Treprostinil, a prostacyclin analogue, in pulmonary arterial hypertension associated with connective tissue disease

Systemic sclerosis: hypothesis-driven treatment strategies

We review data from controlled trials and randomised controlled trials to examine the hypothesis for the pathogenesis of systemic sclerosis. Strategies used to treat the vascular complications in systemic sclerosis have so far shown the biggest successes, especially in the management of renal crisis and pulmonary arterial hypertension. Because these drugs have improved function and quality of life and have increased survival rates, they can truly be classified as disease-modifying compounds. Immunosuppressive therapy with cyclophosphamide in particular has also shown evidence of efficacy, and randomised controlled trials of autologous stem-cell transplantation are underway. So far, strategies to reduce or control fibrosis directly (bosentan, interferon gamma, and relaxin) have been disappointing but new strategies against fibrosis based on advanced understanding of the molecular biology of systemic sclerosis hold promise. Treatments against several cardinal features of the disorder simultaneously have not yet been examined but are being considered for future trials.

Safety and Efficacy of IV Treprostinil for Pulmonary Arterial Hypertension

BACKGROUND

Pulmonary arterial hypertension (PAH) is a life-threatening disease for which both continuous IV epoprostenol and continuous subcutaneous treprostinil have proven effective. With continuous IV treprostinil having potential advantages over both of the above therapies, we investigated the safety and efficacy of this regimen in patients with PAH.

METHODS

We conducted a 12-week, prospective, open-label, uncontrolled, multicenter study of continuous IV treprostinil in 16 patients with PAH that was idiopathic (n = 8), related to connective tissue disease (n = 6), or related to congenital heart disease (n = 2). The primary end point was change from baseline to week 12 in exercise capacity assessed by the 6-min walk (6MW) test.

RESULTS

Continuous IV treprostinil increased 6MW distance (mean +/- SE) by 82 m from baseline (319 +/- 22 m) to week 12 (400 +/- 26 m) [n = 14; p = 0.001]. There were also significant improvements in the secondary end points of Naughton-Balke treadmill time (p = 0.007), Borg dyspnea score (p = 0.008), and hemodynamics (mean pulmonary artery pressure, p = 0.03; cardiac index, p = 0.002; pulmonary vascular resistance, p = 0.001) at week 12 compared with baseline. Side effects were mild and consistent with those reported with prostacyclin treatment. One death, unrelated to study drug, occurred during the 12-week study in a patient who received 3 days of treprostinil and died 2 weeks later.

CONCLUSIONS

Long-term IV infusion of treprostinil is safe and appears to be effective for the treatment of patients with PAH.

Pulmonary Involvement in Systemic Sclerosis

Scleroderma, also known as progressive systemic sclerosis (SSc), is a multisystem autoimmune disorder characterized by inflammation and fibrosis involving the skin as well as internal organs such as the vasculature, esophagus, and the respiratory tract. Pulmonary involvement consists most often of interstitial fibrosis and pulmonary vascular disease leading to pulmonary arterial hypertension (PAH). Bronchiectasis is an uncommon pulmonary manifestation of systemic sclerosis. Pulmonary hemorrhage with acute renal failure and diffuse alveolar hemorrhage in the absence of a history of renal involvement or penicillamine intake have rarely been reported in patients with systemic sclerosis.On high resolution CT, evidence of interstitial disease is seen in approximately 90% of patients, the main findings being a fine reticular pattern involving the subpleural regions of the lower lobe. Other common findings include ground-glass opacities, honeycombing, and parenchymal micronodules. The most distinctive pulmonary histologic findings in patients with scleroderma are the vascular changes found in PAH in the absence of significant interstitial fibrosis.There is no strong evidence that any drug alters the course of the two main types of lung disease in systemic sclerosis. This apparent failure of therapy may reflect the fact that pulmonary involvement is usually identified at an established or late stage. It has been suggested that, for fibrosing alveolitis, corticosteroids are most effective if given in combination with cyclophosphamide. In some patients with SSc, PAH has been considered as a major cause of morbidity and mortality. Centrally infused prostacyclin (epoprostenol) and its subcutaneously infused analog treprostinil improve hemodynamics, as well as the quality of life and survival in these patients. Iloprost has also shown a positive effect on PAH in SSc patients. More recently, bosentan, an endothelin receptor antagonist, has proved effective in controlling PAH after 6 months' treatment. Sildenafil has been used as a selective pulmonary vasodilator in SSc patients with isolated PAH. This drug decreased mean pulmonary artery pressure and pulmonary vascular resistance, and increased cardiac output, with much improvement of the physical condition of the patients. Lung transplant can be considered as a last option.Clinicians must be aware of the possibility of lung disease in patients with SSc so that it can be treated as early as possible.

