Anticoagulation in pulmonary arterial hypertension: a qualitative systematic review

Effects of bergapten on the pharmacokinetics of macitentan in rats both in vitro and in vivo

Macitentan was approved by the United States Food and Drug Administration (FDA) in 2013 for the treatment of pulmonary arterial hypertension (PAH). Bergapten is a furanocoumarin that is abundant in Umbelliferae and Rutaceae plants and is widely used in many Chinese medicine prescriptions. Considering the possible combination of these two compounds, this study is aimed to investigate the effects of bergapten on the pharmacokinetics of macitentan both in vitro and in vivo. Rat liver microsomes (RLMs), human liver microsomes (HLMs), and recombinant human CYP3A4 (rCYP3A4) were used to investigate the inhibitory effects and mechanisms of bergapten on macitentan in vitro. In addition, pharmacokinetic parameters were also studied in vivo. Rats were randomly divided into two groups (six rats per group), with or without bergapten (10 mg/kg), and pretreated for 7 days. An oral dose of 20 mg/kg macitentan was administered to each group 30 min after bergapten or 0.5% CMC-Na administration on day 7. Blood was collected from the tail veins, and the plasma concentrations of macitentan and its metabolites were assessed by ultra-performance liquid chromatography - tandem mass spectrometer (UPLC-MS/MS). Finally, we analyzed the binding force of the enzyme and two small ligands by in silico molecular docking to verify the inhibitory effects of bergapten on macitentan. The in vitro results revealed that the IC₅₀ values for RLMs, HLMs, and rCYP3A4 were 3.84, 17.82 and 12.81 μM, respectively. In vivo pharmacokinetic experiments showed that the AUC_(0-t), AUC_(0-∞), and C_max of macitentan in the experimental group (20,263.67 μg/L*h, 20,378.31 μg/L*h and 2,999.69 μg/L, respectively) increased significantly compared with the control group (7,873.97 μg/L*h, 7,897.83 μg/L*h and 1,339.44 μg/L, respectively), while the CL_z/F (1.07 L/h/kg) of macitentan and the metabolite-parent ratio (MR) displayed a significant decrease. Bergapten competitively inhibited macitentan metabolism in vitro and altered its pharmacokinetic characteristics in vivo. Further molecular docking analysis was also consistent with the experimental results. This study provides a reference for the combined use of bergapten and macitentan in clinical practice.

State-of-the-art evidence in the treatment of systemic sclerosis

Systemic sclerosis (SSc) is a rare autoimmune connective tissue disease with multi-organ involvement, fibrosis and vasculopathy. Treatment in SSc, including early diffuse cutaneous SSc (dcSSc) and the use of organ-specific therapies, has improved, as evident from randomized clinical trials. Treatments for early dcSSc include immunosuppressive agents such as mycophenolate mofetil, methotrexate, cyclophosphamide, rituximab and tocilizumab. Patients with rapidly progressive early dcSSc might be eligible for autologous haematopoietic stem cell transplantation, which can improve survival. Morbidity from interstitial lung disease and pulmonary arterial hypertension is improving with the use of proven therapies. Mycophenolate mofetil has surpassed cyclophosphamide as the initial treatment for SSc-interstitial lung disease. Nintedanib and possibly perfinidone can be considered in SSc pulmonary fibrosis. Pulmonary arterial hypertension is frequently treated with initial combination therapy (for example, with phosphodiesterase 5 inhibitors and endothelin receptor antagonists) and, if necessary, the addition of a prostacyclin analogue. Raynaud phenomenon and digital ulcers are treated with dihydropyridine calcium channel blockers (especially nifedipine), then phosphodiesterase 5 inhibitors or intravenous iloprost. Bosentan can reduce the development of new digital ulcers. Trial data for other manifestations are mostly lacking. Research is needed to develop targeted and highly effective treatments, best practices for organ-specific screening and early intervention, and sensitive outcome measurements.

Pulmonary arterial hypertension due to antiphospholipid syndrome initially mimicking chronic thromboembolic pulmonary hypertension

Pulmonary arterial hypertension (PAH) is the second most common lung complication in antiphospholipid syndrome (APS) patients. However, the concurrent development of APS-related nonthrombotic PAH is rarely reported. Lack of awareness for group 1 PAH in APS patient may contribute to underdiagnosis of this condition. Herein, we reviewed the case of a 56-year-old female who was diagnosed with PAH related to APS that mimicked chronic thromboembolic pulmonary hypertension (CTEPH). It is crucial to be aware of the possibility of a group 1 PAH diagnosis, even though patients have already been diagnosed with CTEPH. Furthermore, a multidisciplinary approach and serial follow-up right heart catheterization with echocardiography are important to make a timely diagnosis and provide optimal treatment for APS-related PAH in patients with CTEPH-like clinical features.

A review of indications and comorbidities in which warfarin may be the preferred oral anticoagulant

WHAT IS KNOWN AND OBJECTIVE

Direct oral anticoagulants (DOACs) are increasingly prescribed instead of warfarin for chronic anticoagulation for ease of dosing, fewer interactions, and less stringent monitoring. However, it is important to consider indications and comorbidities for which warfarin is still the preferred anticoagulant. This review aims to capture these clinical scenarios in which warfarin may still be preferred over DOACs.

METHODS

We undertook a comprehensive literature search using the PubMed database. Key search terms were based on DOAC clinical trial exclusion criteria, as well as indications and conditions in which the use of DOACs for anticoagulation has suggested harm. Society guidelines and tertiary literature were used to inform expert opinion where necessary. Studies were included if they investigated the use of DOACs or warfarin in the identified indications or conditions.

RESULTS AND DISCUSSION

Currently, evidence for the use of warfarin over DOACs for anticoagulation is strongest for patients with prosthetic valves, antiphospholipid syndrome, or a high risk of gastrointestinal bleeding. For several clinical situations, including mitral stenosis, obesity, altered gastrointestinal anatomy, pulmonary arterial hypertension, renal or hepatic impairment, and left ventricular thrombus, evidence is lacking but may eventually support the use of DOACs. Depending on indication and condition, appropriateness of DOAC use may vary by agent.

