Wiegerinck Esther M A, van de Hoef Tim P, Rolandi M Cristina, Yong ZeYie, van Kesteren Floortje, Koch Karel T, Vis Marije M, de Mol Bas A J M, Piek Jan J, Baan Jan
From the AMC Heartcenter, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
Circ Cardiovasc Interv. 2015 Aug;8(8):e002443. doi: 10.1161/CIRCINTERVENTIONS.114.002443.
Aortic valve stenosis (AS) induces compensatory alterations in left ventricular hemodynamics, leading to physiological and pathological alterations in coronary hemodynamics. Relief of AS by transcatheter aortic valve implantation (TAVI) decreases ventricular afterload and is expected to improve microvascular function immediately. We evaluated the effect of AS on coronary hemodynamics and the immediate effect of TAVI.
Intracoronary pressure and flow velocity were simultaneously assessed at rest and at maximal hyperemia in an unobstructed coronary artery in 27 patients with AS before and immediately after TAVI and in 28 patients without AS. Baseline flow velocity was higher and baseline microvascular resistance was lower in patients with AS as compared with controls, which remained unaltered post-TAVI. In patients with AS, hyperemic flow velocity was significantly lower as compared with controls (44.5±14.5 versus 54.3±18.6 cm/s; P=0.04). Hyperemic microvascular resistance (expressed in mm Hg·cm·s(-1)) was 2.10±0.69 in patients with AS as compared with 1.80±0.60 in controls (P=0.096). Coronary flow velocity reserve in patients with AS was lower, 1.9±0.5 versus 2.7±0.7 in controls (P<0.001). Improvement in coronary hemodynamics after TAVI was most pronounced in patients without post-TAVI aortic regurgitation. In these patients (n=20), hyperemic flow velocity increased significantly from 46.24±15.47 pre-TAVI to 56.56±17.44 cm/s post-TAVI (P=0.003). Hyperemic microvascular resistance decreased from 2.03±0.71 to 1.66±0.45 (P=0.050). Coronary flow velocity reserve increased significantly from 1.9±0.4 to 2.2±0.6 (P=0.009).
The vasodilatory reserve capacity of the coronary circulation is reduced in AS. TAVI induces an immediate decrease in hyperemic microvascular resistance and a concomitant increase in hyperemic flow velocity, resulting in immediate improvement in coronary vasodilatory reserve.
主动脉瓣狭窄(AS)可引起左心室血流动力学的代偿性改变,进而导致冠状动脉血流动力学的生理和病理改变。经导管主动脉瓣植入术(TAVI)缓解AS可降低心室后负荷,并有望立即改善微血管功能。我们评估了AS对冠状动脉血流动力学的影响以及TAVI的即刻效应。
在27例AS患者TAVI术前和术后即刻以及28例无AS患者中,于静息状态和最大充血状态下同时评估通畅冠状动脉内的压力和流速。与对照组相比,AS患者的基线流速较高,基线微血管阻力较低,TAVI术后这些指标保持不变。与对照组相比,AS患者的充血流速显著较低(44.5±14.5对54.3±18.6 cm/s;P=0.04)。AS患者的充血微血管阻力(以mmHg·cm·s⁻¹表示)为2.10±0.69,而对照组为1.80±0.60(P=0.096)。AS患者的冠状动脉血流储备较低,为1.9±0.5,而对照组为2.7±0.7(P<0.001)。TAVI术后无主动脉瓣反流的患者冠状动脉血流动力学改善最为明显。在这些患者(n=20)中,充血流速从TAVI术前的46.24±15.47显著增加至TAVI术后的56.56±17.44 cm/s(P=0.003)。充血微血管阻力从2.03±0.71降至1.66±0.45(P=0.050)。冠状动脉血流储备从1.9±0.4显著增加至2.2±0.6(P=0.009)。
AS患者冠状动脉循环的血管舒张储备能力降低。TAVI可使充血微血管阻力即刻降低,同时充血流速增加,从而使冠状动脉血管舒张储备即刻改善。