Hemodynamic and microcirculatory early adaptations following transcatheter aortic valve implantation (TAVI): A physiological pilot study

TL;DR

This study shows that TAVI improves tissue perfusion quickly after surgery, but microcirculation and VEGF levels may predict postoperative complications.

Contribution

The study identifies microcirculatory changes and VEGF dynamics as potential early markers of post-TAVI organ dysfunction.

Findings

TAVI rapidly improves tissue perfusion within 24 hours, independent of macrocirculatory changes.

Higher baseline VEGF and greater postoperative increases are linked to postoperative organ dysfunction.

Microcirculatory parameters like perfusion index and oxygen re-saturation improve early after TAVI.

Abstract

Transcatheter aortic valve implantation (TAVI) abruptly relieves aortic stenosis. The consequences for the peripheral vascular network, organ perfusion and postoperative organ dysfunction remain unclear. This study assessed hemodynamic and microcirculatory changes after TAVI, and their association with postoperative organ dysfunction.

This prospective, single‐center physiological study included 20 patients with severe aortic stenosis undergoing transfemoral TAVI at Geneva University Hospitals (January–June 2024). Hemodynamic and microcirculatory assessment included arterial stiffness (tonometry), temperature gradients (T grad), reactive hyperemia (near‐infrared spectroscopy and photoplethysmography) and plasma vascular endothelium growth factor (VEGF) concentrations before and after TAVI. The primary outcome was perioperative changes in macro‐ and microcirculatory parameters; secondary outcomes were organ dysfunction within 7 days.

TAVI immediately increased aortic pressures and amplified pressure waves. By day 1, central‐peripheral T grad decreased, perfusion index rose (from 2.5 [0.9–4.2] to 3.9 [1.9–5.5]; p < 0.05), and tissue oxygen re‐saturation slope increased (from 2.6 [1.5–3.4] to 3.9 [2.8–4.7] %/s; p < 0.05), independent of macrocirculatory parameters. Large artery stiffness decreased, despite a reduction in the total arterial compliance, without changes in small‐vessel resistance. Cardiac index changes showed wide interindividual variability and correlated with vascular and VEGF dynamics. Patients with postoperative organ dysfunction had higher baseline VEGF (52.9 vs. 28.7 pg/mL, p = 0.033) and greater postoperative increases.

TAVI induces rapid macro‐ and microcirculatory changes, with early tissue perfusion improvement despite transient microcirculatory reserve impairment. VEGF dynamics were associated with postoperative complications, suggesting endothelial activation as a marker of vulnerability and linking baseline endothelial status to vascular adaptation and outcomes.

This pilot physiological study, involving 20 patients with severe aortic stenosis, shows that transcatheter aortic valve implantation (TAVI) induces rapid changes in both macrocirculatory parameters, reflecting the release of chronic obstruction. We observed improved tissue perfusion by postoperative Day 1, independent of macrocirculatory parameters. Cardiac index changes correlated with vascular and VEGF dynamics. Patients with postoperative organ dysfunction had higher baseline VEGF and greater postoperative increases. These findings highlight the role of microcirculation in recovery after TAVI and suggest potential prognostic markers for patient stratification.

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