Hypertension artérielle pulmonaire

Does Portopulmonary Hypertension Impede Liver Transplantation in Cirrhotic Patients? A French Multicentric Retrospective Study

BACKGROUND

Portopulmonary hypertension is defined by the presence of pulmonary arterial hypertension associated with portal hypertension. Its presence is a major stake for cirrhotic patients requiring liver transplantation (LT), with increased postoperative mortality and unpredictable evolution after transplantation. The aim was to study outcomes after liver transplantation in patients with portopulmonary hypertension and to identify factors associated with normalization of pulmonary hypertension.

METHODS

Patients with portopulmonary hypertension who underwent LT between 2008 and 2016 in 8 French centers were retrospectively included. Pulmonary artery pressure was established by right heart catheterization before and after LT. Primary endpoint was the normalization of pulmonary artery pressure after LT.

RESULTS

Twenty-three patients who received liver transplant between 2008 and 2016 were included. Two (8.7%) patients died in the immediate posttransplant period from right heart failure. With appropriate vasoactive medical treatment and LT, pulmonary arterial pressure was normalized in 14 patients (60.8%), demonstrating recovery from portopulmonary hypertension. In univariate analysis, the use of vasoactive combination therapy was the only prognostic factor for pulmonary arterial hypertension normalization after LT.

CONCLUSIONS

Treatment of portopulmonary hypertension with a combination of vasoactive drugs allows LT with acceptable postoperative cardiovascular-related mortality and normalization of pulmonary hypertension in the majority of the patients.

Endothelin receptor antagonists -- their role in pulmonary medicine

INTRODUCTION

Understanding of the function of endothelin-1 in the pathophysiology of endothelial disease, in particular pulmonary arterial hypertension (PAH), has paved the way for the development of endothelin-receptor antagonists (ERAs) and explains the leading role they now play in the treatment armamentarium for this disease.

BACKGROUND

Three active ERA drugs (bosentan, sitaxentan, ambrisentan) are currently approved for the treatment of PAH in France. Several randomised clinical trials have demonstrated their efficacy and safety in PAH.

PERSPECTIVES AND CONCLUSION

Besides its vasoconstrictor effect, endothelin-1 (ET-1) plays a pivotal role in cell proliferation and apoptosis. ERAs are innovative drugs potentially useful in some pulmonary disorders such as idiopathic pulmonary fibrosis or systemic sclerosis, even though the preliminary results published remain insufficient or controversial.

CONCLUSION

ERAs play a major role in the management of pulmonary vascular disease. Other drugs, still under study, could prove useful in the treatment of infiltrating pneumonias.

Hypertension pulmonaire des affections respiratoires chroniques

Pulmonary hypertension of chronic respiratory disease is defined as elevation of the mean resting pulmonary artery pressure to over 20 mm Hg. It is the commonest cause of pre-capillary pulmonary hypertension on account of the high prevalence of chronic obstructive pulmonary disease. It is primarily due to alveolar hypoxia that leads to remodelling of the distal pulmonary vasculature and consequently to an increase in pulmonary resistance. It is not as severe as idiopathic pulmonary hypertension. The mean pulmonary artery pressure is usually moderately increased (20-35 mm Hg) when patients are seen during a stable period of the disease. There are, however, more severe cases of pulmonary hypertension called, in some cases, disproportionate but these are uncommon. Increased right ventricular afterload can lead to the development of right ventricular failure that is a definite prognostic factor. The clinical symptoms of pulmonary hypertension are at a secondary level compared with those of the causal disease. Non-invasive diagnosis depends on Doppler echocardiography. Currently the most effective treatment is long term oxygen therapy (16-18 hr/24 hr). This improves or, at least stabilises, the pulmonary hypertension.

Hypertension pulmonaire postembolique

INTRODUCTION

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare disease characterized by the persistence of thromboemboli obstructing the pulmonary arteries as an organized tissue. The consequence is an increase in pulmonary vascular resistance resulting in pulmonary hypertension (PH) and progressive right heart failure.

BACKGROUND

It is difficult to recognize the postembolic nature of PH because there is no known history of thromboembolic disease in more than 50% of cases. Diagnosis is based on the presence of mismatched segmental defects in the ventilation-perfusion scanning. When CTEPH is suspected, pulmonary angiography and high-resolution CT scan are required to establish the diagnosis and to assess the operability. Pulmonary angiography is always performed in conjunction with a diagnostic right heart catheterization, which is required to confirm the diagnosis of PH and to determine the degree of hemodynamic impairement. If there is a good correlation between the pulmonary vascular resistance and the anatomical obstruction, pulmonary endarterectomy (PEA) must be proposed. Otherwise, vasodilator and antiproliferative treatments and lung transplantation represent interesting alternatives.

VIEWPOINT AND CONCLUSION

PEA remains the treatment of choice for eligible patients. Nevertheless, there is a need to conduct randomized trials to assess the efficacy of novel medical therapies in some situations: (1) in inoperable CTEPH due to distal lesions, (2) before PEA (therapeutic bridge) in patients who are considered "high risk" due to extremely poor hemodynamics, (3) in patients with persistent pulmonary hypertension after surgery.

Hypertension artérielle pulmonaire postembolique tumorale

INTRODUCTION

Pulmonary arterial hypertension (PAH) is rare in the presence of malignancy and tumour embolisation is one of several possible pathological mechanisms.

CASE REPORTS

We report our experience of 5 clinical cases and undertake a literature revue of the pathophysiological mechanisms and of the possible diagnostic and therapeutic approaches.

CONCLUSIONS

Neoplastic PAH due to tumour micro-emboli is rare and the diagnosis difficult to establish. Cytological examination of pulmonary arterial blood could allow early institution of appropriate chemotherapy and lead to an improvement in the grave prognosis of this condition.

Hypertension portopulmonaire

INTRODUCTION

Porto-pulmonary hypertension (PoPH) is the association of pulmonary artery hypertension and portal hypertension. The diagnosis of PoPH is based on pulmonary haemodynamic criteria, obtained via right heart catheterisation, including an increase in mean pulmonary arterial pressure (> 25 mmHg) and in pulmonary vascular resistance (> 240 dyn.s.cm-5).

STATE OF THE ART

The exact pathophysiological mechanisms of PoPH are unknown. However, since PoPH has been reported in patients with non-hepatic portal hypertension, the factor that determines the development must be portal hypertension rather than liver disease per se. Moreover, no simple relationship has been identified between the degree of hepatic impairment and the severity of PoPH. The clinical presentation is non-specific with haemodynamic failure occurring at the end stage. As a consequence, screening by annual transthoracic echocardiography is highly recommended in potential liver transplant candidates. Therapy with prostacyclin analogues may partially relieve pulmonary arterial hypertension (PAH). Liver transplantation has an uncertain effect in PoPH and because PoPH is associated with a high perioperative mortality, moderate to severe PoPH remains a contraindication for liver transplantation.

PERSPECTIVES AND CONCLUSIONS

Recent advances in the management of PoPH have improved the prognosis. The safety and efficacy of oral endothelin receptor antagonists and oral phosphodiesterase inhibitors is currently under evaluation. A therapeutic approach utilising combinations of drugs should provide better long-term results.