functional-assessment-donor-heart-during-ex-situ-perfusion-insights

Functional Assessment of the Donor Heart During <em>Ex Situ</em> Perfusion: Insights from Pressure-Volume Loops and Surface Echocardiography

Heart transplantation remains the gold standard treatment for advanced heart failure. However, the current critical organ shortage has resulted in the ...

coronary-angiography-during-ex-situ-heart-perfusion-in-a-porcine-model

Coronary Angiography During Ex-Situ Heart Perfusion in a Porcine Model

Heart transplantation is the gold standard treatment for advanced heart failure. The procurement of extended criteria donors (ECD) increases due to the ...

innovative-strategies-for-organ-preservation-heart-transplantation

Innovative Strategies for Organ Preservation in Heart Transplantation: Uniform Cooling Preservation and <em>Ex-situ</em> Normothermic Perfusion

Nearly 4,500 heart transplantations are performed annually worldwide. Given the current organ shortage, extended criteria are frequently accepted nowadays ...

Groupe Hospitalier Paris Saint Joseph

Marie Lannelongue Hospital

University of Paris Saclay

The spatial and temporal evolution of the field backscattered by a beating heart while illuminated with a coherent light reveals its macro- and microvascularization in real time. To perform these vascularization images, we use a recently published method of laser speckle imaging, based on the selective detection of spatially depolarized speckle field that is mainly generated by multiple scattering. We consider the calculation of the speckle contrast, by a spatial or temporal estimation. We show that the signal-to-noise ratio of the observed vascular structure can be noticeably increased by a postprocessing method implying the calculation of a motion field that allows the selection of similar frames extracted from different heartbeat periods. This later optimization reveals vascular microstructures with a spatial resolution of the order of  .

Imaging the vasculature of a beating heart by dynamic speckle: the challenge of a quasiperiodic motion.

Right ventricular failure after left ventricular assist device (LVAD) implantation is a major concern that remains challenging to predict. We sought to investigate the relationship between preoperative pulmonary artery pulsatility index (PAPi) and mortality after LVAD implantation.

Association between pulmonary artery pulsatility and mortality after implantation of left ventricular assist device.

Targeted vasopeptide therapies have significantly advanced the management of pulmonary arterial hypertension (PAH). However, due to insufficient preclinical evidence regarding the involvement of the endothelin-1 (ET-1) pathway in chronic thromboembolic pulmonary hypertension (CTEPH) pathophysiology, the potential of ET-1 receptor antagonism in treating CTEPH remains uncertain. In this study, we investigated the role of the ET-1 pathway in CTEPH microvasculopathy using a multifaceted approach. Plasma ET-1 levels were measured in a cohort of 59 CTEPH patients and 41 healthy controls. Additionally, we evaluated the expression of key ET-1 pathway members in pulmonary explants from CTEPH, idiopathic PAH, and control patients. We used an in vitro system to test the hypothesis that the turbulent flow, observed near the vascular obstructions pathognomonic of CTEPH, enhances ET-1 expression. Our findings were further validated in vivo using a CTEPH piglet model that contains distinct regions representing pre- and post-thrombus lung territories. We found a twofold increase in circulating ET-1 levels in CTEPH patients compared to healthy subjects. Pulmonary explants from CTEPH patients exhibited pronounced overexpression of ET-1, endothelin receptor A (ET), and phosphorylated myosin light chain (p-MLC) in muscularized pulmonary microvessels, suggesting heightened vascular contraction. In vitro experiments showed that turbulent flow facilitates ET-1 secretion compared to laminar flow regions. Additionally, in the CTEPH piglet model, elevated plasma ET-1 levels were observed compared to controls. Immunofluorescence and confocal microscopy analyses confirmed increased ETA and p-MLC in remodeled arteries from both pulmonary territories. However, ET-1 protein elevation was exclusively observed in the obstructed territory. These findings collectively indicate impaired vascular tone in microvessels of CTEPH patients and the CTEPH piglet model. Furthermore, our data implicates the ET-1 pathway in microvasculopathy, with turbulent flow playing a pathological role. These insights underscore the potential utility of ET-1 receptor antagonists as a promising therapeutic approach for CTEPH treatment.

ArticleTotal : 3	Year
Publication title Cited by 2	2022
Publication title	2024
Publication title	2025

Article	Year
Imaging the vasculature of a beating heart by dynamic speckle: the challenge of a quasiperiodic motion. Journal of biomedical optics\| PubMed ID: 37114200	2023
Association between pulmonary artery pulsatility and mortality after implantation of left ventricular assist device. ESC heart failure\| PubMed ID: 38581135	2024
Exploring the Endothelin-1 pathway in chronic thromboembolic pulmonary hypertension microvasculopathy. Scientific reports\| PubMed ID: 39550495	2024

Ali Akamkam

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