Abstract An ascending thoracic aortic aneurysm (ATAA) is a life-threatening cardiovascular consequence of vessel dilatation that portends adverse events and death. From a clinical perspective, ATAA should not be treated as an isolated disease, and surgery is often carried out in the presence of AS, aortic insufficiency or a calcified valve leaflet. Aortic stenosis (AS) is common in ATAAs and leads to both vessel rigidity and left ventricular (LV) impairment. In this study, lumped-parameter modeling and computational analysis were used to assess the change in the wall shear stress (WSS) and intramural wall stress of patient-specific ATAA models with different degrees of AS (ie, mild to severe). The ATAAs of four patients were reconstructed from imaging data and AS was simulated virtually using the lumped-based CircAdapt tool using clinical and echocardiographic data. Results show that LV work derived from pressure-volume loops increased with the severity of AS. Post-stenotic hemodynamic and structural variables markedly increased with AS severity, with WSS showing a 10-fold increase for the most severe AS model as compared to the baseline model with a well-functioning aortic valve. Most importantly, the increase in WSS and aortic wall stress was associated with pronounced values of valvulo-arterial impedance as an indicator of LV dysfunction. This study provides novel insights into progression of AS in patients with ATAAs at high risk of adverse events, and the potential value of valvulo-arterial impedance to predict changes in hemodynamic and structural parameters with the severity of AS.

中文翻译：

---

升主动脉瘤中主动脉瓣狭窄的严重程度：检查心室-动脉相互作用和主动脉壁应力的计算工具

摘要 升胸主动脉瘤 (ATAA) 是血管扩张的危及生命的心血管后果，预示着不良事件和死亡。从临床角度来看，ATAA不应被视为孤立的疾病，手术常在存在AS、主动脉瓣关闭不全或瓣叶钙化的情况下进行。主动脉瓣狭窄 (AS) 在 ATAA 中很常见，会导致血管僵硬和左心室 (LV) 损伤。在本研究中，集总参数建模和计算分析用于评估具有不同程度 AS（即轻度至重度）的患者特定 ATAA 模型的壁剪切应力 (WSS) 和壁内壁应力的变化。四名患者的 ATAA 是根据成像数据重建的，并且使用基于集总的 CircAdapt 工具使用临床和超声心动图数据虚拟模拟 AS。结果表明，来自压力-容积环的 LV 工作随着 AS 的严重程度而增加。狭窄后血流动力学和结构变量随着 AS 的严重程度而显着增加，与具有功能良好的主动脉瓣的基线模型相比，最严重的 AS 模型的 WSS 增加了 10 倍。最重要的是，WSS 和主动脉壁应力的增加与作为 LV 功能障碍指标的瓣膜动脉阻抗的显着值相关。这项研究为不良事件高风险的 ATAA 患者的 AS 进展提供了新的见解，