WHAT IS NEW AND CONCLUSION

New evidence continues to support new indications and conditions in which DOACs may be appropriate to use for anticoagulation. There are key clinical scenarios, however, in which emerging literature continues to support warfarin as the preferred anticoagulant.

Anticoagulation in Pulmonary Arterial Hypertension: Do We Know the Answer?

The shear stress and hypoxia in the pulmonary artery in patients with pulmonary arterial hypertension(PAH) causes endothelial dysfunction, smooth muscle proliferation and activation of thrombotic pathways leading to in situ thrombosis. Targeting the thrombotic pathways is a proposed mechanism to slow disease progression and improve survival. Over the years, the survival in patients with PAH has improved due to multiple factors with the increased use of anticoagulation as one of them. Both European Respiratory Society/European Society of Cardiology and American College of Cardiology/American Heart Association guidelines make grade II recommendations for using anticoagulation in PAH. The guidelines are based on weak observational studies with high risk of bias which have only studied warfarin as the choice of anticoagulation. In this article, we review the pathophysiology, rationale and the current literature investigating the role of anticoagulation in PAH.

Schistosome infection and its effect on pulmonary circulation

Schistosomiasis is the most common parasitic disease associated with pulmonary hypertension. It induces remodelling via complex inflammatory processes, which eventually produce the clinical manifestation of pulmonary hypertension. The pulmonary hypertension shows clinical signs and symptoms that are not distinguishable from other forms of pulmonary arterial hypertension.

Anticoagulation in the cardiac patient: A concise review

Anticoagulation has multiple roles in the treatment of cardiovascular disease, including in management of acute myocardial infarction, during percutaneous coronary intervention, as stroke prophylaxis in patients with atrial arrhythmias, and in patients with mechanical heart valves. Clinical anticoagulation choices in the aforementioned diseases vary widely, due to conflicting data to support established agents and the rapid evolution of evidence-based practice that parallels more widespread use of novel oral anticoagulants. This review concisely summarizes evidence-based guidelines for anticoagulant use in cardiovascular disease, and highlights new data specific to direct oral anticoagulants.

Principles of pharmacological correction of pulmonary arterial hypertension

Definition and classification: Pulmonary hypertension (PH) is a group of life-threatening progressive diseases of various genesis, characterized by a progressive increase in arterial pressure (AP) in the pulmonary artery (PA), the remodeling of pulmonary vessels, which leads to an increase in pulmonary vascular resistance and pulmonary arterial pressure and more often leads to right ventricular heart failure and premature death. Pulmonary hypertension is clinically divided into five groups: patients in the first group have idiopathic pulmonary arterial hypertension (IPAH), whereas in patients of other groups secondary PH associated with cardiopulmonary or other systemic diseases is observed. The development of secondary LH is caused by congenital heart defects, collagenoses, presence of thrombus in the pulmonary artery, prolonged high pressure in the left atrium, hypoxemia, chronic obstructive pulmonary diseases (COPDs). In case of secondary PH, thrombosis and other changes in the pulmonary veins occur.

Ways of pharmacological correction of pulmonary hypertension: Over the last decade pharmacotherapy of PH has been developing rapidly, and the introduction of modern methods of treatment, especially for primary PAH, has led to positive results. However, despite the progress in treatment, the functional limitations and survival of patients remain unsatisfactory. Currently, there are two levels of treatment for pulmonary hypertension: primary and specific pathogenetic therapies. Primary therapy is aimed at the main cause of PH. It also includes supportive therapy. Pathogenetic therapy includes prostanoids, endothelin receptor antagonists, and phosphodiesterase-5 inhibitors. Tactics of therapy can be established on the basis of either clinical classification, or functional class. Prostanoids are a promising group of drugs for the treatment of pulmonary arterial hypertension (PAH), since they possess not only vasodilating, but also antiplatelet and antiproliferative actions. Therefore, it seems logical to use prostacyclin and its analogs to treat patients with various forms of PAH.

Platelet and coagulation disorders in newly diagnosed patients with pulmonary arterial hypertension

There is a complex and not fully elucidated association between pulmonary arterial hypertension (PAH) and coagulation disorders. The goal of this study was to evaluate platelet function, coagulation and fibrinolysis in PAH patients at diagnosis, before PAH-specific treatment initiation. We enrolled 20 healthy controls and 30 PAH patients (20 with connective tissue disease (CTD-PAH) and 10 idiopathic (iPAH)). None of the participants was on any antiplatelet or anticoagulation therapy. Blood samples from PAH patients were collected during the initial right heart catheterization. All subjects were assessed with platelet function analyzer-100 (PFA-100), epinephrine (Epi) and ADP-induced light transmission aggregometry (LTA), thromboelastometry (ROTEM) and endogenous thrombin potential (ETP). Our results showed that Epi and ADP-LTA values were significantly lower in newly diagnosed PAH patients compared to controls. Disaggregation was present in 73% of patients, a characteristic not seen in healthy individuals. In ROTEM assay, CT and CFT measurements were significantly higher and a angle lower compared to controls. ETP testing revealed significantly reduced outcomes in AUC, Cmax and Tmax. When CTD-PAH and iPAH patient groups were compared, iPAH ADP-LTA values were significantly decreased compared to CTD-PAH. In conclusion, newly diagnosed PAH patients presented with decreased platelet aggregation, clot propagation and thrombin generation, along with delayed initiation of the coagulation process. These hemostatic deficits could indicate an "exhaustion" of the coagulation process that could be caused by endothelial dysfunction and chronic activation of the procoagulant pathways. Further studies are warranted to confirm these laboratory findings and assess their potential clinical significance.

Diagnostic criteria, severity classification and guidelines of systemic sclerosis

Several effective drugs have been identified for the treatment of systemic sclerosis (SSc). However, in advanced cases, not only their effectiveness is reduced but they may be also harmful due to their side-effects. Therefore, early diagnosis and early treatment is most important for the treatment of SSc. We established diagnostic criteria for SSc in 2003 and early diagnostic criteria for SSc in 2011, for the purpose of developing evaluation of each organ in SSc. Moreover, in November 2013, the American College of Rheumatology and the European Rheumatology Association jointly developed new diagnostic criteria for increasing their sensitivity and specificity, so we revised our diagnostic criteria and severity classification of SSc. Furthermore, we have revised the clinical guideline based on the newest evidence. In particular, the clinical guideline was established by clinical questions based on evidence-based medicine according to the New Minds Clinical Practice Guideline Creation Manual (version 1.0). We aimed to make the guideline easy to use and reliable based on the newest evidence, and to present guidance as specific as possible for various clinical problems in treatment of SSc.

