KODEX-EPD mapping for AF ablation

Consultant cardiologist Professor Andre Ng, University of Leicester and Glenfield General Hospital who is leading the trial of the Philips KODEX-EPD cardiac mapping and navigation system, suggests the approach could also deliver more personalized atrial fibrillation (AF) therapy. The system uses di-electric imaging to create CT-like three-dimensional, high-definition images of cardiac structures in real time and was used for the first time in the UK in August by Professor Ng on two AF patients at the National Institute for Health Research (NIHR) Leicester Biomedical Research Centre (BRC). Cardiac mapping and navigation is standard care to guide catheter ablation for patients with heart rhythm disturbance that fail to respond to drugs and require intervention to help identify targets for lesions. But catheter ablation still requires high levels of skill to create lesions in the heart muscle at exactly the right points. In using the new system to guide the procedures, Professor Ng was able to apply lesions with greater precision, increasing the operation’s effectiveness and reducing the risk of complications. The KODEX-EPD mapping system uses a novel di-electric energy source which allows electrophysiologists to electrically image unique characteristics of the heart, detailing the heart wall and other structures, providing advantages over other mapping systems currently used. The sensor can be contact or non-contact on the heart wall, offer a before and after view, and provide images of structures in fine detail. ‘Even without touching the heart wall, the di-electric sensing—which is the novelty of this technology—allows us to see intricate details of the inside of the heart and other structures such as the mouth of the coronary sinus, systemic and pulmonary veins, and valve structure. They are normally not accessible with other mapping systems, whereas KODEX allows us to see it almost like a real-time CT image’, said Professor Ng, who is Professor of Cardiac Electrophysiology at the University of Leicester, research director for the Department of Cardiovascular Sciences, deputy cardiovascular lead at the BRC and a Consultant Cardiologist at Glenfield Hospital (Figures 1 and 2). Screenshot before ablation with left panel showing a posterior view of the three-dimensional geometry of the left atrium and four pulmonary veins generated within the KODEX-EPD system and right panel showing the high definition image inside the left atrium of the mouths (ostia) of the pulmonary veins, indicating the precise locations of the ablation region. The purple colour on the left panel denotes high voltage, i.e. healthy tissues prior to ablation. Screenshot after ablation with similar arrangement as Figure 1. Purple colour denotes healthy unablated atrial tissue and successful ablation is achieved at the mouths of the four pulmonary veins. Cryoablation for AF is currently conducted with X-ray and without any mapping, meaning there is no way of immediately checking the ablation. ‘AF ablation has been around for about 20 years and while the technique has evolved the results are now a little stagnant and are variable’, he added. ‘An Achilles heel of this therapy is that we do not have real-time information of how good the ablation lesions we deliver are. Using KODEX in a cryoablation setting allows us to see the effects of ablation before and after and, because it gives us a good three-dimensional image of the structure of the heart in real time, I felt I needed to rely on the X-ray less, though I think we need to do more cases to collect the data to verify that’. The KODEX-EPD software is part of the Patient Specific Outcome Trial (PSOT) multicentre study with Glenfield Hospital as the UK’s lead for the trial to validate the system for patients undergoing ablation for AF and other arrhythmias. And although the software is proprietary, the hardware used to generate it is not, creating a more open platform in terms of the hardware. Professor Ng suggests the system can change the way patients are treated, particularly as practitioners have at times been slow to recognize the individual differences in AF patients in terms of age, gender, different sizes of heart muscle, and comorbidities. ‘While all these are thrown into the mix, we are doing the procedure with the same approach and maybe being a little naïve in thinking the procedure is a one-size-fits-all. At present, the clinician does not have access to real-time intricate detail of the heart muscle. We are blind’, he continued, ‘but the KODEX system can potentially unblind us to the different characteristics of a patient’. That can help influence decisions on the amount of energy to give to different areas of the muscle wall that are of a different thickness, for example. With KODEX potentially delivering real-time beat-by-beat information of heart muscle characteristics and an indication of ablation quality once the lesion has been applied, he said it could prove a significant advance on current mapping systems. ‘If KODEX delivers that real-time data, that is not being delivered in current conventional mapping systems, then this can be a potential game-changer because we can then guide the procedure almost burn by burn or freeze by freeze with the amount of energy we deliver at each point of the heart’. With the procedure tailored to the local characteristics of heart muscle and delivering real-time feedback on whether the lesion has been effective, he sees di-electric sensing as a ‘prime example of personalized stratified precision medicine’. Professor Ng is hopeful there will be benefits for the patient and the cardiologist with improved procedure outcomes and safety, a reduction in the need for patients to return for a repeat procedure and less use of X-ray and radiation. He added that the initial results are ‘very promising’. Conflict of interest: none declared.