An emerging phenotype of pulmonary arterial hypertension patients carrying SOX17 variants.

BACKGROUND: The phenotype of pulmonary arterial hypertension (PAH) patients carrying SOX17 pathogenic variants remains mostly unknown. METHODS: We report the genetic analysis findings, characteristics and outcomes of patients with heritable PAH carrying SOX17 variants from the French Pulmonary Hypertension Network. RESULTS: 20 patients and eight unaffected relatives were identified. The median (range) age at diagnosis was 17 (2-53) years, with a female:male ratio of 1.5. At diagnosis, most of the patients (74%) were in New York Heart Association Functional Class III or IV with severe haemodynamic compromise, including a median pulmonary vascular resistance of 14.0 (4.2-31.5) WU. An associated congenital heart disease (CHD) was found in seven PAH patients (35%). Patients with CHD-associated PAH were significantly younger at diagnosis than PAH patients without CHD. Four patients (20%) suffered from recurrent haemoptysis requiring repeated arterial embolisations. 13 out of 16 patients (81%) for whom imaging was available displayed chest computed tomography abnormalities, including dilated, tortuous pulmonary vessels, ground-glass opacities as well as anomalies of the bronchial and nonbronchial arteries. After a median (range) follow-up of 47 (1-591) months, 10 patients underwent lung transplantation and one patient benefited from a heart-lung transplantation due to associated CHD. Histopathological analysis of lung explants showed a congested lung architecture with severe pulmonary arterial remodelling, subpleural vessel dilation and numerous haemorrhagic foci. CONCLUSIONS: PAH due to SOX17 pathogenic variants is a severe phenotype, frequently associated with CHD, haemoptysis and radiological abnormalities. Pathological assessment reveals severe pulmonary arterial remodelling and malformations affecting pulmonary vessels and thoracic systemic arteries.

Multifactorial pulmonary hypertension in infantile scimitar syndrome.

BACKGROUND: Pulmonary hypertension in infantile scimitar syndrome is highly prevalent at diagnosis, and has a multifactorial origin. AIMS: To analyse the constellation of anatomical anomalies and initial physiology, and their contribution to pulmonary hypertension and outcome in infantile scimitar syndrome. METHODS: Pulmonary hypertension causes were classified into five categories: associated with systemic supply to the right lung; associated with left-to-right shunt; postcapillary; related to respiratory or developmental lung disease; and "idiopathic-like" pulmonary arterial hypertension. Co-morbidities contributing to pulmonary hypertension were also classified according to the World Symposium on Pulmonary Hypertension (WSPH) and Panama classifications. RESULTS: Of 111 patients, 64 had pulmonary hypertension; 24 patients had one cause of pulmonary hypertension, 23 had two potential causes and 17 had at least three potential causes. Co-morbidities contributing to pulmonary hypertension described the multifactorial origin in>80% of patients, with associated congenital heart disease being the main contributor. Mortality was 41% in patients with and 7% in patients without pulmonary hypertension. The proportions of deaths among patients with one, two or more than two causes of pulmonary hypertension were similar. Eight of 38 survivors had persisting pulmonary hypertension at last follow-up. The risk of death was associated pulmonary hypertension at diagnosis (P=0.002) and the presence of an associated congenital heart disease requiring surgical repair (P=0.039). CONCLUSIONS: Scimitar syndrome is an archetypal example of multifactorial causes of pulmonary hypertension, with associated congenital heart disease and pulmonary vascular anomalies being the main contributors. Infants with scimitar syndrome require accurate phenotyping to guide management and predict outcome.

Long-term outcomes of transcatheter Potts shunt in children with suprasystemic pulmonary arterial hypertension.