Impact on survival of warfarin in patients with pulmonary arterial hypertension receiving subcutaneous treprostinil

INTRODUCTION

Anticoagulation is a common treatment modality in patients with pulmonary arterial hypertension (PAH). Further studies are needed to appropriately assess the risk/benefit ratio of anticoagulation, particularly in PAH patients receiving PAH-specific therapies.

AIMS

We use observational long-term data on PAH patients treated with subcutaneous (SQ) treprostinil from a large open-label study. Patients were followed for up to 4 years. The use of warfarin and bleeding events were recorded.

RESULTS

At total of 860 patients (age [mean±SD] 46±15 years, 76% female, 83% Caucasian, 49% idiopathic PAH, and 76% New York Heart Association [NYHA] functional class III) were included. All patients received SQ treprostinil (15% also other pulmonary hypertension [PH]-therapies) and 590 (69%) received warfarin during the study. The proportions of women, African American, and idiopathic pulmonary hypertension (IPAH) patients were higher in the group receiving warfarin. A higher proportion of patients with congenital heart disease and portopulmonary hypertension did not receive warfarin. There were no differences in unadjusted long-term survival between PAH patients receiving warfarin or not (log-rank test, P value=.69), even when only considering idiopathic PAH (P=.32). In addition, no difference was found in adjusted long-term survival both in PAH (P=.84) and idiopathic PAH patients (P=.44) based on the use of warfarin. Furthermore, no survival difference based on the use of warfarin were noted between propensity score-matched PAH patients (P=.37).

CONCLUSIONS

Long-term anticoagulation with warfarin was not associated with any significant effect on survival in PAH or idiopathic PAH patients treated with SQ treprostinil.

Anticoagulant treatment in patients with pulmonary arterial hypertension associated with systemic sclerosis: More shadows than lights

Pulmonary arterial hypertension is a chronic and progressive disease characterized by elevated pulmonary artery pressure and pulmonary vascular resistance leading to heart failure and premature death. Pulmonary arterial hypertension is characterized by proliferative and obstructive lesions in the distal pulmonary arteries and some descriptions include also thrombotic lesions. Despite this, in an era when multiple effective pulmonary arterial hypertension therapies are available, the role of anticoagulation in the treatment of pulmonary arterial hypertension remains uncertain. In particular, anticoagulant treatment in pulmonary arterial hypertension associated with connective tissue disease seems to be associated with unfavorable risk to benefit ratio due to an increased rate of bleeding from the gastrointestinal tract. However, anticoagulation may be required in conditions with increased thrombophilia like in the presence of lupus anticoagulant phenomenon or in the presence of anticardiolipin antibodies.

Evaluation and management approaches for scleroderma lung disease

Interstitial lung disease (ILD) and pulmonary arterial hypertension (PAH) are leading causes of morbidity and mortality in systemic sclerosis (SSc). As symptoms are often under-reported in SSc, early screening of ILD and PAH is of paramount importance, and early treatment may be associated with better clinical outcomes. Serologies are particularly helpful in identifying patients at risk for pulmonary involvement. Pulmonary function testing, high-resolution computed tomography of the chest and echocardiography are important tools in the initial screening of these patients. Extensive research has also led to an improved understanding of the mediators involved in the pathogenesis of ILD and PAH. As a result, there have been significant advances in the development of novel targeted therapeutics and an increase in the number of early-phase clinical trials in SSc.

Anticoagulation in Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is characterized by molecular and pathologic alteration to the pulmonary circulation, resulting in increased pulmonary vascular resistance, right ventricular failure, and eventual death. Pharmacologic treatment of PAH consists of use of a multitude of pulmonary vasodilators, sometimes in combination. PAH has been associated with increased thrombosis and disrupted coagulation and fibrinolysis, making anticoagulation an attractive and frequently employed therapeutic modality. Observational studies have provided some insight into the therapeutic potential of anticoagulation in idiopathic PAH, but there is a distinct lack of well-controlled prospective trials. Due to the conflicting evidence, there is a large amount of heterogeneity in the application of therapeutic anticoagulation in PAH and further well-controlled prospective trials are needed to clarify its role in treating PAH.

Multicentre randomised placebo-controlled trial of oral anticoagulation with apixaban in systemic sclerosis-related pulmonary arterial hypertension: the SPHInX study protocol

INTRODUCTION

Systemic sclerosis (SSc) is a severe and costly multiorgan autoimmune connective tissue disease characterised by vasculopathy and fibrosis. One of the major causes of SSc-related death is pulmonary arterial hypertension (PAH), which develops in 12-15% of patients with SSc and accounts for 30-40% of deaths. In situ thrombosis in the small calibre peripheral pulmonary vessels resulting from endothelial dysfunction and an imbalance of anticoagulant and prothrombotic mediators has been implicated in the complex pathophysiology of SSc-related PAH (SSc-PAH), with international clinical guidelines recommending the use of anticoagulants for some types of PAH, such as idiopathic PAH. However, anticoagulation has not become part of standard clinical care for patients with SSc-PAH as only observational evidence exists to support its use. Therefore, we present the rationale and methodology of a phase III randomised controlled trial (RCT) to evaluate the efficacy, safety and cost-effectiveness of anticoagulation in SSc-PAH.

METHODS AND ANALYSIS

This Australian multicentre RCT will compare 2.5 mg apixaban with placebo, in parallel treatment groups randomised in a 1:1 ratio, both administered twice daily for 3 years as adjunct therapy to stable oral PAH therapy. The composite primary outcome measure will be the time to death or clinical worsening of PAH. Secondary outcomes will include functional capacity, health-related quality of life measures and adverse events. A cost-effectiveness analysis of anticoagulation versus placebo will also be undertaken.

ETHICS AND DISSEMINATION

Ethical approval for this RCT has been granted by the Human Research Ethics Committees of all participating centres. An independent data safety monitoring board will review safety and tolerability data for the duration of the trial. The findings of this RCT are to be published in open access journals.

