Division of Cardiology, Johns Hopkins University School of Medicine, Baltimore, Maryland; Division of Cardiology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York.
Department of Medicine, Erasmus Medical Center, Rotterdam, the Netherlands.
JACC Cardiovasc Imaging. 2019 Dec;12(12):2417-2427. doi: 10.1016/j.jcmg.2019.02.021. Epub 2019 Apr 17.
This study sought to assess the association of baseline left atrial (LA) phasic function measured with cardia magnetic resonance (CMR) and incident ischemic cerebrovascular events (CVE).
LA remodeling is a known predictor of atrial fibrillation (AF), which is a risk factor for ischemic CVE. Despite studies showing an association between LA remodeling and ischemic CVE, the association of LA mechanical function with ischemic CVE in a population free of known cardiovascular disease is not fully studied.
Phasic LA volumes; total, passive, and active LA emptying fractions (LAEF); and peak longitudinal LA strain were measured using feature-tracking CMR in 4,261 MESA (Multi-Ethnic Study of Atherosclerosis) participants (61 ± 10 years of age; 48% male). All individuals were free of clinical cardiovascular disease at baseline. Participants were followed for 11.6 ± 3.5 years for the diagnosis of incident ischemic CVE, defined as ischemic stroke or transient ischemic attack adjudicated by vascular neurologists.
During the follow-up, 193 (1.26 per 1,000 person-years) ischemic CVE (134 ischemic strokes and 59 TIAs) occurred. Individuals with incident ischemic CVE had larger LA volumes and lower passive, active, and total LAEFs at baseline. In multivariate analysis adjusted for known CVE risk factors, left ventricular mass and interim AF, total LAEF was associated with incident ischemic CVE (hazard ratio [HR]: 0.85 per SD; 95% confidence interval [CI]: 0.74 to 0.98; p = 0.027). The unadjusted HR for the lowest tertile of total LAEF compared to the highest tertile was 2.0 (95% CI: 1.43 to 2.79; p < 0.001), and the adjusted HR was 1.47 (95% CI: 1.04 to 2.05; p = 0.031). Addition of total LAEF to known clinical risk factors of CVE and left ventricular mass resulted in an improved predictive accuracy (C statistic of 0.76 vs. 0.73, respectively; p = 0.039).
Reduced total LAEF was associated with incident ischemic CVE independent of known cerebrovascular risk factors and incident AF. Assessment of LA function may add further information in stratifying asymptomatic individuals at risk for ischemic stroke.
本研究旨在评估心脏磁共振（CMR）测量的基线左心房（LA）时相功能与缺血性脑血管事件（CVE）之间的关联。
LA 重构是心房颤动（AF）的已知预测因子，AF 是缺血性 CVE 的危险因素。尽管研究表明 LA 重构与缺血性 CVE 之间存在关联，但在无已知心血管疾病的人群中，LA 机械功能与缺血性 CVE 的关联尚未得到充分研究。
在 4261 名 MESA（动脉粥样硬化的多民族研究）参与者（61 ± 10 岁；48%为男性）中使用特征追踪 CMR 测量 LA 时相容积；总、被动和主动 LA 排空分数（LAEF）；和峰值纵向 LA 应变。所有参与者在基线时均无临床心血管疾病。在 11.6 ± 3.5 年的随访期间，根据血管神经病学家的评估，诊断为缺血性 CVE（定义为缺血性中风或短暂性脑缺血发作）。
在随访期间，发生了 193 例（每 1000 人年 1.26 例）缺血性 CVE（134 例缺血性中风和 59 例 TIA）。发生缺血性 CVE 的个体在基线时 LA 容积较大，被动、主动和总 LAEF 较低。在调整已知 CVE 危险因素、左心室质量和中间 AF 后，总 LAEF 与缺血性 CVE 相关（风险比 [HR]：每 SD 为 0.85；95%置信区间 [CI]：0.74 至 0.98；p = 0.027）。与最高三分位相比，总 LAEF 最低三分位的未调整 HR 为 2.0（95%CI：1.43 至 2.79；p<0.001），调整后的 HR 为 1.47（95%CI：1.04 至 2.05；p=0.031）。将总 LAEF 与已知的 CVE 和左心室质量临床危险因素相加，可提高预测准确性（C 统计量分别为 0.76 和 0.73；p=0.039）。
总 LAEF 降低与缺血性 CVE 相关，与已知的脑血管危险因素和新发 AF 无关。评估 LA 功能可能会在分层缺血性中风风险的无症状个体方面提供更多信息。
