Intraplaque calcium and its relation with the progression of carotid atheromatous disease.

Abstract

Calcification and progression of atheromatous disease (AD) both have been independently related with the risk of stroke. However, the link between the two phenomena is still unclear. The main objective of this study was to analyze the temporal evolution of Ca content of carotid atheromatous plaques and its relation with the progression of carotid AD using quantitative CT Angiography (CTA). Forty-three asymptomatic patients with stenosis of the internal carotid artery (ICA)>50% completed the study. Contrast mold volume and calcium (Ca) content by quantitative CTA and Modified Agatston Score (Ca volume × radiological density) were assessed at baseline and after 12±2 months. Biochemical parameters, including main markers of Ca/Phosphorus (P) metabolism, were determined. CTA measurement showed an increase of volumetric stenosis (volume decrease of the contrast mold), compared to baseline (475.45 [155.6] mm3 × U.H vs. 501.3 [171.9] mm3 × U.H; P=0.04) as well as an increase of intraplaque Ca (64.58 [57.8] mm3 × U.H. vs. 56.8 [52.3] P=0.002). An inverse correlation between baseline Ca content and volumetric stenosis progression (r=-0.481; P<0.001), as well as between the increase of carotid Ca and plasma levels of vitamin D (r=0.4; P=0.025) were also found. Multiple regression analysis found a model with baseline intraplaque Ca, adjusted by Body Mass Index (BMI) as most predictive of carotid AD progression. These results suggest that a higher content of Ca confers greater stability against the progression of carotid AD and, eventually, its ability to generate symptomatology.