Hello, I'm Professor Luigi Di Biase from the Albert Einstein College of Medicine at the Montefiore Health System in New York.

During the AFib Symposium 2025, the 30th anniversary, I had the pleasure to present the subanalysis of the VARIPULSE FDA IDE trial on the early versus late recurrence of atrial fibrillation with the pulsed field ablation system. And this presentation ended with a simultaneous publication in Europace. I would like to thank all the co-authors for this amazing outcome.

What is the importance behind the trial?

This was a subanalysis of the admIRE trial. The admIRE trial was an IDE FDA clinical trial that looked at the safety, efficacy and feasibility of performing catheter ablation of paroxysmal atrial fibrillation with the VARIPULSE catheter from Johnson & Johnson MedTech. And that was a study that aimed to that the 12-month follow up was published last October in Circulation.

The aim of this subanalysis was to look at the importance of the blanking period in PFA ablation, and in this case, the PFA with the VARIPULSE catheter. But in general, we wanted to expand this to the pulsed field ablation field. Preliminary data from the group of Dr Natale, post author, Dr Mohanty, I'm a co-author and preliminary data also from another PFA technology such as the one from Medtronic also proved with Dr [indistinct], first author, and I'm a co-author on that either, that PFA blanking period has less importance than radiofrequency / cryoablation.

What was the study design and patient population?

So the study design in this case were paroxysmal atrial fibrillation, paroxysmal symptomatic atrial fibrillation patients that had failed the medication that were undergoing a catheter ablation with the pulse field ablation VARIPULSE. In this patient population, we looked at the outcome and we evaluated the blanking period.

Historically, the blanking period for radiofrequency cryo was introduced in trial design because after the procedure the heart is kind of irritated by the procedure, there is kind of an inflammation and so if you have a recurrence in the first, second or third month, this was not a failure of the procedure but was considered blanking period, meaning we don't count as a failure. And most of the time we had that this recurrence either AFib or AFlutter were going to terminate on their own at the end of the three months blanking period.

In 2024, the new consensus document of cardiac ablation of atrial fibrillation led by Dr Tzeis. I'm a co-author of this consensus document. But reduce the duration of the blanking period to two months for the radiofrequency / cryoablation.

The aim of this study was to evaluate what happened with PFA. Do we still have the same amount of inflammation? Does the blanking period still have a role in trial design with pulsed field ablation?

What were the key findings?

The key finding of the study that enrolled or analysed, since it was on enrolment as a subanalysis, about 165 patients, was to compare early recurrence of atrial fibrillation documented in the first two, three months versus late recurrence and look at what was going to happen in these patients. And the surprising findings were that with PFA, looks like if you have a recurrence at month one / month two, most likely you're going to have a recurrence after that period.

So this means that blanking period does not count that much with pulsed field ablation. If you have a recurrence in the first / second month, this means it's a failure of the procedure and intervention is necessary. Either a cardioversion, an additional medication to whatever you were taking on, an escalation of the medication or a repeat ablation. We no longer will be able to tell our patients that they will need to wait before a determination has to be made. And this of course, if the patient are asymptomatic for their recurrence.

How should these insights impact clinical practice for PFA?

Well, these results will probably not impact the patient selection but will teach us how to design future randomized control trial, an IDE trial, or approval trial, kind of eliminating the need of a blanking period. And this will guide us clinically.

Again, as I said before, we no longer have to wait more than one month to determine what to do with the patient. Of course, if the patient is symptomatic for anything, this needs to be taken care of immediately. But if the patient is asymptomatic, when we had blanking period, we kind of waited about two months before any new therapy was going to be offered. We now know that we can offer that therapy because that recurrence is going to stay. This will change practice.

Of course we need a bigger randomized control trial to do that, but this subanalysis has the potential of change clinical practice, change patient management and potentially change future study design on AF ablation with pulse field ablation.

What are the next steps?

I mean, the next comment is that pulse field ablation has changed a lot. We practice medicine, we don't have to worry any longer about many things like esophageal damage, phrenic nerve damage and probably inflammation. We still create some damage to the heart cell, but with less inflammation. This is extremely important information. We keep learning from this, but this has very good advantages.