OBJECTIVE
Epicardial fat quantification could have prognostic benefit over traditional cardiovascular risk stratification in the HIV population. In general, methods to evaluate reproducibility of epicardial fat have varied. We aim to evaluate the reproducibility of different epicardial fat measurements using non-contrast cardiac CT in HIV+ and HIV- patients.
METHODS AND MATERIALS
This is a cross sectional study, nested in the Canadian HIV and Aging Cohort, a large prospective cohort following more than 800 HIV+ and HIV- patients. Consecutive participants with low/intermediate cardiovascular risk were invited to undergo non-contrast cardiac CT. For inter-observer agreement assessment, two observers performed the measurements of epicardial fat volume, area and thickness in all patients, independently of each other. For intra-observer agreement measurement, observer no 2 repeated all measurements in a random subset of 40 patients, ≥ 1 month after the first assessment. Agreement was assessed with the intraclass correlation coefficient (ICC).
RESULTS
A total of 167 HIV+ and 58 HIV- patients underwent cardiac CT. The inter-observer agreement was excellent for epicardial fat volume (ICC 0.75) and area (ICC 0.95) and good for epicardial fat thickness (ICC at a level near the left anterior descending artery (LAD) 0.64, ICC near right coronary artery (RCA) 0.64). The intra-observer agreement was excellent for epicardial fat volume (ICC 0.97), area (ICC 0.99), thickness at the level of the LAD (ICC 0.71) and good for epicardial fat thickness at the level of the RCA (ICC 0.68).
CONCLUSION
Quantification of epicardial fat using non-contrast cardiac CT is adequately  reproducible for volume and area.

Reproducibility of epicardial fat quantification using non-contrast cardiac CT in an HIV population