O. Sitbon

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.

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.

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.

BMPR2 germline mutations in pulmonary hypertension associated with fenfluramine derivatives

This study investigated whether patients developing pulmonary arterial hypertension (PAH) after exposure to the appetite suppressants fenfluramine and dexfenfluramine have mutations in the bone morphogenetic protein receptor 2 (BMPR2) gene, as reported in primary pulmonary hypertension. BMPR2 was examined for mutations in 33 unrelated patients with sporadic PAH, and in two sisters with PAH, all of whom had taken fenfluramine derivatives, as well as in 130 normal controls. The PAH patients also underwent cardiac catheterisation and body mass determinations. Three BMPR2 mutations predicting changes in the primary structure of the BMPR-II protein were found in three of the 33 unrelated patients (9%), and a fourth mutation was found in the two sisters. No BMPR2 mutations were identified in the 130 normal controls. This difference in frequency was statistically significant. Moreover, the mutation-positive patients had a somewhat shorter duration of fenfluramine exposure before illness than the mutation-negative patients, a difference that was statistically significant when the two sisters were included in the analysis. In conclusion, the present authors have detected bone morphogenetic protein receptor 2 mutations that appear to be rare in the general population but may combine with exposure to fenfluramine derivatives to greatly increase the risk of developing severe pulmonary arterial hypertension.

Long term imatinib treatment in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a life threatening condition characterised by progressive obliteration of the small pulmonary arteries leading to increased pulmonary arterial resistance and right heart failure. Treatment for PAH has developed in the last few years since the description of new pathways related to the disease.1 Recently, short term (6 months) use of imatinib, a platelet derived growth factor (PDGF) receptor antagonist, in combination with maximal PAH treatment (prostacyclin derivative, endothelin receptor antagonist, and type 5 phosphodiesterase inhibitor) has been shown to improve the haemodynamics and functional capacity in a single case of severe PAH.2 We here report the first two cases of the long term (3 years or more) use of imatinib, as monotherapy or in combination with bosentan, a dual endothelin receptor antagonist. …

Prognostic factors of acute heart failure in patients with pulmonary arterial hypertension

Acute right ventricular failure in the setting of pulmonary arterial hypertension (PAH) often requires hospitalisation in intensive care units (ICU) to manage the subsequent low cardiac output and its consequences. There are very few data on these acute events. We recorded demographic, clinical and biological data and therapy in consecutive patients suffering from acute right heart failure requiring catecholamine treatment in the ICU of the French referral centre for pulmonary hypertension. These variables were analysed according to the survival status in ICU. 46 patients were included, the mean age was 50.3 yrs. ICU mortality was 41%. We found no difference in terms of demographics, clinical data, last haemodynamic measurements at admission. Systemic arterial pressure was significantly lower in the subgroup of patients whose clinical course was fatal. Plasma brain natriuretic peptide (BNP), C-reactive protein (CRP), serum sodium and creatinine at admission correlated with survival. Demonstration of an infection during the ICU stay was associated with a worse prognosis. These preliminary results underline the importance of some simple clinical and biological parameters in the prognostic evaluation of acute heart failure in the setting of PAH. Whether these parameters can guide therapy needs to be further investigated.

Advances in Therapeutic Interventions for Patients With Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a disease characterized by progressive remodeling of the distal pulmonary arteries, resulting in the loss of vascular cross-sectional area and elevated pulmonary vascular resistance (PVR).1 Without intervention, PAH is usually progressive, leading to right heart failure and death. Since the first reported studies of calcium channel blockers >30 years ago,2,3 we have witnessed major advances in the therapeutic armamentarium available to treat this devastating condition. The development of drugs that specifically target pathways involved in disease pathogenesis has led to improvements in the quality of life and clinical outcomes in patients with PAH. At present, there are 10 drugs approved for PAH by regulatory authorities worldwide. This review will focus on recent advances in pharmacological therapy in adult PAH, including our current treatment approaches and potential future strategies. PAH is an uncommon disease with an estimated prevalence of 15 to 50 per million population.4,5 Under the current clinical classification (Table 1),6 PAH consists of different etiologies leading to precapillary pulmonary hypertension (PH), which is defined by an end-expiratory mean pulmonary artery pressure (PAP) ≥25 mm Hg, pulmonary artery wedge pressure ≤15 mm Hg, and PVR >3 Wood units at rest.7 PAH is termed idiopathic (IPAH) when no causative factors are identified, but it can also be heritable, induced by drugs or toxins, or associated with conditions such as connective tissue disease, congenital heart disease, portal hypertension, and HIV infection. These conditions have been classified under PAH because they share common pathological changes in the small pulmonary arteries, and a similar therapeutic approach, as well. View this table: Table 1. Pulmonary Arterial Hypertension in Current Clinical Classification (Nice, 2013) ### Endothelial Dysfunction – the Target of Current Therapies Endothelial dysfunction leading to an imbalance of vasodilator and vasoconstrictor mediators is an important aspect of PAH pathogenesis. These pathways also exert, …