New therapeutic strategies for systemic sclerosis--a critical analysis of the literature

Systemic sclerosis (SSc) is a multi-system disease characterized by skin fibrosis and visceral disease. Therapy is organ and pathogenesis targeted. In this review, we describe novel strategies in the treatment of SSc. Utilizing the MEDLINE and the COCHRANE REGISTRY, we identified open trials, controlled trials, for treatment of SSc from 1999 to April 2005. We used the terms scleroderma, systemic sclerosis, Raynaud's phenomenon, pulmonary hypertension, methotrexate, cyclosporin, tacrolimus, relaxin, low-dose penicillamine, IVIg, calcium channel blockers, losartan, prazocin, iloprost, N-acetylcysteine, bosentan, cyclophosphamide, lung transplantation, ACE inhibitors, anti-thymocyte globulin, and stem cell transplantation. Anecdotal reports were omitted.

Methotrexate, cyclosporin, tacrolimus, relaxin, low-dose penicillamine, and IVIg may be beneficial in improving the skin tightness in SSc. Calcium channel blockers, the angiotensin II receptor type 1 antagonist losartan, prazocin, the prostacyclin analogue iloprost, N-acetylcysteine and the dual endothelin-receptor antagonist bosentan may be beneficial for Raynaud's phenomenon. Epoprostenol and bosentan are approved for therapy of pulmonary hypertension (PAH). Other options under investigation include intravenous or aerolized iloprost. Cyclophosphamide (CYC) pulse therapy is effective in suppressing active alveolitis. Stem cell and lung transplantation is a viable option for carefully selected patients. Renal crisis can be effectively managed when hypertension is aggressively controlled with angiotensin converting enzyme (ACE) inhibitors. Patients should continue taking ACE inhibitors even after beginning dialysis in hope of discontinuing dialysis. Anti-thymocyte globulin and mycophenolate mofetil appear safe in SSc. The improvement in skin score and the apparent stability of systemic disease during the treatment period suggest that controlled studies of these agents are justified. Stem cell transplantation is under investigation for severe disease. Novel therapies are currently being tested in the treatment of SSc and have the potential of modifying the disease process and overall clinical outcome. The evaluation of these studies is still a difficult process.

Pulmonary rehabilitation for COPD

Pulmonary rehabilitation is a therapeutic process, which entails taking a holistic approach to the welfare of the patient with chronic respiratory illness--most commonly chronic obstructive pulmonary disease (COPD). Pulmonary rehabilitation is considered essential throughout the lifetime management of patients with symptomatic chronic respiratory disease. It requires the coordinated action of a multidisciplinary healthcare team in order to deliver an individualised rehabilitation programme to best effect--incorporating multiple modalities, such as advice on smoking cessation, exercise training and patient self-management education, among others. As core components of pulmonary rehabilitation, exercise training and self-management education have been shown to be beneficial in improving health-related quality of life (HRQoL) in patients with chronic respiratory disease. Physical training can help to reduce the muscle de-conditioning that occurs when the activity of patients is restricted by their breathlessness and fatigue, and is often associated with an increase in patient HRQoL. HRQoL can also be improved by the use of self-management education, which is designed to provide the patient with the skills to manage the health consequences of their disease. In doing so, patients are better able to cope with disease symptoms, potentially leading to reduced healthcare costs. A great deal of research has been conducted to try and fully define which patients will benefit most from pulmonary rehabilitation. Although progress has been made, many questions remain as to the best means of delivering rehabilitation, particularly with respect to the optimum programme of physical training and patient self-management education.

Les traitements de l’hypertension artérielle pulmonaire à l’heure de la T2A. Recommandations du groupe de travail “Maladies vasculaires pulmonaires” de la Société de pneumologie de langue française

Activity-based financing (that is, casemix-based hospital payments, known as T2A) is intended to harmonize and improve the fairness of remuneration of public and private hospitals. T2A will ultimately rely mainly on a flat rate per admission, set according to the diagnosis-related group (DRG). Although payment for drugs is usually included in the DRG price, some expensive drugs will be reimbursed on an additional cost basis after implementation of a "best practices" agreement. Four drugs used for treatment of pulmonary arterial hypertension are eligible for this additional reimbursement: 3 prostacyclin derivatives (intravenous epoprostenol, inhaled iloprost, and subcutaneous treprostinil), and oral bosentan, an endothelin receptor antagonist. The Pulmonary Vascular Diseases working group of the French Society of Pulmonary Medicine has developed guidelines for the best practices in use of these drugs.

Treatment of mixed connective tissue disease

Mixed connective tissue disease (MCTD) is believed to be incurable and seems to have a variable prognosis. Some patients have a mild self-limited disease, whereas others develop major organ involvement that requires aggressive treatment. Because no controlled clinical trials have been performed to guide therapy in MCTD, treatment strategies must rely largely upon the conventional therapies that are used for similar problems in other rheumatic conditions (systemic lupus erythematosus, scleroderma, polymyositis). Given the heterogeneous clinical course of MCTD, therapy should be individualized to address the specific organ involved and the severity of underlying disease activity. Corticosteroids, antimalarials, methotrexate, cytotoxics (most often cyclophosphamide), and vasodilators have been used in the treatment of MCTD with varying degrees of success.

