Ventricular Size and Value Calcification Measures by CT

描述(申请人提供)：这项研究是动脉粥样硬化多种族研究(MESA)试验的辅助研究建议，这是一项关于动脉粥样硬化的病因和自然病史的前瞻性调查，以及非侵入性工具在基于人群的大型队列中测量动脉粥样硬化负担和识别高危个体的能力。计算机断层扫描(CT)评价冠状动脉钙化(CC)的发展为无创、直接测量冠状动脉粥样硬化提供了一种工具。然而，CT获得的信息比CC本身提供了更多的信息。CT可以测量和定量显示主动脉瓣钙化(AVC)、二尖瓣环钙化(MAC)、主动脉壁钙化和左心室大小(LVS)。这项研究的纵向性质将允许建立多种风险因素和这些措施的流行病学关联，既确定每项措施的时间顺序，又确定不同人群(种族、性别、地理位置和年龄)的相关性。作为MESA试验的一部分，还将获得心脏的磁共振成像，并将进行CT测量的LV大小与磁共振测量的比较。我们建议利用已经获得的扫描作为钙扫描的一部分(在基线和3.5年随访时)，并在获得的基线和后续扫描的基础上进行这四项测量。这些简单测量CC评分的附加价值可能会为临床医生提供更多的力量来识别和分层这两种发现的高危心脏病患者。这项研究还将在一项基于人群的研究中确定所有AVC和MAC的患病率，使用一种高度敏感的技术来观察这些异常。有人推测，在胸主动脉钙化中加入CAC可以获得“总的动脉粥样硬化负荷”，而且这个总的动脉粥样硬化评分(有或没有MAC和AVC)可能比单独的CAC更好地预测心血管事件。同样，这组6500名重复扫描的患者可以评估促进或抑制LVS、二尖瓣环、主动脉瓣或壁钙化进展的因素，从而深入了解对主动脉硬化或左心室增大进展有效的治疗方法。

DESCRIPTION (provided by applicant): This study is ancillary study proposal for the MultiEthnic Study of Atherosclerosis (MESA) Trial, a prospective investigation of the etiology and natural history of atherosclerosis and the ability of non-invasive tools to measure atherosclerotic burden and identify high, risk individuals in a large, population-based cohort. The development of computed tomography (CT) to evaluate coronary calcification (CC) now provides a tool to directly measure coronary atherosclerosis non-invasively. The information obtained by CT however provides more information than CC alone. CT has the ability to measure and quantitate aortic valve calcification (AVC), mitral annular calcification (MAC), aortic wall calcification and left ventricular size (LVS). The longitudinal nature of this study will allow epidemiologic associations to be established for a multitude of risk factors and these measures, establishing both the time sequence for each measure and consistency of the association in a variety of populations (ethnicity, gender, geographical location and age). Magnetic resonance imaging of the heart will also be obtained as part of the MESA trial, and comparisons of LV size by CT to magnetic resonance measures will also be performed. We propose to utilize scans already obtained as part of the calcium scanning (at baseline and 3.5 year follow-up), and make these four measures on baseline and follow-up scans obtained. The additive value of these simple measures to CC score could possibly provide clinicians with even more power to identify and stratify the high-risk cardiac patient with both findings. This study will also establish the prevalence, in a population based study, of all both AVC and MAC, using a technique highly sensitive to see these abnormalities. It has been postulated that a 'total atherosclerotic burden' could be obtained by adding CAC to thoracic aortic calcification, and this total atherosclerosis score (with or without MAC and AVC) might better predict cardiovascular events than CAC alone. Similarly, this cohort of 6500 patients with repeat scans can be assessed for factors that enhance or inhibit progression of LVS, mitral annular, aortic valve or wall calcification, lending insight into therapies that have efficacy against progression of aortic sclerosis or left ventricular enlargement.