new guidelines

Purpose: Patients with atrial fibrillation (AF) and concomitant coronary artery disease (CAD) represent a challenging therapeutic problem since combinations of antithrombotic medications may be needed. In this report, we examined the characteristics and the antithrombotic therapy of patients with AF with or without CAD. Methods: The Registry of Atrial Fibrillation To Investigate New Guidelines (RAFTING) is a countrywide prospective observational study of the Hellenic Society of Cardiology. We enrolled 1127 consecutive patients with a diagnosis of AF during their admission for any reason in the Emergency Departments of 31 hospitals trying to capture a representative picture of the characteristics and treatment of AF patients in Greece. After excluding patients with newly diagnosed AF, we identified 195 patients with AF and CAD (group A) and 533 patients with AF without CAD (group B). Results: Patients of group A vs group B were older (74±8 vs 70±12 years; p<0.001), with higher calculated CHADS2 score (2.5±1.2 vs 1.9±1.3; p<0.001) and had less often paroxysmal AF (34% vs 50%; p<0.001). Overall, the antithrombotic strategy in group A was antiplatelet-only therapy in 42%, vitamin-K antagonist (VKA)-only therapy in 41% and combination of antiplatelet plus VKA in 17% of patients, while in group B the respective rates were 27%, 53% and 1% (p<0.001). Of those patients with antiplatelet-only strategy, 18% in group A and 3% in group B received dual antiplatelet therapy (p<0.001). In patients with a history of previous stenting, combination therapy with antiplatelet plus VKA was used in 23%. Patients with a CHADS2 score ≥2 were treated without VKA in 41% of group A and 35% of group B (p<0.01). In group B, 31% of patients with a CHADS2 score=0 were treated with VKA. At 6 months follow-up, 11 major bleeding episodes were reported (only 1 with combination therapy). Conclusion: In this representative countrywide registry of AF we found that combination of antithrombotics is kept at low rates especially in patients without CAD resulting in low bleeding at follow-up. However, it seems that patients without CAD at low embolic risk as assessed by CHADS2 score are rather overtreated with VKA while at the same time patients with CAD at high embolic risk are undertreated. At national level, more efforts to base anticoagulation therapeutic decisions by estimating embolic risk objectively with the use of appropriate scoring systems are needed.