Abstract 949: Carotid Intima-Media Thickness is Superior to other Non-invasive Vascular Assessments in Risk Stratification of Subjects with Established Cardiovascular Disease
Objective: In pts (pts) with cardiovascular disease (CVD), risk scores based on traditional risk factors of atherosclerosis do not apply & alternative methods of risk stratification are needed. We aim to compare the prognostic implications of a range of non-invasive vascular assessments in pts with CVD.
Methods: We determined the brachial endothelial function (flow-mediated dilatation (FMD), nitroglycerin-mediated dilatation (NMD)), carotid artery atheroma burden (carotid intima-media thickness (IMT) & plaque), ABI & arterial stiffness (pulse wave velocity (PWV)) in 387 pts with CVD. Pts were followed-up at 25±6mths & presence of a major adverse cardiovascular event (MACE) was documented.
Results: A total of 46 MACE occurred during follow-up. IMT was greater in pts with MACE (1.18±0.29mm vs 1.07±0.31mm, P=0.027) but there were no significant differences in FMD, NMD, carotid plaque prevalence, ABI or PWV in subjects with or without MACE. Pts with IMT>1.2mm (P<0.001, Fig1⇓) & PWV>1445cm/s (P=0.005) had a significantly greater number of adverse events. Univariate analysis with cox regression identified IMT>1.2mm, PWV>1445cm/s, ABI≤1.1, NMD≤13.5%, age & nitrate use as positive predictors of MACE (all P<0.1). Multivariate analysis revealed that out of all vascular assessments, only IMT>1.2mm (HR 2.37, 95% CI 1.14 – 4.94, P=0.027) was an independent predictor of MACE. Furthermore, pts with a combined impairment of IMT & PWV was associated with an increased risk of MACE compared with those with impairment of either marker alone (P<0.007, Fig2⇓).
Conclusions: Amongst commonly used vascular assessments, carotid IMT provides the best predictive value for MACE in pts with known CVD.