The Association between Epicardial Fat and Cardiac Allograft Vasculopathy

Purpose Cardiac allograft vasculopathy (CAV) is a poorly understood, accelerated form of coronary artery disease in patients that underwent heart transplantation (HT), and substantially contributes to post-transplantation morbidity and mortality. Increasing evidence shows an active role for epicardial fat (EF) in the development of coronary artery disease, as a result of its inflammatory properties. Yet, whether the amount of EF is also related to CAV remains unknown. Hence, we investigated the association of epicardial fat volume (EFV) with CAV. Methods For this pilot study, we included post HT-patients whom underwent cardiac computed tomography (CCT) for CAV screening between February 2018 and January 2019. CCT included a non-enhanced CT (NECT) and CT angiography (CCTA). Using the NECT, we quantified the EFV using an automated algorithm (Fig 1.). CAV was graded on CCTA similar to the guidelines of the International Society for Heart and Lung Transplantation. The association of EFV with the presence and grade of CAV was investigated using binary- and ordinal logistical regression models, adjusted for recipient age and gender, time since HT and number of rejections pre-CCT. Results We included 74 patients, with a median age of 45 years [IQR 27-51] at HT of whom 29 were women. Median time since HT was 10.0 years [IQR 8.0-15.3]. CAV was prevalent in 28 (38%) patients, of whom 17 (61%) had CAV 1, 5 (18%) had CAV 2 and 6 (21%) had CAV 3. Median EFV was 198.5 [IQR 123.4-262.1] mm3. The median EFV was larger with higher CAV grades: 162.2 (CAV 0), 211.5 (CAV 1), 230.0 (CAV 2) and 278.3 (CAV 3) mm3 (p=0.031). Albeit not statistically significant, we found an association of EFV with the presence of CAV (odds ratio (OR) per 1-standard deviation increase in log-transformed EFV: 1.48 (95%CI: 0.80-2.72), p=0.21) and with CAV grade (OR 1.52 (95%CI: 0.85-2.71), p=0.15). Conclusion Our preliminary results show a promising trend towards an association of the amount of epicardial fat and the presence of CAV, which should be confirmed in larger studies.