Department of Cardiology, Saga-ken Medical Centre Koseikan, Saga, Japan; EP Expert Doctors-Team Tsuchiya, Kumamoto, Japan.
EP Expert Doctors-Team Tsuchiya, Kumamoto, Japan.
J Cardiol. 2018 Nov;72(5):427-433. doi: 10.1016/j.jjcc.2018.04.010. Epub 2018 May 26.
Low-voltage zones (LVZs), as measured by electroanatomic mapping, are thought to be associated with fibrosis. We reported the efficacy of atrial fibrillation (AF) ablation aiming to homogenize left atrial (LA) LVZ. The purpose of this study was to evaluate the impact of LVZ extension outcomes after LVZ homogenization in patients with nonparoxysmal AF.
This prospective observational cohort study included 172 patients with nonparoxysmal AF undergoing their initial ablation. LVZ was defined as an area with bipolar electrograms <0.5mV during sinus rhythm. LVZ extent was calculated as the percentage of LA surface area, and subsequently, LVZ was categorized into stages I (<5%), II (≥5% to <20%), III (≥20% to <30%), and IV (≥30%). Patients with LVZs underwent LVZ ablation aimed at homogenization of ≥80% of LVZs following pulmonary vein isolation. The primary endpoint was atrial tachyarrhythmia recurrence-free survival after a single procedure at 18 months off antiarrhythmic drugs. The association of %LVZ with recurrence-free survival was examined using Cox proportional hazard models.
The survival rates were 76%, 74%, 57%, and 28% in patients with stages I, II, III, and IV LVZ, respectively. The difference was significant between stages I and IV (log-rank, p<0.001), while not significant between stages I vs. II and I vs. III (p=0.843, p=0.073, respectively). Cox proportional hazard model revealed that %LVZ was an independent predictor of recurrence-free survival (hazard ratio, 1.025 per 1% increase, p<0.001; unadjusted model). The results were similar after demographic and clinical covariate adjustments and after excluding 12 patients who did not achieve homogenization of ≥80% of LVZ.
The extent of LVZ is an independent predictor for recurrence even after LVZ homogenization.
电生理标测所测量的低电压区（LVZ）被认为与纤维化有关。我们报告了旨在使左心房（LA）LVZ 均质化的房颤（AF）消融的疗效。本研究的目的是评估非阵发性 AF 患者 LVZ 均质化后 LVZ 扩展结果的影响。
这项前瞻性观察队列研究纳入了 172 名接受首次消融的非阵发性 AF 患者。LVZ 定义为窦性心律时双极电图 <0.5mV 的区域。LVZ 程度计算为 LA 表面积的百分比，随后将 LVZ 分为 I 期（<5%）、II 期（≥5%至<20%）、III 期（≥20%至<30%）和 IV 期（≥30%）。LVZ 患者行 LVZ 消融，旨在在肺静脉隔离后使≥80%的 LVZ 均质化。主要终点是抗心律失常药物停药后 18 个月单次手术的房性快速心律失常无复发生存率。使用 Cox 比例风险模型检查%LVZ 与无复发生存之间的关系。
I、II、III 和 IV 期 LVZ 患者的生存率分别为 76%、74%、57%和 28%。I 期和 IV 期之间的差异有统计学意义（对数秩检验，p<0.001），而 I 期与 II 期和 I 期与 III 期之间的差异无统计学意义（p=0.843，p=0.073）。Cox 比例风险模型显示，%LVZ 是无复发生存的独立预测因子（风险比，每增加 1%为 1.025，p<0.001；未调整模型）。在调整人口统计学和临床协变量后，以及在排除未达到≥80%LVZ 均质化的 12 名患者后，结果相似。
即使在 LVZ 均质化后，LVZ 的程度也是复发的独立预测因子。
