Long-term progression from paroxysmal to permanent atrial fibrillation following transcatheter ablation in a large single-center experience.

BACKGROUND: The natural history of atrial fibrillation (AF) is characterized by gradual increase in duration and frequency of relapses until a definitive shift to permanent AF. Heart disease and comorbidities modulate AF progression. However, to date the influence of catheter ablation on AF evolution has rarely been investigated. OBJECTIVE: The purpose of this study was to identify long-term predictors of AF progression in a large cohort of patients undergoing AF transcatheter ablation (AFTCA). METHODS: A total of 889 patients (mean age 57 ± 11 years; 53.3% paroxysmal AF, 40.5% persistent AF, 6.2% long-standing AF) underwent AFTCA. All patients underwent pulmonary vein isolation, with linear lesions and complex fractionated atrial electrogram ablation reserved for patients with persistent/long-standing AF and/or confirmed structural heart disease. RESULTS: After median follow-up of 64 months (range 41-84 years), AF progression despite AFTCA occurred in 57 cases (6.4%). However, AF progression was much more pronounced in patients with persistent (10%) or long-standing persistent AF (14.6%) than in those with paroxysmal AF (2.7%, P <.001). Furthermore, AF progression was more frequently reported in patients who presented with underlying comorbidities/cardiomyopathies (9.1%) than in those who presented with lone AF (29.9%, P <.001). At multivariate analysis, comorbidities/cardiomyopathies and baseline persistent/long-standing AF proved to be independent predictors of progression (odds ratio 11.3, 95% confidence interval 2.6-48.0, P <.001, and odds ratio 1.6, 95% confidence interval 1.2-2.1, P <.001, respectively). CONCLUSION: The presence of comorbidities/cardiomyopathies and persistent/long-standing AF seem to predict AF progression in patients undergoing AFTCA. Performing AFTCA in the paroxysmal phase of the arrhythmia may reduce progression of AF to its permanent form.

Iatrogenic atrial septal defects following atrial fibrillation transcatheter ablation: a relevant entity?

AIMS: The previous literature has suggested that the iatrogenic atrial septal defects (IASDs) may follow left atrial (LA) access by transseptal (TS) puncture, especially in the case of a single TS for more than one catheter. The aim of the present study is to describe the prevalence of patent foramen ovale (PFO) and IASDs in a cohort of atrial fibrillation (AF) patients undergoing redo catheter ablation (CA) procedures in a high-volume centre accessing LA by a standardized single TS puncture. METHODS AND RESULTS: Patients (n = 197) who underwent at least one redo AFCA, between 2004 and 2012, were retrospectively enroled. Transoesophageal echocardiography was performed before each procedure during which LA was accessed via a PFO, if present, or by single TS for both the mapping and ablation catheters. At baseline, PFO was detected in 43 (21.8%) patients. Clinical and echocardiographic parameters recorded did not differ within patients presenting with or without PFO. Left atrium was accessed via PFO in 39 (90.7% of those with PFO) patients during the first procedure. New-onset IASD occurred in 11 (5.6%) patients following the first procedure and in 1 (2.2%) patient following the second procedure. The clinical and echocardiographic parameters did not differ within the patients irrespective of whether IASD was reported or not. No TS-related complications occurred. CONCLUSION: In the present cohort, LA access by PFO or single TS for both the mapping and ablation catheters lead to a small risk of asymptomatic IASD, not increased by redo procedures, confirming that it represents a safe approach. No clinical and/or echocardiographic parameters seemed to predict IASD occurrence.

Incidence of cerebral thromboembolic events during long-term follow-up in patients treated with transcatheter ablation for atrial fibrillation.

AIMS: Net clinical benefit of long-term oral anticoagulation therapy (OAT) continuation after successful atrial fibrillation (AF) ablation is still controversial. To evaluate long-term thromboembolic (TE) and haemorrhagic events incidence according to OAT strategy used after AF transcatheter ablation. METHODS AND RESULTS: Three months after AF ablation, OAT was discontinued in patients with CHADS2 ≤ 1 if no recurrences were documented, while OAT was maintained in patients with CHADS2 ≥ 2 regardless of AF recurrences. CHA2DS2VASc and HAS-BLED scores have been retrospectively evaluated. Seven hundred and sixty-six patients were followed for a median of 60.5 months. Six (6/267 = 2.2%) and five (5/499 = 1%) TE events occurred in the ON and the OFF-OAT patients, respectively (P = 0.145), all in concomitance with the AF recurrence. CHADS2 and CHA2DS2VASc ≥ 2 were associated with high TE incidence (P = 0.047 and P = 0.020). Among patients with a CHADS2 score of 0 or 1, a CHA2DS2VASc score ≥ 2 was predictive of TE events (P = 0.014). Overall, the incidence of the TE events in patients with CHA2DS2VASc ≥ 2 was 0.6 per 100 patient-years whereas seven haemorrhagic events occurred, all of them in the ON-OAT patients (7/267 = 2.6%). CONCLUSION: Patients with AF undergoing transcatheter ablation have a lower incidence of TE events as compared with the general AF population, regardless of OAT maintenance. The unpredictable risk of AF recurrence, mandate the routine use of the CHADS2, CHA2DS2VASc, and HAS-BLED scores to guide clinical decision regarding OAT management in this peculiar setting of patients. The potential protective role of rhythm control strategy in the TE events needs to be confirmed by future large randomized trials.

