Contact force data reduce pulmonary vein reconnection but do not impact ablation success rates

SAN FRANCISCO — Having contact force data available to the operator during catheter ablation was associated with reduced pulmonary vein reconnection, but no improvement in overall 1-year success rates, researchers reported at the Heart Rhythm Society Annual Scientific Sessions.

“Many members of the EP community feel that Contact Force sensing Catheters represent a huge advance in their ability to create effective RF lesions. However, randomized control trial data assessing whether this translates to a significant improvement in the success rates of Pulmonary Vein Isolation (PVI) have been lacking so far,” Dhiraj Gupta, MD, a consultant cardiologist at the Liverpool Heart and Chest Hospital, United Kingdom, said during a presentation.

Dhiraj Gupta

At seven centers in the United Kingdom, 117 patients undergoing ablation for paroxysmal AF were randomly assigned to ablation with (n = 59) or without (n = 58) contact force data. Follow-up was for 1 year. Primary endpoints included procedural parameters and acute and long-term success rates. The target contact force during ablation was 5 g to 40 g.

According to the results, no difference was found in the rate of complication between contact force on and contact force off (3% vs 5%; P = .7) or in 1-year success rates (log-rank P = .6). However, patients who had the contact force data on during the procedure saw a 30% reduction in acute pulmonary vein reconnection rates (22% vs. 32%; P = .04).

In addition, Gupta and colleagues observed that, while mean ablation contact force did not differ (contact force on, 13.4 g; contact force off, 13.4 g; P = .5), a larger percentage of readings in the contact-force-on group were in the 5 g to 40 g target range than the contact-force-off group (80% vs. 68%; P < .0005).

This suggests, Gupta said, that the contact force data allow greater control during the procedure.

“So, the question is why were our results different from what we anecdotally expected?” Gupta asked during the presentation.

“One important difference is that we used the same equipment in both arms and that our operators were very experienced with the technology,” he said. “There are other things that are important besides tissue thickness, like for instance, the stability of the catheter. In the future, there are other targets that will be used such as ablation index and force-time integral.” – by Tracey Romero

Reference:

Ullah W, et al. LBCT 02. Presented at: Heart Rhythm Society Annual Scientific Sessions; May 4-7, 2016; San Francisco.

Disclosure: The trial was supported by Biosense Webster. Gupta reports receiving speaking fees and research funding from Biosense Webster.