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Biomedical subjects

G Simonneau

Publications and source records attributed to G Simonneau.

At least 91 records · Page 5Linked to original sources
PubMed1998

New perspectives for treatment of pulmonary embolism.

Subcutaneous low-molecular-weight heparins (LMWHs) have been shown to be as safe and effective as intravenous unfractionated heparin (UFH) for the initial treatment of patients with deep vein thrombosis and acute symptomatic pulmonary embolism. In comparison with UFH, LMWHs have a longer half-life, greater bioavailability and more predictable antithrombotic effect when administered in fixed doses, thus obviating the need for laboratory monitoring. It is therefore feasible that LMWH preparations may replace UFH for the treatment of pulmonary embolism in the future. It is recommended that LMWH should be administered for 5-10 days and should overlap with oral anticoagulant therapy by at least 4 days. Surgical pulmonary embolectomy should only be considered in patients with life-threatening pulmonary embolism who have failed to respond during the first 3 h of thrombolytic therapy. The systematic use of vena cava filters is not recommended in patients presumed to be at high risk for pulmonary embolism.

Anticoagulants↗
PubMed1998

Pulmonary edema complicating continuous intravenous prostacyclin in pulmonary capillary hemangiomatosis.

Continuous intravenous epoprostenol (prostacyclin) produces hemodynamic and symptomatic responses and improves survival in patients with severe primary pulmonary hypertension refractory to conventional medical therapy. However, it has been recently shown that short-term infusion of epoprostenol can produce pulmonary edema in pulmonary veno-occlusive disease, presumably because of increased pulmonary perfusion in the presence of downstream vascular obstruction. We describe two additional cases of pulmonary edema complicating continuous intravenous epoprostenol in patients displaying severe pulmonary hypertension and pulmonary capillary hemangiomatosis, a rare condition characterized by the proliferation of thin-walled microvessels in the alveolar walls. This report indicates that epoprostenol therapy should not be used in patients with severe pulmonary hypertension secondary to pulmonary capillary hemangiomatosis.

Adult↗
PubMed1998

Nitric oxide deficiency in fenfluramine- and dexfenfluramine-induced pulmonary hypertension.

Dexfenfluramine and fenfluramine greatly increase the risk of developing pulmonary hypertension (PHT). The mechanism of anorexigen-associated PHT (AA-PHT) and the reason PHT occurs in a minority of people exposed are unknown. Anorexigens are weak pulmonary vasoconstrictors, but they become potent when synthesis of the endogenous vasodilator nitric oxide (NO) is suppressed. We hypothesized NO deficiency predisposes affected individuals to develop AA-PHT. A prospective, case-control, study was performed on consecutive patients with AA-PHT (n = 9). Two sex-matched control groups were selected: patients with primary PHT (P-PHT, n = 8) and normal volunteers (n = 12). Lung NO production (VNO) and systemic plasma oxidation products of NO (NOx) were measured at rest and during exercise. AA-PHT developed 17 +/- 6 mo after a short course of anorexigen (6 +/- 2 mo) and was irreversible. VNO was lower in AA-PHT than in P-PHT and correlated inversely with PVR (p < 0.05). The apparent VNO deficiency may have resulted from increased oxidative inactivation of NO in patients with AA-PHT, as their NOx levels were elevated (p < 0.05) in inverse proportion to VNO (r2 = 0. 55; p < 0.02). In susceptible persons, anorexigens can cause an irreversible syndrome of PHT, hypoxemia, and systemic vascular complications after brief exposures. These patients have a relative NO deficiency years after discontinuing the anorexigen, perhaps explaining their original susceptibility.

Adult↗
PubMed1998

Pulmonary vascular disorders in portal hypertension.

The wide spectrum of pulmonary vascular disorders in liver disease and portal hypertension ranges from the hepatopulmonary syndrome characterized by intrapulmonary vascular dilatations, to pulmonary hypertension (portopulmonary hypertension), in which pulmonary vascular resistance is elevated. Since hepatopulmonary syndrome and portopulmonary hypertension have been reported in patients with nonhepatic portal hypertension, the common factor that determines their development must be portal hypertension. The clinical presentations are very different, with gas exchange impairment in the hepatopulmonary syndrome and haemodynamic failure in portopulmonary hypertension. The severity of hepatopulmonary syndrome seems to parallel the severity of liver failure, whereas no simple relationship has been identified between hepatic impairment and the severity of portopulmonary hypertension. Resolution of hepatopulmonary syndrome is common after liver transplantation, which has an uncertain effect in portopulmonary hypertension. The pathophysiology of both syndromes may involve vasoactive mediators and angiogenic factors.

