Randomized controlled trial of Amigo® robotically controlled versus manually controlled ablation of the cavo-tricuspid isthmus using a contact force ablation catheter
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Radiofrequency catheter ablation (RFCA) of the cavo-tricuspid isthmus (CTI) is a common treatment for atrial flutter (AFL). However, achieving bi-directional CTI conduction block may be difficult, partly due to catheter instability.
To evaluate the safety and efficacy of the Amigo® Remote Catheter System (RCS) compared to manual catheter manipulation, during CTI ablation for AFL.
Fifty patients (pts) were prospectively randomized to robotically (25 pts) versus manually (25 pts) controlled catheter manipulation during CTI ablation, using a force-contact sensing, irrigated ablation catheter. The primary outcome was recurrence of CTI conduction after a 30-min waiting period. Secondary outcomes included total ablation, procedure, and fluoroscopy times, contact force measurement, and catheter stability.
Recurrence of CTI conduction 30 min after ablation was less with robotically (0/25) versus manually (6/25) controlled ablation (p = 0.023). Total ablation and procedure times to achieve persistent CTI block (6.7 ± 3 vs. 7.4 ± 2.5 min and 14.9 ± 7.5 vs. 15.2 ± 7 min, respectively) were not significantly different (p = 0.35 and p = 0.91, respectively). There was a non-significant trend toward a greater force time integral (FTI in gm/s) with robotically versus manually controlled CTI ablation (571 ± 278 vs. 471 ± 179, p = 0.13). Fluoroscopy time was longer with robotically versus manually controlled CTI ablation (6.8 ± 4.4 min vs. 3.8 ± 2.3 min, p = 0.0027). There were no complications in either group.
Robotically controlled CTI ablation resulted in fewer acute recurrences of CTI conduction compared to manually controlled CTI ablation, and a trend toward higher FTI. The longer fluoroscopy time during robotically controlled ablation was likely due to a steep learning curve.
Clinicaltrials.gov Identifier: NCT02467179
KeywordsAtrial flutter Ablation Robotically controlled ablation Contact force
Robotic control system
Force time integral
Radiofrequency catheter ablation
Pulmonary vein isolation
Tricuspid valve annulus
Low lateral right atrium
Left ventricular ejection fraction
Compliance with ethical standards
This study was approved by the local Investigational Review Board (IRB) for human subjects, prior to its initiation. Informed consent was obtained from each patient prior to participation.
Conflict of interest
Hoffmayer, Krainski, Hunter, and Alegre declare no conflict of interest. Dr. Hsu has received honoraria from Medtronic, St. Jude Medical, Boston Scientific, and Biotronik and research funding from Biotronik and Biosense Webster. Feld, as Director of the CCEP Fellowship Training Program, has received stipends from Medtronic, Biosense Webster, Boston Scientific, Biotronik, and St. Jude Medical.
- 4.Feld GK, Fleck RP, Chen PS, et al. Radiofrequency catheter ablation for the treatment of human type 1 atrial flutter. Identification of a critical zone in the reentrant circuit by endocardial mapping techniques. Circulation. 1992;86(4):1233–40. https://doi.org/10.1161/01.CIR.86.4.1233.CrossRefPubMedGoogle Scholar
- 7.Saoudi N, Cosio F, Waldo A, et al. Classification of atrial flutter and regular atrial tachycardia according to electrophysiologic mechanism and anatomic bases: a statement from a joint expert group from the Working Group of Arrhythmias of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology. J Cardiovasc Electrophysiol. 2001;12:852–66.CrossRefPubMedGoogle Scholar
- 10.Scheinman MM, Cheng J, Yang Y. Mechanisms and clinical implications of atypical atrial flutter. J Cardiovasc Electrophysiol. 1999;10(8):1153–7. https://doi.org/10.1111/j.1540-8167.1999.tb00288.x.CrossRefPubMedGoogle Scholar
- 11.Scheinman MM and Yang Y. Atrial flutter: historical notes—part 1. PACE. 2004:1–3.Google Scholar
- 16.Mangat I, Tschopp DR Jr, Yang Y, Cheng J, Keung EC, Scheinman MM. Optimizing the detection of bidirectional block across the flutter isthmus for patients with typical isthmus-dependent atrial flutter. Am J Cardiol. 2003;91(5):559–64. https://doi.org/10.1016/S0002-9149(02)03306-4.CrossRefPubMedGoogle Scholar
- 19.Saoudi N, Ricard P, Rinaldi JP, Yaici K, Darmon JP, Anselme F. Methods to determine bidirectional block of the cavotricuspid isthmus in radiofrequency ablation of typical atrial flutter. J Cardiovasc Electrophysiol. 2005;16(7):801–3. https://doi.org/10.1111/j.1540-8167.2005.40624.x.CrossRefPubMedGoogle Scholar
- 25.Bru P, Duplantier C, Bourrat M, Valy Y, Lorillard R. Resumption of right atrial isthmus conduction following atrial flutter radiofrequency ablation. Pacing Clin Electrophysiol. 2000;23(11P2):1908–10. https://doi.org/10.1111/j.1540-8159.2000.tb07050.x.CrossRefPubMedGoogle Scholar