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

Background: Use of lesion metric indices is a proposed strategy to support pulmonary vein isolation procedures and these indices show good correlations with lesion sizes. The aim of this in silico study is to provide a detailed analysis of radiofrequency (RF) settings, including high-power short-duration (HPSD) settings, and resulting lesion metric indices.Methods and Results: A software program was designed which simulated virtual RF ablations. Lesion metric indices (Ablation index: AI, Lesion size index: LSI) were calculated based on underlying RF settings (contact force [CF], power, duration). In series of calculations, the applied settings were varied within defined ranges (CF: 1-80 g, power:1-60 W, duration: 1-60 seconds). Overall, n = 388 000 virtual ablations were calculated.The resulting lesion metric indices were compared with each other and analyzed in relation to respective RF settings. Increasing contact force from 1 to 10 g resulted in a 4.4-fold LSI value, whilst increasing contact force from 10 to 20g resulted in a 1.5-fold value (P < .01). When RF power was increased by 10 W, lesion metric indices increased between 1.3-and 1.6-fold. A prolongation of RF duration by 10 seconds resulted in a 1.2-to-1.3-fold increase of lesion metric indices. HPSD RF applications of 50 W, 11 to 13 seconds, and 60 W, 8 to 10 seconds resulted in equivalent lesion metric indices when compared with 30 W, 30 seconds conventional ablations. Conclusions:The findings support the clinical use of contact forces within a 10 to 20 g range. AI is more sensitive to RF duration, whereas LSI is more sensitive to contact force. HPSD RF settings can successfully be derived from lesion metric indices. K E Y W O R D Sablation, contact force, high-power short-duration, lesion, radiofrequency

Section: Discussionmentioning

confidence: 99%

“…High‐power short‐duration (HPSD) is an increasingly used ablation strategy for pulmonary vein isolation (PVI) procedures 12‐14 . More recently, AI‐guided HPSD RF application has also been described in a clinical setting 15 …”

Section: Introductionmentioning

confidence: 99%

In silico analysis of the relation between conventional and high‐power short‐duration RF ablation settings and resulting lesion metrics

Bourier

Vlachos

Frontera

et al. 2020

“…[5][6][7][8][9] However, the use of higher power could also potentially increase the complication rate, the risk of steam pop or esophageal injury. 10 While historically the power was set below 35 W (mostly ≤ 25 W at the posterior wall), 1,11,12 recent studies using AI as targeted endpoint have shown promising results with a power ≥35 W. 9,13,14 In all three of these studies, STSF catheters were used (SmartTouch Surround Flow;…”

Section: Introductionmentioning

confidence: 99%

“…In group A, the median CF (13 g [IQR: 12-15] vs 14 g [IQR: 12-15]; P = .035) and force-time integral (FTI) were lower (283 gs [IQR: 258-314] vs 365 gs [IQR: 339-402]; P < .001) when compared with group B. The impedance drop was similar in both groups (12 Ω [IQR: 11-13] vs13 Ω [IQR:[11][12][13][14]; P = .192), in group A and group B, respectively (Table 2andFigure 2).…”

mentioning

confidence: 99%

Evaluation of higher power delivery during RF pulmonary vein isolation using optimized and contiguous lesions

Kyriakopoulou

Wielandts

Strisciuglio

et al. 2020

Aims: "CLOSE"-guided pulmonary vein isolation (PVI) is based on contiguous (≤6 mm) and optimized radiofrequency (RF) ablation lesions (ablation index[AI] ≥ 400 posteriorly and ≥ 550 anteriorly]. However, the optimal RF power to reach the desired AI is unknown. Therefore we evaluated the efficiency of an ablation strategy using higher power (40 W) during a first "CLOSE"-guided PVI.Methods: Eighty consecutive patients undergoing "CLOSE"-guided PVI for symptomatic paroxysmal atrial fibrillation were ablated with 40 W (group A). Results were compared with 105 consecutive patients enrolled in the "CLOSE to CURE"-study and were ablated using the same protocol with 35 W (group B). Results:In group A, ablation was associated with shorter ablation procedure time (91 vs 111 minutes; P < .001), shorter fluoroscopy time (5 vs 11 minutes; P < .001), shorter PVI time (48 vs 64 minutes; P < .001), shorter RF time (20 vs 28 minutes; P < .001), lower RF time per application (22 vs 29 seconds; P < .001), less RF applications (52 vs 58; P < .001), and less catheter dislocations (1 vs 2; P = .002). The impedance drop (12 vs 13 Ω; P = .192), first-pass isolation rate (99% vs 93%; P = .141) and acute reconnection rate (6% vs 4%; P > .733) were similar in both groups (groups A and B, respectively). No complications occurred. In group A, a gastroscopy-performed in five patients with esophageal temperature rise more than 42°C-did not reveal any esophageal lesion. Postprocedural recurrence of atrial tachyarrhythmia at 1 year was not significantly different between both groups.Conclusions: Using the "CLOSE"-protocol, increased power increases the efficiency of PVI without compromising patients' safety. K E Y W O R D S atrial fibrillation, contact force, high power ablation, pulmonary vein isolation Maria Kyriakopoulou and Jean-Yves Wielandts contributed equally to this study. a Adenosine test performed in 97 out of 105 patients. F I G U R E 1 Two representative examples of "CLOSE"-guided encirclement of the pulmonary veins (PV) and the radiofrequency parameters (median/median value) of all VISITAG points in one patient from group A (40 W; A) and one patient from group B (35 W; B). Posteroanterior view. Red VISITAG points with ablation index (AI) > 550 and pink VISITAG points with AI > 400. Asterisk (*) on two dislocation points in group B (35 W) 1094 | KYRIAKOPOULOU ET AL.

“…It is calculated by integrating the ablation time, energy, catheter stability, and CF. The FAFA AI High Power Study 25 was a first clinical study to evaluate the procedural data and initial results of a combined ablation technique using AI‐guided high‐power (50 W) ablation for PVI. For all of the ablation lesions, the RF power was set to 50 W targeting AI values (550 at the anterior, 400 at the posterior LA wall) with a CF‐sensing catheter (Biosense Webster).…”

Section: Clinical Studiesmentioning

confidence: 99%

Update on high‐power short‐duration ablation for pulmonary vein isolation

Qiu

Wang

et al. 2020

Pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) ablation. However, this procedure remains complex and time‐consuming, and the recurrence of AF after PVI is still unsatisfactory. Current technologies have improved our knowledge of the association between radiofrequency lesion creation and ablation parameters (power and duration), which triggered the development of high‐power short‐duration (HPSD). During the past decade, several preclinical and clinical studies have been conducted to confirm the feasibility, safety, and outcome of PVI ablation with HPSD or very high‐power short‐duration (vHPSD) settings, which increased electrophysiologists' interests in the utility of HPSD strategies. This paper describes the theoretical basis and recent research findings of HPSD or vHPSD ablation and summarizes the state‐of‐the‐art evidence behind the role of this strategy in PVI.