TRIAL REGISTRATION NUMBER

ACTRN12614000418673, Pre-results.

Where do we go from here? Reappraising the data on anticoagulation in pulmonary arterial hypertension

The use of anticoagulation as part of the treatment regimen in pulmonary arterial hypertension (PAH) remains a topic of debate. A recently published analysis of anticoagulation use in the Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL) study offers conflicting conclusions regarding the benefit of this therapeutic strategy. There remains no robust randomized trial in PAH weighing the risks versus benefits of including anticoagulation in treatment regimens, leaving clinicians to surmise value in individual patients. Reexamination of available data may help to provide guidance on this controversial topic in the absence of future dedicated investigations.

Current Concepts in Management of Pulmonary Hypertension: Fighting the Old Demon with Modern Weapons

Pulmonary hypertension in children is a rare disease associated with high morbidity and mortality. The pathogenesis is not fully understood. Diagnostic evaluation focuses on ruling out other etiologies of pulmonary hypertension and prognosticating the disease. Congenital heart disease and left sided heart disease associated pulmonary hypertension are more common in children. Therapies for idiopathic pulmonary hypertension have evolved over the past decade. Phosphodiesterase 5 inhibitors (sildenafil, tadalafil), endothelin antagonists (Bosentan and ambrisentan) and prostanoids are the classes of drugs shown to be useful in pulmonary hypertension. However, use of these drugs in children is based on extrapolation of adult usage and on expert consensus rather than based on randomized controlled trial evidence. Despite these advances, the outcomes of various forms of pulmonary hypertension remain poor, especially in India, where some forms of therapy are not available and children often are diagnosed at an advanced stage of disease.

Anticoagulation in patients with pulmonary arterial hypertension: An update on current knowledge

Pulmonary hypertension is a severe clinical condition characterized by molecular and anatomic changes in pulmonary circulation. It is associated with increased pulmonary vascular resistance, which leads to right-sided heart failure if left untreated and, ultimately, death. Treatment of patients with pulmonary arterial hypertension (PAH) involves a complex strategy that takes into consideration disease severity, general and supportive measures, and combination drug regimens. Abnormalities of blood coagulation factors, anti-thrombotic factors, and the fibrinolytic system may contribute to a prothrombotic state in patients with idiopathic PAH. These physiologic changes, in concert with the presence of non-specific risk factors for venous thromboembolism such as heart failure and immobility, are thought to be the basis for oral anticoagulation in PAH. Several observational studies provide helpful information in favor of anticoagulation use in idiopathic PAH but not in other pulmonary hypertension etiologies. Guideline recommendations are based on the lack of prospective comparative trials in this regard. For that reason, large differences exist in the use of anticoagulants in different countries and centers. More studies should be carried out to clarify the risks and the potential benefits of anticoagulant use in a heterogeneous population of patients who are already at considerable life risk.

Influence of Age on Outcome in Patients with Pulmonary Arterial Hypertension

BACKGROUND

The development of effective orally administered medical therapy for pulmonary arterial hypertension (PAH) has made a significant impact on outcome in patients with PAH. Identification of patient groups likely to derive optimal benefit is important, given cost and potential side effects; the clinical effectiveness of these therapies in older patients with PAH is unclear as the presence of co-morbidity may limit benefits of therapy.

AIMS

We evaluated the epidemiology of PAH in a contemporary cohort to assess the influence of age on long-term outcome using PAH-specific therapies.

RESULTS

A total of 119 patients (88% female; mean age 65±12 years) were reviewed, comprising 52% with underlying connective tissue disease. Bosentan was the PAH specific agent most frequently used. The baseline 6MWT distance in the entire cohort was 304m with age associated with a significant decline in 6MWT.

CONCLUSIONS

In a large cohort of patients treated with PAH-specific therapies, patients less than 55 years of age showed improvement in 6MWT with older patients demonstrating stabilisation or decline.

Recent strategies in treatment of pulmonary arterial hypertension, a review

Pulmonary arterial hypertension (PAH) is a disease characterized by an elevation in pulmonary artery pressure that can lead to right ventricular failure and death. The pulmonary circulation has to accommodate the entire cardiac output in each cardiac cycle and evolution has adapted to this by making it a low-pressure high-flow system. However, pathology can affect both the arterial and venous components of this system. Pulmonary venous hypertension mainly refers to diseases that result in elevated venous pressure and occurs mainly from mitral valve and left-sided heart disease. Standard treatment options include oral anticoagulation, diuretics, oxygen supplementation, and for a small percentage of patients, calcium channel blockers. Newer treatments include prostacyclin analogues, endothelin receptor antagonists, and phosphodiesterase type 5 inhibitors. This article reviews the current treatments strategies for PAH and provides guidelines for its management.

Schistosomiasis-associated pulmonary hypertension

Schistosomiasis, a parasite-borne disease, is highly prevalent in Africa and Asia; it is estimated that close to 20 million people worldwide have a severe form of the disease. The chronic form can affect the gastrointestinal system and lead to hepatosplenic disease, and it may cause cardiopulmonary complications, including pulmonary hypertension. The exact pathogenesis of schistosomiasis-associated pulmonary hypertension (Sch-PH) remains unclear, although several mechanisms, including parasitic arterial embolization, pulmonary arteriopathy, and portopulmonary hypertension-like pathophysiology, have been suggested. The immunopathology of the disease is also unclear, although there are similarities with the immunology of idiopathic pulmonary arterial hypertension (PAH). Finally, the treatment of Sch-PH has not been well studied. There is some evidence on treating the underlying infection, with unclear effect on Sch-PH, and advanced PAH therapies are now being suggested, but more studies are needed to confirm their efficacy.

Saudi Guidelines on the Diagnosis and Treatment of Pulmonary Hypertension: General management for pulmonary hypertension

Treatment of pulmonary hypertension (PH) patients is challenging and should only be initiated after a comprehensive diagnostic evaluation. Such treatment should ideally be done in specialized centers with full capability for hemodynamic measurements, having access to a broad range of PAH therapies, and adequate experience in the management of critically ill patients. The following discussion is intended to review the general measures and the non-specific (supportive) therapy used in managing PH patients, while the specific therapy will be discussed in a subsequent different article.

