Use of Ablation Index-Guided Ablation Results in High Rates of Durable Pulmonary Vein Isolation and Freedom From Arrhythmia in Persistent Atrial Fibrillation Patients

Abstract

Background Catheter ablation for persistent atrial fibrillation (AF) is associated with less favorable outcomes than for paroxysmal AF. Substrate modification is often added to pulmonary vein isolation (PVI) to try to improve success rates. Recent studies have shown improved clinical outcomes with use of regional ablation index (AI) targets for PVI. We hypothesized that prospective use of AI-guided PVI in persistent AF patients would result in a low rate of PV reconnection at repeat electrophysiology study and that a high success rate can be achieved with durable PVI alone. Methods Forty consecutive patients with persistent AF underwent AI-guided PVI with target values of 550 for anterior and 400 for posterior left atrial regions, followed by a protocol-mandated repeat procedure after 2 months. Patients were monitored for atrial tachyarrhythmia recurrence via daily plus symptom-initiated ECG recordings for 12 months. Recurrence was defined as ≥30 seconds of any atrial tachyarrhythmia after a 3-month blanking period. Results PV reconnection was seen at repeat electrophysiology study in 22% of patients, affecting 7% of PVs. Ablation on the intervenous carina was required in 44% patients to achieve durable PVI. Atrial tachyarrhythmia recurrence was documented in 8 (20%) patients, only one of whom had PV reconnection at repeat study. At 12 months, 38/40 (95%) patients were in sinus rhythm, with 4 (10%) patients having started antiarrhythmic drugs. Higher body mass index and excess alcohol consumption were the only significant factors associated with atrial tachyarrhythmia recurrence. Conclusions Use of AI targets results in a high level of durable PVI. A good clinical outcome can be achieved in the great majority of persistent AF patients with AI-guided PVI alone. Clinical Trial Registration URL: https://www.clinicaltrials.gov . Unique identifier: NCT02628730.

Ablation index‐guided 50 W ablation for pulmonary vein isolation in patients with atrial fibrillation: Procedural data, lesion analysis, and initial results from the FAFA AI High Power Study

“…Interestingly, the first clinical study utilizing AI‐guided PVI demonstrated that insufficient AI values predicted PV reconnection, and a minimum AI value of 370 (posterior wall) and 480 (anterior wall) was associated with durable lesions . Recent clinical studies targeting AI values of 550 (anterior wall) and 400 (posterior wall) were associated with high single‐procedure success rate and low rate of PV reconnection …”

“…The Visitag (CARTO3; Biosense Webster) settings included: ILD ≤6 mm, minimum force 3 g, force‐over‐time 30%, minimum time 3 seconds, maximal range 2 mm, and lesion tag size 3 mm. According to LA location different target AI values were defined (AI 550 for anterior, and AI 400 for posterior) …”

“…Recently, the ablation index (AI) which is composed of power, contact force, and time has been introduced to improve lesion formation and PVI durability; moreover, the novel AI‐guided PVI targeting AI values of 550/400 (anterior/posterior) with an interlesion distance (ILD) of 6 mm or less demonstrated promising clinical success rates along with high rates of durable PVI …”

High‐power application is associated with shorter procedure time and higher rate of first‐pass pulmonary vein isolation in ablation index‐guided atrial fibrillation ablation

“…Recently, the ablation index (AI) was proposed as a similar quantitative ablation lesion marker by including CF, RF application time, and RF power in a weighted formula. AI was reported to be useful to create durable ablation lesion and to minimize AF recurrence after ablation . However, these studies did not evaluate the impact of RF application power on AI‐guided CPVI.…”

High‐power radiofrequency ablation for atrial fibrillation: Establishing a standardized protocol

“…Prior studies have demonstrated that when the achieved lesion AI value is ≥370 for the posterior/floor segments and ≥480 for the anterior/roof segments, no PV reconnections were seen at 2 months . This protocol has been shown to result in high levels of first‐pass PVI and relative fast procedures using standard power settings in two single center pilot studies …”