Significance of Atrial Fibrillation and Atrial Fibrillation Burden Detected by Novel ECG Monitoring in Community-Dwelling Elderly

 说明(申请人提供)：房颤(AF)是一个严重的公共卫生问题，因为它在老龄化人口中的发病率和流行率不断上升，并与心血管事件和死亡的风险增加有关。我们对房颤的危险因素和并发症的了解主要基于当患者出现症状时依赖于其临床识别的研究；对使用心脏植入式电子设备的患者的研究表明，很大比例的房颤发作没有症状(亚临床房颤)。此外，大多数研究都以存在或不存在的二元方式评估房颤，而没有研究房颤的负担(一个人处于房颤中的时间百分比)。因此，关于房颤的认识仍然存在许多空白，特别是在房颤最严重的老年人中：亚临床房颤的患病率，房颤负担的决定因素，以及房颤负担的预后意义都需要澄清。这项提案将全面定义由一种新的动态心电监测仪在混血社区老年队列中检测到的房颤和房颤负荷的患病率、动脉粥样硬化危险因素和临床意义]。我们将应用ZIOXT贴片-一种创新的无创、无铅、连续两周的心电记录设备-在社区动脉粥样硬化风险研究中的4,000名参与者(年龄范围为75-94岁)中，他们将在2016-19年返回进行计划的第6次访问(V6)检查，并利用社区动脉粥样硬化风险研究的优势(广泛的测量和表型数据、队列的混血性质以及对未来事件的持续监测)来调查这些目的：(1)[在没有已知房颤诊断的老年ARIC参与者中，我们将使用心电监测仪来确定亚临床房颤和房颤负担的患病率，(2)评估(A)[动脉粥样硬化标志物与房颤及其在老年心电监护仪上的房颤负荷]之间的关系，(B)过去30年(V1：1987-89至V5：2011-13)内可改变的动脉粥样硬化危险因素与老年人心电监测中房颤及房颤负荷的关系，以及(3)量化老年人房颤负荷与(A)[非致命性缺血性中风、非致命性心肌梗死、心力衰竭住院和心血管死亡的综合风险]以及(B)认知能力下降或痴呆的风险的关系。[我们的项目可能会对公共卫生和临床产生重要影响。首先，通过定义亚临床房颤患病率最高的老年人亚组，我们可以通过动态心电监测有针对性地筛查亚临床房颤。其次，该项目可能会加强动脉粥样硬化作为房颤发病机制的基本组成部分，这将支持战略的转变，从主要关注节律或心率管理转向全面的战略，还包括对动脉粥样硬化危险因素的最佳控制，包括对中年动脉粥样硬化危险因素的强化干预，以预防老年房颤。第三，我们可以将房颤负荷定义为临床上重要的指标，从而支持减轻房颤负荷的努力。最后，通过估计不同房颤负荷水平的心血管结局的绝对风险，该项目可能阐明治疗房颤的门槛。]

 DESCRIPTION (provided by applicant): Atrial fibrillation (AF) is a serious public health problem because of its increasing incidence and prevalence in the aging population and its association with elevated risks of cardiovascular (CV) events and death. Our understanding of the risk factors and complications of AF is based mostly on studies that rely on its clinical recognition when a patient presents with symptoms; research on patients with cardiac implantable electronic devices indicates that a large proportion of AF episodes are not symptomatic (subclinical AF). Moreover, most studies have evaluated AF in a binary fashion-present or absent-and have not investigated AF burden (% time a person is in AF). Therefore, many knowledge gaps remain regarding AF, particularly in the elderly in whom AF exerts its greatest toll: the prevalence of subclinical AF, determinants of AF burden, and prognostic significance of AF burden all need clarification. This proposal will comprehensively define the prevalence, atherosclerosis risk factors, and clinical significance of AF and AF burden detected by a novel ambulatory ECG monitor in a biracial community-dwelling elderly cohort]. We will apply the ZioXT Patch-an innovative non-invasive, leadless, 2-week continuous ECG recording device-to 4,000 participants (age range, 75-94 years) in the Atherosclerosis Risk in Communities (ARIC) study who will return for a planned visit 6 (V6) exam in 2016-19 and leverage the strengths of the ARIC study (extensive measurements and phenotypic data, biracial nature of the cohort, and continuous surveillance for future events) to investigate these aims: (1) [In elderly ARIC participants without a known diagnosis of AF, we will use the ECG monitor to define the prevalence of subclinical AF and AF burden, and identify subgroups with high prevalence of subclinical AF], (2) Assess the association of (a) [markers of atherosclerosis with AF and AF burden on ECG monitor in older age], (b) modifiable atherosclerosis risk factors over the previous 30 years (V1:1987-89 to V5:2011-13) with AF and AF burden on ECG monitor in older age, and (3) Quantify the relationship of AF burden in the elderly to risk of (a) [composite of nonfatal ischemic stroke, nonfatal myocardial infarction, heart failure hospitalization, and CV death], and (b) cognitive decline or dementia. [Our project may have important public health and clinical impact. First, by defining subgroups of the elderly with the highest prevalence of subclinical AF, we can target screening for subclinical AF with ambulatory ECG monitoring. Second, this project may reinforce atherosclerosis as a fundamental component in AF pathogenesis which will support a shift in strategy from one that is focused heavily on rhythm or rate management to a comprehensive one that also includes optimal control of atherosclerosis risk factors, including intensive intervention on midlife atherosclerosi risk factors to prevent AF in older age. Third, we may define AF burden as a clinically important measure, thus supporting efforts to reduce AF burden. Finally, by estimating the absolute risks of CV outcomes by different levels of AF burden, this project may elucidate the thresholds for treating AF.]