Emerging Pulsed Field Ablation Technologies to Treat Atrial Fibrillation: Interview With Steven Mickelsen, MD

For this feature interview, EP Lab Digest spoke with Steven Mickelsen, MD, during the 2023 Western Atrial Fibrillation (AFib) Symposium. Dr Mickelsen is the CEO of Field Medical and a renowned cardiac electrophysiologist who has dedicated most of his medical career to advancing cardiac ablation technology, both as a practicing physician and an inventor. In 2012, he launched FARAPULSE, which pioneered pulsed field ablation (PFA) procedures. After successfully conducting several proof-of-concept clinical trials in Europe, FARAPULSE was acquired by Boston Scientific in 2014. In 2022, Dr Mickelsen founded Field Medical, a medical device technology company pioneering the next generation of PFA technology with a mission to bring the most advanced ablation tools to market. Field Medical was named after the electrical “field,” which is the cornerstone of PFA technology. The team at Field Medical is busy developing a new kind of non-thermal ablation technology called field bending. The tools will be highly effective, yet minimize unintended impacts on surrounding areas of the body, allowing for the best possible outcomes during cardiac ablation procedures.

Among your peers, you have been a pioneer in advancing PFA technologies. What initially inspired you to work in this field?

I started working at the University of Iowa as a fellow in training, and during that time, I developed a new technology that was used for treating AFib. We started a company called FARAPULSE. It was originally started as a company called Iowa Approach, because the technology and the initial invention came out of the University of Iowa. That success really drove my interest to become an expert in that energy source.

You recently launched Field Medical to bring next-generation PFA catheters to market. However, this is not your first time starting a company. What inspires you to be an entrepreneur and innovator?  

I think probably the most exciting thing that you can do is create something new, and especially when you can do it in a way that helps your patients and improves medicine overall. You can treat patients as a physician and it is very rewarding. It is immediate gratification. But, I have found that I am drawn to create new tools just by being frustrated in these procedures that we do every day in the hospital. We can definitely make it better. So, I started Iowa Approach, which became FARAPULSE, which is now Boston Scientific, and brought this new technology. Through the last decade, I have continually stayed active as a consultant for many other new, novel companies that are trying to create something, I helped develop a few more technologies for Acutus Medical, and that eventually led to me deciding it was time to start a new company, Field Medical.

Can you tell us more about what the team at Field Medical is currently working on?

Right now, there is an arms race going on in pulsed electric field for specialized tools that do pulmonary vein isolation (PVI) extremely well. Everyone is really a fast follower for FARAPULSE. I see all the parts of the heart for my patients that need to be treated. There are huge drawbacks in thermal ablation that, if you study it very well, you know how technically challenging it is to be able to safely create reliable, precise lesions in the heart. Despite 35 years of iterative improvement in radiofrequency (RF), in order to treat all the other arrhythmias—not just PVI, but to treat flutter, focal arrhythmias, ventricular tachycardia (VT), and PVCs—I feel that pulsed electric field is uniquely positioned to be superior to RF eventually. So, that is what we are focused on. A focal deflectable catheter takes optimizing of pulsed field and brings it to this very familiar platform, which is like riding a bicycle for EP doctors. The difference will be that we optimize the way that the electric field is generated at the tip, and that is what the company is really focused on.

For those who might say current methods used to treat AFib and other cardiac conditions are sufficient, what do you hope Field Medical can do to further improve outcomes? 

I think that most people recognize that we have not found a sufficient way to actually treat all the arrhythmias yet. So many people have arrhythmias that go untreated, primarily because the medicines that we have are ineffective and have a lot of side effects and toxicities, which can even include mortality. With catheter ablation, although it is a huge step forward in our ability to manage these arrhythmias and can be very safely achieved, the procedural efficiency is a problem to being able to treat millions of people when you only have thousands of doctors. Getting the procedures so that they are more predictable, faster, safer, and cost-effective is an important part of this next phase of development of the next 2 or 3 decades.

Several prominent cardiologists have joined Field Medical as advisory board members. Can you elaborate on their role? 

As a practicing EP, I am incredibly flattered that I was able to attract some of the most talented and well-known colleagues in the world. In particular, I was very happy to bring on Kars Neven, MD, PhD. At the same time I was pioneering pulsed field for FARAPULSE, he was working closely with Dr Wittkamp’s group and Abbott developing another technology, but more from a basic science point of view. So over the decades, we have become pretty close. We have a bunch of other physicians who are contributing but not officially on the board. So, the way I see it, every single physician who is practicing out there who really wants to make this field better and improve our ability to treat patients is on our advisory board, because that is what we are focused on—to listen to the physicians and patients, and try to improve science.

Field Medical uses a term called field bending—can you elaborate further?  

The way I see first-generation pulsed field technology platforms is that most of the focus has been on creating tools that do PVI, but development of the waveform. They have been playing with biphasic and monophasic, pulse patterns, and unipolar and bipolar. There are a lot of variables, but not a lot of people, especially in focal catheters, have paid a lot of attention to geometry. And it turns out that you can actually change the way that the electric field is shaped by playing with that geometry and with some of the way that the pulse generator delivers that energy. This allows us to really decrease the total amount of energy used in order to make the ablation happen. That means it is less likely to be thermal. Field bending is our ability to move the current path around an obstacle that changes the shape and optimizes it for tolerability and efficacy.

What is one thing that cardiac electrophysiologists and other health care professionals should know when this new PFA technology hits the market?

Field Medical is completely focused on a focal catheter platform. What I want them to know is that once we get this technology optimized and ready for people, we have a tool that can completely replace the RF ablation catheter. That is what we are designing and building toward, to be able to take this very versatile and well-understood tool and deliver all the advantages of pulsed field, so that we can treat VT and PVCs much more effectively, and open up and address that unmet need.

From your perspective, what will be the benefits of next-generation PFA catheters for patients?

Let's use VT as an example. A focal ablation tool can actually treat 100% of all arrhythmias that are out there. You do not need a specialized tool, but the specialized tools do have a value proposition, such as a linear catheter or the FARAPULSE flower. What we do by expanding the capabilities of this platform so that you can treat things like VT is improve speed, and thereby, safety, and potentially the need for long anesthesia. We can take that away and make more predictable lesions. For patients, the real fundamental potential outcome of this type of a project is that we take the 80% of patients who are currently being treated by a focal catheter, and increase availability and potentially reduce the cost. Most importantly, it is also about the availability, so that when there are 7 million people who have ventricular arrhythmias, a large segment of that group can benefit from ablation. It is very hard to treat that many people when you only have 4,000 doctors and each procedure takes 4 hours. So, getting the procedure time down and have it be predictable and effective can really reach patients much more effectively than what we have today.