The Race-Specific Prevalence of Atrial Fibrillation Measured by 48-Hour Holter

描述(申请人提供)：房颤(房颤)是全世界最常见的持续性心律失常，也是中风的已知危险因素。尽管非裔美国人的中风患病率比白人高得多，但非裔美国人的房颤患病率较低。非洲裔美国人也经历了与房颤相关的高风险因素，包括高血压、肥胖症和糖尿病。有理论认为，非裔美国人的房颤发生率出乎意料地低，这一矛盾可能是由于种族对房颤的差异检测(确定偏差)。大多数先前的研究通过自我报告、住院、索赔数据和/或12导联心电图来定义房颤，所有这些都可能漏诊亚临床和间歇性房颤。房颤的检测可能具有挑战性，因为它可能是阵发性的和无症状的，需要动态心电图(Holter)来确定。国家心、肺和血液研究所(NHLBI)呼吁通过在纵向研究中增加对房颤的监测，特别是在非白人群体中，促进房颤流行病学的进步。我们建议在正在进行的社区动脉粥样硬化风险(ARIC)研究中嵌套的一项信息性研究中，测量特定种族的房颤患病率。为了根据种族评估房颤的患病率和特征，我们计划利用正在进行的第五次ARIC队列检查(2011年6月至2013年5月)，包括最先进的超声心动图(ECOS)，作为一种有效识别信息丰富的亚组进行Holter监测的方法。本研究有四个主要目的。目的1：估计70岁及以上非裔美国人和白人中房颤的种族患病率。目的2：根据动态心电图监测时长，量化房颤检测中的不确定度，以此来校正房颤的患病率。目的3：通过心电图仪、超声心动图、肺活量测定仪和生物标记物监测，评估非裔美国人房颤的近端危险因素和触发因素。目的4：确定与非裔美国人房颤发病率相关的中年代谢、行为和共病因素，以及它们在随后四次队列检查过程中的变化。我们将对ARIC队列中来自2个研究地点的825名非洲裔美国人和400名白人成员进行房颤指标的阶段性验证，并对没有证实的房颤的参与者进行48小时连续动态心电图监测。分层随机抽样将基于种族、中心、性别和增加房颤发生率的特征(超声心动图左房增大或射血分数低，或临床心力衰竭)。根据ARIC队列的5次检查的先前特征和对事件超过25年的全面跟踪，我们将能够有效地检查特定种族的房颤患病率和特征，并提供已发表报告中没有的针对低估的保障措施。本研究将探讨非裔美国人低度房颤的种族悖论，这对非裔美国人房颤的预防和临床治疗具有重要意义。

DESCRIPTION (provided by applicant): Atrial fibrillation (AF) is the most common sustained arrhythmia worldwide and it is a known risk factor for stroke. Despite a much higher prevalence of stroke in African-Americans compared to Whites, African Americans have a lower prevalence of AF. African-Americans also experience high rates of risk factors associated with AF including hypertension, obesity and diabetes. It has been theorized that this paradox of unexpected low rates of AF in African Americans may be due to differential detection of AF by race (ascertainment bias). Most prior studies have defined AF by self-report, hospitalizations, claims data, and/or 12-lead electrocardiography, all of which may miss subclinical and intermittent AF. The detection of AF can be challenging as it can be paroxysmal and asymptomatic requiring ambulatory electrocardiography (Holter) for ascertainment. The National Heart Lung and Blood Institute (NHLBI) has called for advancements in AF epidemiology through increased surveillance of AF in longitudinal studies, especially among non-White ethnic groups. We propose to measure the race-specific prevalence of AF, in an informative study nested in the ongoing, bi-ethnic Atherosclerosis Risk in Communities (ARIC) Study. With the goal of estimating the prevalence and characteristics of AF by race, we plan to take advantage of the ongoing 5th ARIC cohort examination (June 2011-May 2013) inclusive of state-of-the-art echocardiograms (ECHOs) as a way to efficiently identify an informative subgroup for Holter monitoring. This study has four main aims. Aim 1: Estimate the race-specific prevalence of AF in African-Americans and Whites aged 70 years and older. Aim 2: Calibrate the prevalence of AF by quantifying under-ascertainment in the detection of AF according to length of Holter monitoring. Aim 3: Evaluate the proximal risk factors and triggering factors of AF in African Americans from the electrocardiographic, echocardiographic, spirometry, and biomarker measures performed proximal to Holter monitoring. Aim 4: Identify the metabolic, behavioral and comorbid factors in middle age, and their change over the course of the subsequent four cohort examinations, associated with the incidence of AF in African Americans. We will perform a staged validation of indicators of AF, and 48-hour continuous Holter monitoring on participants without substantiated AF, for 825 African American and 400 White members of the ARIC cohort from 2 study sites. Stratified random sampling will be based on race, center, gender, and characteristics that increase yield of AF(enlarged left atrial size or low ejection fraction on echocardiogram, or clinical heart failure). From the prior characterization of the ARIC cohort's 5 examinations and over 25 years of comprehensive follow-up for events, we will be able to efficiently examine the race-specific prevalence and characteristics of AF, with safeguards against under-ascertainment not available in published reports. This study will investigate the racial paradox of low atrial fibrillation in African Americans which has implications for the prevention and clinical management of AF in African Americans.