Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands.
J Am Soc Echocardiogr. 2013 Jul;26(7):691-8. doi: 10.1016/j.echo.2013.04.003. Epub 2013 May 11.
Elderly patients with severe aortic stenosis undergoing transcatheter aortic valve implantation (TAVI) often have increased calcification and fibrosis of the aorta. Indices that account for the severity of valvular obstruction and systemic vascular impedance may better assess total left ventricular afterload. The aims of the present study were to evaluate changes in valvuloarterial impedance (Zva), systemic arterial compliance, and systemic vascular resistance after TAVI and to investigate the prognostic value of these parameters.
A total of 116 patients (49% men; mean age, 81 ± 8 years) with symptomatic severe aortic stenosis underwent TAVI. Zva, systemic arterial compliance, and systemic vascular resistance were measured at baseline and 1 and 12 months after TAVI. The primary end point was all-cause mortality.
After TAVI, there was a significant reduction in Zva (from 5.40 ± 1.52 mm Hg/mL/m(2) at baseline to 4.13 ± 1.17 mm Hg/mL/m(2) at 1 month and 4.35 ± 1.38 mm Hg/mL/m(2) at 1 year, P < .001). Systemic arterial compliance (from 0.57 ± 0.27 to 0.57 ± 0.28 and 0.53 ± 0.27 mL/m(2)/mm Hg, P = .408) and systemic vascular resistance (from 1,938 ± 669 to 1,856 ± 888 and 1,871 ± 767, dyne·s·cm(-5), P = .697) did not change significantly over time. During a median follow-up period of 25 months, survival rates of patients with baseline Zva ≥ 5 mm Hg/mL/m(2) were lower compared with those with Zva < 5 mm Hg/mL/m(2) (82% vs 91%, respectively, log-rank P = .04). On multivariate Cox proportional-hazards analysis, baseline Zva was independently associated with all-cause mortality (hazard ratio, 1.48; 95% confidence interval, 1.05-2.07; P = .025).
In patients undergoing TAVI, there is a significant postprocedural reduction in Zva, but there is no reduction in systemic arterial compliance or vascular resistance. Baseline Zva is an independent predictor of overall mortality at 2-year follow-up.
接受经导管主动脉瓣植入术（TAVI）的老年严重主动脉瓣狭窄患者主动脉常有严重的钙化和纤维化。能反映瓣膜阻塞严重程度和系统血管阻抗的指数可能更能评估左心室总后负荷。本研究旨在评估 TAVI 后瓣-动脉阻抗（Zva）、全身动脉顺应性和全身血管阻力的变化，并探讨这些参数的预后价值。
共 116 名（49%为男性；平均年龄 81±8 岁）有症状的严重主动脉瓣狭窄患者接受了 TAVI。在基线时和 TAVI 后 1 个月和 12 个月时测量 Zva、全身动脉顺应性和全身血管阻力。主要终点是全因死亡率。
TAVI 后，Zva 显著降低（从基线时的 5.40±1.52mm Hg/mL/m2降至 1 个月时的 4.13±1.17mm Hg/mL/m2和 1 年时的 4.35±1.38mm Hg/mL/m2，P<0.001）。全身动脉顺应性（从 0.57±0.27 至 0.57±0.28 和 0.53±0.27mL/m2/mm Hg，P=0.408）和全身血管阻力（从 1938±669 至 1856±888 和 1871±767dyne·s·cm-5，P=0.697）在整个随访期间 25 个月内没有显著变化。中位随访 25 个月时，基线 Zva≥5mm Hg/mL/m2的患者生存率低于 Zva<5mm Hg/mL/m2的患者（分别为 82%和 91%，log-rank P=0.04）。多变量 Cox 比例风险分析显示，基线 Zva与全因死亡率独立相关（风险比，1.48；95%置信区间，1.05-2.07；P=0.025）。
在接受 TAVI 的患者中，术后 Zva 显著降低，但全身动脉顺应性或血管阻力没有降低。基线 Zva 是 2 年随访时总死亡率的独立预测因子。
