Ngiam Jinghao Nicholas, Kuntjoro Ivandito, Tan Benjamin Y Q, Sim Hui-Wen, Kong William K F, Yeo Tiong-Cheng, Poh Kian-Keong
Department of Medicine, National University Health System, Singapore, Singapore.
Department of Cardiology, National University Heart Centre Singapore, National University Health System, Singapore, Singapore.
Echocardiography. 2017 Nov;34(11):1568-1574. doi: 10.1111/echo.13676. Epub 2017 Sep 13.
BACKGROUND/OBJECTIVES: Controversy surrounds the prognosis and management of patients with paradoxical low-flow severe aortic stenosis (AS) with preserved left ventricular ejection fraction (LVEF). It was not certain if patients in a particular flow category remained in the same category as disease progressed. We investigated whether there were switches in categories and if so, their predictors.
Consecutive subjects (n = 203) with isolated severe AS and paired echocardiography (>180 days apart) were studied. They were divided into 4 groups, based on their flow categories and if they progressed on subsequent echocardiography to switch or remain in the same flow category. Univariate analyses of clinical and echocardiographic parameters identified predictors of these changes in flow category.
One hundred eighteen were normal flow (SVI ≥ 35 mL/m ), while 85 were low flow on index echocardiography. In the patients with normal flow, 33% switched to low flow. This was associated with higher valvuloarterial impedance (Zva, P < .001) and lower systemic arterial compliance (SAC, P < .001) compared to index echocardiography, and predicted by higher initial Zva (optimized cutoff >4.77 mm Hg/mL/m , AUC = 0.81 [95% CI:0.75-0.87, P < .001]). In patients with low flow, 25% switched to normal flow, which was associated with lower Zva and higher SAC and the switch was predicted by a higher initial mean transaortic pressure gradient.
A significant number of patients switched flow categories in severe AS with preserved LVEF on subsequent echocardiography. Changes in flow were reflected by respective changes in Zva and SAC. Identifying echocardiographic predictors of a switch in category may guide prognostication and management of such patients.
背景/目的：对于左心室射血分数（LVEF）保留的矛盾性低流量严重主动脉瓣狭窄（AS）患者的预后和管理存在争议。随着疾病进展，特定流量类别的患者是否仍处于同一类别尚不确定。我们研究了是否存在类别转换，如果存在，其预测因素是什么。
对连续的孤立性严重AS患者（n = 203）及配对的超声心动图检查（间隔>180天）进行研究。根据其流量类别以及后续超声心动图检查时是否进展为转换或保持在相同流量类别，将他们分为4组。对临床和超声心动图参数进行单因素分析，确定这些流量类别变化的预测因素。
118例为正常流量（每平方米体表面积的左心室流出道速度时间积分[SVI]≥35 mL/m）而85例在首次超声心动图检查时为低流量。在正常流量患者中，33%转换为低流量。与首次超声心动图检查相比，这与更高的瓣动脉阻抗（Zva，P <.001）和更低的体动脉顺应性（SAC，P <.001）相关，且由更高的初始Zva预测（优化截断值>4.77 mmHg/mL/m，曲线下面积[AUC]=0.81 [95%可信区间：0.75 - 0.87，P <.001]）。在低流量患者中，25%转换为正常流量，这与更低的Zva和更高的SAC相关，且该转换由更高的初始平均跨主动脉压力梯度预测。
在LVEF保留的严重AS患者中，相当数量的患者在后续超声心动图检查时转换了流量类别。流量变化反映在Zva和SAC的相应变化中。识别类别转换的超声心动图预测因素可能指导此类患者的预后评估和管理。
