Rhythm Control and Its Relation to Symptoms during the First Two Years after Radiofrequency Ablation for Atrial Fibrillation.

Clinical Trial Registration: URL: http://clinicaltrials.gov. Unique Identifier: NCT00697359.

Objectives: To evaluate rhythm control up to two years after atrial fibrillation (AF) ablation and its relation to reported symptoms.

Background: The implantable loop recorder (ILR) continuously records the electrocardiogram (ECG), has an automatic AF detection algorithm, and has a possibility for patients to activate an ECG recording during symptoms.

Methods: Fifty-seven patients (mean age 57 ± 9 years, 60% male, 88% paroxysmal AF) underwent AF ablation following ILR implantation. Device data were downloaded at the ablation and three, six, 12, 18, and 24 months after ablation.

Results: Fifty-four patients completed the two-year follow-up. Thirteen (24%) patients had no AF episodes detected by ILR during follow-up. Ten of 41 patients (24%) with AF recurrence were only detected by ILR and AF recurrences were detected earlier by ILR (P < 0.001). The median AF burden in patients with AF recurrence was 5.7% (interquartile range 0.4-14.4) and was even lower in patients with AF only detected by ILR (P = 0.001). Forty-eight % of the patients indicated symptoms via the patient activator but 33% of those recordings were not due to AF. Early AF recurrence (within 3 months) was highly associated with later AF recurrence (P < 0.001). AF burden >0.5% and longest AF episode >6 hours before the ablation were independent predictors of AF recurrence during intermittent but not continuous monitoring.

Conclusions: After AF ablation, the AF burden was low throughout the 24 months follow-up. Nevertheless, symptoms were commonly indicated but one-third of patient-activated recordings did not show AF. Continuous monitoring was superior to intermittent follow-up in detecting AF episodes and assessing the AF burden.