Prospective randomised comparison of irrigated-tip and large-tip catheter ablation of cavotricuspid isthmus-dependent atrial flutter.
BACKGROUND
Radiofrequency (RF) ablation of cavotricuspid isthmus (CTI) dependent flutter can be performed using different types of ablation catheters. It has been proposed that irrigated and large-tip catheters are capable of creating larger lesions, resulting in greater efficacy. This prospective, randomised clinical study compared the efficacy of irrigated and large-tip catheters of different designs.


METHODS
Eighty patients (69 men, 66+/-11 years) undergoing de novo RF ablation of CTI-dependent flutter were randomised to ablation using one of the following catheters: (i) externally-irrigated 20), (ii) internally-cooled (n=20), (iii) single sensor, 8-mm tip (n=20), or (iv) double sensor, 8-mm tip (n=20). The study endpoint was the demonstration of bidirectional CTI conduction block within 12 min of cumulative RF delivery. Crossover to the externally-irrigated catheter was permitted if this was not achieved. The ablation and procedural parameters, safety and efficacy were compared.


RESULTS
The primary endpoint was achieved in 64 patients (80%), including all 20 patients randomised to the externally-irrigated catheter. Crossover was required in 16 patients: 9 initially using the internally-cooled catheter (45%), 3 using single-sensor, 8-mm-tip (15%), and 4 using double-sensor, 8-mm-tip (20%) catheters. The higher initial failure rate with the internally-cooled-tip catheter was significant compared to the externally-irrigated (p = 0.001) and single-sensor, 8-mm-tip (p = 0.04) catheters. The externally-irrigated catheter achieved the study endpoint more frequently with fewer RF applications of shorter duration compared to the internally-cooled-tip catheter and 8-mm-tip catheters, the difference being significant compared with internally cooled ablation. No major complications were observed.


CONCLUSIONS
Among commonly used ablation catheters, the externally-irrigated catheter has a higher efficacy for rapid achievement of CTI block.
Scavée
Christophe
C
Hôpital Cardiologique du Haut-Lévêque, Service de Rythmologie, Avenue de Magallen, 33000 Bordeaux-Pessac, France. scavee@ziplip.com
Jaïs
Pierre
P
Hsu
Li-Fern
LF
Sanders
Prashanthan
P
Hocini
Meleze
M
Weerasooriya
Rukshen
R
Macle
Laurent
L
Raybaud
Florence
F
Clementy
Jacques
J
Haïssaguerre
Michel
M
D000368:Aged; D001282:Atrial Flutter / Q000601:surgery*; D017115:Catheter Ablation / Q000009:adverse effects / Q000295:instrumentation*; D004594:Electrophysiology; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D011446:Prospective Studies; D007507:Therapeutic Irrigation / Q000379:methods