Automated Template Matching versus Conventional Pace-Mapping during PVC Ablation:Results from a randomized controlled trial

Nele Schulz (Köln)1, D. Steven (Köln)1, A. Sultan (Köln)1, J.-H. van den Bruck (Köln)1, J. Wörmann (Köln)1, J.-H. Schipper (Köln)1, C. Scheurlen (Köln)1, S. Dittrich (Köln)2, K. Filipovic (Köln)1, S. C. R. Erlhöfer (Köln)1, J. Lüker (Köln)1

1Herzzentrum der Universität zu Köln Elektrophysiologie Köln, Deutschland; 2Herzzentrum der Universität zu Köln Klinik III für Innere Medizin Köln, Deutschland



Pace-mapping has an important role in the ablation of idiopathic premature ventricular contractions (PVC). An automated algorithm annotating and visualizing template matching points is part of the CARTO3 software version (PASO, Biosense-Webster). Automated template matching (ATM) facilitates the matching process and may thus shorten the procedure duration and potentially increase ablation success. 

In this randomized study we evaluate whether the use of the PASO automated template matching (ATM) software compared to conventional pace-mapping (PM) influences outcomes and procedural parameters in patients undergoing PVC ablation.


The study was performed as a prospective randomized controlled single-center clinical trial. Patients scheduled for de-novo PVC ablation were included and randomly assigned to either PVC ablation using the ATM algorithm (PASO) or conventional pace-mapping (PM). 

The primary endpoint was the procedural outcome represented by the PVC burden after three and twelve months. Secondary endpoints were periprocedural parameters including procedure duration, number, and duration of radiofrequency application (RFA), fluoroscopy (FS) dose, and duration.

An interim analysis was predetermined after 72 patients had completed their three-month follow-up. This trial is registered at (NCT04778696).


After the interim analysis, the study was prematurely ended for futility.

At termination of the trial 108 patients had been included. 18 patients dropped out of the study. Out of the remaining 90 patients, 88 patients (97%) have completed the three-month follow-up, and 73 patients (81%) the twelve-month follow-up. The mean age at the time of procedure was 57.3 years [18-82] without significant differences between both groups.

Before ablation, the mean PVC burden was 20.8% [0.1-55.0] (PASO: 20.8% [3.0-55.9]; PM: 20.7% [0.1-44.0]; p=0.959). At 3-month follow-up, the mean PVC burden in both groups (PASO: 4.7% [0-29.4]; PM: 3.6% [0-45.7]; p=0.512) showed no significant difference between the groups. At 12-month follow-up the mean PVC burden in both groups (PASO: 3.8% [0-31]; PM: 2.2% [0-25.6]; p=0.282) also resulted in a non-significant difference between the groups. 

Furthermore, the procedural parameters (table 1) did not differ significantly between both groups.


In this randomized trial, the use of the PASO automated template matching software integrated with the CARTO3 system did not result in improved outcomes or procedure-related parameters. Conventional pace-mapping appeared to be equally effective compared to the PASO automated template matching as used in this study.





Fluoroscopy duration [min]

8.4 [0.62-27.6]

7.8 [0.58-26.25]


Fluoroscopy dose [mGycm2]

2110.7 [80.2-14819]

1951.1 [48.6-9588]


RF applications

13.2 [1-68]

13.6 [2-61]


RF energy [Joule]

29772.5 [4644-90297]

28829.4 [4667-87435]


RF duration [ms]

992.5 [93-8955]

868.9 [65-3335]


Procedure duration [min]

114.2 [50-220]

111.0 [50-190]


Pace-mapping points

213.7 [20-1900]

178.6 [4-1274]


Table 1 Secondary endpoints



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