The Direction of Therapies for Atrial Fibrillation

The therapies for patients with atrial fibrillation (AF) are headed in multiple directions, but can be placed into four categories: the directions of better, safer, faster, and cheaper (Figure 1).

The success rates for therapies to restore and maintain sinus rhythm in patients with AF, including catheter ablation, surgery, and antiarrhythmic drugs for AF are still not acceptable. Fortunately, there is much work being done to create more predictably durable ablation lesions using catheter-based ablation, and to develop strategies to improve the outcomes for patients with AF, particularly for those with persistent AF. Examples are the development of contact force catheters, ablation indices to help determine when a lesion has been created, balloon-based technologies to isolate the pulmonary veins, and alternative energy sources such as ultra-low temperature cryoablation, radiotherapy, and pulsed field ablation (PFA). Other examples include new techniques to electrically isolate the entire posterior left atrium with catheter or surgery. Left atrial appendage (LAA) closure devices for patients with AF are also getting better. The recent data from the PINNACLE FLX trial show that the newer plug-type LAA occlusion device is associated with even higher acute and long-term closure rates. 

In addition to making AF procedures better, it is important that these efforts continue to make it safer. The goal should be zero complications. Avoiding known adverse events by using vascular ultrasound to gain femoral venous access, using better tools for difficult transseptal catheterization cases, and designing strategies to minimize esophageal and phrenic injury are critical. Continued efforts are also important to reduce fluoroscopy by taking advantage of non-fluoroscopic imaging systems such as intracardiac echocardiography and high-density three-dimensional mapping systems. Despite improvements in safety, it is clear that patients often require multiple procedures, exposing them to the compounding risks of repeated interventions, and at times leaving the substrate for recurrent left atrial tachycardias despite extensive left atrial destruction. More work is needed to develop nondestructive methods to provide better rhythm control by taking advantage of autonomic modulation, radiotherapy, or gene therapy.

Procedure times for AF interventions over the past 20 years have been heading in the right direction with shorter left atrial dwell times and shorter overall procedure times. However, continued improvements in efficiency are needed. There is promising work with high-power short-duration radiofrequency delivery to speed up point-by-point ablation, and single-shot techniques to further improve our efficiency. A major potential benefit of PFA is a dramatic reduction in procedure times. Reducing procedure times also means devising approaches that avoid the need for general anesthesia, and allowing early ambulation using vascular closure devices or other creative measures to quickly restore hemostasis.

Despite increasingly minimalistic approaches in the EP laboratory, the supply costs for catheter ablation procedures have increased over time with the adoption of balloon-based devices and high-density mapping catheters, and routine use of intracardiac echocardiography, esophageal protection devices, and general anesthesia. Any technology or technique that is better, safer, or faster will only be adopted if it is at least cost neutral. More efforts are needed to develop strategies that require fewer catheters and take advantage of reprocessing. Other ways to minimize the overall costs of AF procedures is to develop pathways for same-day discharge.

Interventions for AF are headed in multiple directions. Developments that push the field in more than one direction will more likely succeed. 

Disclosures: Dr. Knight reports that he is a consultant, speaker, investigator, and offers fellowship support for Abbott, Baylis Medical, Biosense Webster, Inc., BIOTRONIK, Boston Scientific, Medtronic, and SentreHEART. He has received compensation for serving as a consultant to CVRx, Inc.