Hemodynamics↗
PubMed1998

Inhaled nitric oxide as a screening agent for safely identifying responders to oral calcium-channel blockers in primary pulmonary hypertension.

In a subset of patients with primary pulmonary hypertension (PPH), high doses of oral calcium-channel blockers (CCB) produce a sustained clinical and haemodynamic improvement. However, significant side-effects have been reported during acute testing with CCB. Therefore, to identify accurately patients who may benefit from long-term CCB therapy, there is a need for a safe, potent and short-acting vasodilator. The aim of this study was to compare the acute response to inhaled nitric oxide (NO) and oral high doses of CCB in 33 consecutive patients with PPH. A significant acute vasodilator response was defined by a fall in both mean pulmonary artery pressure and total pulmonary resistance by >20%. Ten patients responded acutely to NO, nine of whom responded acutely to CCB, without any complications. The 23 other patients failed to respond to NO and CCB. In these nonresponders, nine serious adverse events were observed with CCB (38%). There was no clinical or baseline haemodynamic feature predicting acute vasodilator response. Long-term oral treatment with CCB was restricted to the nine acute responders and a sustained clinical and haemodynamic improvement was observed in only six patients. In primary pulmonary hypertension, the acute response rate to high doses of calcium-channel blockers is low (27%). Serious adverse reactions to high doses of calcium-channel blockers during acute testing are frequently observed in nonresponders. It is concluded that nitric oxide may be used as a screening agent for safely identifying patients with primary pulmonary hypertension who respond acutely to calcium-channel blockers and may benefit from long-term treatment with these agents.

Administration, Inhalation↗
PubMed1998

Primary pulmonary hypertension associated with the use of fenfluramine derivatives.

Fenfluramine derivatives (Fds) are a well-established risk factor for primary pulmonary hypertension (PPH). We compared 62 Fd-PPH patients (61 women) evaluated in our center between 1986 and 1997 with 125 sex-matched PPH patients nonexposed to Fd referred during the same period (control PPH). In the Fd-PPH group, 33 patients (53%) used dexfenfluramine alone, 7 patients (11%) used fenfluramine alone, and 5 patients (8%) used both drugs. In 17 cases (27%), Fd use was associated with that of amphetamines. Most of the exposed patients used Fd for at least 3 months (81%). The interval between the onset of dyspnea and that of drug intake was 49+/-68 months (27 days to 23 years). At the time of diagnosis, Fd-PPH and control PPH were similar in terms of New York Heart Association functional class and symptoms. The two groups significantly differed only in terms of age (50+/-12 vs 40+/-14 years) and body mass index (28+/-6 vs 23+/-4). The two groups displayed similar severe baseline hemodynamics (total pulmonary vascular resistance: 32+/-12 vs 31+/-12 IU/m2), but the percentage of responders to acute vasodilator testing was higher in control PPH (27% vs 10%, p < 0.01). As a result, more patients were treated with oral vasodilators in the control PPH group (36% vs 16%, p < 0.01) and long-term epoprostenol infusion was more frequently used in the Fd-PPH group (52% vs 31%, p < 0.01). Overall survival was similar in the two groups with a 3-year survival rate of 50%.

Adult↗
PubMed1998

High-resolution CT of the chest in four patients with pulmonary capillary hemangiomatosis or pulmonary venoocclusive disease.

OBJECTIVE: Clinical differentiation of isolated pulmonary hypertensive arteriopathy from pulmonary capillary hemangiomatosis or pulmonary venoocclusive disease can be difficult on a clinical basis alone. Differentiation is important because misdiagnosis of pulmonary capillary hemangiomatosis or pulmonary venoocclusive disease may lead to severe vasodilator-induced pulmonary edema. The objective of our study was to determine whether high-resolution CT of the chest could distinguish pulmonary capillary hemangiomatosis or pulmonary venoocclusive disease from isolated pulmonary hypertensive arteriopathy. CONCLUSION: Pulmonary hypertension in patients who also have pulmonary capillary hemangiomatosis or pulmonary venoocclusive disease shows characteristics on high-resolution CT that are not seen in patients with isolated pulmonary hypertensive arteriopathy.

Adult↗
PubMed1998

Platelet-derived growth factor expression in primary pulmonary hypertension: comparison of HIV seropositive and HIV seronegative patients.

