Da Costa Antoine, Romeyer-Bouchard Cécile, Dauphinot Virginie, Lipp Damien, Abdellaoui Loucif, Messier Marc, Thévenin Jérôme, Barthélémy Jean-Claude, Isaaz Karl
Department of Cardiology, Faculty of Medicine J. Lisfranc, The Jean Monnet University, 42 055 Saint-Etienne, Cedex 2, France.
Eur Heart J. 2006 Aug;27(15):1833-40. doi: 10.1093/eurheartj/ehl121. Epub 2006 Jun 28.
Radiofrequency ablation (RFA) of cavotricuspid isthmus (CTI)-dependent atrial flutter can be performed using various types of ablation catheters. Recent evaluations comparing externally cooled-tip RFA (ecRFA) catheters and large-tip (8 mm) catheters found that ecRFA catheter may have a higher efficacy for CTI ablation. The aim of this prospective study was to compare both catheters by stratifying on CTI morphology in order to explain, in part, the discrepancies between previous randomized studies, and to validate predictive factors of difficult CTI ablation on clinical, echocardiographic, and angiographic data.
Over a period of 24 months, 281 patients were included and stratified on CTI morphology: 'straight', 'concave', and 'pouch-like recess'. In straight CTI (n=150), the duration of application time with a median of 6 min [interquartile range (IQR) 4-9] vs. a median of 12 min (IQR 16-19; P<0.0001) and the duration of X-ray exposure with a median of 6 min (IQR 4.4-9.7) vs. a median of 10.4 min (IQR 7-17; P<0.0001) were significantly lower with an 8 mm-tip when compared with ecRFA catheter. In contrast, in concave CTI (n=95), a trend towards both shorter application time with a median of 12.5 min (IQR 6-23) vs. a median of 19 min (IQR 7-28; P=0.08) and X-ray duration exposure with a median of 10.4 min (IQR 6-20) vs. a median of 13 min (IQR 8-24; P=0.08) with an ecRFA catheter when compared with 8 mm-tip catheter were evidenced. No significant difference was shown between 8 mm-tip and ecRFA catheters in the pouch-like recess group (n=36). Predictive factors of difficult ablation include right CTI length and morphology.
This study demonstrates that the 8 mm-tip catheter is more effective for ablation in case of a straight angiographic isthmus morphology and that the ecRFA catheter tends to be more effective in case of concave angiographic isthmus morphology. Thus, angiographic isthmus evaluation may predict both the effectiveness of an RF catheter, and the risk of an expensive crossover. These data may explain, in part, the discrepancies of previous studies comparing both catheters.
对于三尖瓣峡部（CTI）依赖性房扑，可使用多种类型的消融导管进行射频消融（RFA）。最近比较外部冷却尖端RFA（ecRFA）导管和大尖端（8mm）导管的评估发现，ecRFA导管在CTI消融方面可能具有更高的疗效。这项前瞻性研究的目的是通过对CTI形态进行分层来比较这两种导管，以便部分解释先前随机研究之间的差异，并验证基于临床、超声心动图和血管造影数据的CTI消融困难的预测因素。
在24个月的时间里，纳入了281例患者，并根据CTI形态进行分层：“直线型”、“凹面型”和“袋状凹陷型”。在直线型CTI（n = 150）中，与ecRFA导管相比，8mm尖端导管的应用时间中位数为6分钟[四分位间距（IQR）4 - 9]，显著低于中位数12分钟（IQR 16 - 19；P < 0.0001），X线暴露时间中位数为6分钟（IQR 4.4 - 9.7），显著低于中位数10.4分钟（IQR 7 - 17；P < 0.0001）。相比之下，在凹面型CTI（n = 95）中，与8mm尖端导管相比，ecRFA导管的应用时间有缩短趋势，中位数为12.5分钟（IQR 6 - 23），而对照组为19分钟（IQR 7 - 28；P = 0.08），X线暴露时间中位数为10.4分钟（IQR 6 - 20），而对照组为13分钟（IQR 8 - 24；P = 0.08）。在袋状凹陷型组（n = 36）中，8mm尖端导管和ecRFA导管之间未显示出显著差异。消融困难的预测因素包括右CTI长度和形态。
本研究表明，对于血管造影显示峡部为直线形态的情况，8mm尖端导管消融更有效；而对于血管造影显示峡部为凹面形态的情况，ecRFA导管往往更有效。因此，血管造影峡部评估可预测射频导管的有效性以及昂贵的交叉使用风险。这些数据可能部分解释了先前比较这两种导管研究结果的差异。
