Epicardial Electroporation Effectively Ablates Myocardium Without Compromising Coronary Artery Patency

Ammar Killu1, Niyada Naksuk1, Elad Maor1, Roshini Asirvatham1, Jason Tri1, Christopher DeSimone1, Scott Suddendorf2, Dorothy Ladewig3, Joanne Powers2, Samuel Asirvatham1
1 Cardiovascular Disease, Mayo Clinic, USA
2 Surgical Research Services, Mayo Clinic, USA
3 Mayo Clinic Ventures, Mayo Clinic, USA

Aims: Epicardial ablation is commonly performed; however, concern exists regarding the potential for epicardial coronary artery damage. Electroporation is a non-thermal mode of ablation that induces cell death by formation of pores within the membrane. We sought to determine the efficacy and safety of epicardial electroporation.

Methods and Results: Percutaneous epicardial mapping and electroporation in the vicinity of coronary arteries was performed using a 4 or 8 mm Blazer catheter (Biosense Webster, CA) connected to a Nanoknife system (Angiodynamics, NY). Electroporation delivery protocol consisted of 500-3000V in 20-100 pulses of 20-100┬Ás duration. Pre and post-electroporation coronary angiograms were performed. Changes in electrogram (EGM) were deemed consistent with ablation if there was reduced amplitude, splitting or loss of the signal.

Fifteen therapies were delivered in two acute canine (27-30 kg) studies. In one therapy, catheter position changed after electroporation and, therefore, was excluded from the analysis. Of the remaining 14 therapies, EGM evidence of ablation was seen in all locations (top panel). Transient ST-segment change was seen following only one therapy. Coronary angiography pre and post electroporation showed no coronary artery stenosis (bottom panel). Atrial fibrillation occurred in 1 delivery; ventricular fibrillation and ventricular tachycardia requiring defibrillation occurred in 1 delivery each, the cause of which is undetermined. At necropsy, no gross lesions were identified.

Conclusion: Electroporation effectively ablates epicardial tissue without acute effects on coronary artery patency.