Cryoballoon Ablation Strategy in Persistent Atrial Fibrillation

Background: Cryoballoon ablation is established for pulmonary vein isolation (PVI) in paroxysmal atrial fibrillation (AF). The objective was to evaluate CBA strategy in consecutive patients with persistent AF in the initial AF ablation procedure.Material and Methods: Prospectively, patients with symptomatic persistent AF scheduled for AF ablation all underwent cryoballoon PVI. Technical enhancements, laboratory management, safety, single-procedure outcome, predictors of recurrence, and durability of PVI were evaluated.Results: From 2007 to 2020, a total of 1,140 patients with persistent AF, median age 68 years, underwent cryoballoon ablation (CBA). Median left atrial (LA) diameter was 45 mm (interquantile range, IQR, 8), and Congestive heart failure, Hypertension, Age ≥75 years (doubled), Diabetes mellitus, prior Stroke or TIA or thromboembolism (doubled), Vascular disease, Age 65 to 74 years, Sex category (CHA2DS2-VASc) score was 3. Acute isolation was achieved in 99.6% of the pulmonary veins by CBA. Median LA time and median dose area product decreased significantly over time (p < 0.001). Major complications occurred in 17 (1.5%) patients including 2 (0.2%) stroke/transitory ischemic attack (TIA), 1 (0.1%) tamponade, relevant groin complications, 1 (0.1%) significant ASD, and 4 (0.4%) persistent phrenic nerve palsy (PNP). Transient PNP occurred in 66 (5.5%) patients. No atrio-esophageal fistula was documented. Five deaths (0.4%), unrelated to the procedure, occurred very late during follow-up. After initial CBA, arrhythmia recurrences occurred in 46.6% of the patients. Freedom from atrial arrhythmias at 1-, and 2-year was 81.8 and 61.7%, respectively. Independent predictors of recurrence were LA diameter, female sex, and use of the first cryoballoon generation. Repeat ablations due to recurrences were performed in 268 (23.5%) of the 1,140 patients. No pulmonary vein (PV) reconduction was found in 49.6% of the patients and 73.5% of PVs. This rate increased to 66.4% of the patients and 88% of PVs if an advanced cryoballoon was used in the first AF ablation procedure.Conclusion: Cryoballoon ablation for symptomatic persistent AF is a reasonable strategy in the initial AF ablation procedure.

Outcomes of radiofrequency catheter ablation for persistent and long-standing persistent atrial fibrillation

Introduction Catheter ablation has become the first-line treatment for symptomatic patients with atrial fibrillation (AF). Several approaches of substrate ablation have been used for persistent and long-standing persistent AF and the best protocol procedure is yet to be established. The purpose of this study was to evaluate the outcomes of patients submitted to catheter ablation of persistent and long-standing persistent AF adding extra-pulmonary substrate approaches to pulmonary vein isolation. Methods We retrospectively studied 67 consecutive patients referred for the first procedure of catheter ablation of persistent or long-standing persistent AF from May 2016 to October 2018. The first 27 patients were subjected to pulmonary vein isolation and complex fractionated atrial electrograms (CFAE) ablation (group 1) and the last 40 patients were subjected to a tailored approach guided by voltage map areas and CFAE (group 2). Patient characteristics, procedure details and follow-up were assessed, and predictors of recurrence were determined. Results Mean age was 59±11 years with 58% being male. During a mean follow-up of 16±6 months 27% of the patients showed AF recurrence. There were no differences in baseline characteristics of group 1 and 2. A higher recurrence rate was found in group 1 by comparison with group 2 (40.7% vs 17.5%, Log Rank X2 = 5.076, P=0.024) (Figure 1). Also, recurrence was associated with a longer AF duration, an increased baseline Brain Natriuretic Peptide (BNP), an increased left atrium (LA) volume, the presence of hyperthyroidism, the absence of sinus rhythm after procedure, the inducibility of AF post-ablation and the absence of an antiarrhythmic drug at hospital discharge. After adjustment for other confounders, the patient group (HR 5.16 [1.23–21.71] P=0.025), a long-standing AF (HR 9.09 [1.41–58.82] P=0.020), the BNP value at admission (HR 1.03 [1.01–1.05] P=0.033) and the LA volume index (HR 1.13 [1.02–1.25] P=0.017) were the only independent predictors of recurrence. Conclusion Ablation of persistent and long-standing persistent AF is feasible with good results when a substrate approach is added to pulmonary vein isolation. A tailored approach seems to be more efficient, showing best outcomes in mid-term follow-up. A long-standing AF, higher BNP value and the LA enlargement are important predictors of recurrence and should be used to better select patients and to manage follow-up. FUNDunding Acknowledgement Type of funding sources: None.