Coronary Calcium Score Method and Cardiovascular Disease Events in Two Cohorts

冠状动脉钙评分方法和两个队列的心血管疾病事件

• 批准号: 9272987
• 负责人: MICHAEL H CRIQUI
• 金额: $ 9.98万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-01 至 2019-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9272987
• 关键词: Achievement; Address; Area; Atherosclerosis; Calcified; Calcium; Cardiac; Cardiovascular Diseases; Case-Control Studies; Cessation of life; Chest; Classification; Cohort Studies; Coronary; Coronary artery; Coronary heart disease; Data; Development; Event; Future; Health; Individual; Lead; Left; Low Dose Radiation; Measurement; Measures; Methodology; Methods; Myocardial Infarction; Patients; Persons; Pilot Projects; Placebos; Predictive Value; Receiver Operating Characteristics; Research; Risk Factors; Scanning; Scoring Method; Slice; Spatial Distribution; System; Testing; Thick; Time; Unstable angina; Weight; X-Ray Computed Tomography; base; cardiovascular disorder risk; clinical care; clinical practice; cohort; comparative; density; follow-up; hazard; heart imaging; improved; indexing; research study; validation studies

DESCRIPTION (provided by applicant): The amount of coronary artery calcium (CAC) on a computed tomography (CT) scan provides strong and incremental information as to cardiovascular disease (CVD) risk status beyond standard CVD risk factors. The Agatston method is the standard CAC scoring methodology. For a given CAC volume, the Agatston score is increased 2, 3, or 4 fold based on reaching selectively higher CAC density cutpoints, thus "upweighting" the Agatston score for greater CAC density. However, extensive evidence exists that densely calcified coronary plaques may pose a lower CVD risk than less densely calcified plaques. As examples, 1) persons who have only calcified plaques have a relatively low risk of CVD 2) patients with unstable angina have fewer calcified plaques than patients with stable angina, and 3) statin treatment may increase Agatston score compared to a placebo group. In preliminary studies, our group has explored CVD risk in two large cohorts, the Multi-ethnic Study of Atherosclerosis (MESA) and the LifeScore Study. Preliminary analyses in both MESA and LifeScore have shown that the volume score, which ignores density, was slightly more predictive than the Agatston score for CVD events. We then created a density score and have shown that CAC density is actually protective for future CVD events at any given CAC volume. In addition, in a case-control study of CVD death in LifeScore, we have shown that a simplified un-weighted score measured on standard chest CTs, the ordinal score, was a better predictor than the Agatston score, particularly at the higher end of the score range. In order to determine the optimal scoring system or systems for CAC from CT scans, we propose to compare four CAC scoring systems in both the MESA and the LifeScore Study. The first two scores will be the volume and ordinal scores discussed above. The other two scores will be newly developed in MESA and validated in LifeScore and both will employ "reverse density weighting". Rather than "upweighting" the score for more dense calcified plaque as the Agatston score does, these two scores, called the volume-2 and the ordinal-2 scores, will empirically "downweight" the CAC score for denser plaques; that is, less dense plaques will produce a higher score and denser plaques a lower score, the opposite of the Agatston method. The volume-2 and ordinal-2 scores will also consider the number of coronary arteries and the specific coronary arteries with CAC. They will be empirically developed in MESA and validated in LifeScore. We will then compare CVD prediction by these four scores in terms of the strength and statistical significance of the hazard ratios, the areas under Receiver Operating Characteristic curves, and the Net Reclassification Index. Finally, in the LifeScore study we will then compare the results when the scores are calculated on electrocardiographic gated cardiac CT scans vs. standard chest CT scans. If CAC measured on standard chest CTs is equally predictive of CVD events as CAC measured on cardiac CTs, CAC assessment could become more widely available, technically easier, and done with a lower radiation dose.

描述（由申请人提供）：计算机断层扫描（CT）扫描中冠状动脉钙（CAC）的量提供了有关心血管疾病（CVD）风险状态的强大和增量信息，而不是标准CVD风险因素。 Agatston方法是标准的CAC评分方法。对于给定的CAC体积，基于选择性地达到更高的CAC密度切割点，Agatston评分增加了2、3或4倍，从而“使更高的CAC密度”“上升” Agatston评分。然而，有广泛的证据表明，密集钙化的冠状斑块可能比降低钙化的斑块造成更低的CVD风险。作为示例，1）只有钙化斑块的人患CVD的风险相对较低。2）不稳定心绞痛的患者的钙化斑块比稳定的心绞痛患者少，而3）他汀类药物治疗可能会增加阿加斯顿分数与安慰剂组相比。在初步研究中，我们的小组探索了两个大型队列的CVD风险，即动脉粥样硬化的多种族研究（MESA）和Lifescore研究。在MESA和LIFESCORE中的初步分析表明，忽略密度的体积评分比CVD事件的Agatston评分更具预测性。然后，我们创建了一个密度分数，并表明CAC密度实际上是在任何给定的CAC量下对将来的CVD事件的保护性。此外，在一项对Lifescore中CVD死亡的病例对照研究中，我们表明，在标准胸部CTS上测得的简化的非加权分数（序数得分）比Agatston评分更好，尤其是在得分范围的高端。为了确定CT扫描中CAC的最佳评分系统或系统，我们建议在MESA和LIFESCORE研究中比较四个CAC评分系统。前两个分数将是上面讨论的音量和序数得分。其他两个分数将在MESA中新开发，并在Lifescore中进行验证，并且两者都将采用“反向密度加权”。这两个分数（称为体积2和Ordinal-2得分）并没有像Agatston分数那样“上升”更致密的校准斑块的得分，而是在经验上“下降”了密度斑块的CAC得分。也就是说，较少的斑块将产生较高的分数，并且斑块的得分较低，而分数则是Agatston方法的相反。体积2和Ordinal-2分数还将考虑带有CAC的冠状动脉数量和特定的冠状动脉。它们将在MESA中进行经验开发，并在Lifescore中得到验证。然后，我们将根据危险比的强度和统计意义，接收器操作特征曲线和净重新分类指数的强度和统计意义来比较这四个分数的CVD预测。最后，在LIFESCORE研究中，我们将比较当分数在心电图门控心脏CT扫描与标准胸部CT扫描中计算时的结果。如果在标准胸部CTS上测量的CAC同样可以预测CVD事件，因为CAC在心脏CTS上测量，则CAC评估可能会变得更广泛，在技术上更容易，并且使用较低的辐射剂量进行。