Primary pulmonary hypertension (PPH) is characterized by intimal fibrosis and cell proliferation (including fibroblasts, smooth muscle and endothelial cells) in the distal pulmonary arterial tree. Considerable interest has been generated by recent reports of PPH in human immunodeficiency virus (HIV)-1-infected individuals. Although the lack of evidence for a pulmonary artery infection has suggested that in such cases HIV may act through mediator release rather than by direct endothelial infection, the mechanisms underlying HIV-associated PPH remain poorly defined. Platelet-derived growth factor (PDGF) has the ability to induce smooth muscle cell and fibroblast proliferation and migration. Given these considerations, we have attempted to document a possible role for PDGF in PPH occurring in HIV seropositive and seronegative patients. Using semiquantitative polymerase chain reaction (PCR), PDGF A-chain messenger ribonucleic acid (mRNA) expression was analysed in surgical lung biopsies from 13 HIV seronegative patients and one HIV seropositive patient, all displaying severe PPH. In parallel, lung samples from two patients with HIV-1-associated PPH were studied by immunohistochemistry and in situ hybridization. Results were compared to those obtained in three HIV-1-infected individuals with no pulmonary complication (as demonstrated by clinical, radiological, bacteriological, and necropsy findings) and five control lung biopsies. As compared to controls, PDGF A-chain mRNA expression is elevated in lung biopsies from patients displaying PPH (p=0.029). In HIV-1-associated PPH, interstitial perivascular cells expressing PDGF A-chain mRNA and protein could be detected by in situ hybridization and immunohistochemistry, respectively. Platelet-derived growth factor expression is elevated in lung biopsies of patients displaying primary pulmonary hypertension. Growth factors such as platelet-derived growth factor may play a part in the initiation and/or progression of primary pulmonary hypertension.

Adult↗
PubMed1997

A comparison of low-molecular-weight heparin with unfractionated heparin for acute pulmonary embolism. The THESEE Study Group. Tinzaparine ou Heparine Standard: Evaluations dans l'Embolie Pulmonaire.

BACKGROUND: Low-molecular-weight heparin appears to be at least as effective and safe as standard, unfractionated heparin for the treatment of deep-vein thrombosis, but only limited data are available on the use of low-molecular-weight heparin to treat acute symptomatic pulmonary embolism. METHODS: We randomly assigned 612 patients with symptomatic pulmonary embolism who did not require thrombolytic therapy or embolectomy to either subcutaneous low-molecular-weight heparin (tinzaparin) given once daily in a fixed dose or adjusted-dose, intravenous unfractionated heparin. Oral anticoagulant therapy was begun between the first and the third day and was given for at least three months. We compared the treatments at day 8 and day 90 with respect to a combined end point of recurrent thromboembolism, major bleeding, and death. RESULTS: In the first eight days of treatment, 9 of 308 patients assigned to receive unfractionated heparin (2.9 percent) reached at least one of the end points, as compared,with 9 of 304 patients assigned to low-molecular-weight heparin (3.0 percent; absolute difference, 0.1 percentage point; 95 percent confidence interval, -2.7 to 2.6). By day 90, 22 patients assigned to unfractionated heparin (7.1 percent) and 18 patients assigned to low-molecular-weight heparin (5.9 percent) had reached at least one end point (P=0.54; absolute difference, 1.2 percentage points; 95 percent confidence interval, -2.7 to 5.1). The risk of major bleeding was similar in the two treatment groups throughout the study. CONCLUSIONS: Under the conditions of this study, initial subcutaneous therapy with the low-molecular-weight heparin tinzaparin appeared to be as effective and safe as intravenous unfractionated heparin in patients with acute pulmonary embolism.

Acute Disease↗
PubMed1997

Prognostic value of pulmonary hypertension in patients with chronic interstitial lung disease referred for lung or heart-lung transplantation.

BACKGROUND: The purpose of this study was to identify precise and reliable prognostic parameters in patients affected by serious chronic interstitial lung disease, who were undergoing screening for lung or heart-lung transplantation. METHODS: Hemodynamic and respiratory function parameters of 67 patients (43 with idiopathic pulmonary fibrosis, 18 with histiocytosis X, and 6 with lymphangioleiomyomatosis) undergoing clinical screening for lung transplantation. RESULTS: Statistical analysis showed that hemodynamic and respiratory function parameters in patients affected by histiocytosis X and idiopathic pulmonary fibrosis were not related to survival time. Moreover, the degree of pulmonary hypertension showed no correlation between respiratory function parameters in all the groups of diseases examined. Patients affected with histiocytosis X, even with higher degrees of pulmonary hypertension, had a better survival rate (p < 0.0005) compared with patients with idiopathic pulmonary fibrosis. CONCLUSIONS: Hemodynamic and respiratory parameters obtained during the clinical screening for lung transplantation do not predict survival and cannot be used as prognostic indicators.

