Abstract 5132: Serum Pentraxin 3, Matrix Metalloproteinase 9 and Intraplaque Hemorrhage in Carotid Atherosclerosis
Background - Carotid intraplaque hemorrhage (IPH) is a marker of atheroma instability. In the present study, we evaluated the potential association between serum levels of pentraxin 3 (PTX3, a novel marker of vascular inflammation) and matrix metalloproteinases (MMPs) with in vivo assessment of IPH by high-resolution magnetic resonance imaging (MRI).
Methods and Results - Consecutive patients submitted to carotid endarterectomy underwent high-resolution MRI; independent evaluation of neurological symptoms; histological analysis and measurement of serum PTX3, MMP-3 and MMP-9. IPH was determined non-invasively by the presence of a hyperintense signal on MRI. Eighty-two predominantly male (65%) and hypertensive (89%) patients (67±9 years-old) were studied. MR angiography identified 19(23%) patients with 50 – 69% stenosis, 23(28%) with 70 –90% stenosis, and 40(49%) with > 90% stenosis. High-resolution MRI depicted a hyperintense signal suggestive of intraplaque bleeding in 48 (58.5%) subjects. No usual clinical characteristic was predictive of the hyperintense signal on MRI (all p values >0.10). Serum PTX3 and MMPs levels were similar in different degrees of carotid stenosis assessed by MR angiography, but were significantly augmented in patients with signs of IPH on MRI and on histological analysis (all p values <0.05). We observed a strong positive association between PTX3 and MMP-9 levels (r=0.76; p<0.0001) and a weak to moderate association between hs-C-reactive protein and PTX3 (r=0.40; p=0.0002) and MMP-9 (r=0.35; p=0.001). In a multivariate logistic regression model adjusted for potential blood-derived markers, clinical neurological instability was the only variable independently associated to MRI-based IPH.
Conclusions - MRI-based IPH identified neurologically unstable patients, with increased levels of PTX3 and MMP-9, regardless of the degree of carotid luminal stenosis.