Anticoagulation in pulmonary arterial hypertension: Contemporary data from COMPERA registry

The use of anticoagulant therapy in patients with pulmonary arterial hypertension (PAH) has been controversial for decades. Recommendations for anticoagulation in these patients are often derived from small, retrospective, and single centre studies without any placebo-controlled randomized study. Furthermore, uncertainties exist regarding a number of issues such as patient selection, risk stratification for bleeding, the intensity of anticoagulation, appropriateness of anticoagulation in different types of PAH, and the potential use of new oral anticoagulants.

Recently, the database of the Comparative, Prospective Registry of Newly Initiated Therapies for Pulmonary Hypertension (COMPERA) has been analyzed to assess the effect of anticoagulation on the long-term outcome of patients with various forms of PAH. This analysis is the largest to date to assess anticoagulant therapy in PAH patients in a prospective design with long observation period. The results of COMPERA lend support to current recommendations for the use of anticoagulant therapy in patients with idiopathic PAH, but not in other forms of PAH. Also, the study confirmed the previously reported concern that anticoagulant therapy may be harmful in patients with scleroderma-associated PAH.

Anticoagulation therapy versus placebo for pulmonary hypertension

BACKGROUND

Elevation of pulmonary pressure is no longer a rare disease, given its multifactorial etiology. However data on the actual incidence of this condition are still limited, and controversies regarding its management are ongoing. Use of anticoagulation in the management of pulmonary hypertension is based on the presence of in situ thrombosis in the patient with pulmonary arterial hypertension (PAH) and on retrospective evidence of clinical benefit. Current practice is dependent mostly on expert opinion and individualised experience. The real benefit of its use in different types of pulmonary hypertension is still debatable, and the therapeutic target of the international normalised ratio (INR) among treated patients remains inconclusive. Adverse outcomes associated with anticoagulants are significant and can include fatal haemorrhage. Justification for the use of this intervention requires critical evaluation of randomised controlled trials.

OBJECTIVES

1. To evaluate the effectiveness of, and potential adverse events associated with, anticoagulation in the management of pulmonary hypertension (PH).2. To evaluate the effective therapeutic INR in pulmonary hypertensive patients receiving anticoagulants (North American centres 1.5 to 2.5, European centres 2.0 to 3.0).

SEARCH METHODS

We identified trials through searches of the following databases.Cochrane Airways Group Trials Register; Cochrane Central Register of Controlled Trials (CENTRAL), part of The Cochrane Library; MEDLINE (Ovid); EMBASE (Ovid); CINAHL (EBSCOhost); Clinical trials.gov and the World Health Organization (WHO) trials portal. The trial search date was 28 March 2014.

SELECTION CRITERIA

We planned to include only randomised controlled trials. Participants with PH with co-morbidities including medical conditions requiring long-term anticoagulation were to be included. We also planned to include trials comparing any anticoagulant with placebo.

DATA COLLECTION AND ANALYSIS

Review authors (IE and HE) independently appraised all identified citations to establish their relevance for inclusion in the review. IE and HE independently screened the titles and abstracts of all identified potential studies for inclusion.

MAIN RESULTS

No eligible trials were identified for inclusion in this review.

AUTHORS' CONCLUSIONS

No eligible studies were identified for inclusion in this review. Although our review of available non-randomised studies shows beneficial effect, this finding should be interpreted with caution since there are likely to be biases associated with their design and our methods were not designed to identify, appraise and summarise evidence from them. So that better decisions can be made regarding the effectiveness of this intervention, well-designed randomised controlled trials are needed.

Pulmonary hypertension survival effects and treatment options in cystic fibrosis

PURPOSE OF REVIEW

This review discusses the current impact of pulmonary hypertension on the outcome and treatment of cystic fibrosis (CF).

RECENT FINDINGS

Pulmonary hypertension is commonly encountered in advanced lung diseases such as CF. The prevalence of pulmonary hypertension in CF patients varies based on disease severity and methodology used for diagnosis. Chronic alveolar hypoxia is the most likely cause. The majority of recent studies have shown worse survival in CF patients who develop pulmonary hypertension. The impact of pulmonary hypertension-specific therapies on symptomatology and outcomes in CF patients has not been well studied.

SUMMARY

Pulmonary hypertension is common in patients with CF and it occurs largely because of hypoxemia. The presence of pulmonary hypertension in patients with CF is likely associated with worse outcome; however, it remains unknown whether treatment with pulmonary hypertension-specific therapies would be beneficial.

A descriptive evaluation of warfarin use in patients with pulmonary arterial hypertension

INTRODUCTION

Although warfarin is often recommended for pulmonary arterial hypertension (PAH) management to mitigate thrombotic risk and improve survival, limited information exists to guide anticoagulation therapy. The purpose of this study was to compare and contrast warfarin therapy monitoring requirements and outcomes in patients with PAH and atrial fibrillation (AF) receiving long-term anticoagulation.

MATERIALS AND METHODS

Patients initiated on warfarin for PAH between January 1, 2000 and December 31, 2008 were matched by warfarin initiation date (±90 days), age (±5 years), chronic disease score (±1 points), and sex to patients initiated for AF. The primary study endpoint was frequency of INR monitoring per 30 days of observation. Secondary endpoints included indicators of INR control and warfarin-related adverse events.

RESULTS AND CONCLUSION

A total of 84 patients were included - 18 and 66 in the PAH and AF groups, respectively. Patients with PAH had a higher median rate of INR measurements per 30 days compared to patients with AF (median=2.0, interquartile range [IQR]=1.5 - 2.3 vs. median=1.6, IQR=1.3 - 2.0, p=0.046). There were no differences between groups with respect to percent of INR measurements in range, overall time in therapeutic range (TTR), or warfarin-related adverse events (all p>0.05). Study results suggest that patients with PAH may be more difficult to manage as seen through more frequent INR monitoring. Potential management difficulties did not translate to a lower performance on indicators of INR control or increased risk of warfarin-related adverse events.

Should patients with systemic sclerosis-related pulmonary arterial hypertension be anticoagulated?

