Department of Medicine, National University Health System, Singapore, Singapore.
Department of Cardiology, National University Heart Centre Singapore, National University Health System, Singapore, Singapore.
Sci Rep. 2020 Jun 3;10(1):9086. doi: 10.1038/s41598-020-65758-8.
Background Paradoxical low-flow (LF) severe aortic stenosis (AS) with preserved left ventricular ejection fraction (LVEF) may have poorer prognosis than normal-flow (NF) AS, though its pathophysiology remained unclear. In particular, LV stiffness has not been compared between LF vs NF. We used a novel echocardiography-derived index of LV stiffness to compare between these groups. Consecutive patients with medically-managed isolated severe AS (aortic valve area < 1 cm) and preserved LVEF (>50%) were studied. Echocardiographic LV stiffness index was measured by a method previously validated against cardiac catheterization. We compared LF (stroke volume index, SVI < 35 ml/m) and NF severe AS. Of the 352 patients, 121 (34%) were LF. Both LF and NF groups had similar demographics, valve areas and indices. Compared to NF, LF severe AS had higher LV stiffness indices (>0.11 ml OR 3.067, 95% CI 1.825-5.128, p < 0.001). Increased LV stiffness was associated with concentric remodelling and more severe diastolic dysfunction, especially in LF AS. An LV stiffness index of > 0.11 ml was independently associated with increased mortality, after adjusting for age, clinical and echocardiographic parameters (HR 2.283 95% CI 1.318-3.968, p = 0.003). Non-invasive echocardiographic-derived index of LV stiffness may be important in LF AS. Increased LV stiffness was related to LV concentric remodelling and diastolic dysfunction, and associated with poorer clinical outcomes in medically-managed AS.
尽管左心室射血分数（LVEF）保留的反常低流量（LF）重度主动脉瓣狭窄（AS）的预后可能比正常流量（NF）AS 差，但其病理生理学仍不清楚。特别是，LF 与 NF 之间的 LV 僵硬度尚未进行比较。我们使用一种新的超声心动图衍生的 LV 僵硬度指数来比较这两组。连续研究了经药物治疗的孤立性重度 AS（主动脉瓣面积<1cm）和保留 LVEF（>50%）的患者。LV 僵硬度指数通过一种先前经过与心导管检查对比验证的方法进行测量。我们比较了 LF（每搏量指数，SVI<35ml/m）和 NF 重度 AS。在 352 例患者中，121 例（34%）为 LF。LF 和 NF 两组的人口统计学、瓣膜面积和指数相似。与 NF 相比，LF 重度 AS 的 LV 僵硬度指数更高（>0.11ml 或 3.067，95%CI1.825-5.128，p<0.001）。与 NF 相比，LF 重度 AS 患者的 LV 僵硬度增加与向心性重构和更严重的舒张功能障碍有关，尤其是在 LF AS 中。在调整年龄、临床和超声心动图参数后，LV 僵硬度指数>0.11ml 与死亡率增加独立相关（HR2.28395%CI1.318-3.968，p=0.003）。LV 僵硬度的无创超声心动图衍生指数在 LF AS 中可能很重要。LV 僵硬度增加与 LV 向心性重构和舒张功能障碍有关，与药物治疗的 AS 患者的不良临床结局相关。
