Evaluating cardioversion outcomes for atrial fibrillation on novel oral anticoagulants versus warfarin: experience at a tertiary referral centre.

Abstract

Current guidelines recommend anticoagulation prior to cardioversion in patients with atrial fibrillation of >48h or unknown duration to reduce thromboembolic risk. Therapeutic anticoagulation with warfarin, with INR between 2 and 3, is consistently achieved in approximately 60% of patients. We evaluated outcomes and assessed differences in direct current cardioversion (DCCV) in patients treated with warfarin and novel oral anticoagulants (NOAC) at our institution. A retrospective analysis of consecutive DCCV at a tertiary referral over 18months was conducted. Analysis of cardioversion records allowed completion of a standardised dataset. Clinical variables recorded included (1) CHADSVASC score, (2) anticoagulant use, and (3) bleeding complications. During this period 187 DCCVs were scheduled; 119 on warfarin and 68 on NOAC. DCCV was deferred in 26% (n=31) of the warfarin group and 4.4% (n=3) of the NOAC group (p=0.0002). The average time interval between referral and DCCV was 144.43 and 109.32days for the warfarin and NOAC groups, respectively (p value=0.023). 7.56% (n=9) of the warfarin population had a bleeding event compared to a 2.94% total bleeding rate in NOAC group (p=0.213). Deferral of elective DCCV and additional anticoagulant monitoring was estimated at €1160 per procedure. In elective cardioversions, the group anticoagulated with NOAC was less likely to have subtherapeutic anticoagulation and hence deferred procedures and had reduced health care consumption when compared to the group anticoagulated with warfarin.