Abstract P379: Atherosclerotic Abdominal Aortic Plaque and All-Cause Mortality: The Framingham Heart Study

Abstract

Introduction: Atherosclerotic abdominal aortic plaque (AAP) is often seen incidentally on magnetic resonance (MR) scans. Prevalence and burden of AAP are associated with cardiovascular disease (CVD) risk factors, but the relationship between AAP and all-cause mortality (“Death”) is not well characterized. We sought to determine whether AAP predicts Death among community-dwelling adults initially without clinically overt CVD. Methods: 318 Framingham Offspring cohort members (age 60±9 yrs, 51% women) underwent noncontrast abdominal MR at 1.5 Tesla in 1998-1999. Participants were recruited from equal strata of age, sex and quintile of Framingham Risk Score (FRS), with double sampling of the top quintile. MR used ECG-triggered black-blood T2W turbo spin-echo with 1.03 x 0.64 x 5-mm 3 voxels. AAP was hand-traced and comprised discrete protrusions of ≥1mm into the aortic lumen. Participants were stratified into three levels of AAP: zero (AAP0); then among those with nonzero-AAP, subdivided into below median (AAP1) and above median (AAP2). FRS was calculated for each participant (using age, sex, systolic blood pressure, total and HDL cholesterol, diabetes, smoking); A Cox proportional hazards model adjusted for standardized, log-transformed FRS (zFRS) was used to determine hazard ratio (HR) for Death with AAP0 as the referent. The log-rank test was used to compare event-free survival. Results: AAP by MR was present in 40.4% of women and 42.1% of men. Over a median 14.8 years of follow up, there were 52 Deaths (5 CVD, 22 cancer, 25 other causes). AAP2 had HR=2.08 (95% CI 1.07 - 4.08, p=0.03); AAP1 was HR=1.37 (CI=0.65 - 2.92, p=0.4). The figure shows the Kaplan-Meier plot for survival; log-rank p=0.034. Conclusions: Among adults initially free of clinically overt CVD, above median burden of AAP was associated with 2-fold greater hazard of all-cause mortality. Although the majority of deaths were not principally due to CVD, excess AAP was a predictor of mortality over nearly 15 year follow up.