Department of Cardiac Electrophysiology, Liverpool Heart and Chest Hospital, Thomas Drive, Liverpool L14 3PE, UK.
Department of Cardiology and Cardiovascular Research Institute Basel (CRIB), University Hospital Basel, University of Basel, Basel, Switzerland.
Europace. 2021 Jun 7;23(6):878-886. doi: 10.1093/europace/euab031.
The safety of Ablation Index (AI)-guided 50 W ablation for atrial fibrillation (AF) remains uncertain, and mid-term clinical outcomes have not been described. The interplay between AI and its components at 50 W has not been reported.
Eighty-eight consecutive AF patients (44% paroxysmal) underwent AI-guided 50 W ablation. Procedural and 12-month clinical outcomes were compared with 93 consecutive controls (65% paroxysmal) who underwent AI-guided ablation using 35-40 W. Posterior wall isolation (PWI) was performed in 44 (50%) and 23 (25%) patients in the 50 and 35-40 W groups, respectively, P < 0.001. The last 10 patients from each group underwent analysis of individual lesions (n = 1230) to explore relationships between different powers and the AI components. Pulmonary vein isolation was successful in all patients. Posterior wall isolation was successful in 41/44 (93.2%) and 22/23 (95.7%) in the 50 and 35-40 W groups, respectively (P = 0.685). Radiofrequency times (20 vs. 26 min, P < 0.001) and total procedure times (130 vs. 156 min, P = 0.002) were significantly lower in the 50 W group. No complication or steam pop was seen in either group. Twelve-month freedom from arrhythmia was similar (80.2% vs. 82.8%, P = 0.918). A higher proportion of lesions in the 50 W group were associated with impedance drop >7 Ω (54.6% vs. 45.5%, P < 0.001). Excessive ablation (AI >600 anteriorly, >500 posteriorly) was more frequent in the 50 W group (9.7% vs. 4.3%, P < 0.001).
Ablation Index-guided 50 W AF ablation is as safe and effective as lower powers and results in reduced ablation and procedure times. Radiofrequency lesions are more likely to be therapeutic, but there is a higher risk of delivering excessive ablation.
消融指数（AI）指导的 50W 消融治疗心房颤动（AF）的安全性仍不确定，且尚未描述其中期临床结果。AI 及其在 50W 下的组件之间的相互作用尚未有报道。
连续 88 例 AF 患者（44%为阵发性）接受 AI 指导的 50W 消融。比较 88 例连续患者（44%为阵发性）与 93 例接受 AI 指导、使用 35-40W 消融的连续对照患者的手术和 12 个月的临床结果。在 50W 和 35-40W 组中，分别有 44 例（50%）和 23 例（25%）患者进行了后壁隔离（PWI），P<0.001。每组的最后 10 例患者进行了 1230 例单个病灶的分析，以探讨不同功率与 AI 成分之间的关系。所有患者均成功进行了肺静脉隔离。在 50W 和 35-40W 组中，后壁隔离成功率分别为 41/44（93.2%）和 22/23（95.7%），P=0.685。50W 组的射频时间（20 分钟 vs. 26 分钟，P<0.001）和总手术时间（130 分钟 vs. 156 分钟，P=0.002）明显更低。两组均未见并发症或蒸汽弹出。12 个月时无心律失常的比例相似（80.2% vs. 82.8%，P=0.918）。50W 组中与阻抗下降>7Ω相关的病变比例更高（54.6% vs. 45.5%，P<0.001）。50W 组中过度消融（AI 前向>600，后向>500）的发生率更高（9.7% vs. 4.3%，P<0.001）。
AI 指导的 50W AF 消融与较低功率一样安全有效，可减少消融和手术时间。射频消融病灶更有可能具有治疗作用，但过度消融的风险更高。
