Randomized controlled trial of Amigo® robotically controlled versus manually controlled ablation of the cavo-tricuspid isthmus using a contact force ablation catheter

  • Kurt S. Hoffmayer
  • Felix Krainski
  • Sanjay Shah
  • Jessica Hunter
  • Maylene Alegre
  • Jonathan C. Hsu
  • Gregory K. Feld



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.

Trial registration

Clinicaltrials.gov Identifier: NCT02467179


Atrial flutter Ablation Robotically controlled ablation Contact force 



Cavo-tricuspid isthmus


Atrial flutter


Atrial fibrillation


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.


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Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2018

Authors and Affiliations

  • Kurt S. Hoffmayer
    • 1
  • Felix Krainski
    • 1
  • Sanjay Shah
    • 1
  • Jessica Hunter
    • 1
  • Maylene Alegre
    • 1
  • Jonathan C. Hsu
    • 1
  • Gregory K. Feld
    • 1
  1. 1.Division of Cardiology, Cardiac Electrophysiology Program, UCSD Health SystemUniversity of California, San DiegoLa JollaUSA

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