Abstract 2893: Defining the “Blanking Period” after ablation of Atrial Fibrillation: Systematic Study Using a Continuous Autotrigger Recorder for 3 Months
Background: Early recurrence of atrial fibrillation (AF) following radiofrequency ablation (RFA) therapy remains a clinical and regulatory challenge, although thought not to predict ultimate RFA failure. Variable recurrence rates over a variable time interval have been reported. This period is often “blanked” from determining RFA success or failure and an accurate measure of this blanking period has not been studied. Knowledge of when this period ends would be invaluable for planning clinical management and regulatory assessment of new interventions and tools.
Methods: 60 consecutive patients (60 ±11yrs, 70% male) were studied immediately following RFA for paroxysmal and persistent AF. Subjects were fitted with an external event recorder (LifeWatch AF Express) for the continuous detection of AF recurrence at 2 week intervals for a total 3 mos. The device automatically recorded events and patients were also instructed to record when suggestive symptoms were experienced. AF recurrence was defined as at least 1 event ≥ 30 secs.
Results: The prevalence of AF recurrence was quite high early after RFA and gradually tapered to a nadir at 3 mos (Fig 1⇓). Similarly, the number of AF events in the total group peaked in the first 2 mos then gradually dropped reaching a low at 3 mos (Fig 2⇓). Of all the pts with ≥+1 AF event, all had ≥+1 symptomatic event. Out of a total of 1343 AF events, 101 (8%) were asymptomatic.
Conclusion: Recurrent AF prevalence and burden during the “blanking period” in the weeks following RFA peaks early reaching a nadir at 3 mos. All patients with AF recurrence experienced ≥ 1 symptomatic event. These data suggest a blanking period of 3 mos be employed in clinical practice and trials.