Image Integration to Identify Histologic and Electroanatomic Ventricular Scar: A Clinicopathological Study Comparing...

Area of Science:

• Cardiovascular Imaging
• Electrophysiology
• Medical Device Technology

Background:

• Cardiac magnetic resonance (CMR) image integration holds promise for guiding ventricular tachycardia (VT) ablation by delineating scar tissue.
• Limited histological data and comparative studies exist for commonly used CMR segmentation tools in VT ablation.

Purpose of the Study:

• To validate two vendor systems, ADAS-3D and inHEART, for integrating CMR late gadolinium enhancement (LGE) with electroanatomic mapping (EAM) in VT catheter ablation.
• To compare the accuracy of ADAS-3D and inHEART in characterizing scar distribution against histological data.

Main Methods:

• Sheep models with induced myocardial infarction were used to create a histological scar model.
• CMR images were segmented using ADAS-3D and inHEART, then validated against whole-heart histology for endocardial, intramural, and epicardial layers.
• A clinical validation involved 5 human subjects undergoing VT ablation, matching critical VT sites to segmented scar regions.

Main Results:

• Both ADAS-3D and inHEART demonstrated comparable accuracy (>75%) and moderate agreement with histology for endocardial and intramural scar.
• Performance was poorer for epicardial layers (modest accuracy 60%-68%) and non-compact scar.
• Critical VT sites reliably colocalized with segmented scar (88% within one layer), with over 80% of sites showing scar in multiple layers.

Conclusions:

• ADAS-3D and inHEART offer similar scar characterization and display of scar-reentry circuit relationships for VT ablation.
• Limitations persist in accurately identifying epicardial and non-compact scar patterns with these technologies.