Anticoagulation after catheter ablation of atrial fibrillation guided by implantable cardiac monitors

Abstract

Background: Discontinuation of oral anticoagulation (OAC) after catheter ablation of atrial fibrillation (AF) is not recommended in patients with elevated CHADS2 scores. However, a low incidence of thromboembolic events is reported when OAC is stopped in these patients. We introduce an algorithm for discontinuation of OAC after ablation based on the AF burden documented by implantable cardiac monitors (ICM).

Methods: Sixty-five patients with CHADS2 scores 1-3 free from AF 3 months after ablation (AF ablation [n = 49] or ablation of possible AF triggers [n = 16]) were included. One day after implantation of the ICM, OAC was stopped. Patients performed a daily interrogation of the ICM which was programmed to alarm the patient if daily AF burden exceeded 1 hour. Study end point was the first recurrence of a daily AF burden ≥1 hour or a thromboembolic event, which both triggered reinitiation of OAC.

Results: During a follow-up time of 32 ± 12 months (126 patient-years), 41 of the 65 patients (63%) had an AF burden <1 h/day and were able to stay off OAC. Twenty-one patients (32%) had to reinitiate OAC due to an AF burden ≥1 hour and three patients due to other reasons. No stroke, transitory ischemic attack, or other thromboembolic event was observed during follow-up.

Conclusions: Rhythm monitoring by ICM in patients who have stopped OAC after catheter ablation of AF or ablation of possible AF triggers seems to be a safe and promising method to monitor for AF recurrence. Within 1.3 years after ablation, about two-thirds of patients were able to stay off OAC.

Keywords: atrial fibrillation; catheter ablation; implantable cardiac monitors; oral anticoagulation; thromboembolism.