Laboratory of Hemodynamics and Cardiovascular Technology, Institute of Bioengineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
Division of Anesthesiology, Geneva University Hospitals, Geneva, Switzerland.
Am J Physiol Heart Circ Physiol. 2020 Dec 1;319(6):H1451-H1458. doi: 10.1152/ajpheart.00451.2020. Epub 2020 Oct 16.
Transcatheter aortic valve replacement (TAVR) is increasingly used to treat severe aortic stenosis (AS) patients. However, little is known regarding the direct effect of TAVR on the ventricular-aortic interaction. In the present study, we aimed to investigate changes in central hemodynamics after successful TAVR. We retrospectively examined 33 cases of severe AS patients (84 ± 6 yr) who underwent TAVR. Invasive measurements of left ventricular and aortic pressures as well as echocardiographic aortic flow were acquired before and after TAVR (maximum within 5 days). We examined alterations in key features of central pressure and flow waveforms, including the aortic augmentation index (AIx), and performed wave separation analysis. Arterial parameters were determined via parameter-fitting on a two-element Windkessel model. Resolution of AS resulted in direct increase in the aortic systolic pressure and maximal aortic flow (131 ± 22 vs. 157 ± 25 mmHg and 237 ± 49 vs. 302 ± 69 mL/s, < 0.001 for all), whereas the ejection duration decreased ( < 0.001). We noted a significant decrease in the AIx (from 42 ± 12 to 19 ± 11%, < 0.001). Of note, the arterial properties remained unchanged. There was a comparable increase in both forward (61 ± 20 vs. 77 ± 20 mmHg, < 0.001) and backward (35 ± 14 vs. 42 ± 10 mmHg, = 0.013) pressure wave amplitudes, while their ratio, i.e., the reflection coefficient, was preserved. Our results highlight the impact of TAVR on the ventricular-aortic interaction by affecting the amplitude, shape, and related attributes of the aortic pressure and flow pulse and challenge the interpretation of AIx as a solely vascular measure in AS patients. Transcatheter aortic valve replacement (TAVR) is linked with an immediate increase in aortic systolic blood pressure and maximal flow, as well as steeper aortic pressure and flow wave upstrokes. After TAVR, the forward wave pumped by the heart is enhanced. Although the arterial properties remain unchanged, the central augmentation index (AIx) is markedly decreased after TAVR. This challenges the interpretation of AIx as a solely vascular measure in patients with aortic valve stenosis.
经导管主动脉瓣置换术（TAVR）越来越多地用于治疗严重的主动脉瓣狭窄（AS）患者。然而，对于 TAVR 对心室-主动脉相互作用的直接影响知之甚少。在本研究中，我们旨在研究 TAVR 后中心血流动力学的变化。我们回顾性检查了 33 例接受 TAVR 的严重 AS 患者（84 ± 6 岁）。在 TAVR 前后（最多在 5 天内）获得左心室和主动脉压力以及超声心动图主动脉血流的侵入性测量。我们检查了中央压力和流量波形的关键特征的变化，包括主动脉增强指数（AIx），并进行了波分离分析。通过双元素风箱模型的参数拟合确定动脉参数。AS 的解决导致主动脉收缩压和最大主动脉流量直接增加（131 ± 22 与 157 ± 25mmHg 和 237 ± 49 与 302 ± 69mL/s，所有均<0.001），而射血持续时间缩短（<0.001）。我们注意到 AIx 显著降低（从 42 ± 12%降至 19 ± 11%，<0.001）。值得注意的是，动脉特性保持不变。正向（61 ± 20 与 77 ± 20mmHg，<0.001）和反向（35 ± 14 与 42 ± 10mmHg， = 0.013）压力波幅度均有可比增加，而它们的比值，即反射系数，得以维持。我们的结果强调了 TAVR 通过影响主动脉压力和流量脉冲的幅度、形状和相关属性对心室-主动脉相互作用的影响，并对 AIx 作为 AS 患者的血管测量的解释提出了挑战。经导管主动脉瓣置换术（TAVR）与主动脉收缩压和最大流量的即刻增加以及更陡峭的主动脉压力和流量波上升有关。TAVR 后，由心脏泵出的正向波增强。尽管动脉特性保持不变，但 TAVR 后中心增强指数（AIx）明显降低。这对 AIx 作为主动脉瓣狭窄患者的血管测量的解释提出了挑战。
