Department of Cardiology, Hospital General Universitario Gregorio Maranon, Madrid, Spain.
Facultad de Medicina, Universidad Complutense de Madrid.
Heart. 2019 Jun;105(12):911-919. doi: 10.1136/heartjnl-2018-314482. Epub 2019 Feb 16.
To obtain reference values of aortic valve area (AVA) in a large population and to infer the risk of overestimating aortic stenosis (AS) when focusing on flow-corrected indices of severity.
We prospectively measured indices of AS in all consecutive echocardiograms performed in a large referral cardiac imaging laboratory for 1 year. We specifically analysed the distribution of AVA, indexed AVA and velocity ratio (Vratio) in patients with and without AS, the latter defined as the coexistence of valvular outflow obstruction (Vmax ≥2.5 m/s) and morphological findings of valve degeneration.
16 156 echocardiograms were analysed, 14 669 of which did not show valvular obstruction (peak jet velocity <2.5 m/s). In the latter group, AVA was 2.6±0.7 cm in 8190 studies with normal valves and 2.3±0.7 cm in 6479 studies with aortic sclerosis (AScl). There was a relatively wide overlap between values of AVA, indexed AVA and velocity ratio between studies of patients with AScl and AS. Values of AVA ≤1.0 cm were found in 0.5% of studies with normal valves and 1.8% of studies with AScl. These proportions were 3.1% and 9.3% for AVA ≤1.5 cm, respectively. Vratio ≤0.25 were found in 0.1% of patients without obstruction. Risk factors for a small AVA in patients without obstruction were AScl, female sex, small body surface area, low ejection fraction and mitral regurgitation.
Normal values of continuity-equation derived AVA are smaller than previously considered. AVA values below cutoffs of moderate or severe AS can be found in patients without the disease. Flow-corrected indices may overestimate AS in patients with low gradients, particularly in the presence of well-identified risk factors.
获取大样本人群中主动脉瓣口面积（AVA）的参考值，并推断在关注严重程度的流量校正指数时高估主动脉瓣狭窄（AS）的风险。
我们前瞻性地测量了在一个大型转诊心脏成像实验室进行的所有连续超声心动图中 AS 的指数。我们特别分析了有和无 AS 的患者的 AVA、指数化 AVA 和速度比（Vratio）的分布，后者定义为瓣流出道阻塞（Vmax≥2.5m/s）和瓣膜退行性改变的形态学发现共存。
共分析了 16156 次超声心动图，其中 14669 次未显示瓣口阻塞（峰值射流速度<2.5m/s）。在后一组中，8190 次正常瓣膜研究中 AVA 为 2.6±0.7cm，6479 次主动脉硬化（AScl）研究中 AVA 为 2.3±0.7cm。AScl 和 AS 患者研究之间的 AVA、指数化 AVA 和速度比值存在相对较宽的重叠。正常瓣膜研究中AVA 值≤1.0cm 的比例为 0.5%，AScl 研究中为 1.8%。AVA 值≤1.5cm 的比例分别为 3.1%和 9.3%。无梗阻患者中 Vratio≤0.25 的比例为 0.1%。无梗阻患者中 AVA 较小的危险因素为 AScl、女性、小体表面积、低射血分数和二尖瓣反流。
连续性方程衍生的 AVA 的正常值小于先前认为的。无疾病患者也可能出现低于中度或重度 AS 截断值的 AVA 值。在低梯度患者中，特别是在存在明确的危险因素时，流量校正指数可能高估 AS。
