Impact of Complete Versus Incomplete Circumferential Lines Around the Pulmonary Veins During Catheter Ablation of Paroxysmal Atrial Fibrillation

Abstract

Background— Ablation of atrial fibrillation (AF) is an established treatment option for symptomatic patients. It is not known whether complete pulmonary vein isolation (PVI) is superior to incomplete PVI with regard to the patients’ clinical outcome. Methods and Results— Patients with drug-refractory, symptomatic paroxysmal AF were randomly assigned to either incomplete (group A) or complete PVI (group B). In group A, a persistent gap was intentionally left within the circumferential ablation line, whereas in group B, complete PVI without any gaps was intended. At 3 months, all patients underwent invasive reevaluation to assess the rate of persistent PVI. Clinical follow-up was based on daily 30-s transtelephonic ECG transmissions. Primary study end point was the time to first recurrence of (symptomatic or asymptomatic) AF. A total of 233 patients were enrolled (116 in group A and 117 in group B). AF recurrence within 3 months was observed in a total of 161 patients (136 [84.5%] with symptomatic and 25 [15.5%] with asymptomatic AF); AF recurred in 62.2% of group B patients and 79.2% of group A patients ( P <0.001), for a difference in favor of complete PVI of 17.1% (95% confidence interval, 5.3%–28.9%). Invasive restudy in 103 group A patients and 93 group B patients revealed conduction gaps in 92 (89.3%) and 65 (69.9%) patients, respectively. Conclusions— This study proves the superiority of complete PVI over incomplete PVI with respect to AF recurrence within 3 months. However, the rate of electric reconduction 3 months after PVI is high in patients with initially isolated PVs. Clinical Trial Registration— URL: http://clinicaltrials.gov ; Unique identifier: NCT00293943.

Stand-Alone Pulmonary Vein Isolation Versus Pulmonary Vein Isolation With Additional Substrate Modification as Index Ablation Procedures in Patients With Persistent and Long-Standing Persistent Atrial Fibrillation

“…The difference between the surgical and the radiofrequency current ablation approach is that surgical PVI is permanent, whereas radiofrequency current-induced PVI at the index procedure is associated with a high likelihood of reconduction from the PVs to the LA through gaps in the circumferential ablation lines. 19 In this study, conduction gaps were found in 80% of patients undergoing repeat ablation, indicating that the development of conduction gaps along the ablation lines is the dominant mechanism of AF recurrence after radiofrequency current-induced PVI in both ablation strategies. Therefore, the demonstration of a potential longterm benefit of additional substrate modification at the time of PVI is prevented by the high reconduction rate through gaps in the PVI lines.…”

Catheter ablation in patients with persistent atrial fibrillation

“…When interpreting results from studies evaluating novel ablation strategies, it seems important to recognise a major limitation of current catheter ablation interventions: Even when the PVI is performed in selected, highly experienced centres with a clear aim to achieve complete isolation, this is only achieved in a minority of patients. 72 Hence, better technology is needed to achieve transmural lesions. This has implications not only for the evaluation of linear lesions but also for other ablation concepts.…”

Automated Ablation Annotation Algorithm Reduces Re-conduction of Isolated Pulmonary Vein and Improves Outcome After Catheter Ablation for Atrial Fibrillation

“…8,9 A recent study proved the superiority of complete PVI over incomplete PVI with respect to AF recurrence. 10 Methods to detect incomplete reversible lesions in clinical practice remain to be fully clarified. The presence of dormant conduction in response to adenosine or ATP that hyperpolarizes atrial cell membranes and triggers transient conduction, might indicate incomplete cell injury.…”