Human in vitro assay for irreversible electroporation cardiac ablation

Abstract

Introduction: Pulsed electric field (PEF) cardiac ablation has been recently proposed as a technique to treat drug resistant atrial fibrillation by inducing cell death through irreversible electroporation (IRE). Improper PEF dosing can result in thermal damage or reversible electroporation. The lack of comprehensive and systematic studies to select PEF parameters for safe and effective IRE cardiac treatments hinders device development and regulatory decision-making. Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) have been proposed as an alternative to animal models in the evaluation of cardiac electrophysiology safety.Methods: We developed a novel high-throughput in vitro assay to quantify the electric field threshold (EFT) for electroporation (acute effect) and cell death (long-term effect) in hiPSC-CMs. Monolayers of hiPSC-CMs were cultured in high-throughput format and exposed to clinically relevant biphasic PEF treatments. Electroporation and cell death areas were identified using fluorescent probes and confocal microscopy; electroporation and cell death EFTs were quantified by comparison of fluorescent images with electric field numerical simulations.Results: Study results confirmed that PEF induces electroporation and cell death in hiPSC-CMs, dependent on the number of pulses and the amplitude, duration, and repetition frequency. In addition, PEF-induced temperature increase, absorbed dose, and total treatment time for each PEF parameter combination are reported.Discussion: Upon verification of the translatability of the in vitro results presented here to in vivo models, this novel hiPSC-CM-based assay could be used as an alternative to animal or human studies and can assist in early nonclinical device development, as well as inform regulatory decision-making for cardiac ablation medical devices.

Utilizing Human-Induced Pluripotent Stem Cells to Study Cardiac Electroporation Pulsed-Field Ablation

“…Significant cardiomyocyte recovery was observed following PFA, with resumption of electric activity in 40% to 67% of the initial functional lesion within 1-hour post-PFA. Consistent with previous reports, 33 , 34 , 38 protocol modifications could influence the extent of reversible electroporation, with a tight spatial correlation between the expected distribution of the electric field intensity and the eventual occurrence of irreversible electroporation. These observations have important clinical consequences, as the immediate development of localized electric silencing and functional conduction blocks does not necessarily mean long-term persistence of these lesions.…”

“…This is consistent with previous in vivo and in vitro reports, including recent studies utilizing hiPSC-CMs. 13,14,33,34,37,41 In regions of the culture subjected to lower field intensities, a delayed recovery of electric activity could be detected. These findings further emphasize that initial electric silencing following PFA does not necessarily translate into durable lesions, and that recovery of electric activity may occur over the course of hours/days.…”

“… 32 Recently, hiPSC-based cellular models were used to study PFA cardioselectivity and irreversibility thresholds using cell-viability markers, not addressing however electrophysiological parameters. 13 , 33 In the current study, we aimed to harness the advancements made in using hiPSC-derived cardiac tissue models in electrophysiology research to study the fundamentals of cardiomyocyte electroporation, with a specific focus on the impact of PFA on the functional and electrophysiological properties of these models.…”

Opportunities and Challenges in Catheter-Based Irreversible Electroporation for Ventricular Tachycardia

“…Published data evaluating the molecular effects of PFA on cell cultures have revealed a differential response and toxicity threshold from both murine and human cardiomyocytes, neurons, and cardiac adipocytes based on electric field strengths [ 43 , 44 , 45 , 46 , 47 ]. Human esophageal smooth muscle cells have also been assessed and exhibited a greater resistance to FPA [ 48 ].…”

Nonclinical evaluation of chronic cardiac contractility modulation on 3D human engineered cardiac tissues

“…9 Toward that end, we have shown that hiPSC-CM models are sufficient to evaluate various cardiac electrophysiology device signals in vitro, including novel cardiac ablation modalities and acute CCM parameters. 7,[10][11][12][13][14] Human 3D cardiac microphysiological systems, including hiPSC-CM engineered cardiac tissues (ECTs), cardiac microtissues or cardiac microbundles, are established models for the acute evaluation of cardiac electrophysiology medical device signals and cardiac drugs. 12,15 However, such models may not be appropriate for long-term chronic in vitro studies.…”