Background: Transcatheter Potts shunt (TPS) is a palliation alternative for children with severe pulmonary arterial hypertension (PAH). Debates on the long-term outcomes remain unsolved. Objectives: To evaluate long-term clinical and procedural outcomes of TPS intervention. Methods: Single-center retrospective data review of children with severe PAH who had TPS between 2009 and 2018. Patients who died per-operatively and early post-procedure were excluded. Long-term outcomes of survivors were evaluated. Results: Out of 13 identified patients (53.8% males), 7 had endovascular stenting of probe/patent arterial ducts, while 6 individuals had aorta-to-pulmonary radiofrequency perforation and covered stent placement. Compared to baseline, the overall clinical condition significantly improved at discharge (p < 0.001) and stayed better at the last visit (p < 0.05) despite frequent clinical worsening events across follow-up. Improvement in functional class across follow-up was significant (p < 0.001). There was, however, no significant improvement in other disease markers (TPASE, 6MWD z-scores, and NT-proBNP levels) or reduction in PAH medications. The median follow-up was 77.4 months (IQR, 70.7-113.4). Survival was 100% at 1 year and 92.3% at 6 years. Freedom from reinterventions was 77% at 1 year and 21% at 6 years. Nine (69.2%) patients had stent reinterventions at a median of 25 months (IQR, 9.5-56) postoperative. Balloon dilatation and restenting were performed in 53.8% and 46.2% of patients, respectively. High-pressure post-dilatation of implanted stents was performed in 53.8% of patients during TPS intervention for incomplete stent expansion and/or residual pressure gradient and was associated with higher rates of reinterventions (p = 0.021). Stent malfunctioning was present in 46.2% of patients at last follow-up. Two patients are listed for heart-lung transplantation. Conclusion: Survivors of TPS procedures experience significant improvement in functional class that can be durable. Clinical worsening and stent malfunctioning are frequent morbid events indicating recurrent transcatheter reinterventions throughout follow-up. Six-year survival is, however, satisfactory.

Potts shunt in children with idiopathic pulmonary arterial hypertension: long-term results.

BACKGROUND: Idiopathic pulmonary arterial hypertension (IPAH) remains a progressive fatal disease. Palliative Potts shunt has been proposed in children displaying suprasystemic IPAH. METHODS: A retrospective multicenter study was performed to evaluate Potts shunt in pediatric IPAH. RESULTS: Between 2003 and 2010, 8 children with suprasystemic IPAH and in World Health Organization functional class IV despite medical pulmonary arterial hypertension therapy underwent Potts shunt. Age at IPAH diagnosis ranged from 4 to 180 months (median age, 64 months). Surgical procedure was performed in a mean delay of 41.9±54.3 months (range, 4 to 167 months; median delay, 20 months) after IPAH diagnosis. Mean size of the Potts shunt was 9.25±3.30 mm. Two patients, whose medical pulmonary arterial hypertension therapy had been interrupted just after surgery, died at postoperative days 11 and 13 of acute pulmonary hypertensive crisis. After a mean follow-up of 63.7±16.1 months, the 6 children who were discharged from the hospital were alive. Functional status improved markedly in the 6 survivors, with a World Health Organization functional class I (n=4) or II (n=2) at last follow-up, consistent with significant improvement of 6-minute-walk distance (302±95 m [51%±20% of theoretical values] versus 456±91 m [68%±10% of theoretical values]; p=0.038) and decrease of brain natriuretic peptide levels (608±109 pg/mL versus 76±45 pg/mL; p=0.035). No Potts shunt was found to be restrictive at last echocardiography. CONCLUSIONS: Palliative Potts shunt constitutes a new alternative to lung transplantation in severely ill children with suprasystemic IPAH, carrying a prolonged survival and persistent improvement in functional capacities.

Development of a seeded scaffold in the great omentum: feasibility of an in vivo bioreactor for bladder tissue engineering.

OBJECTIVES: Tissue engineering is very promising in bladder reconstruction. However, one of the main problems is to limit the development of ischaemic fibrosis during tissue maturation. We describe a model using the omentum as an in vivo bioreactor for a previously seeded scaffold. METHODS: Bladder biopsies were taken from five female pigs, from which both urothelial and smooth muscle cells cultures were made. These cultured cells were used to seed a sphere-shaped small intestinal submucosa (SIS) matrix, which was transferred into the omentum after 3 wk of cell growth. The grafts were harvested 3 wk later and histologic, immunohistochemical, and functional studies were performed. RESULTS: We obtained a highly vascularized tissue-engineered construct that contracted in response to acetylcholine stimulation. The wall thickness was 4mm, on average. Histologic and immunostaining analysis of the construct confirmed the presence of a multilayer urothelium on the luminal aspect and deeper fascicles organised tissue composed of differentiated smooth muscle cells and mature fibroblasts without evidence of inflammation or necrosis. Large- and small-diameter vessels were clearly identified histologically in the tissue obtained. CONCLUSION: The omentum permitted in vivo maturation of seeded scaffolds with the development of a dense vascularisation that is anticipated to prevent fibrosis and loss of contractility. This in vivo maturation into the omentum could be the first step before in situ implantation of the construct.