A recent feasibility study has found irrigated multi-electrode radiofrequency ablation of atrial fibrillation using the novel 10-pole circular, open-irrigated mapping and ablation catheter nMARQ device (Biosense Webster) to be fast and effective.
Study authors, Stephan Zellerhoff (Hôpital Cardiologique du Haut-Lévêque, Bordeaux-Pessac, France) and others, report in Europace that they observed a very high rate of isolated pulmonary veins without the need of touch-up lesions in an unselected, consecutive cohort of patients, simplifying and accelerating this otherwise complex ablation procedure.
The prospective study included 39 consecutive patients (60±10 years, eight females) suffering from drug-refractory paroxysmal atrial fibrillation referred for pulmonary vein isolation. A total of 154 pulmonary veins were targeted using the nMARQ catheter, and of these, 151 could be acutely isolated using solely the circular ablation catheter. The authors report that three veins could only be completely isolated by touch-up lesions using a conventional, irrigated-tip ablation catheter.
“Thus, 37/39 patients were treated successfully using exclusively the nMARQ mapping/ablation catheter by applying a mean of 10±4.6 minutes of radiofrequency energy to achieve complete pulmonary vein isolation [….] Transient reconnection was significantly more frequently observed in the right superior pulmonary vein compared with the remaining pulmonary veins.
Reconnected veins were re-ablated and adenosine triphosphate testing was repeated until no reconnection was observed,” they state.
They add, “Therefore, more subsequent radiofrequency applications using the nMARQ catheter were necessary for complete isolation of the right superior pulmonary vein, reaching the level of statistical significance while comparing both inferior pulmonary veins.”
Additionally, a total of 13 patients with documented cavo-tricuspid isthmus-dependent flutter also underwent cavo-tricuspid isthmus ablation. “In nine patients solely the nMARQ catheter was used to achieve bidirectional block using 4.6±2.4 minutes of radiofrequency ablation; in four patients additional radiofrequency lesions using a conventional, irrigated-tip catheter (Navistar Thermocool, Biosense Webster) were necessary.”
Mean follow-up was 140±75 days. According to Zellerhoff et al the single procedure success rate was 66%, increasing to 77% after a mean of 1.2 procedures per patient. Approximately three-fourths of the patients were in sinus rhythm and free of symptomatic or documented asymptomatic atrial fibrillation or atrial tachycardia episodes. No late complications were recorded and no pulmonary vein stenosis was detected by magnetic resonance imaging.
The authors conclude: “Irrigated multi-electrode radiofrequency ablation of atrial fibrillation using the nMARQ device is fast and effective. We observed a very high rate of isolated pulmonary veins without the need of touch-up lesions in an unselected, consecutive cohort of patients, simplifying and accelerating this otherwise complex ablation procedure. Success rates were comparable with other techniques applied in the interventional treatment of the symptomatic atrial fibrillation with a low complication rate. Longer follow-up and larger, multicentre randomised studies are needed to confirm these results.”