Schmermund A, Baumgart D, Erbel R
Department of Cardiology, University Clinic Essen, Germany.
J Cardiovasc Risk. 2000 Apr;7(2):99-106. doi: 10.1177/204748730000700203.
The development and progression of coronary artery disease is the result of exposure to a variety of different risk factors. In larger populations, strong associations exist between risk factors and the development of both angiographic and clinical coronary artery disease. But, this relationship is extremely variable in individual subjects. Coronary calcification is a specific marker of coronary artery disease. Its formation and progression is determined by largely identical risk factors compared with angiographic coronary artery disease. Coronary calcification quantitated by electron beam tomography (EBT) thus enables the non-invasive assessment of whether the risk factor exposure has actually led to the development of coronary atherosclerosis in an individual subject. Whereas other non-invasive tests focus on the physiological consequences of coronary obstruction, EBT represents anatomic disease itself. Because the propensity of plaques to cause coronary obstruction partly depends on the degree of arterial remodelling, large plaques may not necessarily appear as high-grade stenoses angiographically. Indeed, angiography and EBT evaluate two facets of atherosclerotic plaque disease, i.e. luminal obstruction and calcified plaque itself. Coronary calcification is strongly associated with the presence, extent, and severity of angiographic coronary artery disease. A number of studies have shown that it is clearly superior in this respect compared with conventional risk factors. However, because of the indirect relationships between plaque formation and luminal obstruction, EBT does not permit the site-specific prediction of coronary stenoses. Recent investigations have focused on the ability of EBT to represent the extent of anatomic coronary artery disease, which is an important predictor of future cardiac events. The availability of a simple, non-invasive test for the direct visualization of coronary artery disease holds great promise regarding improved definitions of the relationships between risk factors and coronary atherosclerosis as well as regarding the diagnosis of non-obstructive coronary disease, which can nevertheless result in acute events.
冠状动脉疾病的发生和发展是多种不同危险因素作用的结果。在较大规模人群中，危险因素与血管造影显示的冠状动脉疾病以及临床冠状动脉疾病的发生之间存在着密切关联。但是，这种关系在个体中差异极大。冠状动脉钙化是冠状动脉疾病的一种特殊标志。与血管造影显示的冠状动脉疾病相比，其形成和进展在很大程度上由相同的危险因素所决定。因此，通过电子束断层扫描（EBT）对冠状动脉钙化进行定量分析，能够对个体受试者因暴露于危险因素而实际引发冠状动脉粥样硬化的情况进行无创评估。其他无创检查关注的是冠状动脉阻塞的生理后果，而EBT呈现的是解剖学上的疾病本身。由于斑块导致冠状动脉阻塞的倾向部分取决于动脉重塑的程度，因此在血管造影中，大的斑块不一定表现为高度狭窄。事实上，血管造影和EBT评估的是动脉粥样硬化斑块疾病的两个方面，即管腔阻塞和钙化斑块本身。冠状动脉钙化与血管造影显示的冠状动脉疾病的存在、范围和严重程度密切相关。多项研究表明，在这方面，冠状动脉钙化明显优于传统危险因素。然而，由于斑块形成与管腔阻塞之间存在间接关系，EBT无法对冠状动脉狭窄进行部位特异性预测。最近的研究聚焦于EBT呈现解剖学冠状动脉疾病范围的能力，而解剖学冠状动脉疾病范围是未来心脏事件的重要预测指标。一种用于直接可视化冠状动脉疾病的简单无创检查方法的出现，对于更好地界定危险因素与冠状动脉粥样硬化之间的关系以及诊断可能引发急性事件的非阻塞性冠状动脉疾病具有重大前景。
