Related Experiment Video
Updated: Nov 17, 2025
Analysis of Extracellular Vesicle-Mediated Vascular Calcification Using In Vitro and In Vivo Models
Published on: January 27, 2023
Energy loss associated with in-vitro modeling of mitral annular calcification
Philip C Wiener1, Ahmed Darwish2, Evan Friend1
1Division of Cardiology, Heart and Vascular Institute, Einstein Medical Center, Philadelphia, PA, United States of America.
Introduction:
Study aims were to compare hemodynamics and viscous energy dissipation (VED) in 3D printed mitral valves-one replicating a normal valve and the other a valve with severe mitral annular calcification (MAC). Patients with severe MAC develop transmitral gradients, without the commissural fusion typifying rheumatic mitral stenosis (MS), and may have symptoms similar to classical MS. A proposed mechanism relates to VED due to disturbed blood flow through the diseased valve into the ventricle.
Methods:
A silicone model of a normal mitral valve (MV) was created using a transesophageal echocardiography dataset. 3D printed calcium phantoms were incorporated into a second valve model to replicate severe MAC. The synthetic MVs were tested in a left heart duplicator under rest and exercise conditions. Fine particles were suspended in a water/glycerol blood analogue for particle image velocimetry calculation of VED.
Results:
Catheter mean transmitral gradients were slightly higher in the MAC valve compared to the normal MV, both at rest (3.2 vs. 1.3 mm Hg) and with exercise (5.9 vs. 5.0 mm Hg); Doppler gradients were 2.7 vs. 2.1 mm Hg at rest and 9.9 vs 8.2 mm Hg with exercise. VED was similar between the two valves at rest. During exercise, VED increased to a greater extent for the MAC valve (240%) versus the normal valve (127%).
Conclusion:
MAC MS is associated with slightly increased transmitral gradients but markedly increased VED during exercise. These energy losses may contribute to the exercise intolerance and exertional dyspnea present in MAC patients.