Pulmonary arterial hypertension (PAH) is a major cause of mortality in scleroderma and despite 'advanced' therapies confers a median survival of less than 5 years. Anticoagulation in systemic sclerosis-related PAH (SSc-PAH) is currently one of the most contentious issues in the management of patients with connective tissue disease. While some studies have shown a survival benefit with warfarin therapy in this disease, others have not. Accordingly, a state of clinical equipoise exists in relation to anticoagulation in SSc-PAH. With an over fivefold reduction in mortality demonstrated in some observational studies, the issue of anticoagulation in SSc-PAH demands resolution through a well-designed randomised controlled trial.

Anticoagulation and Survival in Pulmonary Arterial Hypertension

Background—

For almost 30 years, anticoagulation has been recommended for patients with idiopathic pulmonary arterial hypertension (IPAH). Supporting evidence, however, is limited, and it is unclear whether this recommendation is still justified in the modern management era and whether it should be extended to patients with other forms of pulmonary arterial hypertension (PAH).

Methods and Results—

We analyzed data from Comparative, Prospective Registry of Newly Initiated Therapies for Pulmonary Hypertension (COMPERA), an ongoing European pulmonary hypertension registry. Survival rates of patients with IPAH and other forms of PAH were compared by the use of anticoagulation. The sample consisted of 1283 consecutively enrolled patients with newly diagnosed PAH. Anticoagulation was used in 66% of 800 patients with IPAH and in 43% of 483 patients with other forms of PAH. In patients with IPAH, there was a significantly better 3-year survival ( P =0.006) in patients on anticoagulation compared with patients who never received anticoagulation, albeit the patients in the anticoagulation group had more severe disease at baseline. The survival difference at 3 years remained statistically significant ( P =0.017) in a matched-pair analysis of n=336 IPAH patients. The beneficial effect of anticoagulation on survival of IPAH patients was confirmed by Cox multivariable regression analysis (hazard ratio, 0.79; 95% confidence interval, 0.66–0.94). In contrast, the use of anticoagulants was not associated with a survival benefit in patients with other forms of PAH.

Conclusions—

The present data suggest that the use of anticoagulation is associated with a survival benefit in patients with IPAH, supporting current treatment recommendations. The evidence remains inconclusive for other forms of PAH.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT01347216.

Markers of thrombogenesis and fibrinolysis and their relation to inflammation and endothelial activation in patients with idiopathic pulmonary arterial hypertension

Background

Chronic anticoagulation is a standard of care in idiopathic pulmonary arterial hypertension (IPAH). However, hemostatic abnormalities in this disease remain poorly understood. Therefore, we aimed to study markers of thrombogenesis and fibrinolysis in patients with IPAH.

Methods

We studied 27 consecutive patients (67% female) with IPAH aged 50.0 years (IQR: 41.0 - 65.0) and 16 controls without pulmonary hypertension. Prothrombin fragment 1+2 (F1+2) and thrombin-antithrombin (TAT) complexes were measured to assess thrombogenesis; tissue-type plasminogen activator (tPA) antigen and plasmin-anti-plasmin complex to characterize activation of fibrinolysis; plasminogen activator inhibitor 1 (PAI-1) to measure inhibition of fibrinolysis; and endothelin-1 (ET-1) and interleukin-6 (IL-6) to assess endothelial activation and systemic inflammation, respectively. In addition, in treatment-naive IPAH patients these markers were assessed after 3 months of PAH-specific therapies.

Results

TPA (10.1[6.8-15.8] vs 5.2[3.3-7.3] ng/ml, p<0.001), plasmin-anti-plasmin (91.5[60.3-94.2] vs 55.8[51.1-64.9] ng/ml, p<0.001), IL-6 (4.9[2.5-7.9] vs 2.1[1.3-3.8] pg/ml, p=0.001) and ET-1 (3.7 [3.3-4.5] vs 3.4[3.1-3.5], p= 0.03) were higher in patients with IPAH than in controls. In IPAH patients plasmin-anti-plasmin and tPA correlated positively with IL-6 (r=0.39, p=0.04 and r=0.63, p<0.001, respectively) and ET-1 (r=0.55, p=0.003 and r=0.59, p=0.001, respectively). No correlation was found between tPA or plasmin-anti-plasmin and markers of thrombogenesis. Plasmin-anti-plasmin decreased after 3 months of PAH specific therapy while the other markers remained unchanged.

Conclusions

In the present study we showed that markers of fibrynolysis were elevated in patients with IPAH however we did not find a clear evidence for increased thrombogenesis in this group of patients. Fibrinolysis, inflammation, and endothelial activation were closely interrelated in IPAH.

Thrombin has biphasic effects on the nitric oxide-cGMP pathway in endothelial cells and contributes to experimental pulmonary hypertension

Background

A potential role for coagulation factors in pulmonary arterial hypertension has been recently described, but the mechanism of action is currently not known. Here, we investigated the interactions between thrombin and the nitric oxide-cGMP pathway in pulmonary endothelial cells and experimental pulmonary hypertension.

Principal Findings

Chronic treatment with the selective thrombin inhibitor melagatran (0.9 mg/kg daily via implanted minipumps) reduced right ventricular hypertrophy in the rat monocrotaline model of experimental pulmonary hypertension. In vitro, thrombin was found to have biphasic effects on key regulators of the nitric oxide-cGMP pathway in endothelial cells (HUVECs). Acute thrombin stimulation led to increased expression of the cGMP-elevating factors endothelial nitric oxide synthase (eNOS) and soluble guanylate cyclase (sGC) subunits, leading to increased cGMP levels. By contrast, prolonged exposition of pulmonary endothelial cells to thrombin revealed a characteristic pattern of differential expression of the key regulators of the nitric oxide-cGMP pathway, in which specifically the factors contributing to cGMP elevation (eNOS and sGC) were reduced and the cGMP-hydrolyzing PDE5 was elevated (qPCR and Western blot). In line with the differential expression of key regulators of the nitric oxide-cGMP pathway, a reduction of cGMP by prolonged thrombin stimulation was found. The effects of prolonged thrombin exposure were confirmed in endothelial cells of pulmonary origin (HPAECs and HPMECs). Similar effects could be induced by activation of protease-activated receptor-1 (PAR-1).

