Left Atrial abNormality, ThromboEmbolism, and Race: Novel risk factors for stroke (LANTERN)

项目概要/摘要 非裔美国人面临的缺血性中风风险是美国白色居民的两倍。 这种黑白笔画不一致的原因还不完全清楚。该建议旨在确定是否 心房性心脏病是一种新的危险因素，它部分解释了黑人中风风险较高的原因。与白人相比， 黑人较少经历心房颤动，这是一种心律紊乱，是已知最强的风险因素之一 治疗中风在流行的临床范例中，认为房颤是血栓形成所必需的 在心脏的左心房，从那里他们可以栓塞到大脑，并导致中风。但最近的 研究表明，当心房组织存在异常时， 和功能-一种称为心房性心脏病的疾病-无论是否有心房纤维性颤动。 初步数据表明，心房性心脏病在黑人中的表现与白人不同： 12导联心电图（ECG）上的心房异常，较少发生房颤或其典型 伴随超声心动图显示左心房增大因此，心房血栓栓塞可能经常 在黑人中不被识别，因为它发生在没有心房颤动和心房扩大的情况下。的 拟议的研究将测试中心假设，目前无法解释的差异，中风之间， 白人和黑人的部分原因是心房性心脏病的表现不同。这 申请用于卒中地理和种族差异原因的辅助研究 （REGARDS）研究和大辛辛那提/北方肯塔基州卒中研究（GCNKSS）。尊重是一个 一项纵向队列研究，旨在阐明基线风险因素与未来 在> 30，000名黑人和白色人中发生中风。GCNKSS是一项基于人群的种族流行病学研究， 130万双胞胎人群中卒中发病率和结局的差异。利用 这些研究的互补设计，建议的研究将首先确定关系 在REGARDS中，基线ECG定义的左心房异常、种族和未来卒中之间的关系。然后它将 确定标志物中GCNKSS的黑白差异，表明潜在的心房血栓栓塞原因 中风具体目标1将检验黑人左心房异常患病率较高的假设， 左心房异常与未来的中风有关，左心房异常有助于 黑人中风风险更高。具体目标2将检验以下假设： ECG定义的左心房异常更常见，超声心动图左心房异常更少 比白人更大。所有ECG和超声心动图图像子集将集中解读。这 研究有望表明，黑人中风风险较高，部分反映了黑人生物学上的可操作差异 中风这些发现可能最终导致使用现有的药物治疗房颤。

PROJECT SUMMARY/ABSTRACT African Americans face a two-fold higher risk of ischemic stroke than white residents of the U.S. The reasons for this black-white stroke disparity are not completely known. This proposal seeks to identify whether atrial cardiopathy, a novel risk factor, partly explains the higher stroke risk in blacks. Compared to whites, blacks experience less atrial fibrillation, a heart-rhythm disorder that is one of the strongest known risk factors for stroke. In the prevailing clinical paradigm, it is thought that atrial fibrillation is required for blood clots to form in the heart's left atrium, from where they can embolize to the brain and cause stroke. However, recent research indicates that embolization from the left atrium can occur when there are abnormalities in atrial tissue and function—a condition referred to as atrial cardiopathy—regardless of whether there is atrial fibrillation. Preliminary data suggest that atrial cardiopathy manifests differently in blacks than whites: more often with left atrial abnormality on a 12-lead electrocardiogram (ECG) and less often with atrial fibrillation or its typical accompaniment, left atrial enlargement on an echocardiogram. As a result, atrial thromboembolism may often go unrecognized in blacks because it occurs in the absence of atrial fibrillation and atrial enlargement. The proposed research will test the central hypothesis that currently unexplained disparities in stroke between whites and blacks can be partly explained by differences in the manifestation of atrial cardiopathy. This application is for an ancillary study to the REasons for Geographic and Racial Differences in Stroke (REGARDS) study and the Greater Cincinnati/Northern Kentucky Stroke Study (GCNKSS). REGARDS is a longitudinal cohort study that seeks to shed light on the relationship between baseline risk factors and future stroke in >30,000 black and white individuals. GCNKSS is a population-based epidemiological study of racial disparities in the incidence and outcomes of stroke in a biracial population of 1.3 million. Taking advantage of the complementary designs of these studies, the proposed research will first determine the relationship between baseline ECG-defined left atrial abnormality, race, and future stroke in REGARDS. It will then determine black-white differences in GCNKSS in markers that signify a potential atrial thromboembolic cause of stroke. Specific Aim 1 will test the hypotheses that blacks have a higher prevalence of left atrial abnormality, that left atrial abnormality is associated with future stroke, and that left atrial abnormality contributes to the higher stroke risk in blacks. Specific Aim 2 will test the hypotheses that black patients with ischemic stroke more often have ECG-defined left atrial abnormality and less often have echocardiographic left atrial enlargement than whites. All ECGs and a subset of echocardiogram images will be centrally interpreted. This research promises to show that blacks' higher stroke risk partly reflects actionable differences in the biology of stroke. Such findings may ultimately lead to therapy using existing medications approved for atrial fibrillation.