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G Simonneau

Publications and source records attributed to G Simonneau.

At least 37 records · Page 2Linked to original sources
PubMed2005

[Genetics of pulmonary arterial hypertension: recent data and practical applications].

INTRODUCTION: Pulmonary arterial hypertension (PAHT) is defined as an increase of mean pulmonary artery pressure above 25 mmHg at rest, or 30 mmHg on exercise, due to obliteration of small calibre pulmonary arteries by proliferation of endothelial cells and smooth muscle. Beside idiopathic PAHT and that associated with other conditions, a familial form has been identified. STATE OF THE ART: Family studies have shown an association between mutations of the BMPR2 gene and PAHT phenotypes. The products of this gene appear to be involved in vascular homeostasis and its mutations are the basis of a loss this function and, in consequence, proliferation of pulmonary vascular cells. PERSPECTIVES: Certain characteristics, such as incomplete penetrance and genetic anticipation, lead to a complex relationship between genotype and phenotype and make genetic counselling difficult. Other members of the extended family of TGF-beta receptors are implicated in the development of the Osler-Rendu syndrome, but may also be associated with the development of PAHT. CONCLUSION: Progress in genetics allows better understanding of the pathophysiology of this disease and could lead to new therapeutic possibilities.

Bone Morphogenetic Protein Receptors, Type II↗
PubMed2005

Anti-endothelial cell antibodies in idiopathic and systemic sclerosis associated pulmonary arterial hypertension.

BACKGROUND: It has previously been shown that IgG antibodies from patients with limited cutaneous systemic sclerosis (SSc) bind to specific microvascular endothelial cell antigens. Since patients with limited cutaneous SSc are prone to develop pulmonary arterial hypertension (PAH), and since endothelial cell activation is involved in the pathogenesis of idiopathic PAH (IPAH), a study was undertaken to examine the presence of anti-endothelial cell antibodies in patients with idiopathic or SSc associated PAH. METHODS: PAH was confirmed by right heart catheterisation (mean pulmonary artery pressure at rest >25 mm Hg). Serum IgG and IgM reactivities were analysed by immunoblotting on human macrovascular and microvascular lung and dermal endothelial cells from patients with IPAH (n = 35), patients with PAH associated with SSc (n = 10), patients with diffuse (n = 10) or limited cutaneous (n = 10) SSc without PAH, and 65 age and sex matched healthy individuals. RESULTS: IgG antibodies from patients with IPAH bound to a 36 kDa band in macrovascular endothelial cell extracts with a higher intensity than IgG from other patient groups and controls. IgG antibodies from patients with IPAH bound more strongly to a 58 kDa band in microvascular dermal endothelial cells and to a 53 kDa band in microvascular lung endothelial cells than IgG antibodies from other patients and controls. IgG antibodies from patients with limited cutaneous SSc with or without PAH, but not from other groups or from healthy controls, bound to two major bands (75 kDa and 85 kDa) in microvascular endothelial cells. CONCLUSION: IgG antibodies from patients with idiopathic or SSc associated PAH express distinct reactivity profiles with macrovascular and microvascular endothelial cell antigens.

Adult↗
PubMed2005

Survival with first-line bosentan in patients with primary pulmonary hypertension.

Primary pulmonary hypertension (PPH) is a progressive disease with high mortality. Administration of i.v. epoprostenol has demonstrated improved exercise tolerance, haemodynamics, and survival. The orally active, dual endothelin receptor antagonist bosentan improves exercise endurance, haemodynamics, and functional class over the short term. To determine the effect of first-line bosentan therapy on survival, this study followed 169 patients with PPH treated with bosentan in two placebo-controlled trials and their extensions. Data on survival and alternative treatments were collected from September 1999 (start of the first placebo-controlled study) to December 31, 2002. Observed survival up to 36 months was reported as Kaplan-Meier estimates and compared with predicted survival as determined for each patient by the National Institutes of Health Registry formula. Kaplan-Meier survival estimates were 96% at 12 months and 89% at 24 months. In contrast, predicted survival was 69% and 57%, respectively. In addition, at the end of 12 and 24 months, 85% and 70% of patients, respectively, remained alive and on bosentan monotherapy. Factors that predicted a worse outcome included World Health Organization Functional Class IV and 6-min walk distance below the median (358 m) at baseline. First-line bosentan therapy was found to improve survival in patients with advanced primary pulmonary hypertension.

Adolescent↗
PubMed2005

Reversibility of pulmonary arterial hypertension in HIV/HHV8-associated Castleman's disease.