Single center experience of fluoroless AVNRT ablation guided by electroanatomic reconstruction in children and adolescents.

BACKGROUND: Anatomical considerations and risks related to x-ray exposure make atrioventricular nodal reentrant tachycardia (AVNRT) ablation in pediatric patients a concerning procedure. We aimed to evaluate the feasibility, safety, and efficacy of performing fluoroless slow-pathway cryoablation guided by the electroanatomic (EA) mapping in children and adolescents. METHODS: Twenty-one consecutive patients (mean age 13.5 ± 2.4 years) symptomatic for AVNRT were prospectively enrolled to right atrium EA mapping and electrophysiological study prior to cryoablation. Cryoablation was guided by slow-pathway potential and performed using a 4-mm-tip catheter. RESULTS: Sustained slow-fast AVNRT was inducible in all the patients with a dual AV nodal physiology in 95%. Acute success was achieved in 100% of the patients with a median of two cryo-applications. Fluoroless ablation was feasible in 19 patients, while in two subjects 50 seconds and 45 seconds of x-ray were needed due to difficult progression of the catheters along the venous system. After a mean follow-up of 25 months, AVNRT recurred in five patients. All the recurrences were successfully treated with a second procedure. In three patients, a fluoroless cryoablation with a 6-mm-tip catheter was successfully performed, while in the remaining two patients, a single pulse of 60 seconds of radiofrequency energy was applied under fluoroscopic monitoring. No complications occurred. CONCLUSIONS: Combination of EA mapping systems and cryoablation may allow to perform fluoroless slow-pathway ablation for AVNRT in children and adolescents in the majority of patients. Fluoroless slow-pathway cryoablation showed a high efficacy and safety comparable to conventional fluoroscopy guided procedures.

Long-term efficacy and safety of two different rhythm control strategies in elderly patients with symptomatic persistent atrial fibrillation.

BACKGROUND: We prospectively compared the efficacy, safety, and quality of life (QoL) impact of catheter ablation versus antiarrhythmic drugs (AAD) in elderly patients with persistent atrial fibrillation (AF). METHODS AND RESULTS: Four hundred and twelve consecutive patients, aged ≥ 70 years, underwent ablation (Group A, 153 patients) or AAD (Group B, 259 patients). Study endpoints: treatment failure (any AF/AT lasting >30 seconds) and treatment-related adverse events (acute when ≤1 month of procedure and long term when >1 month). At a follow-up of 60 ± 17 months, 43% and 46% patients in Group B versus 58% and 76% in Group A were in sinus rhythm (SR), respectively, after one (P = 0.003) and 2 procedures (P < 0.001). Fifteen acute adverse events occurred (6.7% in Group A vs 1% in Group B, P < 0.001), mainly periprocedural cerebral thromboembolism (3.3% in Group A vs 0.7% in Group B, P = 0.058). Previous TIA/stroke resulted the only independent predictor of periprocedural cerebrovascular accidents (OR 1.2, 95%IC 1.1-1.3). At follow-up, 74 long-term adverse events occurred (7.7% in Group A vs 23.9% in Group B, P < 0.001) with Group B patients more often experiencing AAD-related adverse events (12.7% vs 2.6%, P < 0.001). Group A and absence of AF/AT recurrences significantly improved QoL scores (P < 0.001). CONCLUSIONS: In elderly persistent AF patients, catheter ablation is more effective in maintaining SR and in improving QoL than AAD but is affected by a higher risk of embolic complications, particularly in patients with previous TIA/stroke. Over time, Group A patients more likely discontinued AAD with a reduction of long-term adverse events.

Electrical cardioversion of persistent atrial fibrillation: acute and long-term results stratified according to arrhythmia duration.

BACKGROUND: Current definition of persistent atrial fibrillation (PAF) enrolls a heterogeneous population with different atrial fibrillation (AF) exposure and degree of atrial substrate. Study aims were to evaluate acute and long-term results of electrical cardioversion (ECV) and to identify temporal cutoff of previous AF exposure to reclassify PAF in subgroups with different chance of sinus rhythm (SR) maintenance. METHODS: Five hundred twenty-one patients (66% men; age 69 ± 10 years) with PAF undergoing ECV, were divided in four groups according to AF duration at the time of ECV: group A with AF ≤2 months (141 patients); group B with AF >2 and ≤4 months (176 patients); group C with AF >4 and ≤6 months (89 patients); and group D with AF >6 months and <1 year (115 patients). RESULTS: There was no difference in term of acute success among groups (98.5% vs 97.1% vs 98.9% vs 96.5%, respectively, P = 0.95). At 5-year follow-up, 198 (41%) patients were in SR: 50% in group A, 44% in group B, 42% in group C, and 25% in group D (P < 0.001). At the multivariate analysis, previous ECV (hazard ratio [HR] 1.55, P < 0.001), left atrium enlargement (HR 1.39, P = 0.013), and AF duration >6 months at time of procedure (HR 1.59, P = 0.001) independently predict ECV failure. CONCLUSION: ECV is associated with high acute success rate and low complications rate. Long-term results are strongly related with AF duration at time of ECV: a cutoff of >6 months helps in selecting patients that can take greater advantage of the procedure.