VIDEO: Advances in atrial fibrillation treatment have improved outcomes

 

Interview with Dhanunjaya "DJ" Lakkireddy, MD, executive medical director for the Kansas City Heart Rhythm Institute at HCA Midwest Health, a professor of medicine at the University of Missouri, Columbia, and deputy editor for the the Journal of Atrial Fibrillation, and a member Heart Rhythm Society (HRS) Board of Trustees, section steering committee chair for the American College of Cardiology (ACC). He explains explains the advances in electrophysiology (EP) ablation and mapping systems to improve outcomes in atrial fibrillation (AFib) therapy.

Advances in EP ablation and mapping systems have greatly improved outcomes in atrial fibrillation (AFib) ablation therapy. In 2016, about a third of patients who underwent ablation for AFib needed to come back for repeat ablations because of incomplete ablations allowing arrhythmia electrical signals to still get through. However, in just a few years, that number has dropped significantly thanks to new technologies. 

"The introduction of open irrigation catheters about a decade ago, contact force catheters, the automation of the electrograms into 3D imaging and fusing the electrograms with catheter contact force sensing, all of these things really changed the pulmonary vein reconnection rates," Lakkireddy said. "Today, instead of 30%, I would say we are more in the order of 5% to 10% because the durability of pulmonary lesions is much better." 

Evolution from single-point mapping and ablation to single-shot systems and high-density mapping

About 10-15 years ago, ablations were limited to single-point ablation catheters where EPs had to connect the dots to isolate areas of cardiac tissue, Lakkireddy said. Mapping systems were also primitive, using crude 3D structures to show the cardiac structures. Mapping catheters were point-by-point, and it took hours to create an electromap. Today, newer catheter technologies allow for contact force sensing to create better lesions and new types of catheters enable one-shot pulmonary vein isolations in minutes. As such, the mapping technology went from manually creating a couple hundred points to newer basket catheters now creating high-density maps using thousands of points in a very short amount of time. 

"We have experienced the most unprecedented technological innovation in the field of electrophysiology," Lakkireddy explained. "We have leveraged all the advances in digital technology. The computer chips got smaller, better and the processing power of computers got better. This enabled our ability to quickly map the heart. We moved from single-dot electro mapping catheters to high-density mapping catheters where we can get 50,000 data points in five minutes, and that was unheard of. And that really fine-tuned the cardiac anatomy, the electrical substrate, and the targets became much easier to identify. Technology now takes those squiggly lines that electrophysiologists used to identify the location arrhythmia and translates it into a real, three-dimensional color map that will really aid in making the procedures safer and more efficacious. And we have much better outcomes."

He said the dramatic revolution of the technology really changed how arrhythmia patients are cared for. In addition to offering better care for patients with straightforward arrhythmias, it also enabled ablation of much more complex conditions. 

"I think high-density mapping is here to stay because it offers amazing data that is irreplaceable," Lakkireddy explained. 

In addition to better mapping and ablation technology, there has been a rapid evolution in how complex arrhythmias are examined, including through the use of artificial intelligence (AI), which has furthered our understanding of these diseases.

"Using deep learning has made this process so much faster. The technology is constantly aiding the operator in getting them to the target much quicker, thereby we can potentially decrease the patient morbidity that is associated with these procedures," Lakkireddy explained.

Pulsed field ablation is seen as the next frontier in EP

The most exciting technology advance is with pulsed field ablation. The technology uses electrical fields to cause electroporation, where holes open up in the cell walls and cause cell death rather than direct heat or cold. This causes less collateral damage to healthy surrounding tissue. This technology is seen as a way to eliminate damage to underlying, neighboring structures such as the esophagus. 

"This is basically tinkering with the frequency of energy that is being delivered, and you can potentially cause cell destruction without destroying the tissue integrity, thereby mitigating the potential collateral damage that was experienced with traditional RF ablation technology," he said. "The early trial results are looking amazing, and nearly every major EP company has technology on this front. This will be the next big frontier EP will experience and a great leap forward."

Cryoballoon ablation has become very popular in EP labs over the past several years, partly because it solved the problem of causing damage to the AV node and AV block during ablation procedures. It was realized that if balloon catheter ablation limits collateral damage and speeds up procedures, other balloon technologies may also be beneficial. This includes balloons with multiple RF electrodes and the idea of using a balloon-like, self-expanding metal sphere to enable faster pulmonary vein isolation (PVI) ablations.

One of the balloon technologies that developed was a ballon to stabilize the catheter inside the pulmonary vein while a laser mounted in the ballon rotated to form a circle scar for faster and more precise ablation. This catheter also allows real-time visualization of the scar formation during the procedure. 

However, it is not all about PVI, he said. 

"The next frontier is how do we improve the success rates of arrhythmia ablation beyond pulmonary vein isolation? Lakkireddy said. "So this is where the existing delivery tools for cryo and laser are not viable in terms of substrate modification ablation, or if you want to do a focal ablation of an area like the left atrial appendage, or the coronary sinus. This is where the single-shot technologies fall behind and where single-shot catheters are more versatile and have advantages over the other technologies."

According to Lakkireddy, non-contact electromapping is another exciting EP area. This uses electrical sensors in a basket catheter array inside the heart to detect electrical signals without the need to touch the myocardium.

Dave Fornell is a digital editor with Cardiovascular Business and Radiology Business magazines. He has been covering healthcare for more than 16 years.

Dave Fornell has covered healthcare for more than 17 years, with a focus in cardiology and radiology. Fornell is a 5-time winner of a Jesse H. Neal Award, the most prestigious editorial honors in the field of specialized journalism. The wins included best technical content, best use of social media and best COVID-19 coverage. Fornell was also a three-time Neal finalist for best range of work by a single author. He produces more than 100 editorial videos each year, most of them interviews with key opinion leaders in medicine. He also writes technical articles, covers key trends, conducts video hospital site visits, and is very involved with social media. E-mail: dfornell@innovatehealthcare.com

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