MYOCARDIAL PERFUSION, RISK FACTORS, AND CORONARY CALCIUM

描述(申请人摘要)：冠状动脉血管功能受损 被认为是冠心病最早的表现之一 (CHD)。风险因素的影响，如胆固醇水平升高， 糖尿病、高血压和吸烟对冠状动脉微循环的影响 很大程度上是未知的。我们的主要目标是在横断面上进行调查 研究心肌灌注储备受损是否提供了 冠心病标志物与其他亚临床血管新指标的比较 疾病，并通过测试其与冠心病风险因素的相关性。建议数 这项研究是动脉粥样硬化(MESA)多种族研究的辅助研究，该研究 是一项由NHLBI资助的前瞻性观察研究 亚临床心血管疾病，即以前非侵入性检测到的疾病 它已经产生了迹象和症状。在MESA中对亚临床疾病的新测量 如冠状动脉钙化和臂动脉反应性受损 接受检查，以调查它们与公认的风险因素的关系 和临床事件。我们认为心肌灌注储备(MPR)是一个 冠状动脉血管功能的有用测量应包括在 亚临床疾病新措施的评价。MPR受损似乎 是脑血管功能损害的早期指标 微循环与冠心病危险因素的关系。我们 建议使用磁共振成像(MRI)作为一种先进的、定量的 短时间(20分钟)检查心肌的影像方法 一组400名MESA参与者的灌注储备。我们假设 心肌灌注储备受损提示存在亚临床 冠状动脉粥样硬化和冠状动脉微血管疾病。由于冠心病仍然是 在美国的主要死因中，人们对开发这种 亚临床疾病的新措施将提供早期机会 用于干预和改变生活方式，以预防冠心病和/或充血 心力衰竭。

DESCRIPTION (Applicant's abstract): Impairment of coronary vasofunction is believed to be one of the earliest manifestations of coronary heart disease (CHD). The impact of risk factors such as elevated cholesterol levels, diabetes, hypertension, and smoking on the coronary microcirculation remains largely unknown. Our major objective is to investigate in a cross-sectional study whether an impairment of the myocardial perfusion reserve provides a marker of CHD by comparing it to other novel measures of subclinical vascular disease, and by testing its association with risk factors for CHD. The proposed study is ancillary to the Multi-Ethnic Study of Atherosclerosis ("MESA"), which is an NHLBI funded, prospective observational study of the characteristics of subclinical cardiovascular disease, i.e. disease detected non-invasively before it has produced signs and symptoms. In MESA new measures of subclinical disease such as coronary artery calcium and impaired brachial artery reactivity are to be examined to investigate their relationships to well-established risk factors and clinical events. We believe that myocardial perfusion reserve (MPR)is a useful measure of coronary vasofunction that should be included in an evaluation of new measures of subclinical disease. An impaired MPR appears to be a specific early indicator of the functional impairment of the microcirculation in patients with risk factors for coronary artery disease. We propose to use magnetic resonance imaging (MRI) as an advanced, quantitative imaging modality to determine in short (20 minute) exams the myocardial perfusion reserve in a group of 400 MESA participants. We hypothesize that impaired myocardial perfusion reserve indicates the presence of subclinical coronary atherosclerosis and coronary microvascular disease. As CHD remains the leading cause of death in the U.S. there is strong interest in developing such new measures of subclinical disease which would provide an early opportunity for intervention and lifestyle modification to prevent CHD and/or congestive heart failure.