Oral anticoagulation during atrial fibrillation ablation: Facts and controversies

On the background of population ageing atrial fibrillation (AF) has reached epidemic dimensions in developed countries. This condition is associated with major cardiovascular morbidity and mortality mainly due to its thrombo-embolic and heart failure related complications. Left atrial (LA) catheter ablation has emerged as a suitable alternative to antiarrhythmic drugs for sinus rhythm maintenance at least for paroxysmal atrial fibrillation in the settings of no/mild LA dilatation. Chronic oral anticoagulation (OAC) is helpful to prevent AF thromboembolic complications in high-risk patients. OAC is also protective around ablation procedures in patients with or without an indication for long-term OAC therapy, emphasizing a slight increase in periprocedural risk of stroke. Due to the potential catastrophic hemorrhagic complications during trans-septal LA instrumentation, traditional approach on LA ablations involved warfarin discontinuation with periprocedural heparin bridging. Recent observational data suggests that radiofrequency (RF) catheter ablation of AF under therapeutic OAC (mainly vitamin K antagonists [VKA]) may reduce the periprocedural risk of complications, mainly thromboembolic events (possibly including silent strokes). Uninterrupted OAC has been acknowledged as an alternative to heparin bridging by the recently published consensus and guidelines update on AF ablation. Currently the recommended therapeutic level of OAC during ablation is low (such as an INR of 2-2.5). In the general AF settings new OAC (NOAC) have shown non-inferiority compared to VKA for stroke prevention, with better safety. Rapidly acting NOAC seems a tempting alternative to VKA at least for the patients taken off OAC before the ablation, possibly avoiding any post-procedural heparin bridging. However, limited experience with periprocedural use of NOAC (mainly dabigatran) suggests an increased risk of bleeding or thromboembolic complications compared with VKA.