A simple visual score to estimate epicardial adipose tissue volume on non-contrast ECG-triggered cardiac CT post-heart transplantation

Epicardial adipose tissue (EAT) is an active endocrine organ associated with cardiometabolic risk, coronary artery disease, and adverse outcomes after heart transplantation (HT). Quantitative EAT assessment typically relies on echocardiography or, with superior accuracy, ECG-triggered cardiac computed tomography (CT), limiting applicability in routine clinical care. We developed a qualitative visual method to assess EAT non-contrast, ECG-triggered cardiac CT scans in HT recipients. In this single-center retrospective study, adult HT recipients who underwent annual CT imaging for cardiac surveillance were included. Absolute EAT volume (mL) was quantified using a validated automated algorithm. The qualitative visual EAT score was independently assessed on axial CT images at three predefined anatomical levels, each graded on a 4-point scale, yielding a total EAT score from 3 to 12 per scan. Correlation between visual and quantitative EAT was evaluated using Spearman’s rank correlation. Intra- and inter-observer agreement were assessed using weighted Cohen’s kappa. A total of 155 HT recipients (median age: 44 years, 34% female) were included. The visual EAT score showed a very strong correlation with absolute EAT volume (ρ = 0.965, p < 0.001). Intra-observer agreement was excellent (κ = 0.81, p < 0.001), while inter-observer agreement ranged from substantial to excellent (κ = 0.66-0.81, p < 0.001). Visual scoring required ±1 min per scan after limited training. The qualitative EAT assessment demonstrated strong agreement with absolute volumetric measurements and good reproducibility on non-contrast CT in heart transplant recipients. It provides a simple, practical approach for EAT estimation, enabling broader clinical and research applications. Question Routine clinical practice lacks a fast, practical method to assess EAT, associated with cardiovascular risk, on non-contrast CT in HT recipients . Findings The visual, qualitative EAT assessment demonstrates strong agreement with automated EAT volumetric measurements and high reproducibility after limited training . Relevance statement This simple, reliable score enables accurate estimation of EAT on routine non-contrast CT, even post-transplant, with potentially more artifacts. This facilitates longitudinal monitoring and broader clinical use, especially in patients without contrast-enhanced CT and in centers without specialized software .