The present study describes a case of pulmonary arterial hypertension (PAH) associated with multicentric Castleman's disease in a patient infected with HIV type 1 and human herpes virus 8. Therapy included highly active antiretroviral therapy, warfarin, diuretics, continuous i.v. epoprostenol and 12-monthly pulses of cyclophosphamide. The patient's condition improved dramatically with complete reversibility of PAH, allowing weaning of continuous i.v. epoprostenol therapy. After 5 yrs, both Castleman's disease and PAH have not relapsed. This supports the hypothesis that control of inflammation and retroviral replication may be of interest in the context of PAH, complicating the course of an inflammatory condition associated with viral infection. In conclusion, further studies should help in characterising the best candidates for anti-inflammatory treatment in the setting of pulmonary arterial hypertension.

Adult↗
PubMed2004

[Treatments for pulmonary arterial hypertension].

PURPOSE: Pulmonary arterial hypertension (PAH) is characterized by vasoconstriction, in situ thrombosis and vascular remodeling of small pulmonary arteries inducing a fixed pulmonary arterial obstruction and persistent elevation of pulmonary arterial resistance. Conventional treatment is based on simple measures (exercise limitation) and non-specific drugs (warfarine, diuretics, oxygen). CURRENT KNOWLEDGE AND KEY POINTS: Pure vasodilators like calcium channel antagonists have little or no effect on the vast majority of patients, presumably because fixed pulmonary arteriopathy predominate over vasoconstriction. Intravenous prostacyclin (epoprostenol) and endothelin receptor antagonists have vasodilator and antiproliferative properties. Epoprostenol therapy has resulted in significant improvements in prognosis of this disease and this drug remains the first-line treatment of the most severe patients. Bosentan is an interesting first-line treatment for NYHA functional class III patients. Availability of novel specific drugs (endothelin receptor type A antagonists, prostacyclin analogues, type 5 phosphodiesterase inhibitors) open new perspectives in treatment of PAH. The long-term benefit of these drugs remains to be evaluated and their respective place in treatment of these patients is still uncertain. We here present the different therapeutic alternatives available in the PAH and propose an algorithm for treatment of these patients. FUTURE PROSPECTS AND PROJECTS: The evolution of therapy from vasodilators to antiproliferative agents reflects the advancement in our understanding of the mechanisms mediating pulmonary arterial hypertension.

Algorithms↗
PubMed2004

[Surgical treatment of post-embolism pulmonary hypertension].

Pulmonary hypertension is a serous condition which, after a long history as an orphan disease, has raised renewed interest due to the development of efficacious therapeutic options including lung transplantation and continuous infusion of prostacycline. Bilateral endarteriectomy of the pulmonary arteries is another possibility for post-embolism pulmonary hypertension. The procedure is complex and must be performed in conditions of cardiac arrest and deep hypothermia but, unlike transplantation, provides definitive cure. Recognizing the post-embolic nature of pulmonary hypertension is not simple because old episodes of venous thrombosis or embolus migration are not found in 50% of patients. Segmentary defects on the perfusion scintigraphy contrasting with the homogeneous respiratory scintigraphy is the primary diagnostic feature. Lesions must be located in a main trunk or at the origin of lobular or segmentary branches to be accessible to endarteriectomy. An antero-posterior and lateral angiogram of each lung and a multiple-array helicoidal angioscan performed with a precise protocol by an experienced team are needed to identify the localization of the lesions. If the pulmonary resistance determined at right catheterism is correlated with anatomic obstruction, the risk of mortality of pulmonary endarteriectomy is low, offering patients a significant chance for normal or nearly normal cardiorespiratory function.

Endarterectomy↗
PubMed2004

[Clinical, haemodynamic and genetic features of familial pulmonary arterial hypertension].

INTRODUCTION: Pulmonary arterial hypertension (PAH) is defined by a raised pressure in the pulmonary arterial circulation associated with small vessel narrowing due to proliferation of the endothelium and vascular smooth muscle. Idiopathic PAH should be distinguished from PAH associated with a causal disease. One familial type (familial PAH), gathered from one family, has recently been linked to a mutation of the BMPR 2 (bone morphogenetic protein receptor 2) gene. It seems important to compare the idiopathic form of PAH with these familial forms to confirm that the same diagnostic and therapeutic principles can be applied to familial PAH. MATERIAL AND METHODS: The demographic, clinical, haemodynamic and prognostic data from 34 cases of familial PAH were compared with those of 451 cases of idiopathic PAH. The genetic characteristics of the familial forms were also defined. RESULTS: Familial PAH presented at a younger age than idiopathic PH (31 +/- 15 vs. 45 +/- 18 years p=0.002) without any other demographic difference (sex-ratio 2.09/1 et 1.42/1 p=NS). There was no difference in exercises tolerance (6 minute walking test 341 +/- 98 and 289 +/- 135 metres p=NS), in haemodynamic parameters (mean PAP 65 +/- 12 and 62 +/- 15 mmHg, p=NS), or in prognosis, with the exception of an absence of a vasodilator response in the familial group to nitric oxide challenge. We found the BMPR 2 gene mutation to be quantitatively and qualitatively comparable to previously published data. CONCLUSION: The only difference between these two forms of this illness were of a younger age at presentation and an absent vasodilator response in the familial PAH group. We do not propose that familial PAH should be treated any differently from the idiopathic form. Genetic counselling will need to be developed in line with the progress being made in the understanding of this condition.

