Subclinical Atrial Fibrillation and Supraventricular Ectopy in the Jackson Heart Study

摘要 心房颤动（AF）是一种常见的心律失常，可造成破坏性后果，包括 中风和认知功能的加速下降。由于房颤通常无症状， 检测（亚临床AF），识别AF的传统方法低估了人群 非裔美国人比白人有更低的临床识别AF的风险，但他们遭受更多 中风和认知障碍。亚临床AF和另一种重要心律失常的患病率较高， 室上性异位（SVE）可能有助于解释这一矛盾。此外，一些新出现的风险因素 AF和SVE，包括血压的长期变化、低钾血症、某些药物的使用， 和心理社会因素，是可以改变的，并代表潜在的目标，房颤预防。使用敏感 无偏的方法来检测AF和SVE，并发现这些新的可改变的风险因素 心律失常，可能为改善非洲人的心血管疾病（CVD）预防提供机会。 美国人我们的项目将使用一种非侵入性心电图（ECG）监测设备，该设备既具有良好的- 对于检测亚临床心律失常以测量亚临床AF、AF类型（阵发性vs. 持续性）和SVE频率。在这项辅助研究中，我们建议进行14天连续ECG检查 监测2,000名参与者，他们返回杰克逊心脏研究（JHS）的现场中心检查4， 非裔美国人心血管疾病危险因素的前瞻性队列研究。我们还将使用预期的数据 合同资助的外地中心考试的组成部分，包括认知评估和脑磁 磁共振成像（MRI）。我们的目标是评估亚临床AF和SVE的人群负担， 非裔美国人，并确定亚临床AF和SVE的相关性，这些相关性可能是可改变的风险因素， 这些心律失常的后果。有四个目标。目标1：估计年龄和性别特异性 JHS中非裔美国人亚临床AF和AF类型（阵发性vs.持续性）的患病率， 并与接受14天治疗的白色受试者中亚临床AF和AF类型的患病率进行比较 动脉粥样硬化多种族研究中的连续心电图监测和动脉粥样硬化风险 社区研究。目的2：使用JHS检查1-4的数据，（a）评价传统AF风险因素是否 与亚临床AF和SVE相关，以及（B）识别这些心律失常的新的、可改变的风险因素。 目的3：评价临床AF风险评分、NT-proBNP水平和目的2中确定的风险因素的效用 目的4：在横断面分析中，确定亚临床房颤和 SVE与较差的认知功能和脑MRI异常相关。该项目将产生 关于亚临床AF和SVE的新知识，将与患者相关，并将为预防提供信息 和治疗策略，以减少非裔美国人的AF和AF相关并发症的负担。

ABSTRACT Atrial fibrillation (AF) is a common arrhythmia that can have devastating consequences, including stroke and accelerated decline in cognitive function. Because AF is often asymptomatic and escapes clinical detection (subclinical AF), conventional methods for identifying AF have underestimated the population burden of AF. African Americans have a lower risk of clinically-recognized AF than whites, yet they suffer more stroke and cognitive impairment. A high prevalence of subclinical AF and of another important arrhythmia, supraventricular ectopy (SVE), may help to explain this paradox. In addition, several emerging risk factors for AF and SVE, including long-term changes in blood pressure, hypokalemia, the use of certain medications, and psychosocial factors, are modifiable and represent potential targets for AF prevention. The use of sensitive and unbiased methods to detect AF and SVE, and the discovery of novel modifiable risk factors for these arrhythmias, may offer opportunities for improved cardiovascular disease (CVD) prevention among African Americans. Our project will use a non-invasive electrocardiographic (ECG) monitoring device that is both well- tolerated and sensitive for detecting subclinical arrhythmia to measure subclinical AF, AF type (paroxysmal vs. persistent), and SVE frequency. In this ancillary study, we propose to conduct 14-day continuous ECG monitoring on 2,000 participants who return for Field Center Exam 4 of the Jackson Heart Study (JHS), a large prospective cohort study of CVD risk factors in African Americans. We will also use data from anticipated contract funded components of the Field Center Exam, including cognitive assessments and brain magnetic resonance imaging (MRI). Our goals are to assess the population burden of subclinical AF and SVE among African Americans, and to identify correlates of subclinical AF and SVE that may be modifiable risk factors or consequences of these arrhythmias. There are four aims. Aim 1: Estimate the age- and sex-specific prevalence of subclinical AF and AF type (paroxysmal vs. persistent) among African Americans in the JHS, and compare with the prevalence of subclinical AF and AF type among white participants undergoing 14-day continuous ECG monitoring in the Multi-Ethnic Study of Atherosclerosis and the Atherosclerosis Risk in Communities Study. Aim 2: Using data from JHS Exams 1-4, (a) evaluate whether traditional AF risk factors are associated with subclinical AF and SVE, and (b) identify novel, modifiable risk factors for these arrhythmias. Aim 3: Evaluate the utility of a clinical AF risk score, NT-proBNP levels, and risk factors identified from Aim 2 for the prediction of subclinical AF. Aim 4: In cross-sectional analyses, determine whether subclinical AF and SVE are associated with worse cognitive function and with brain MRI abnormalities. This project will generate new knowledge about subclinical AF and SVE that will be relevant to patients, and that will inform prevention and treatment strategies to reduce the burden of AF and AF-related complications among African Americans.