Catheter-free ablation of infarct scar through proton beam therapy: Tissue effects in a porcine model
| Autor: | Seán Fitzgerald, Jon J. Kruse, Maryam E. Rettmann, Laura K. Newman, Kristi H. Monahan, Amanda J. Deisher, Douglas L. Packer, Kay D. Parker, Atsushi Suzuki, Michael G. Herman, Stephan Hohmann, Hiroki Konishi, Robert L. Foote, Kenneth W. Merrell |
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| Rok vydání: | 2020 |
| Předmět: |
Cardiac function curve
Ablation Techniques Radiofrequency ablation Swine medicine.medical_treatment Myocardial Infarction Magnetic Resonance Imaging Cine Catheter ablation 030204 cardiovascular system & hematology Ventricular tachycardia law.invention 03 medical and health sciences 0302 clinical medicine Cardiac magnetic resonance imaging law Physiology (medical) Proton Therapy Medicine Animals cardiovascular diseases 030212 general & internal medicine Myocardial infarction medicine.diagnostic_test business.industry Myocardium Magnetic resonance imaging Dose-Response Relationship Radiation medicine.disease Ablation Disease Models Animal Treatment Outcome cardiovascular system Tachycardia Ventricular Cardiology and Cardiovascular Medicine business Nuclear medicine |
| Zdroj: | Heart rhythm. 17(12) |
| ISSN: | 1556-3871 |
| Popis: | Background Scar-related ventricular arrhythmias are common after myocardial infarction. Catheter ablation can improve prognosis, but the procedure is invasive and results are not always satisfactory. Noninvasive, catheter-free ablation using ionizing radiation has recently gained interest among electrophysiologists, but the tissue effects and physiological outcome have not been fully characterized. Objective The purpose of this study was to investigate the structural effects of cardiac scanned pencil beam proton therapy on infarct scar, the time course of imaging biomarkers, arrhythmias, and cardiac function in a porcine model. Methods Fourteen infarcted swine underwent proton beam treatment of the scar (40 or 30 Gy) and were followed for up to 30 weeks. Magnetic resonance imaging was performed every 4 weeks. Results Treated scar areas showed a significantly lower fraction of surviving myocytes at 30 weeks compared to untreated scar (30.1% ± 18.5% and 59.9% ± 10.1% in treated and untreated infarct, respectively), indicating scar homogenization. Four animals died suddenly during follow-up, all from documented monomorphic ventricular tachycardia. Cardiac function remained stable over the course of the study. Distinct imaging morphologies corresponded to certain tissue dose ranges and time points. Conclusion Radioablation of cardiac infarct scar leads to significant homogenization of the scar, replicating the histologic effects of radiofrequency ablation. These changes correspond to distinct imaging morphologies on delayed contrast-enhanced cardiac magnetic resonance imaging, enabling noninvasive confirmation of tissue ablation effects The present study is the first to thoroughly investigate the structural effects of cardiac proton beam therapy in infarcted myocardium. |
| Databáze: | OpenAIRE |
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