Abstract
Carolina Schwab
Abstract
Atrial Fibrillation (AF) is a modern epidemic, affecting up to 9% of the population. Ablation is a well-established approach to treatment of AF. The success rates are incongruent, ranging from 60 to almost 90%. Some of the causes for that are: diverse definitions of recurrence after ablation difficulty to really document asymptomatic recurrences The established period of 30 seconds has questionable clinical significance. A recent review showed that AF episodes shorter than 6 minutes had no prognostic effect, i.e., showed no higher risk of embolic events compared to no recurrence. Thirty seconds is an arbitrarily given amount of time, not derived from research. How much AF is really significant AF is a hot topic and needs to be further addressed. In this study the groups without recurrence and with recurrence but AF Burden < 2% were compared. Methods: Between April 2016 and December 2017 a total of 141 consecutive patients with symptomatic paroxysmal AF (50% , PVI only) or persistent AF (50%, PVI ± substrate modification) were included in the study. We considered 2 groups of patients according to the AF/AT Burden during follow-up: no recurrence (AF/AT Burden = 0%, n=75) and AF Burden <2% (n=36). We analyzed AF-Burdens of 0.1, 1, 2, 4, 7 and 10%. The cutoff of 2% encompassed the largest population but still showed no statistical significance compared to no recurrence. An implantable loop recorder (ILR, Linq, Medtronic) with remote monitoring was implanted one day after the procedure. Monitoring of the episodes online was made daily in workdays. The AF/AT Burden, duration of episodes and symptoms were registered systematically at 3, 6, 9 and 12 months. Otherwise the patient was contacted in case of symptoms or documented episode. A blanking period of 3 months was considered. Each AF/ AT Episode > 30 sec. was considered as a classical recurrence. Results: There were 111 (111/141, 79%) patients with no recurrence or recurrence with AF Burden < 2%, after 12 months follow up. The groups were divided in AF Burden less than 2% (36/111, 32%) or no AF/AT recurrence (75/111, 68%). The baseline characteristics were comparable between the two groups. As assessed by continuous cardiac rhythm monitoring, AF ablation showed a 12-month arrhythmia free rate of 60% in persistent AF and 58% in paroxysmal AF, with a symptom free rate of 83% and 84%, respectively. Because of no significant symptomatic recurrence occurred in patients with AF Burden < 2%, no reablation or cardioversion was indicated in this patient population. Patients with Burden > 2% (n=30) had a 81% symptom rate, 31% cardioversion rate and 34% reablation rate. Patients without recurrence or recurrence <2% (n=111) had a 8% symptom rate and 0% cardioversion or reablation indication. Conclusion: Patients with an AF Burden < 2% are comparable with patients without recurrence in its baseline characteristics, need of cardioversion after the ablation, symptoms and indication for re-ablation. Patients with no recurrence and AF Burden < 2% have better prognostic indicators when compared to recurrence with AF Burden > 2%. Since the aim of AF ablation is the improvement of symptoms and quality of life, it might be reasonable to consider new endpoints for AF ablation with AF Burden < 2% in future.