Advances May Improve Lesion Formation and Reduce the Risk of Catheter Ablation in Patients With AF

To reduce symptoms, improve quality of life, and prevent recurrences in patients with atrial fibrillation (AF), Duke heart-rhythm specialists are studying innovations in catheter ablation of AF that may improve the safety, efficiency, and durability of the procedure.

Rhythm medications can help prevent recurrent episodes, but many patients seeking a permanent solution opt for catheter ablation, a technique that has progressed significantly during 20 years of use.

Jonathan P. Piccini Sr, MD, a Duke hearth-rhythm specialist, says new technologies such as contact force–sensing catheters and alternative energy ablation sources may lead to significantly improved outcomes.

“What’s the definition of success?” asks Piccini. “If success means that patients have fewer episodes, fewer symptoms, and improved quality of life, then most of our procedures are successful.”

He continues: “On the other hand, if success after ablation means a total cure without any AF in the future, then we still have a lot of work to do,” Piccini cautions. “Many patients experience recurrences, especially several years after the procedure. To improve long-term success, we need to explore better techniques that produce more effective outcomes.”

Piccini and colleagues at Duke published an assessment of advances in lesion formation for catheter ablation in the April 21, 2016, issue of Circulation: Arrhythmia and Electrophysiology. The authors examined the potential of catheter technologies that could be more effective in determining lesion size and durability.

Other innovations reviewed by the authors include the potential use of novel, ultrasonographic techniques to visualize tissue injury in real time. Such techniques may lead to improvements in both the safety and effectiveness of ablation procedures.

Despite some variance in estimates due to differences in disease severity, the overall worldwide, 1-year, drug-free success rate for AF ablation is estimated to be between 40% and 60% for a single procedure and 70% for multiple procedures, the Duke authors conclude.

Drug therapy remains part of the guidelines for AF treatment, but specialists say lack of long-term efficacy—as well as risks of extended use—has shifted the focus to catheter ablation procedures. The emerging technologies, Piccini says, may present better options for ablation and imaging. Those innovations include:

• Monitoring contact force during radiofrequency ablation: More sensitive measures will reduce the risk of complications, such as perforation, and provide a more precise assessment of lesion formation. Previously, contact force has been monitored by less-accurate techniques.
• Multielectrode ablation catheters: Because point-to-point radiofrequency ablation may leave gaps and allow pulmonary vein reconnection, new multipolar ablation catheters create ostial or antral isolation with few energy applications.
• Cryothermal ablation: In development for more than 10 years, the cryothermal procedure cools tissues to between –20 and –40 °C, forming ice that disrupts organelles and cell membranes. The technology also tends to lower the incidence of thrombus formation.
• Endoscopic ablation using light amplification: Endoscopic laser ablation allows the precise aiming of an infrared laser to create point-by-point circumferential lesions.

“The main tenets of our approach have not changed in 2 decades,” says Piccini. “Yet, the procedures are continuously being improved. The procedure we do today is better than the procedure we did 2 years ago, and the procedure we do 2 years from now will be better than the one we do today. The advances in our techniques are becoming much more effective in reducing AF.”