Prevalence of Atrial Fibrillation and use of Oral Antithrombotic Therapy in Patients with Acute Coronary Syndrome

Purpose:To assess the prevalence of atrial fibrillation (AF) and use of antithrombotic agents in adult patients with acute coronary syndrome (ACS).Materials and Methods.We consecutively enrolled all ACS patients (n=1155) who were hospitalized in two Moscowbased percutaneous coronary intervention centers (each center performs over 500 PCIs a year) between October 2017 and February 2018. AF was diagnosed in 204 patients (17.7%). The risk of thromboembolic complications was assessed using the CHA2DS2-VASc Score. The risk of hemorrhagic complications was assessed using the HAS-BLED Score. The data were processed using StatSoft Statistica 10.0 and IBM SPSS Statistics v.23 software.Results. The prevalence of diagnosed AF was 13.6%, while the prevalence of undiagnosed AF was 4.1%. Of the 179 discharged patients with AF, only 2 had a low risk of ischemic stroke (IS). One hundred and fifty patients (83.8%) eligible for oral anticoagulant therapy received oral anticoagulants. Patients with diagnosed AF were administered oral anticoagulants (OACs) significantly more often than patients with undiagnosed AF [125 (91.9%) vs. 25 (58.1%), р<0.001]. Novel oral anticoagulants (NOACs) were administered four times more often than vitamin K antagonists [120 (80.0%) vs. 29 (19.3%), р<0.001]. Rivaroxaban was used in 51.3% of cases. Of the 29 patients treated with warfarin, only 3 (10.3%) achieved the target international normalized ratio (INR) at discharge. Of the 107 patients who underwent percutaneous coronary intervention (PCI), 77 patients (80%) received an OAC and two antiplatelet agents (with 74% receiving this three-agent therapy for one month), 11 patients (10.3%) received an OAC and an antiplatelet agent, and 18 patients (16.8%) received two antiplatelet agents. The only antiplatelet agent used as part of the three-agent therapy was clopidogrel. The three-agent therapy without PCI was administered in 43.1% of cases.Conclusion.We found that the prevalence of AF in patients with ACS was high. The fact that doctors administered NOACs suggests that they are aware of the need to use these agents to prevent thromboembolic complications in AF patients.