Whole-Heart Histological and Electroanatomic Assessment of Postinfarction Cardiac Magnetic Resonance Imaging Scar and Conducting Channels

作者：Kasun De Silva, Timothy Campbell, Richard G. Bennett, Robert D. Anderson, Christopher G. Davey, Alexandra K O’Donohue, Aaron Schindeler, Samual Turnbull, Dinesh Selvakumar, Ashwin Bhaskaran, Yasuhito Kotake, Chi-jen Hsu, James J.H. Chong, Eddy Kizana, Saurabh Kumar · 发表于：Circulation Arrhythmia and Electrophysiology · 年份：2024 · DOI：10.1161/circep.124.012922 · 被引用次数：8 · 研究领域：Cardiac Arrhythmias and Treatments、Cardiac Imaging and Diagnostics、Cardiac electrophysiology and arrhythmias

BACKGROUND: Cardiac magnetic resonance imaging (CMR)–defined ventricular scar and anatomic conduction channels (CMR-CCs) offer promise in delineating ventricular tachycardia substrate. No studies have validated channels with coregistered histology, nor have they ascertained the histological characteristics of deceleration zones (DZs) within these channels. We aimed to validate CMR scar and CMR-CCs with whole-heart histology and electroanatomic mapping in a postinfarction model. METHODS: Five sheep underwent anteroseptal infarction. CMR (116±20 days post infarct) was postprocessed using ADAS-3D, varying pixel intensity thresholds (5545, 6040, 6535, and 7030). DZs were identified by electroanatomic mapping (129±12 days post infarct). Explanted hearts were sectioned and stained with Picrosirius red, and whole-heart histopathologic shells were generated. Scar topography as well as percentage fibrosis, adiposity, and remaining viable myocardium within 3 mm histological biopsies and within CMR-CCs were determined. RESULTS: Using the standard 6040 thresholding, CMR had 83.8% accuracy for identifying histological scar in the endocardium (κ, 0.666) and 61.4% in the epicardium (κ, 0.276). Thirty-seven CMR-CCs were identified by varying thresholding; 23 (62%) were unique. DZs colocalized to 19 of 23 (83%) CMR-CCs. Twenty (87%) CMR-CCs were histologically confirmed. Within-channel histological fibrosis did not differ by the presence of DZs ( P =0.242). Within-channel histological adiposi...