Background: Pulse wave analysis (PWA) is a useful tool for non-invasive assessment of central cardiac measures as subendocardial perfusion (Subendocardial Viability Ratio, SEVR) or contractility (dP/dtmax). The immediate influence of transcatheter aortic valve replacement (TAVR) on these indices has not been investigated yet.
Methods: We prospectively enrolled 40 patients presenting with severe aortic stenosis receiving TAVR. Central pressure curves were derived from radial and carotid sites using PWA up to 2 days before and 7 days after TAVR. Parameters were compared between peripheral measurement sites. Changes in SEVR, dP/dtmax and in indices of vascular stiffness were assessed. Additionally, association of these variables with clinical outcome was evaluated during a 12-month follow-up.
Results: Central waveform parameters were comparable between measurement sites. SEVR, but not dP/dtmax, augmentation Index (AIx) or augmentation pressure height (AGPH) correlated significantly with disease severity reflected by peak transvalvular velocity and mean transvalvular pressure gradient over the aortic valve (Vmax, ΔPm) [r = -0.372,p = 0.029 for Vmax and r = -0.371,p = 0.021 for ΔPm]. Vmax decreased from 4.5m/s (IQR:4.1-5.0) to 2.2m/s (IQR:1.9-2.7), (p<0.001). This resulted in a significant increase in SEVR [135.3%(IQR:115.5-150.8) vs. 140.3%(IQR:123.0-172.5),p = 0.039] and dP/dtmax [666mmHg(IQR:489-891) vs. 927mmHg(IQR:693-1092),p<0.001], and a reduction in AIx [154.8%(IQR:138.3-171.0) vs. 133.5%(IQR:128.3-151.8),p<0.001] and AGPH [34.1%(IQR:26.8-39.0) vs. 25.0%(IQR 21.8-33.7),p = 0.002], confirming the beneficial effects of replacing the stenotic valve. No association of these parameters could be revealed with outcome.
Conclusions: PWA is suitable for assessing coronary microcirculation and contractility mirrored by SEVR and maxdP/dt in the setting of aortic stenosis. PWA parameters attributed to vascular properties should be interpreted with caution.