Pre- and post-procedural hemodynamic changes which could affect adverse outcomes in aortic stenosis (AS) patients who undergo transcatheter aortic valve replacement (TAVR) have not been well investigated. Four-dimensional (4D) flow cardiovascular magnetic resonance (CMR) enables accurate analysis of blood flow dynamics such as flow velocity, flow pattern, wall shear stress (WSS), and energy loss (EL). We sought to examine the changes in blood flow dynamics of patients with severe AS who underwent TAVR. We examined 32 consecutive severe AS patients who underwent TAVR between May 2018 and June 2019 (17 men, 82 ± 5 years, median left ventricular ejection fraction 61%, 6 self-expanding valve), after excluding those without CMR because of a contraindication or inadequate imaging from the analyses. We analyzed blood flow patterns, WSS and EL in the ascending aorta (AAo), and those changes before and after TAVR using 4D flow CMR. After TAVR, semi-quantified helical flow in the AAo was significantly decreased (1.4 ± 0.6 vs. 1.9 ± 0.8, P = 0.002), whereas vortical flow and eccentricity showed no significant changes. WSS along the ascending aortic circumference was significantly decreased in the left (P = 0.038) and left anterior (P = 0.033) wall at the basal level, right posterior (P = 0.011) and left (P = 0.010) wall at the middle level, and right (P = 0.012), left posterior (P = 0.019) and left anterior (P = 0.028) wall at the upper level. EL in the AAo was significantly decreased (15.6 [10.8–25.1 vs. 25.8 [18.6–36.2]] mW, P = 0.012). Furthermore, a significant negative correlation was observed between EL and effective orifice area index after TAVR (r = − 0.38, P = 0.034). In severe AS patients undergoing TAVR, 4D flow CMR demonstrates that TAVR improves blood flow dynamics, especially when a larger effective orifice area index is obtained.

中文翻译：

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主动脉瓣狭窄患者经导管主动脉瓣置换术前后四维血流心血管磁共振血流动力学研究


可能影响接受经导管主动脉瓣置换术 (TAVR) 的主动脉瓣狭窄 (AS) 患者不良结局的术前和术后血流动力学变化尚未得到充分研究。四维 (4D) 血流心血管磁共振 (CMR) 能够准确分析血流动力学，例如流速、血流模式、壁剪切应力 (WSS) 和能量损失 (EL)。我们试图检查接受 TAVR 的严重 AS 患者的血流动力学变化。我们检查了 2018 年 5 月至 2019 年 6 月期间连续接受 TAVR 的 32 名严重 AS 患者（17 名男性，82 ± 5 岁，中位左心室射血分数 61%，6 个自扩张瓣膜），排除了因禁忌症或原因而没有 CMR 的患者。分析中的成像不充分。我们使用 4D 血流 CMR 分析了升主动脉 (AAo) 的血流模式、WSS 和 EL，以及 TAVR 前后的变化。 TAVR 后，AAo 中的半定量螺旋流显着下降（1.4 ± 0.6 vs. 1.9 ± 0.8，P = 0.002），而涡流和偏心率则没有显着变化。沿升主动脉周长的 WSS 在基底层的左壁 (P = 0.038) 和左前壁 (P = 0.033)、中层的右后壁 (P = 0.011) 和左壁 (P = 0.010) 显着降低，以及上层的右壁（P = 0.012）、左后壁（P = 0.019）和左前壁（P = 0.028）。 AAo 中的 EL 显着降低（15.6 [10.8–25.1 vs. 25.8 [18.6–36.2]] mW，P = 0.012）。此外，TAVR 后 EL 与有效孔口面积指数之间存在显着负相关（r = − 0.38，P = 0.034）。 在接受 TAVR 的严重 AS 患者中，4D 血流 CMR 表明 TAVR 改善了血流动力学，特别是当获得更大的有效孔口面积指数时。