Analysis of pre-ablation oral anticoagulation in patients with non-valvular atrial fibrillation in real clinical practice

Objective: To investigate the incidence of left atrial appendage (LAA) thrombosis and to assess the oral anticoagulation (OAC) in patients with non-valvular atrial fibrillation (AF) before catheter ablation.Material and Methods. We studied 638 patients with AF who underwent transesophageal echocardiography before AF ablation from 2014 to 2017. The analysis included the baseline characteristics of patients.Results. There was no statistical difference in the risk of thromboembolic complications (TEC) in patients with and without OAC. All patients were divided into four groups: 167 patients (26.2%) received warfarin (group 1); 128 patients (20.1%) received dabigatran (group 2); 145 patients (22.7%) received rivaroxaban or apixaban (group 3); and 198 patients (31%) were not administered with OAC (group 4). Among patients without OAC, only 26 individuals (13.1%) had a low TEC risk, whereas 172 patients had a moderate or high TEC risk. Half of group 4 received antiplatelet drugs, but a third of them had a high TEC risk and were recommended to take OAC. Patients in the pre-ablation period received different types of OAC with the same frequency. LAA thrombosis was detected in 44 patients (6.9%). Significant differences in the incidence of LAA thrombosis in patients receiving different OAC were not detected. LAA thrombosis was detected in one patient receiving dabigatran with a low risk of TEC. There was also a trend for more frequent therapeutic levels of INR in patients taking warfarin with LAA thrombosis and there were no patients with INR > 3.0. About half of patients without thrombosis were treated with subtherapeutic warfarin therapy, and only a third of them had the therapeutic range of INR.Conclusion. Not all patients with non-valvular AF take OAC at the pre-ablation period. All types of OAC are prescribed with the same frequency. Differences in the incidence of LAA thrombosis, depending on the received OAC, were not detected. There was no association between the detection of thrombosis and the therapeutic range of INR in group 1. There were no significant differences in the incidence rates of LAA thrombosis between warfarin, dabigatran, rivaroxaban, or apixaban.