Dabigatran Versus Warfarin for Direct Current Cardioversion in Atrial Fibrillation

Direct current cardioversion (DCCV) is considered as the most effective treatment for atrial fibrillation (AF). AF is associated with an increased risk of thromboembolism, and DCCV may increase this risk. The current recommendation is, therefore, to anticoagulate for at least 3 weeks before DCCV and 4 weeks after the procedure.

A retrospective study of patients referred for elective DCCV as treatment for AF in Hampshire Hospitals NHS Foundation Trust was performed to compare the safety and efficacy of dabigatran with warfarin in this setting.

During a 12-month period, 129 patients were referred for DCCV for the treatment of AF and 107 patients received DCCV. Fifty-four patients were anticoagulated with dabigatran, 42 patients with warfarin, and 11 patients with other direct oral anticoagulants (DOACs) with choice of agent determined following an informed discussion with the patient. The average number of days between the date of referral for DCCV and the date of DCCV for patients who were on dabigatran was 51 days, while for warfarin, this was 82 (P = 0.001). The proportion of cancelation and rescheduling for warfarin patients was 21.4%, while for dabigatran, this was 5.5%. Patients were reviewed 6-20 weeks after DCCV; the success rate of DCCV for dabigatran patients was 61%, whilst for warfarin patients, this was 52%. The success rate went up to 69% for patients who received DCCV within 45 days of referral (P = 0.165).

This retrospective study supports clinical experience that DCCV is more likely to be successful when there is a shorter duration between the onset of AF and the date of DCCV, and shows that the use of dabigatran in comparison with warfarin facilitates earlier DCCV.