Impact of ablation index settings on pulmonary vein reconnection

Abstract

Purpose Ablation Index (AI) is a radiofrequency lesion quality marker. The AI value that allows effective and safe pulmonary vein isolation (PVI) is still debated.We evaluated the incidence of acute and late PV reconnection (PVR) with different AI settings and its predictors. MethodsThe Ablation Index Registry is a multicentre study that included patients with paroxysmal/persistent atrial fibrillation (AF) underwent first time ablation. Each operator performed the ablation using his preferred ablation catheter (ThermoCool® SmartTouch or Surround Flow) and AI setting (380 posterior-500 anterior and 330 posterior-450 anterior).We divided the study population in two groups according to the AI setting used: Group 1 (330-450) and Group 2 (380-500). Incidence of acute PVR was validated within 30 minutes after PVI, whereas the incidence of late PVR was evaluated at repeat procedure.Results Overall, 490 patients were divided in Group 1 (258) and 2 (232). There was no significant difference in the procedural time, fluoroscopy time, and rate of first-pass PVI between the two study groups. Acute PVR was observed in 5.6% PVs. The rate of acute PVR was slightly higher in Group 2 (64/943, 6.8%, PVs) than in Group 1 (48/1045, 4.6% PVs, p=0.04). Thirty patients (6%) underwent repeat procedure and late PVR was observed in 57/116 (49%) PVs (number of reconnected PV per patient of 1.9±1.6). A similar rate of late PVR was found in the two study groups. No predictors of acute and late PVR were found. ConclusionAblation with lower range of AI is highly effective and is not associated with higher rate of acute and late PVR. No predictors of PV reconnection were found.

CLOSE protocol versus lower ablation index value for paroxysmal atrial fibrillation: A randomized noninferior clinical trial

“…However, the author acknowledged that the success rate may have been overestimated. Then, the same team reported a higher rate of acute reconnections in AI lower group (6.8% vs. 4.6%, p = .04), and similar rates of late reconnections and complications 11 …”

“…In the study by Solimene et al, 11 156 patients with paroxysmal and persistent AF underwent PVI with AI settings of 330–350 at posterior wall and 400–450 at anterior wall. One cardiac perfusion occurred, and 10.8% arrhythmia recurrence was observed during a follow‐up of 14 ± 6 months.…”

“…The CLOSE protocol, proposed in 2017 by targeting an interlesion distance (ILD) ≤ 6 mm and AI ≥ 400 at the posterior wall and ≥550 at the anterior wall, displayed a high rate of first‐pass PV isolation and a high single‐procedure arrhythmia‐free survival at 1 year 9,10 . However, the optimized region‐specific criteria of AI value remain to be defined, and lower AI settings were also reported to be effective in observational studies 11,12 . We hypothesize that a lower AI value is noninferior to the CLOSE protocol in efficacy.…”

Ablation index-guided high-power ablation for superior vena cava isolation in patients with atrial fibrillation

“…Considering the above reasons, an optimal setting of RF energy delivered was needed to ensure the efficacy and safety of SVCI. AI as an ideal parameter for PVI showed a high single procedure success in several clinical studies ( 7 – 9 ). In a recent paper, Kawano et al examined the SVCI’s target AI value for the first time and revealed that 350 may be the SVCI’s target AI value, and this information could be helpful to the safety and efficacy of SVCI ( 25 ).…”

“…In recent years, there has been a growing interest in the highpower ablation strategy (1)(2)(3)(4)(5)(6). The ablation index (AI), which weighs contact force (CF), radiofrequency time, and applied power, has been shown to aid in the creation of long-lasting ablation lesions (7)(8)(9). There are several studies, which applied AI-guided high-power ablation strategy in atrial fibrillation (AF) ablation and had been validated to improve clinical outcomes after ablation (10)(11)(12).…”