Adult↗
PubMed2004

Combination of bosentan with epoprostenol in pulmonary arterial hypertension: BREATHE-2.

The efficacy and safety of combining bosentan, an orally active dual endothelin receptor antagonist and epoprostenol, a continuously infused prostaglandin, in the treatment of pulmonary arterial hypertension (PAH) was investigated. In this double-blind, placebo-controlled prospective study, 33 patients with PAH started epoprostenol treatment (2 ng.kg(-1)min(-1) starting dose, up to 14+/-2 ng.kg(-1)min(-1) at week 16) and were randomised for 16 weeks in a 2:1 ratio to bosentan (62.5 mg b.i.d for 4 weeks then 125 mg b.i.d) or placebo. Haemodynamics, exercise capacity and functional class improved in both groups at week 16. In the combination treatment group, there was a trend for a greater (although nonsignificant) improvement in all measured haemodynamic parameters. There were four withdrawals in the bosentan/epoprostenol group (two deaths due to cardiopulmonary failure, one clinical worsening, and one adverse event) and one withdrawal in the placebo/epoprostenol group (adverse event). This study showed a trend but no statistical significance towards haemodynamics or clinical improvement due to the combination of bosentan and epoprostenol therapy in patients with pulmonary arterial hypertension. Several cases of early and late major complications were reported. Additional information is needed to evaluate the risk/benefit ratio of combined bosentan-epoprostenol therapy in pulmonary arterial hypertension.

Antihypertensive Agents↗
PubMed2004

Chronic thromboembolic pulmonary hypertension.

Pulmonary arterial hypertension is a severe disease that has been ignored for a long time. However, over the past 20 yrs chest physicians, cardiologists and thoracic surgeons have shown increasing interest in this disease because of the development of new therapies, that have improved both the outcome and quality of life of patients, including pulmonary transplantation and prostacyclin therapy. Chronic thromboembolic pulmonary arterial hypertension (CTEPH) can be cured surgically through a complex surgical procedure: the pulmonary thromboendarterectomy. Pulmonary thromboendarterectomy is performed under hypothermia and total circulatory arrest. Due to clinically evident acute-pulmonary embolism episodes being absent in > 50% of patients, the diagnosis of CTEPH can be difficult. Lung scintiscan showing segmental mismatched perfusion defects is the best diagnostic tool to detect CTEPH. Pulmonary angiography confirms the diagnosis and determines the feasibility of endarterectomy according to the location of the disease, proximal versus distal. The technique of angiography must be perfect with the whole arterial tree captured on the same picture for each lung. The lesions must start at the level of the pulmonary artery trunk, or at the level of the lobar arteries, in order to find a plan for the endarterectomy. When the haemodynamic gravity corresponds to the degree of obliteration, pulmonary thromboendarterectomy can be performed with minimal perioperative mortality, providing definitive, excellent functional results in almost all cases.

Chronic Disease↗
PubMed2003

[Pulmonary artery hypertension associated with connective tissue diseases].

