Perioperative Hemodynamic and Microcirculatory Physiological Study During TAVI

Summary

The Physiological Study of Haemodynamic and Microcirculatory Evolution before/after Transcatheter Aortic Valve Replacement (TAVI) aims to investigate the physiological changes induced by the implantation of a prosthetic aortic valve on blood vessels in patients with severe aortic stenosis. The hypothesis of the study is that adaptive microcirculatory phenomena occur during TAVI implantation. The results of preoperative assessment of microcirculatory functional reserve differ according to whether or not organ dysfunction occurs after TAVI. There is a progressive adaptation of the microcirculation to the new cardiovascular load conditions after TAVI. Early features of this adaptation are associated with the occurrence of short- and medium-term complications.

Conditions

• Aortic Valve Stenosis

Interventions

DIAGNOSTIC_TEST

Determination of arterial compliance using blood pressure waveform analysis

Measurement of arterial stiffness using a non-invasive pressure transducer placed on the skin of the wrist, which records the pulse wave at the level of the radial artery in order to analyze the characteristics of the arterial wall. The parameters of interest are the arterial stiffness of large- and small-caliber arteries (ml/mmHg).

DIAGNOSTIC_TEST

Measurement of plasma Vascular Endothelium Growth Factor

Measurement of plasma Vascular Endothelium Growth Factor levels by ELISA

DIAGNOSTIC_TEST

Skin temperature gradient

Measurement of skin surface temperature gradient, defined as the difference in temperature between the skin surface of the forearm and that of the fingertip (forearm-to-fingertip)

DIAGNOSTIC_TEST

Vaso-occlusion test

Measurement of endothelial function by a vaso-occlusion test performed by inflating a cuff on the arm to occlude arterial flow for 3 min. Reactive hyperemia on deflation of the cuff is measured by photoplethysmography placed on the index finger, and tissue oxygen saturation (StO2) by near-infrared spectroscopy (NIRS). The amplitude of the reperfusion flow corresponding to the peak of the perfusion index (ΔPI Peak) and the time to reach this peak (time to peak) are the parameters recorded by photoplethysmography. Tissue resaturation rate (rStO2) is the parameter recorded by NIRS.

DIAGNOSTIC_TEST

Transthoracic echocardiography

The diameter of the left ventricular outflow tract is measured in the tele systolic parasternal long-axis view. The pulsed Doppler flow profile is acquired at the level of the left ventricular chamber in the apical five-chamber view. The time-velocity integral of the aortic flow is then calculated. Left ventricular end-diastolic and end-systolic volumes are also measured using Simpson's method in the 4-cavity monoplane view. Measurements of vena cava diameter and respiratory variability of vena cava diameter provide an estimate of right atrial pressure. These measurements estimate cardiac output and systemic vascular resistance.

DIAGNOSTIC_TEST

Photoplethysmography

The perfusion index (PI) is derived from the signal and represents the ratio between the absorbance or reflectance of pulsatile and non-pulsatile light of the photoplethysmography signal. PI is measured non-invasively using a photoplethysmographic sensor placed on the earlobe or finger.

PROCEDURE

Transcatheter aortic valve insertion (TAVI)

TAVI is a treatment for aortic valve stenosis. A new valve is inserted with minimally invasive procedure without removing the old, damaged valve.

Sponsors & Collaborators

• Stanislas Abrard

  collaborator UNKNOWN

• Noble Stéphane

  collaborator UNKNOWN

• University Hospital, Geneva

  lead OTHER

Principal Investigators

• Karim Bendjelid, Ph.D. · University Hospital, Geneva

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2024-05-08

Primary Completion

2024-06-13

Completion

2024-07-13

Countries

• Switzerland

Study Locations