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: 8843598
• 负责人: MICHAEL H CRIQUI
• 金额: $ 7.33万
• 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 2017-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8843598
• 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）上的冠状动脉钙（CAC）的量提供了除了标准CVD危险因素之外的心血管疾病（CVD）危险状态的强大和增量信息。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密度切点，Agatston评分增加2倍、3倍或4倍，从而“提升”Agatston评分以获得更高的CAC密度。然而，广泛的证据表明，密集钙化的冠状动脉斑块可能比不密集钙化的斑块造成更低的心血管疾病风险。例如，1)只有钙化斑块的人患心血管疾病的风险相对较低；2)不稳定型心绞痛患者的钙化斑块少于稳定型心绞痛患者；3)与安慰剂组相比，他汀类药物治疗可能会增加Agatston评分。在初步研究中，我们的研究小组在两个大型队列中探讨了心血管疾病的风险，即多种族动脉粥样硬化研究（MESA）和LifeScore研究。MESA和LifeScore的初步分析表明，容积评分忽略了密度，比Agatston评分对心血管事件的预测略高。然后，我们创建了一个密度评分，并表明在任何给定的CAC体积下，CAC密度实际上对未来的CVD事件具有保护作用。此外，在LifeScore的CVD死亡病例对照研究中，我们已经表明，在标准胸部ct上测量的简化的非加权评分，即序数评分，比Agatston评分更能预测死亡，特别是在评分范围的高端。为了确定CT扫描CAC的最佳评分系统，我们建议比较MESA和LifeScore研究中的四种CAC评分系统。前两个分数将是上面讨论的音量分数和序数分数。另外两个分数将在MESA新开发并在LifeScore中验证，两者都将采用“反向密度加权”。这两个被称为volume-2和序数-2的评分，将在经验上“降低”CAC评分，而不是像Agatston评分那样“提高”更致密钙化斑块的评分；也就是说，密度较小的斑块得分较高，而密度较大的斑块得分较低，这与Agatston方法相反。volume-2和序数-2评分还将考虑冠状动脉数量和CAC的特定冠状动脉。它们将在MESA进行经验开发，并在LifeScore中进行验证。然后，我们将比较这四个评分在风险比、受试者工作特征曲线下面积和净重分类指数的强度和统计显著性方面对CVD的预测。最后，在LifeScore研究中，我们将比较心电图门控心脏CT扫描与标准胸部CT扫描计算得分的结果。如果标准胸部ct测量的CAC与心脏ct测量的CAC同样能预测CVD事件，那么CAC评估可能会变得更广泛，技术上更容易，并且辐射剂量更低。