Relation between the reperfusion of pulmonary arteries after acute pulmonary embolism to the development of chronic thromboembolic pulmonary hypertension Incomplete resolution of thromboemboli following acute pulmonary embolism (PE) is a key factor in development of chronic thromboembolic pulmonary hypertension (CTEPH). In our study, we evaluated the incidence, risk factors and clinical impact of incomplete reperfusion after acute PE. Study population and methods: 85 patients after the first acute PE were assessed clinically and by pulmonary scintigraphy and echocardiography at month 6, 12 and 24 after an acute PE. Results: Incomplete reperfusion was detected in 23.5 % of patients after 6 months, in 24.9 % of patients after 12 months and in 18.6 % of patients after 24 months. At month 6, patients with incomplete reperfusion were more obese when compared with patients with normal reperfusion BMI 30.8 vs 28.3 kg/m2 ; p=0.012) and their initial hemoglobin levels were higher (143.0 vs 136.0 g/l; p=0.012). Similar results were observed at month 12 - patients with residual perfusion defects were more obese (BMI 31.1 vs 28.5; p=0.016) with higher initial hemoglobin levels (144.0 vs 136.0; p=0.007). Patients with incomplete reperfusion at month 24 were significantly older (67.7 vs 55.0 years; p=0.02), their...

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L’Hypertension Pulmonaire Post-Embolique (HPPE) est une maladie rare et grave résultant d'une obstruction mécanique progressive des artères pulmonaires provoquant une augmentation progressive de la PAPm (>25 mmHg). Cette pathologie a un traitement chirurgical, l’endartériectomie pulmonaire. Bien que cette maladie ait un traitement, les mécanismes qui impliquent la formation et la persistance de thrombus conduisant à un remodelage vasculaire fibreux, restent à ce jour inconnus. La pathogénèse de l’HPPE présente de grandes similitudes avec celles de l’HTAPi.Ce travail a pu mettre en évidence le phénotype anomal de la cellule endothéliale provenant de séquestres de patients ayant une HPPE ainsi que les anomalies moléculaires à l’origine de cette dysfonction. Plusieurs anomalies moléculaires sont à l’origine de ces perturbations fonctionnelles dont notamment une production et une libération anormale d’ICAM-1 et de FGF-2. Ce travail montre le rôle clé de la protéine ICAM-1 grâce à une boucle autocrine qui va maintenir cette dysfonction ainsi que l'association du génotype KE à la maladie (polymorphisme SNP Exon 6 E469K). Ce travail montre également le rôle essentiel que joue la protéine FGF-2 et le recrutement de progéniteurs endothéliaux dans la néo-vascularisation observée dans les thrombus de patients souffrant d’HPPE. / Chronic ThromboEmbolic Pulmonary Hypertension (CTEPH) is a rare and serious disease resulting from progressive mechanical obstruction of the pulmonary arteries causing a gradual increase in the mPAP (> 25 mmHg). This pathology has a surgical treatment: Pulmonary Endarterectomy. Mechanisms that involve the formation and persistence of thrombus leading to a fibrous vascular remodeling remain unknown. The pathogenesis of CTEPH is very similar to idiopathic PAH.This work has been able to demonstrate the abnormal phenotype of endothelial cells taken from thrombus of CTEPH and molecular anomalies in the origin of this dysfunction. Several molecular abnormalities are the cause of these functional disturbances including production and abnormal release of ICAM-1 and FGF-2. This work shows the key role of ICAM-1 protein through an autocrine loop maintains this dysfunction and the association of genotype KE disease (SNP Exon 6 E469K).This work also showed the important role of FGF-2 protein and the recruitment of endothelial progenitor cells in neovascularization observed in thrombus of CTEPH patients.

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