Cardiology Division, Department of Medicine, University of Massachusetts Medical School, Worcester, MA
Department of Quantitative Health Sciences, University of Massachusetts Medical School, Worcester, MA.
J Am Heart Assoc. 2018 Mar 30;7(7):e008435. doi: 10.1161/JAHA.117.008435.
Left atrial (LA) size, a marker of atrial structural remodeling, is associated with increased risk for atrial fibrillation (AF) and cardiovascular disease (CVD). LA function may also relate to AF and CVD, irrespective of LA structure. We tested the hypothesis that LA function index (LAFI), an echocardiographic index of LA structure and function, may better characterize adverse LA remodeling and predict incident AF and CVD than existing measures.
In 1786 Framingham Offspring Study eighth examination participants (mean age, 66±9 years; 53% women), we related LA diameter and LAFI (derived from the LA emptying fraction, left ventricular outflow tract velocity time integral, and indexed maximal LA volume) to incidence of AF and CVD on follow-up. Over a median follow-up of 8.3 years (range, 7.5-9.1 years), 145 participants developed AF and 139 developed CVD. Mean LAFI was 34.5±12.7. In adjusted Cox regression models, lower LAFI was associated with higher risk of incident AF (hazard ratio=3.83, 95% confidence interval=2.23-6.59, lowest [Q1] compared with highest [Q4] LAFI quartile) and over 2-fold higher risk of incident CVD (hazard ratio=2.20, 95% confidence interval=1.32-3.68, Q1 versus Q4). Addition of LAFI, indexed maximum LA volume, or LA diameter to prediction models for AF or CVD did not significantly improve model discrimination for either outcome.
In our prospective investigation of a moderate-sized community-based sample, LAFI, a composite measure of LA size and function, was associated with incident AF and CVD. Addition of LAFI to the risk prediction models for AF or CVD, however, did not significantly improve their performance.
左心房（LA）大小是心房结构重构的标志物，与心房颤动（AF）和心血管疾病（CVD）的风险增加相关。LA 功能也可能与 AF 和 CVD 相关，而与 LA 结构无关。我们检验了这样一个假设，即 LA 功能指数（LAFI），一种评估 LA 结构和功能的超声心动图指数，可能比现有指标更好地描述不良的 LA 重构，并预测 AF 和 CVD 的发生。
在 1786 名弗雷明汉后代研究第八次检查参与者（平均年龄 66±9 岁；53%为女性）中，我们将 LA 直径和 LAFI（由 LA 排空分数、左心室流出道速度时间积分和最大 LA 容积指数化得出）与随访期间 AF 和 CVD 的发生率相关联。在中位数为 8.3 年（范围 7.5-9.1 年）的随访中，145 名参与者发生了 AF，139 名参与者发生了 CVD。平均 LAFI 为 34.5±12.7。在调整后的 Cox 回归模型中，较低的 LAFI 与 AF 发生的风险增加相关（风险比=3.83，95%置信区间=2.23-6.59，最低[Q1]与最高[Q4]LAFI 四分位间距），并且 CVD 发生的风险增加了两倍以上（风险比=2.20，95%置信区间=1.32-3.68，Q1 与 Q4）。将 LAFI、最大 LA 容积指数或 LA 直径添加到 AF 或 CVD 的预测模型中，对两种结局的模型区分度均无显著改善。
在我们对中等规模的社区为基础的样本进行的前瞻性研究中，LAFI，一种 LA 大小和功能的综合测量指标，与 AF 和 CVD 的发生相关。然而，将 LAFI 添加到 AF 或 CVD 的风险预测模型中，并没有显著提高其性能。