Hipertensão pulmonar e esclerose sistêmica

Dentre as diversas condições clínicas associadas ao risco de desenvolvimento de hipertensão pulmonar, a esclerose sistêmica merece particular atenção, não só pela prevalência significativa de hipertensão pulmonar dentre seus portadores, mas também pela piora importante no prognóstico que a presença da hipertensão pulmonar representa. Com isso, temos uma situação em que o rastreamento periódico e a introdução precoce de tratamento específico têm potencial impacto na evolução da doença, embora essa alteração evolutiva ainda mereça melhor caracterização.

Pulmonary Vascular Manifestations of Mixed Connective Tissue Disease

Mixed connective tissue disease (MCTD) refers to a disease process with combined clinical features characteristic of systemic lupus erythematous, scleroderma, and polymyositis-dermatomyositis. This article focuses on the pulmonary vasculature manifestations of MCTD. We briefly discuss associations between MCTD and interstitial lung disease, pleural disease, and alveolar hemorrhage.

Pharmacology of vascular endothelium

Sir John Vane named vascular endothelium 'the maestro of blood circulation'. Recently, 'the maestro' has become a target for pharmacotherapy of atherothrombotic and diabetic vasculopathies with well known cardio-vascular drugs belonging to the families of Angiotensin Converting Enzyme inhibitors, HMG CoA reductase inhibitors or beta1-Adrenoceptor antagonists. These drugs became upgraded to a position of the pleiotropic endothelial drugs. It is not a simple verbal change in the nomenclature. It means that these drugs apart from their well defined mechanisms of action, as indicated in their regular names, in addition they act in an unknown mechanism at the level of vascular endothelium preventing angina, myocardial infarction and stroke. Many biochemical events take place in endothelial cells. I chose for a closer inspection the nitric oxide/prostacyclin defensive system to explain the endothelial pleiotropism of the drugs in question. I tried to examine the validity of this conception according to the general rule: in vitro cognitio sed in vivo veritas.

Prostacyclin for pulmonary hypertension in adults

BACKGROUND

Primary pulmonary hypertension (PPH) is progressive, resulting in right ventricular failure. Pulmonary hypertension can be idiopathic or associated with other conditions. Prostacyclin is a potent vasodilator and inhibitor of platelet aggregation, and can be given orally, subcutaneously, intravenously or inhaled via a nebuliser.

OBJECTIVES

To determine the efficacy of prostacyclin or one of its analogues in idiopathic primary pulmonary hypertension.

SEARCH STRATEGY

Electronic searches were carried out with pre-specified terms. Searches were current as of July 2004.

SELECTION CRITERIA

Two reviewers selected randomised controlled trials (RCTs) involving adults with pulmonary hypertension for inclusion.

DATA COLLECTION AND ANALYSIS

Study quality was assessed and data extracted independently by two reviewers. Outcomes were analysed as continuous and dichotomous outcomes. We sub-grouped data where possible by aetiology of PH (PPH, PH secondary to connective tissue disorder or mixed populations).

MAIN RESULTS

Nine RCTs of mixed duration (3 days-52 weeks), recruiting 1175 participants were included (NYHA functional classes II-IV). Intravenous prostacyclin versus usual care (four studies): There were significant improvements in exercise capacity of around 90 metres, cardiopulmonary haemodynamics and NYHA functional class over 3 days-12 weeks. Effects were consistent in primary and secondary pulmonary hypertension. Oral prostacyclin versus placebo (two studies): Short-term data (3-6 months) indicated that there was a significant improvement in exercise capacity, but data from one study of 52 weeks reported no significant difference at 12 months. No significant differences were observed for any other outcome. Subcutaneous treprostinil versus placebo (two studies, 8-12 weeks):One large study reported a significant median improvement in exercise capacity of around 16 metres. Cardiopulmonary haemodynamics and symptom scores favoured treprostinil. Infusion site pain and withdrawals due to adverse events were more frequent with treprostinil. Inhaled prostacyclin versus placebo (one study, 12 weeks):There was a significant increase in exercise capacity of approximately 36 metres. Treatment led to better symptom scores and functional class status than with placebo. Subgroup analyses reported by individual studies showed a better exercise capacity in participants with PPH, than those participants with PH secondary to other diseases. Side effects and adverse events were common in the studies.

AUTHORS' CONCLUSIONS

There is evidence that intravenous prostacyclin in addition to conventional therapy at tolerable doses optimised by titration, can confer some short-term benefits (up to 12 weeks of treatment) in exercise capacity, NYHA functional class and cardiopulmonary haemodynamics. There is also some evidence that patients with more severe disease based upon NYHA functional class showed a greater response to treatment.