281-LB: The Association between Pericardial Fat Volume and Mortality—The Multi-Ethnic Study of Atherosclerosis

Background: Pericardial fat, a specific measure of ectopic fat, is associated with incident cardiovascular disease (CVD). Both coronary artery calcium (CAC) and body mass index (BMI) may modify the effect of ectopic fat on mortality. However, there are few studies on the association between pericardial fat and mortality and if this association can be modified by CAC and BMI. Objective: We examined the association between pericardial fat volume (PFV) and all-cause and CVD mortality. Methods: This study ascertained PFV using cardiac computed tomography in 6,785 participants without pre-existing cardiovascular disease from the Multi-Ethnic Study of Atherosclerosis (MESA). Cox proportional hazards regression was used to evaluate the association between PFV and mortality. We tested for effect modification in these associations by CAC and BMI categories. Results: The mean age of the analytic sample was 62.1 ± 10.0 years and 53% were female. The mean PFV was 79.6 ± 42.0 cm3. Over a 16.9-year median follow-up, there were 1,701 (25%) all-cause deaths and 411 CVD-related deaths (6%). In unadjusted model, every 1-SD (42 cm3) increase in PFV was associated with a 2-fold higher rate of all-cause mortality (HR=1.99, 95% CI=1.81-2.20). After adjusting for demographics, CV risk factors, income, and waist-to-hip ratio, this association was attenuated but remained significant (HR=1.20, 95% CI=1.06-1.36). Similarly, PFV was associated with CVD mortality in unadjusted model (HR=2.38, 95% CI=1.95 - 2.91) but was no longer statistically significant after multivariable adjustment (HR=1.26, 95% CI=0.97-1.62). There were no significant interactions by CAC. However, a significant interaction by BMI was found (p value for interaction = 0.013); the HR of BMI≥35kg/m2 was 2.4-times higher than the HR of BMI<25kg/m2. Conclusions: In this large, community-based, prospective cohort study, pericardial fat was associated with a higher risk of all-cause mortality especially among obese participants. Disclosure E. Hong: None. L. Brumback: None. M. Allison: None.