Dynamic changes in aortic impedance after transcatheter aortic valve replacement and its impact on exploratory outcome

Yukari Kobayashi, Juyong B. Kim, Kegan J. Moneghetti, Yuhei Kobayashi, Ran Zhang, Daniel A. Brenner, Ryan O’Malley, Ingela Schnittger, Michael Fischbein, D. Craig Miller, Alan C. Yeung, David Liang, Francois Haddad, William F. Fearon

Research output: Contribution to journalArticlepeer-review

9 Scopus citations


Valvulo-arterial impedance (Zva) has been shown to predict worse outcome in medically managed aortic stenosis (AS) patients. We aimed to investigate the association between Zva and left ventricular (LV) adaptation and to explore the predictive value of Zva for cardiac functional recovery and outcome after transcatheter aortic valve replacement (TAVR). We prospectively enrolled 128 patients with AS who underwent TAVR. Zva was calculated as: (systolic blood pressure + mean transaortic gradient)/stroke volume index). Echocardiographic assessment occurred at baseline, 1-month and 1-year after TAVR. The primary endpoints were to investigate associations between Zva and global longitudinal strain (GLS) at baseline as well as GLS change after TAVR. The secondary was to compare all-cause mortality after TAVR between patients with pre-defined Zva (=5 mmHg m2/ml), stroke volume index (=35 ml/m2), and GLS (=−15%) cutoffs. The mean GLS was reduced (−13.0 ± 3.2%). The mean Zva was 5.2 ± 1.6 mmHg*m2/ml with 55% of values ≥5.0 mmHg*m2/ml, considered to be abnormally high. Higher Zva correlated with worse GLS (r = −0.33, p < 0.001). After TAVR, Zva decreased significantly (5.1 ± 1.6 vs. 4.5 ± 1.6 mmHg*m2/ml, p = 0.001). A reduction of Zva at 1-month was associated with GLS improvement at 1-month (r = −0.31, p = 0.001) and at 1-year (r = −0.36 and p = 0.001). By Kaplan–Meier analysis, patients with higher Zva at baseline had higher mortality (Log-rank p = 0.046), while stroke volume index and GLS did not differentiate outcome (Log-rank p = 0.09 and 0.25, respectively). As a conclusion, Zva is correlated with GLS in AS as well as GLS improvement after TAVR. Furthermore, a high baseline Zva may have an additional impact to traditional parameters on predicting worse mortality after TAVR.

Original languageEnglish (US)
Pages (from-to)1693-1701
Number of pages9
JournalInternational Journal of Cardiovascular Imaging
Issue number11
StatePublished - Nov 1 2017
Externally publishedYes


  • Strain imaging
  • Transcatheter aortic valve replacement
  • Ventricular impedance

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging
  • Cardiology and Cardiovascular Medicine


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