Comparison between a 7 French 6 mm tip cryothermal catheter and a 9 French 8 mm tip cryothermal catheter for cryoablation treatment of common atrial flutter.
BACKGROUND
Larger tipped cryothermal catheters may deliver efficacy and procedure benefits in the treatment of patients with atrial flutter.


OBJECTIVE
To compare 7 French 6 mm and 9 French 8 mm tip cryothermal catheters (Freezor, Xtra or Freezor, MAX, CryoCath Technologies Inc., Kirkland, Canada) in terms of acute and chronic efficacy, and procedure characteristics in the treatment of atrial flutter.


METHODS
This non-randomized clinical investigation determined bi-directional isthmus block at intervention, procedure characteristics, and symptom and conduction recurrence rates post procedure in consecutive patients with symptomatic atrial flutter ablated either with the 7 French 6 mm tip cryothermal catheter (n = 43) at -75 degrees C for 4 minutes or the 9 French 8 mm tip cryothermal catheter (n = 51) at -75 degrees C for 8 minutes.


RESULTS
Clinical data showed a higher acute success rate for the larger tipped catheter (100% vs. 88%). Symptom recurrence rates were 0% for both catheters at 3, 6, and 9 month follow-up. Conduction recurrence rates were similar for both catheters on repeat electrophysiological study at 3 months post procedure (35% vs. 32%). Procedure benefits were fewer cryotests (20 +/- 17 vs. 26 +/- 21) and ablations (4 +/- 4 vs. 12 +/- 18), and shorter procedure (80 +/- 61 min vs. 87 +/- 48 min), fluoroscopy (14 +/- 9 min vs. 24 +/- 10 min), and cryoapplication times (37 +/- 18 min vs. 44 +/- 23 min) with the larger tipped catheter. There were no adverse events reported.


CONCLUSIONS
Clinical results showed differences in catheter performance that favoured the larger tipped catheter. However, increased acute success rate did not translate into reduced conduction recurrence rate post ablation, although clinical recurrence was completely absent long-term.
Montenero
Annibale S
AS
Cardiology Department and Arrhythmia Center of Policlinico MultiMedica, Sesto S. Giovanni, Milan, Italy. montenero@hotmail.com
Bruno
Nicola
N
Antonelli
Andrea
A
Mangiameli
Daniele
D
Barbieri
Luca
L
Andrew
Peter
P
Zumbo
Francesco
F
D000328:Adult; D000368:Aged; D001282:Atrial Flutter / Q000175:diagnosis* / Q000401:mortality / Q000601:surgery*; D017115:Catheter Ablation / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D002404:Catheterization; D003452:Cryosurgery / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D004562:Electrocardiography; D004867:Equipment Design; D004869:Equipment Safety; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011336:Probability; D012008:Recurrence; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D013997:Time Factors; D016896:Treatment Outcome