Abstract 16509: Increased Arterial Inflammation by FDG-PET-CT is Associated with an Increased Risk of Cardiovascular Events among Obese Low-Intermediate Risk Individuals

Abstract

Background: Obesity is associated with increased cardiovascular event (CVD) risk. We previously demonstrated that obesity is associated with increased vascular inflammation (measured with FDG-PET-CT) even among the low-risk (framingham risk scores (FRS) <10%). Here, we test the hypothesis that in low-intermediate risk obese, high aortic inflammation (by FDG-PET-CT) is associated with increased CVD risk.

Methods: We serially identified patients (n=513, median age[IQR], 55[45,66], 42% males) who had undergone FDG-PET imaging for clinical indications but who were found to be free of active cancer, prior history of CVD, or acute or chronic inflammatory conditions and for whom clinical follow-up information was available, (median[IQR] 4.2 years[3,5]). Major cardiovascular events or MACE (n=44) were adjudicated (defined as incident stroke, transient ischemic attack, acute coronary syndrome, revascularization, new-onset angina-with evidence of clinical atherosclerosis, peripheral arterial disease, or CVD death). Arterial inflammation was measured as target-to-background ratio (TBR) of ascending aortic FDG uptake on PET-CT images while blinded to clinical data. We then assessed the association between obesity (Body Mass Index ≥ 30 kg/m²), TBR and MACE.

Results: At baseline, TBR was higher among obese vs. non-obese (mean±sd, 2.08±0.28 vs. 1.96±0.28, p<0.0001). Among all obese, baseline TBR was higher in individuals who subsequently developed MACE compared to those who did not (2.30±0.26 vs. 2.06± 0.27, p=0.006), fig.1. Among the low-to-intermediate-risk (FRS ≤ 20) obese, individuals with median TBR ≥ 2.04 were more likely to develop MACE compared to those with TBR < 2.04, (HR[95% CI], 8.64 [1.1, 68], p=0.04.

Conclusions: Obesity is associated with increased arterial inflammation, which in-turn is associated with a higher risk of subsequent cardiovascular event. These findings should be prospectively validated in a larger cohort.