Does cryoballoon ablation affect the symptom severity of atrial fibrillation? Insights from 12-months continuous cardiac monitoring

BACKGROUND: Most data on asymptomatic atrial fibrillation (AF) recurrence following catheter ablation primarily derive from studies on radiofrequency ablation (RFA). Our previous study with a small sample size revealed no significant difference in AF freedom rates detected via patient history, ECG, Holter monitoring, and continuous cardiac monitoring in the cryoballoon ablation (CBA) group. This study aims to evaluate alterations in AF symptoms following pulmonary vein (PV) CBA using implantable loop recorders (ILR) and patient-reported data. METHODS: A total of 145 patients with highly symptomatic AF (EHRA score ≥ 2b) were consecutively enrolled and underwent primary PV CBA with simultaneous ILR implantation. Follow-up visits occurred at 3-, 6-, and 12-months post-ablation. Data were collected from patients' symptom logs, ILR readings, and clinical events at each visit. Clinical efficacy was defined as the absence of AF recurrence based on patients' symptom logs, while absolute efficacy was defined as the absence of AF detected by ILR. ILR detection served as the reference standard, and detection via patient symptom log was considered the test method. RESULTS: The absolute efficacy was 57,2% (n = 83). All cases of AF relapse were also reported by patients in their symptom logs. Agreement between patient-reported data and ILR data was substantial, with a κ statistic value of 0.98. The agreement between patient-reported data and ILR data showed a κ statistic value of 0.98. CONCLUSIONS: CBA using second-generation cryoballoon does not significantly alter AF symptom perception in highly symptomatic patients. Cardiac rhythm in these patients might be effectively monitored through symptom logs, ECGs, or Holter monitoring. TRIAL REGISTRATION: ClinicalTrials.gov NCT03587181, SubstrateAF study, first posted date July 16, 2018.