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) 扫描中的冠状动脉钙 (CAC) 量提供了有关心血管疾病 (CVD) 风险状态的强有力的增量信息，超出了标准 CVD 风险因素。 Agatston 方法是标准 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 密度分界点，Agatston 分数会增加 2、3 或 4 倍，从而“增加”Agatston 分数以获得更大的 CAC 密度。然而，大量证据表明，与钙化程度较低的斑块相比，致密钙化的冠状动脉斑块可能具有较低的 CVD 风险。例如，1) 仅具有钙化斑块的人患 CVD 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，我们的小组在两个大型队列中探索了 CVD 风险，即动脉粥样硬化多种族研究 (MESA) 和 LifeScore 研究。 MESA 和 LifeScore 的初步分析表明，忽略密度的体积评分比 Agatston 评分对 CVD 事件的预测能力稍强。然后，我们创建了一个密度评分，并表明 CAC 密度实际上可以在任何给定 CAC 体积下对未来的 CVD 事件起到保护作用。此外，在 LifeScore 中一项关于 CVD 死亡的病例对照研究中，我们表明，在标准胸部 CT 上测量的简化未加权评分（序数评分）是比 Agatston 评分更好的预测因子，特别是在较高端分数范围。为了根据 CT 扫描确定 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体积分数和序数分数。另外两个分数将在 MESA 中新开发并在 LifeScore 中验证，并且都将采用“反向密度加权”。这两个评分（称为体积 2 和序数 2 评分）不会像 Agatston 评分那样“增加”更致密钙化斑块的评分，而是根据经验“降低”更致密斑块的 CAC 评分；也就是说，密度较小的斑块将产生较高的分数，而密度较大的斑块将产生较低的分数，这与 Agatston 方法相反。第 2 卷和第 2 序数评分还将考虑冠状动脉的数量以及具有 CAC 的特定冠状动脉。它们将在 MESA 中进行实证开发，并在 LifeScore 中进行验证。然后，我们将根据风险比的强度和统计显着性、接受者操作特征曲线下的面积以及净重分类指数来比较这四个分数的 CVD 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 扫描计算分数时的结果。如果标准胸部 CT 测量的 CAC 与心脏 CT 测量的 CAC 同等地预测 CVD 事件，那么 CAC 评估可能会变得更广泛、技术上更容易，并且可以用更低的辐射剂量完成。