Computed Tomography-Based Left Ventricular Tissue Heterogeneity in Ischaemic Cardiomyopathy: Investigation of Adipose Tissue and Fibrosis

Disease-induced cardiac remodeling and the complex healing process post myocardial infarction (MI) are key drivers of arrhythmogenic substrates that predispose patients to ventricular tachycardia (VT). Ten post-MI patients were imaged using computed tomography (CT). Cardiac magnetic resonance (CMR) imaging was additionally performed on three patients. A fully automated segmentation supplemented by manual correction was used to create high-resolution 3D biventricular models. Adipose tissue was identified and introduced into the model, defining different boundaries for computing the wall thickness (WT). Thresholds were personalized by modeling WT distributions with three Gaussian Mixture Models (GMMs). Excluding fat in the WT computation showed better agreement with substrate defined by CMR. Our study reports GMM-personalized mean thresholds for fibrosis as 2.88 ± 0.8 mm and borderzone as 4.53 ± 0.7 mm which fall within experimental and clinical values. The presented reproducible approach for myocardial characterization in post-MI patients, incorporating adipose deposits and personalized WT threshold-defined fibrosis, shows agreement with previous CT studies. This improves identification of arrhythmogenic substrates with highly personalized, patient-specific cardiac models.