Combining RF and CryoBalloon Ablation Techniques, Do Success Rates Increase?
by Steve S. Ryan, PhD
Pulmonary Vein ablation (PVA), using RF point-by-point isolation, or using CryoBalloon technology? It is really a choice of one or the other?
What happens when you combine the two techniques? Do ablation success rates increase?
To answer these questions, UK researcher, Dr. Ross J. Hunter devised a single-center study to compare three different ablation strategies. He divided 237 Paroxysmal A-Fib patients undergoing their first ablation into three treatment groups.
Group 1 Strategy: standard RF point-by-point ablation of the Pulmonary Vein openings (PVs) using an irrigated tip catheter guided by a 3D mapping system.
Group 2 Strategy: CryoBalloon ablation using the Arctic Front CryoBalloon catheter, and if PV isolation wasn’t achieved using the CryoBalloon alone, RF focal lesions were added.
Group 3 Strategy: RF point-by-point ablation followed by two applications of the CryoBalloon.
Success Rates After One Year
Group 1: At one year 47% were A-Fib free and off of all antiarrhythmic drugs; (This is a relatively low success rate compared to some centers using RF ablation.) Average procedure time was 211 minutes;
Group 2: The one year success rate was 67% (significantly better than the RF group); Important Note: In addition to the CryoBalloon, 31% needed RF focal lesions to achieve PV isolation. Average procedure time was 167 minutes;
Group 3: After one year the success rate was 76% which was better than the CryoBalloon alone, but the difference wasn’t ‘statistically significant’ (meaning it could have occurred by chance). Average procedure time was 278 minutes.
The Study Results: How the Three Strategies Compare
Best result: Group 2 Strategy: ‘CryoBalloon plus RF lesions as needed strategy’. It was faster, easier to use and was more effective after one year than the Group 1 strategy ‘RF point-by-point ablation’.
Disappointing result: Using the novel Group 3 strategy of combining ‘RF ablation followed by CryoBalloon ablation’ did not significantly improve results and took longer to do.
Most surprising result: When the authors designed this study, they thought the combined approach of ‘RF ablation followed by CryoBalloon’ (Group 3) would turn out to be superior to the other two strategies. Their prediction was wrong. It turned out it was only superior to ‘RF alone’ strategy (Group 1).
The Bottom Line
The take-away: About 30% of CryoBalloon ablations required RF focal lesions to achieve isolation of all A-Fib signals and to restore the patient to normal sinus rhythm.
What This Means for A-Fib Patients
For the best results with a CyroBalloon ablaltion, you want an electrophysiologist (EP) who is not only experiened with CryoBalloon, but who can also use RF technology when needed to map and isolate A-Fib signals originating beyond the pulmonary veins.
Finding the right EP: Be cautious. With the advent of CryoBalloon ablation, some EPs with little or no expertise with RF ablations are now doing CryoBalloon ablations. Why? Because they’re easier to perform. As a patient, you want to stay away from EPs who only do CryoBalloon ablation.
Here’s an example why:
Recently a patient, still in A-Fib, sent me the O.R. (Operating Room) report of their CryoBalloon ablation. From reviewing the report, after ablating the Pulmonary Veins (PV), it appears the EP didn’t make any attempt to map and isolate non-PV triggers. When the patient didn’t return to normal sinus rhythm on his own, the EP simply cardioverted the patient back into normal sinus rhythm. This may work in some cases. But for this patient the ablation was a failure.
Most experienced EPs who have switched from performing RF ablations to CryoBalloon ablations have the ability, skill and experience when needed to use RF technology to isolate non-PV triggers when needed.
Questions to Ask Prospective EPs: to find the right EP for your CryoBalloon ablation ask:
What do you do if I’m still in A-Fib after you do the CryoBalloon ablation?
Will you use RF techniques to get me back into normal sinus rhythm?
(You want an EP who answers ‘yes’ to the second question.)