A multicentered evaluation of ablation at higher power guided by ablation index: Establishing ablation targets for pulmonary vein isolation

Abstract

Background Pulmonary vein isolation (PVI) using high power delivered by SmartTouch Surround Flow (STSF) catheters guided by ablation index (AI) was evaluated in a multicenter registry. Methods Patients with paroxysmal AF underwent PVI with STSF catheters using 30 W on the posterior wall and 40 W elsewhere. AI targets were 350 posterior walls and 450 elsewhere. Procedures were compared with controls using conventionally irrigated contact force‐sensing catheters using conventional powers (25 W posterior wall and 30 W elsewhere) guided by force‐time integral (no agreed targets). The waiting period of 30 minutes was observed before adenosine administration to assess acute pulmonary vein (PV) reconnection. Results One hundred patients from four centers were included: 50 patients in the high power ablation index (HPAI) group and 50 controls. Procedure time was 22% shorter in the HPAI group (156 [133.8‐179] vs 199 [178.5‐227] minutes; P < 0.001). Duration of the radiofrequency application was 37% shorter in the HPAI group (27.2 [21.5‐35.8] vs 43.2 [35.1‐52.1] minutes; P < 0.001). Acute PV reconnection was reduced (28 of 200 [14%] vs 48 of 200 [24%] veins; P = 0.015). Reconnection was predicted by a largest interlesion distance greater than 6 mm, a lesion with impedance drop less than 2.5 Ω, contact force less than 6 g, or less than 68% of the regional AI target (all P < 0.001). Freedom from atrial arrhythmia at 1 year off antiarrhythmic drugs after a single procedure was 78% in the HPAI group vs 64% in the control group ( P = 0.186). Conclusion High‐powered ablation guided by AI was safe and led to shorter procedure times with reduced acute PV reconnection compared with conventional ablation.

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

“…Few data were reported on the clinical outcome of AI‐guided HP RF application in AF ablation. Recently, the proportion of patients free from atrial tachyarrhythmia recurrence after AF ablation with AI‐guided HP RF application (30 W on posterior walls and 40 W elsewhere) was reported to be higher compared with the FTI‐guided conventional setting (25 W posterior wall and 30 W elsewhere) . But no data on the clinical impact of HP and short‐duration RF application compared with LP and long‐duration RF application with same target AI has been shown.…”

“…14 from atrial tachyarrhythmia recurrence after AF ablation with AIguided HP RF application (30 W on posterior walls and 40 W elsewhere) was reported to be higher compared with the FTI-guided conventional setting (25 W posterior wall and 30 W elsewhere). 13 But no data on the clinical impact of HP and short-duration RF application compared with LP and long-duration RF application with same target AI has been shown. Although a follow-up period was relatively short in this study (median 10.1 months in LP and MP and 6.5 in HP groups), we found no significant difference in AF-free survival rates among the three groups.…”

“…Theoretically, AI‐guided HP RF application can create similar RF lesions for a short duration without excessive RF application. Recently, AI‐guided HP RF application (30‐40 W) was reported to complete CPVI with reduced acute PV reconnection, shorter procedure time and without increasing complication as compared with FTI‐guided CPVI with conventional RF application power (25‐30 W) . However, the procedural impact of HP RF application as compared with low‐power (LP) RF application with the same target AI was not fully elucidated.…”

Safety and efficacy of the ThermoCool SmartTouch SurroundFlow catheter for atrial fibrillation ablation: A meta‐analysis

“…They found that HPSD using STSFc is safe and led to shorter procedure times with a reduced acute PV reconnection as compared to conventional ablation. 35 Thus, the safe and efficacious application of HPSD using STSFc as identified by more clinical trials, informs us that STSFc might be widely applied in the future for AF ablation.…”

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

“…4 Increased power theoretically results in reduced RF application duration when there is a similar CF. [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;…”