MOST IMPORTANT: Pulmonary hypertension (PH) is a severe, potentially life-threatening complication of connective tissue diseases, among which scleroderma is first line. The aim of this paper was to review the literature and report our experience with this particular complication of connective tissue diseases. In our centre of pulmonary vascular diseases, connective tissue diseases represent the third cause of PH. RESULTS: Scleroderma and particularly its limited cutaneous variant, the CREST syndrome, is the most common connective tissue disease affected by pulmonary hypertension. It can be related to a specific lung parenchymal involvement (hypoxic PH), to an isolated pulmonary vascular involvement or to a cardiac dysfunction secondary to specific myocardial lesions. DIAGNOSIS: Echocardiography is an excellent examination to detect pulmonary hypertension. However, right heart catheterisation is necessary to confirm the diagnosis of pulmonary hypertension and to test vasoreactivity with a potent vasodilator such as nitric oxide (NO). REGARDING TREATMENTS: Oral calcium channel blockers are indicated in patients who are responders to acute NO tests. Treatment with continuous intravenous prostacylin is obviously an improvement, at least functionally, although it appears less effective than in primary PH. With the new subcutaneous, oral and inhaled vasodilatators (prostaglandin and endothelin receptor antagonists), a few cases of improvement of PH with intensive immunosuppressive therapy were observed, essentially during systemic lupus erythematosus and Sharp syndrome. IN PRACTICE: PH is a severe complication of connective tissue diseases. Early detection of this complication should allow an earlier and more aggressive therapeutic approach in these patients, before irreversible vascular lesions occur.

Adult↗
PubMed2003

[Pulmonary hypertension complicating systemic diseases other than connective tissue diseases].

A COMPLICATION OF CERTAIN SYSTEMIC DISEASES: Pulmonary hypertension (PH) can complicate the progression of certain systemic diseases such as sarcoidosis, histiocytosis X and some vasculites. The mechanisms at the origin of PH are varied and always require rigorous analysis in order to optimise treatment. DEPENDING ON THE DISEASE: PH associated with sarcoidosis is essentially related to specific lung parenchymal fibrosis and is poorly responder to corticosteroids. Other mechanisms may be more rarely incriminated (compressive andenopathies, mediastinal fibrosis, florid sarcoidosis concomitant to a pulmonary occlusive vascular disease...). During histiocytosis X, the ventilatory limitation of these patients does not always correlate with the severity of the respiratory failure, suggesting the existence of a pulmonary vascular disease progressing independently of the pulmonary parenchymal lesions. The pulmonary artery damage during Takayasu's arteritis and other auto-immune pulmonary arteritis may lead to potentially life-threatening complications, notably through stenosis and/or obstruction of the pulmonary arteries. Pulmonary hypertension is exceptional during Wegener's disease or periateritis nodosa. CONCLUSION: PH can complicate the progression of certain systemic diseases. The physiopathological mechanisms responsible are unclear (specific parenchymal fibrosis, isolated vascular involvement...). Globally, available treatments are disappointing.

Cardiac Catheterization↗
PubMed2003

[Pulmonary hypertension: CT findings in pulmonary veno-occlusive disease].

PURPOSE: To describe the CT findings of pulmonary veno-occlusive disease. MATERIALS AND METHODS: Pre-therapeutic CT of 15 patients suffering from pulmonary veno-occlusive disease were retrospectively reviewed. Pathologic evaluation of pulmonary veno-occlusive disease was obtained after post mortem examination or pulmonary transplantation. CT protocol always included intravenous helical CT and high resolution CT. RESULTS: The most frequent CT-findings in pulmonary veno-occlusive disease were the following: ground glass opacity with poorly defined nodular opacities (73%), septal lines (93%), and adenopathy (80%). Pericardial (60%) and pleural effusions (27%) were also noted. Other parenchymal findings were unusual. CONCLUSION: HRCT must be systematically included in the initial CT evaluation of pulmonary hypertension. Combination of poorly defined nodular opacities, septal lines, and adenopathy are indicative of pulmonary veno-occlusive disease.

Adult↗
PubMed2002

Function of the serotonin 5-hydroxytryptamine 2B receptor in pulmonary hypertension.

Primary pulmonary hypertension is a progressive and often fatal disorder in humans that results from an increase in pulmonary blood pressure associated with abnormal vascular proliferation. Dexfenfluramine increases the risk of pulmonary hypertension in humans, and its active metabolite is a selective serotonin 5-hydroxytryptamine 2B (5-HT(2B)) receptor agonist. Thus, we investigated the contribution of the 5-HT(2B)receptor to the pathogenesis of pulmonary hypertension. Using the chronic-hypoxic-mouse model of pulmonary hypertension, we found that the hypoxia-dependent increase in pulmonary blood pressure and lung remodeling are associated with an increase in vascular proliferation, elastase activity and transforming growth factor-beta levels, and that these parameters are potentiated by dexfenfluramine treatment. In contrast, hypoxic mice with genetically or pharmacologically inactive 5-HT(2B)receptors manifested no change in any of these parameters. In both humans and mice, pulmonary hypertension is associated with a substantial increase in 5-HT(2B) receptor expression in pulmonary arteries. These data show that activation of 5-HT(2B) receptors is a limiting step in the development of pulmonary hypertension.

Animals↗