Adult↗
PubMed1997

Lung perfusion scans and hemodynamics in acute and chronic pulmonary embolism.

UNLABELLED: To assess the relationship between pulmonary vascular obstruction and hemodynamic status in acute pulmonary embolism (APE) and in chronic thromboembolic pulmonary hypertension (CTEPH), perfusion lung scan and hemodynamic measurements were obtained in 31 consecutive patients with APE and in 45 with CTEPH. METHODS: Lung scans were scored independently by two experience observers who determined the percentage of vascular obstruction (PVOs). Mean pulmonary artery pressure (PAP) and total pulmonary resistance (TPR) were obtained during right heart catheterization. In patients with APE, measurements were recorded within a 1-hr interval before and 12 hours after thrombolysis. This yielded 62 paired PVOs values with concomitant PAP and TPR measurements. In patients with CTEPH, data were recorded within a 3-day interval. RESULTS: Mean PVOs (%) values were similar in APE and CTEPH patients (59 +/- 13 vs. 58 +/- 15), whereas PAP and TPR were significantly higher in CTEPH patients (51 +/- 17 mmHg and 23 +/- 11 U/m2, respectively) than in APE patients (23 +/- 8 mmHg and 9 +/- 5 U/m2, respectively, p < 0.001). In APE patients, significant hyperbolic correlations were found linking PVOs with PAP and TPR (r = 0.75, p < 0.01 for PAP; r = 0.71, p < 0.01 for TPR). In CTEPH, there were no significant correlations between PVOs and PAP or TPR. For the same level of PVOs, patients with CTEPH had higher PAP and TPR value than patients with APE. CONCLUSION: In APE without prior cardiopulmonary disease, increases in PAP and TPR are correlated in a nonlinear fashion with the degree of pulmonary vascular obstruction as assessed by lung scanning. In CTEPH patients, the higher PAP and TPR values as compared to APE patients with comparable degrees of PVOs are consistent with previous reports that pulmonary hypertension in CTEPH is due not only to the obstruction of proximal pulmonary arteries but also to remodeling of small distal arteries in nonoccluded areas.

Acute Disease↗
PubMed1996

Appetite-suppressant drugs and the risk of primary pulmonary hypertension. International Primary Pulmonary Hypertension Study Group.

BACKGROUND: Recently, a cluster of patients was observed in France in whom primary pulmonary hypertension developed in patients exposed to derivatives of fenfluramine in appetite suppressants (anorexic agents), which are used for weight control. We investigated the potential role of anorexic agents and other suspected risk factors for primary pulmonary hypertension. METHODS: In a case-control study, we assessed 95 patients with primary pulmonary hypertension from 35 centers in France, Belgium, the United Kingdom, and the Netherlands and 355 controls recruited from general practices and matched to the patients' sex and age. RESULTS: The use of anorexic drugs (mainly derivatives of fenfluramine) was associated with an increased risk of primary pulmonary hypertension (odds ratio with any anorexic-drug use, 6.3; 95 percent confidence interval, 3.0 to 13.2). For the use of anorexic agents in the preceding year, the odds ratio was 10.1 (95 percent confidence interval, 3.4 to 29.9). When anorexic drugs were used to a total of more than three months, the odds ratio was 23.1 (95 percent confidence interval, 6.9 to 77.7). We also confirmed an association with several previously identified risk factors: a family history of pulmonary hypertension, infection with the human immunodeficiency virus, cirrhosis, and use of cocaine or intravenous drugs. CONCLUSIONS: The use of anorexic drugs was associated with the development of primary pulmonary hypertension. Active surveillance for this disease should be considered, particularly since their use is expected to increase in the near future.

Adolescent↗
PubMed1996

Intrapulmonary production of RANTES during rejection and CMV pneumonitis after lung transplantation.

RANTES (regulated upon activation, normally T expressed and secreted) is a chemoattractant for macrophages, memory T lymphocytes, and eosinophils. We investigated whether intrapulmonary production of the chemokine RANTES contributes to the recruitment of immune cells during lung transplantation complications. RANTES concentration was measured in bronchoalveolar lavage (BAL) fluids using an ELISA assay. It was significantly higher during CMV pneumonitis (36.2 +/- l6 pg/ml, n=12, P=0.031) and allograft rejection (31.1 +/- 8.5 pg/ml, n=27, P=0.013) than in patients without complications (9.1 +/- 2.3 pg/ml, n=22). At least some of the RANTES was produced by lung macrophages: BAL macrophages cultured for 24 hr spontaneously released larger amount of RANTES during CMV pneumonitis (140 +/- 53 pg/ml, n=8, P=0.002) and allograft rejection (84 +/- 44 pg/ml, n=11, P=0.037) than in control patients (15.2 +/- 6.5 pg/ml, n=21). Moreover, macrophages in transbronchial biopsies were labeled by an anti-RANTES mAb. RANTES production by BAL macrophages was followed in 2 patients with CMV pneumonitis. It remained high as long as CMV-induced cytopathic effects or clinical symptoms were present, but it returned to baseline as the infection was controlled. These results suggest that the intrapulmonary production of the chemokine RANTES by activated macrophages contributes to the intrapulmonary accumulation of immune cells during complications of lung transplantation.