Conclusion

These findings suggest a link between thrombin generation and cGMP depletion in lung endothelial cells through negative regulation of the nitric oxide-cGMP pathway, possibly mediated via PAR-1, which could be of relevance in pulmonary arterial hypertension.

Pulmonary hypertension in patients with chronic and end-stage kidney disease

Pulmonary hypertension is defined as a mean pulmonary artery pressure ≥25 mm Hg and is a recently recognized complication of chronic kidney disease and end-stage renal disease. There is significant epidemiological overlap with kidney disease and the underlying causes of World Health Organization group 1-4 pulmonary hypertension (pulmonary arteriopathy, left heart disease, chronic pulmonary disease, and chronic thromboembolic disease, respectively). In addition, an entity of 'unexplained pulmonary hypertension,' group 5, in patients with chronic kidney disease and end-stage renal disease has emerged, with prevalence estimates of 30-50%. The pathogenesis of pulmonary hypertension in this population is due to alterations in endothelial function, increased cardiac output, and myocardial dysfunction leading to elevated left heart filling pressure, with recent data suggesting that left heart dysfunction may account for the vast majority of pulmonary hypertension in patients with kidney disease. Pulmonary hypertension is an independent predictor of increased mortality in patients on dialysis and those undergoing kidney transplantation. This review summarizes what is known about the epidemiology, pathogenesis, transplantation outcomes, mortality, and treatment of pulmonary hypertension in patients with chronic kidney disease and end-stage renal disease.

Heart failure in sub-Saharan Africa

The heart failure syndrome has been recognized as a significant contributor to cardiovascular disease burden in sub-Saharan African for many decades. Seminal knowledge regarding heart failure in the region came from case reports and case series of the early 20th century which identified infectious, nutritional and idiopathic causes as the most common. With increasing urbanization, changes in lifestyle habits, and ageing of the population, the spectrum of causes of HF has also expanded resulting in a significant burden of both communicable and non-communicable etiologies. Heart failure in sub-Saharan Africa is notable for the range of etiologies that concurrently exist as well as the healthcare environment marked by limited resources, weak national healthcare systems and a paucity of national level data on disease trends. With the recent publication of the first and largest multinational prospective registry of acute heart failure in sub-Saharan Africa, it is timely to review the state of knowledge to date and describe the myriad forms of heart failure in the region. This review discusses several forms of heart failure that are common in sub-Saharan Africa (e.g., rheumatic heart disease, hypertensive heart disease, pericardial disease, various dilated cardiomyopathies, HIV cardiomyopathy, hypertrophic cardiomyopathy, endomyocardial fibrosis, ischemic heart disease, cor pulmonale) and presents each form with regard to epidemiology, natural history, clinical characteristics, diagnostic considerations and therapies. Areas and approaches to fill the remaining gaps in knowledge are also offered herein highlighting the need for research that is driven by regional disease burden and needs.

WHO Group 1 pulmonary arterial hypertension: current and investigative therapies

Major advances have been made in the treatment of World Health Organization Group 1 pulmonary arterial hypertension (PAH). Since the mid-1990s, nine medications have become available in the United States to target three key pathophysiologic derangements in PAH - the prostacyclin, endothelin, and nitric oxide pathways. As a group, these agents have led to improvements in functional capacity, symptoms, hemodynamics, and survival. Most patients with mild to moderate PAH are started on orally active agents such as endothelin receptor antagonists or phosphodiesterase inhibitors. Patients with more severe disease, particularly those with evidence of right heart failure, should be treated with continuous prostacyclin infusion or a combination of a prostacyclin and oral therapy. Each medication has unique properties and clinical considerations, and the selection of an appropriate therapy must be tailored to the individual patient. None of the currently available WHO Group 1 PAH therapies are curative, however, and it is the hope that new therapies in development may halt or reverse disease progression. This review will discuss the major therapeutic classes of presently available medications and their role in managing the patient with PAH. We will also review data supporting the use of combination therapy, adjuvant background therapy, and new agents currently under investigation.

Inhalation therapy to treat pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a progressive disease of the pulmonary vascular system, which may lead to right-heart failure or early death in the absence of effective treatment. The current therapy for PAH mainly includes phosphodiesterase inhibitors, prostanoids and endothelin receptor antagonists. These, however, have adverse effects when administered via conventional routes. There is a clear and critical need for the development of a novel delivery system that can efficiently deliver the drug to lung vasculature and minimize adverse effects. This article summarizes the inhalation devices and recent patents in the area of inhalable therapy for the treatment of PAH. Various patents are discussed that describe the application of inhalable therapy to target lung vasculature and to reduce dose-related side effects in PAH treatment. Entry of some inhalable delivery approaches into clinical trials is the result of progress in inhalable therapies for the treatment of PAH.

Predictors of mortality in connective tissue disease-associated pulmonary arterial hypertension: a cohort study

Introduction

Pulmonary arterial hypertension (PAH) is a major cause of mortality in connective tissue disease (CTD). We sought to quantify survival and determine factors predictive of mortality in a cohort of patients with CTD-associated PAH (CTD-PAH) in the current era of advanced PAH therapy.

Methods

Patients with right heart catheter proven CTD-PAH were recruited from six specialised PAH treatment centres across Australia and followed prospectively. Using survival methods including Cox proportional hazards regression, we modelled for all-cause mortality. Independent variables included demographic, clinical and hemodynamic data.

Results

Among 117 patients (104 (94.9%) with systemic sclerosis), during 2.6 ± 1.8 (mean ± SD) years of follow-up from PAH diagnosis, there were 32 (27.4%) deaths. One-, two- and three-year survivals were 94%, 89% and 73%, respectively. In multiple regression analysis, higher mean right atrial pressure (mRAP) at diagnosis (hazard ratio (HR) = 1.13, 95% CI: 1.04 to 1.24, P = 0.007), lower baseline six-minute walk distance (HR = 0.64, 95% CI: 0.43 to 0.97, P = 0.04), higher baseline World Health Organization functional class (HR = 3.42, 95% CI: 1.25 to 9.36, P = 0.04) and presence of a pericardial effusion (HR = 3.39, 95% CI: 1.07 to 10.68, P = 0.04) were predictive of mortality. Warfarin (HR = 0.20, 95% CI: 0.05 to 0.78, P = 0.02) and combination PAH therapy (HR = 0.20, 95% CI: 0.05 to 0.83, P = 0.03) were protective.

