Ventricular Size and Value Calcification Measures by CT

描述（由申请人提供）：本研究是多种族动脉粥样硬化研究（MESA）试验的辅助研究计划，该试验是一项前瞻性研究，旨在研究动脉粥样硬化的病因和自然历史，以及在一个大型人群为基础的队列中使用非侵入性工具测量动脉粥样硬化负担和识别高风险个体的能力。计算机断层扫描（CT）评估冠状动脉钙化（CC）的发展现在提供了一种直接测量冠状动脉粥样硬化的无创工具。然而，CT获得的信息比单独的CC提供更多的信息。CT能够测量和量化主动脉瓣钙化（AVC）、二尖瓣环钙化（MAC）、主动脉壁钙化和左心室大小（LVS）。本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，确定每种措施的时间顺序和各种人群（种族、性别、地理位置和年龄）中关联的一致性。作为MESA试验的一部分，还将获得心脏的磁共振成像，并将CT和磁共振测量的左室大小进行比较。我们建议利用已经获得的扫描作为钙扫描的一部分（基线和3.5年随访），并在基线和随访扫描上进行这四项测量。这些简单措施与CC评分的相加值可能为临床医生提供更大的力量来识别和分层具有这两种结果的高危心脏病患者。本研究还将在一项基于人群的研究中，利用一种高度敏感的技术来观察这些异常，确定所有AVC和MAC的患病率。据推测，将CAC加到胸主动脉钙化中可以得到“总动脉粥样硬化负担”，并且这种总动脉粥样硬化评分（包括或不包括MAC和AVC）可能比单独CAC更好地预测心血管事件。同样，该6500例患者的重复扫描可以评估增强或抑制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进展或左心室增大有效的治疗方法。

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.