Antiviral Agents↗
PubMed1996

Treatment of venous thrombosis with intravenous unfractionated heparin administered in the hospital as compared with subcutaneous low-molecular-weight heparin administered at home. The Tasman Study Group.

BACKGROUND: An intravenous course of standard (unfractionated) heparin with the dose adjusted to prolong the activated partial-thromboplastin time to a desired length is the standard initial in-hospital treatment for patients with deep-vein thrombosis, but fixed-dose subcutaneous low-molecular-weight heparin appears to be as effective and safe. Because the latter treatment can be given on an outpatient basis, we compared the two treatments in symptomatic outpatients with proximal-vein thrombosis but no signs of pulmonary embolism. METHODS: We randomly assigned patients to adjusted-dose intravenous standard heparin administered in the hospital (198 patients) or fixed-dose subcutaneous low-molecular-weight heparin administered at home, when feasible (202 patients). We compared the treatments with respect to recurrent venous thromboembolism, major bleeding, quality of life, and costs. RESULTS: Seventeen of the 198 patients who received standard heparin (8.6 percent) and 14 of the 202 patients who received low-molecular-weight heparin (6.9 percent) had recurrent thromboembolism (difference, 1.7 percentage points; 95 percent confidence interval, -3.6 to 6.9). Major bleeding occurred in four patients assigned to standard heparin (2.0 percent) and one patient assigned to low-molecular-weight heparin (0.5 percent; difference, 1.5 percentage points; 95 percent confidence interval, -0.7 to 2.7). Quality of life improved in both groups. Physical activity and social functioning were better in the patients assigned to low-molecular-weight heparin. Among the patients in that group, 35 percent were never admitted to the hospital at all, and 40 percent were discharged early. This treatment was associated with a mean reduction in hospital days of 67 percent, ranging from 29 percent to 86 percent in the various study centers. CONCLUSIONS: In patients with proximal-vein thrombosis, treatment with low-molecular-weight heparin at home is feasible, effective, and safe.

Aged↗
PubMed1996

Clinical significance of the pulmonary vasodilator response during short-term infusion of prostacyclin in primary pulmonary hypertension.

BACKGROUND: The short-term vasodilator response to prostacyclin (PGI2) in patients with primary pulmonary hypertension (PPH) is not only unpredictable but also extremely variable in magnitude. In this retrospective study, we attempted to evaluate in a nonselected population of patients with PPH the degree of vasodilatation achieved during short-term infusion of PGI2 and to investigate whether patients with PPH differed in terms of baseline characteristics and prognoses, according to the level of vasodilatation achieved during initial testing with PGI2. METHODS AND RESULTS: Between 1984 and 1992, 91 consecutive patients with PPH underwent catheterization of the right side of the heart with a short-term vasodilator trial with PGI2 (5 to 10 ng.kg-1.min-1). According to the level of vasodilatation achieved during PGI2 infusion, patients were divided into three groups: nonresponding (NR, n = 40), moderately responding (MR, n = 42), and highly responding (HR, n = 9) patients. All three groups were defined by a decrease in total pulmonary resistance index (TPRi) of < 20%, between 20% and 50%, and > 50%, respectively, relative to control values. Prolonged oral vasodilator therapy was subsequently started only in MR and HR patients. All patients had long-term oral anticoagulant therapy. The survival rate at 2 years (transplant recipients excluded) was significantly higher in HR patients compared with NR and MR patients (62% versus 38% and 47% survivors, respectively; P < .05). Comparisons between groups showed no significant differences in baseline hemodynamics or clinical characteristics except for a longer time between onset of symptoms and diagnosis (ie, first catheterization) of PPH in HR patients than in NR and MR patients (71 +/- 61 versus 35 +/- 34 and 21 +/- 21 months, respectively; P < .05). CONCLUSIONS: In this study, patients with PPH exhibiting a decrease in TPRi > 50% during short-term PGI2 challenge at the time of diagnosis had longer disease evolutions and better prognoses than patients with a lower vasodilator response.

Adolescent↗