Persistent atrial fibrillation: what lies beyond pulmonary vein isolation?

Introduction Catheter ablation is the treatment of choice in symptomatic patients with atrial fibrillation (AF) who do not respond to antiarrhythmic drug therapy, with pulmonary vein isolation (PVI) serving as the cornerstone of AF ablation. Despite advances in ablation techniques, freedom from atrial arrhythmias remains limited, particularly in patients with persistent or long-standing persistent AF. Methods and purpose Prospective single-center, observational study of consecutive patients referred for catheter ablation for persistent AF ablation between August 2022 and August 2024. Patients were submitted to a tailored ablation guided by the presence of low-voltage areas (LVA). Procedural endpoints and 1-year outcomes were assessed and compared to those of a propensity score-matched (1:1 ratio) cohort of patients submitted to only PVI during the same period. All REDO procedures were excluded. The primary endpoint was defined as freedom from any atrial arrhythmia of at least 30 seconds duration, regardless of symptoms, after the 3-month blanking period. Results A total of 118 patients (71% male, mean age of 62±10years) fulfilled our inclusion criteria and were included in our study, corresponding 59 to the tailored approach group and 59 propensity score-matched patients in the control group. Mean LA volume index was 45.5±13 and mean left ventricular ejection fraction was 48.1±14.51%. In the tailored group, sixty percent of patients underwent vein of Marshall (VoM) ethanol infusion, which was followed by creation of a posterior mitral line; A roof line was created in 8% of patients, a posterior box in 73%, and an anterior mitral line in 27%. At 1-year follow-up, 26 patients had recurrences of sustained atrial arrhythmia: AF in 21 patients, atrial flutter in 3 patients and atrial tachycardia in the remaining 2 patients. Overall, single-procedure freedom from atrial arrhythmia after the 3-month blanking period was 78%. The risk of recurrence was significantly lower in the tailored approach group compared with the control group (13.5% vs. 30.5%, p=0.019). The use of VoM ethanol infusion and a tailored approach were associated with freedom from atrial recurrence during follow-up with a HR= 0.271(95% CI 0.081-0.904), p=0.013 and HR=0.382(0.165-0.886), p=0.020, respectively. Conclusion A tailored approach guided by the presence of LVA was associated with a higher arrhythmia-free survival at 1-year of follow-up compared with performing PVI alone and VoM ethanol infusion was associated with a reduced risk of AF recurrence.