MYOCARDIAL PERFUSION, RISK FACTORS, AND CORONARY CALCIUM

描述（申请人摘要）：冠状动脉血管功能受损是 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仍然存在 大部分未知。我们的主要目标是在一个横截面调查 研究心肌灌注储备受损是否提供了 通过将其与亚临床血管的其他新指标进行比较， 疾病，并通过测试其与CHD危险因素的相关性。拟议 这项研究是动脉粥样硬化多种族研究（“梅萨”）的辅助研究， 是一项由NHLBI资助的前瞻性观察性研究， 亚临床心血管疾病，即之前非侵入性检测到的疾病 它已经产生了迹象和症状。在梅萨亚临床疾病的新措施 例如冠状动脉钙和受损的肱动脉反应性， 进行检查，以调查它们与已确立的风险因素的关系 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指标，应包括在一个 评估亚临床疾病的新措施。受损的MPR似乎 是一个特定的早期指标的功能障碍， 冠心病患者微循环障碍的危险因素。我们 建议使用磁共振成像（MRI）作为先进的定量 在短时间（20分钟）检查中确定心肌 400名梅萨参与者中的灌注储备。我们假设 心肌灌注储备受损表明存在亚临床 冠状动脉粥样硬化和冠状动脉微血管疾病。由于CHD仍然是 在美国的主要死亡原因，有强烈的兴趣，发展这样的 亚临床疾病的新措施，这将提供一个早期的机会， 进行干预和改变生活方式，以预防CHD和/或充血性 心衰

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.