Surveillance of AF recurrence post-surgical AF ablation using implantable cardiac monitor

Although pulmonary vein isolation is an effective treatment for recurrent atrial fibrillation (AF), there is no consensus on the definition of success or follow-up strategies. Existing data are limited to intermittent Holter or transtelephonic monitoring with reliance on patient symptoms.

We sought to determine the outcomes of surgical ablation and post-ablation AF surveillance with a leadless implantable cardiac monitor (ICM).

Forty-five patients with drug-refractory paroxysmal or persistent AF underwent video-assisted epicardial ablation using a bipolar radiofrequency clamp. An ICM was implanted subcutaneously post-ablation to assess AF recurrence. AF recurrence was defined as ≥1 AF episode with a duration of ≥30 s. The device-stored data was downloaded weekly over the internet, and all transmitted events were reviewed.

A total of 1,220 AF automatic and patient-activated AF episodes were analyzed over a follow-up of 12 ± 3 months. Of these episodes, 46% were asymptomatic. Furthermore, only 66% of the patient-activated episodes were AF. AF recurrence was highest in first 4 weeks and substantially decreased 6 months post-ablation. The overall freedom from AF recurrence at the end of follow-up was 60%. When 48-h Holter recordings were compared with the device-stored episodes, the sensitivity of the device to detect AF was 98%, and the specificity was 71%.

The ICM provides an objective measure of AF ablation success and may be useful in making clinical decisions. This device may be used in future ablation studies to develop a more rigorous definition of procedural success.