Rivard Lena, Dubuc Marc, Guerra Peter G, Novak Paul, Roy Denis, Macle Laurent, Thibault Bernard, Talajic Mario, Khairy Paul
Electrophysiology Service, Montreal Heart Institute, Montreal, Quebec, Canada.
Heart Rhythm. 2008 Feb;5(2):230-4. doi: 10.1016/j.hrthm.2007.10.013. Epub 2007 Oct 9.
Cryoablation is increasingly used to treat atrioventricular nodal reentrant tachycardia (AVNRT). It is unknown whether larger electrode-tip cryocatheters improve outcomes without compromising safety.
This study sought to compare acute and long-term success with 4-mm versus 6-mm electrode-tip cryocatheters for AVNRT.
We conducted a 2-group cohort study on 289 patients, age 45.5 +/- 15.9 years (76.8% female), who underwent transcatheter cryoablation as a first-time procedure for AVNRT with 4-mm (N = 152) or 6-mm (N = 137) electrode-tip catheters.
Acute procedural success was achieved in 90.7% (95% confidence interval 86.9% to 93.7%) with no difference between the 2 electrode-tip sizes. A shorter fluoroscopy time (16.1 +/- 11.3 versus 20.3 +/- 14.9 minutes, P = .0096) and trend toward briefer procedural duration (166.6 +/- 49.1 versus 173.5 +/- 53.0 minutes, P = NS) were noted with 6-mm electrode tips. Transient AV block occurred in 5.2%, with complete recovery in 4.4 +/- 2.6 seconds. Over a median follow-up of 155 days, recurrences were less common with 6-mm electrode tips. Actuarial event-free survival rates at 1, 3, 6, and 12 months with 6-mm versus 4-mm electrode-tip cryocatheters were 96.7%, 93.4%, 91.9%, and 88.5% versus 89.9%, 87.0%, 84.1%, and 77.1%, respectively, with no recurrence thereafter (P = .0457). In multivariate analyses adjusting for baseline imbalances and medical therapy postablation, cryoablation with a 4-mm-tip catheter incurred a 2.5-fold increased risk of recurrence (hazard ratio 2.5, 95% confidence interval 1.0 to 6.1, P = .0420).
In patients with AVNRT, cryoablation with 6-mm electrode-tip catheters is safe and is associated with fewer recurrences on long-term follow-up compared with 4-mm electrode-tip cryocatheters.
冷冻消融术越来越多地用于治疗房室结折返性心动过速（AVNRT）。目前尚不清楚较大电极尖端的冷冻导管在不影响安全性的情况下是否能改善治疗效果。
本研究旨在比较使用4毫米与6毫米电极尖端冷冻导管治疗AVNRT的急性和长期成功率。
我们对289例年龄为45.5±15.9岁（76.8%为女性）的患者进行了一项两组队列研究，这些患者首次接受经导管冷冻消融治疗AVNRT，分别使用4毫米（N = 152）或6毫米（N = 137）电极尖端导管。
90.7%（95%置信区间86.9%至93.7%）的患者获得急性手术成功，两种电极尖端尺寸之间无差异。6毫米电极尖端的透视时间更短（16.1±11.3分钟对20.3±14.9分钟，P = .0096），手术持续时间有缩短趋势（166.6±49.1分钟对173.5±53.0分钟，P =无显著性差异）。5.2%的患者发生短暂性房室传导阻滞，4.4±2.6秒内完全恢复。在中位随访155天期间，6毫米电极尖端的复发较少见。6毫米与4毫米电极尖端冷冻导管在1、3、6和12个月时的无事件生存率分别为96.7%、93.4%、91.9%和88.5%与89.9%、87.0%、84.1%和77.1%，此后无复发（P = .0457）。在对基线不平衡和消融后药物治疗进行调整的多变量分析中，使用4毫米尖端导管进行冷冻消融的复发风险增加2.5倍（风险比2.5，95%置信区间1.0至6.1，P = .0420）。
对于AVNRT患者，与4毫米电极尖端冷冻导管相比，使用6毫米电极尖端导管进行冷冻消融是安全的，且在长期随访中复发较少。
