Katano Hiroyuki, Mase Mitsuhito, Nishikawa Yusuke, Yamada Kazuo
Department of Neurosurgery, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan; Department of Medical informatics & Integrative Medicine, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
Department of Neurosurgery, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
J Stroke Cerebrovasc Dis. 2015 Jun;24(6):1341-50. doi: 10.1016/j.jstrokecerebrovasdis.2015.02.010. Epub 2015 Mar 21.
The precise mechanism of carotid calcification formation and its clinical significance including the difference in outcomes compared with coronary artery have not been clearly elucidated yet. We applied the calcium score for analyzing carotid plaque calcification in focus on its relationship with symptoms and discuss the difference in transitional patterns and the clinical outcome in comparison with calcified coronary plaques.
Multidetector row computed tomography angiography was performed preoperatively to determine the Agatston calcium score, volume score, and Hounsfield values for a total of 330 carotid arteries from 194 patients. Analysis focused on the relation of "the symptomatic rate" to calcium score, volume score, and Hounsfield value as well as the characteristics of calcified plaques and coexisting diseases. The symptomatic rate of carotid artery plaques in each range of the index was calculated as the percentage of the number of carotid arteries with plaques, which elicited symptoms of the contralateral limbs or the ipsilateral retina to the whole number of carotid arteries with plaques within the range.
Calcified carotids with low symptomatic rate (<40%) tended to have calcification with significantly high calcium scores, high volume scores and mean/maximum Hounsfield values, high circularities, outer positions, positive remodeling, and carotid bulb/common carotid locations by univariate analysis, whereas high maximum Hounsfield value, high circularity, and outer position of calcification were significant independent predictors of low-symptomatic calcified carotid plaques by multivariate logistic regression analysis. When analyzed by calcium score, the rates for symptomatic carotids showed double peaks at calcium scores around 200-400 and 600-800 with a dip at 400-600. Significant independent predictors of low symptomatic carotid artery were high maximum Hounsfield value (odds ratio [OR], 5.70; P = .005), calcification encircling the carotid perimeter (OR, 7.18; P = .005), and the calcium location in the common carotid artery (OR, 6.62; P = .006) in comparing groups with low (0-400) and medium (400-600) calcium scores, whereas a high volume score (OR, .01; P = .003) alone was a significant independent determinant in the comparison between groups with high (600-1000) and medium calcium scores.
Symptomatic rates of carotid plaque calcification were demonstrated to show double peaks with increasing calcium score and represent different features. Assessment of the 2 calcium-score parts might be helpful for appropriate comprehension of symptomatology and the complex process of carotid plaque calcification. We report a hypothesis for the mechanisms of the 2 different sections.
颈动脉钙化形成的确切机制及其临床意义，包括与冠状动脉相比在预后方面的差异，尚未完全阐明。我们应用钙化积分来分析颈动脉斑块钙化，重点关注其与症状的关系，并讨论与钙化冠状动脉斑块相比，其转变模式和临床结局的差异。
对194例患者的330条颈动脉术前进行多排螺旋CT血管造影，以确定阿加斯顿钙化积分、体积积分和亨氏值。分析重点为“症状发生率”与钙化积分、体积积分和亨氏值的关系，以及钙化斑块和共存疾病的特征。计算各指数范围内颈动脉斑块的症状发生率，即引发对侧肢体或同侧视网膜症状的有斑块颈动脉数量占该范围内有斑块颈动脉总数的百分比。
单因素分析显示，症状发生率低（<40%）的钙化颈动脉往往具有显著较高的钙化积分、体积积分和平均/最大亨氏值、较高的圆形度、外部位置、正向重塑以及位于颈动脉球部/颈总动脉部位；而多因素逻辑回归分析表明，钙化的最大亨氏值高、圆形度高和外部位置是症状性钙化颈动脉斑块的显著独立预测因素。按钙化积分分析时，有症状颈动脉的发生率在钙化积分约200 - 400和600 - 800时出现双峰，在400 - 600时出现下降。在比较低（0 - 400）和中（400 - 600）钙化积分组时，症状性颈动脉的显著独立预测因素为最大亨氏值高（比值比[OR]，5.70；P = .005）、钙化环绕颈动脉周长（OR，7.18；P = .005）以及钙化位于颈总动脉（OR，6.62；P = .006）；而在比较高（600 - 1000）和中钙化积分组时，仅高体积积分（OR，.01；P = .003）是显著的独立决定因素。
颈动脉斑块钙化的症状发生率随钙化积分增加呈双峰表现且具有不同特征。评估两个钙化积分部分可能有助于恰当理解症状学和颈动脉斑块钙化的复杂过程。我们报告了关于这两个不同部分机制的一个假说。