Short-term and long-term epoprostenol (prostacyclin) therapy in pulmonary hypertension secondary to connective tissue diseases: results of a pilot study

Continuous intravenous epoprostenol improves exercise capacity, haemodynamics, and survival in severe primary pulmonary hypertension. Pulmonary hypertension can also be life-threatening in patients with connective tissue diseases. In a prospective open monocentre uncontrolled study, the effects of epoprostenol were evaluated in patients with severe pulmonary hypertension secondary to connective tissue diseases who were unresponsive to oral vasodilators (including calcium channel blockers) and continued to be in the New York Heart Association (NYHA) functional class III or IV despite conventional medical therapy. Seventeen patients received epoprostenol administered by a portable infusion pump associated with conventional therapy (oral anticoagulants, diuretics, supplemental oxygen). During the first six weeks of therapy, two (12%) patients died, of pulmonary oedema (n = 1) and severe sepsis (n = 1). In the fifteen remaining subjects, clinical and haemodynamic parameters improved significantly at six weeks. These patients were subsequently monitored for 80+/-48 (range 14-154) weeks after initiation of epoprostenol. Five (33%) patients died, of right heart failure (n = 2), severe sepsis (n = 2) or syncope (n = 1) and two patients were successfully transplanted 24 and 52 weeks after initiation of epoprostenol. Seven of the remaining eight patients had a persistent clinical improvement. Short-term epoprostenol therapy is effective in some patients with connective tissue diseases as demonstrated by better clinical status and haemodynamics at six weeks. However, this study reports several cases of early and late major complications including severe sepsis and pulmonary oedema. Additional information is needed to evaluate the benefit: risk ratio of long-term epoprostenol therapy in pulmonary hypertension secondary to connective tissue diseases.

Pulmonary arterial hypertension associated with fenfluramine exposure: report of 109 cases

The aim of the present study was to describe a large cohort of fenfluramine-associated pulmonary arterial hypertension (fen-PAH) and its possible prognostic markers. The records of all patients with a diagnosis of fen-PAH evaluated at the present authors’ centre from 1986–2004 were retrospectively studied. Baseline clinical and haemodynamic data were collected, as well as survival times. The median duration of fenfluramine exposure was 6 months, with a median of 4.5 yrs between exposure and onset of symptoms. Nine (22.5%) out of 40 patients evaluated resulted positive for the presence of germline bone morphogenetic protein receptor (BMPR) type 2 mutations. In these patients, the duration of exposure to fenfluramine was significantly lower than in patients without mutation. The median survival was 6.4 yrs, without significant difference between fen-PAH and a control group of idiopathic and familial pulmonary arterial hypertension patients referred to the present authors’ centre during the same time frame and treated identically. Duration of fenfluramine exposure showed no relation to survival, while cardiac index was the only independent predictor of multivariate analysis. Fenfluramine-associated pulmonary arterial hypertension shares clinical, functional, haemodynamic and genetic features with idiopathic pulmonary arterial hypertension, as well as overall survival rates. Therefore, the present authors conclude that fenfluramine exposure characterises a potent trigger for pulmonary arterial hypertension without influencing its clinical course.

Occult alveolar haemorrhage in pulmonary veno-occlusive disease

Pulmonary veno-occlusive disease (PVOD) is a rare cause of pulmonary arterial hypertension that affects predominantly post-capillary pulmonary vessels. A major concern with PVOD is the poor response to available therapies and the risk of pulmonary oedema with continuous intravenous epoprostenol. The present authors hypothesised that alveolar haemorrhage may be a characteristic feature of pulmonary veno-occlusive disease, as compared with other forms of pulmonary arterial hypertension that predominantly involve pre-capillary pulmonary arteries. This paper reports a series of 19 patients with either PVOD (n = 8) or idiopathic pulmonary arterial hypertension (IPAH; n = 11) who underwent bronchoalveolar lavage. Cytological analyses were performed and differential counts were made on Perls-stained preparations. The Golde score was used to assess alveolar haemorrhage. As compared with IPAH, PVOD was characterised by a higher percentage of haemosiderin-laden macrophages (40±37 versus 3±6%), resulting in elevated Golde scores (81±88 versus 4±10). It was concluded that occult alveolar haemorrhage is a common feature of pulmonary veno-occlusive disease. Detecting occult alveolar haemorrhage may be of interest in the diagnostic approach of pulmonary veno-occlusive disease.