Conclusions

In this cohort of CTD-PAH patients, three-year survival was 73%. Independent therapeutic predictors of survival included warfarin and combination PAH therapy. Our findings suggest that anticoagulation and combination PAH therapy may improve survival in CTD-PAH. This observation merits further evaluation in randomised controlled trials.

Contemporary treatment of pulmonary arterial hypertension: the North-West Registry data analysis

Aim. Using the prospective Registry data, to assess the effects of conventional and specific therapy on the clinical course and survival of the patients with pulmonary arterial hypertension (PAH). Material and methods. The study included 124 patients (mean age 38,2±13,7 years; 34 men and 78 women): 31 with idiopathic PAH (IPAH), 52 with Eisenmenger syndrome, 17 with inoperable chronic thromboembolic pulmonary hypertension, 9 with PAH and corrected congenital heart disease, 6 with PAH and systemic scleroderma, and 6 with PAH and HIV infection. Results. The cumulative one-year and three-year survival rates were 94% and 75%, respectively. Irrespective of the absence of right heart catheterisation and vasoreactive testing, 42,7% of the patients were treated with calcium antagonists. PAH-specific therapy was administered to 40,3% of the participants (64,5% and 21% of those with IPAH and Eisenmenger syndrome, respectively). PAH-specific therapy was associated with an increase in survival time. Conclusion. In PAH patients, the prognosis is linked to early administration of specific monotherapy and possible combination therapy. Developing a national registry of pulmonary hypertension will facilitate the assessment of the real-world demand for specific therapy and the related costs.

The pharmacological treatment of pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a life-threatening and progressive disease of various origins characterized by pulmonary vascular remodeling that leads to increased pulmonary vascular resistance and pulmonary arterial pressure, most often resulting in right-sided heart failure. The most common symptom at presentation is breathlessness, with impaired exercise capacity as a hallmark of the disease. Advances in understanding the pathobiology over the last 2 decades have led to therapies (endothelin receptor antagonists, phosphodiesterase type 5 inhibitors, and prostacyclins or analogs) initially directed at reversing the pulmonary vasoconstriction and more recently directed toward reversing endothelial cell dysfunction and smooth muscle cell proliferation. Despite these advances, disease progression is common even with use of combination regimens targeting multiple mechanistic pathways. Overall 5-year survival for PAH has increased significantly from approximately 30% in the 1980s to approximately 60% at present, yet remains abysmal. This review summarizes the mechanisms of action, clinical data, and regulatory histories of approved PAH therapies and describes the latest agents in late-stage clinical development.

An update on the evaluation and management of pulmonary hypertension in scleroderma

Pulmonary arterial hypertension associated with scleroderma (SScPAH) is a debilitating, highly lethal condition that responds to an array of therapies. Quality of life and prognosis are substantially improved by treatment, and early diagnosis and treatment are associated with improved outcomes. There are serious limitations to current screening programs. Many more questions need to be addressed. Why is PAH so common in SSc? Why is the tolerance of pulmonary hypertension so poor in scleroderma? What are the best measures of response to therapy in SSc patients with PAH? Should we use different parameters in prognostic scores in SScPAH? Why is postcapillary pulmonary hypertension so common in SSc? How do we reliably differentiate lung disease-associated pulmonary hypertension from PAH? The aim of this review is to summarize the main areas of progress over the past decade and to look to the challenges for the next decade.

Special indications for vitamin K antagonists: a review

In this review, we present some different and special conditions that are generally being treated with anticoagulants such as cerebral vein thrombosis (CVT), mesenteric vein thrombosis (MVT), Budd-Chiari syndrome (BCS), and Pulmonary Hypertension (PH) despite the lack of controlled clinical trials. While either low molecular weight heparins (LMWHs) or unfractioned heparin (UFH) are used in the acute phase of the first three conditions, the potential chronic use of warfarin in PH is controversial. What is not completely known in the management of CVT, MTV, and BCS is whether (a) LMWHs are similar to UFH in terms of efficacy and safety, and (b) a fibrinolytic drug could be employed in the acute phase. The timing at which warfarin should be started, and the duration of its employment are two additional crucial points that deserve to be examined. In the course of PH, the role of warfarin is controversial, but it could be employed after a careful balance of the hemorrhagic and thromboembolic risk. In conclusion, we tried to simplify the approach to this sometimes problematic task considering the available literature with the aim of providing some practical skills to be used by physicians in their daily clinical practice. Since it is improbable that in the future controlled clinical trials will be designed to find the optimal anti-thrombotic management of these conditions, we believe that a physician should be aware of the lack of solid data in the field but at the same time should always exert clinical judgment when considering an aggressive anticoagulant approach. The duration of oral anticoagulant treatment is left to the clinical judgment of the balance between the hemorrhagic and thrombotic risks in any single patient.

Warfarin in systemic sclerosis-associated and idiopathic pulmonary arterial hypertension. A Bayesian approach to evaluating treatment for uncommon disease

OBJECTIVE

Warfarin is recommended in systemic sclerosis-associated pulmonary arterial hypertension (SSc-PAH) and idiopathic PAH (IPAH) to improve survival. There is no evidence to support this in SSc-PAH and the evidence in IPAH is conflicting. We evaluated the ability of warfarin to improve survival using 2 large SSc-PAH and IPAH cohorts.

METHODS

The effect of warfarin on all-cause mortality was evaluated. Bayesian propensity scores (PS) were used to adjust for baseline differences between patients exposed and not exposed to warfarin, and to assemble a matched cohort. Bayesian Cox proportional hazards models were constructed using informative priors based on international PAH expert elicitation.

RESULTS

Review of 1138 charts identified 275 patients with SSc-PAH (n = 78; 28% treated with warfarin) and 155 patients with IPAH (n = 91; 59% treated with warfarin). Baseline differences in PAH severity and medications were resolved using PS matching. In the matched cohort of 98 patients with SSc-PAH (49 treated with warfarin), the posterior median hazard ratio (HR) was 1.06 [95% credible interval (CrI) 0.70, 1.63]. In the matched cohort of 66 patients with IPAH (33 treated with warfarin), the posterior median HR was 1.07 (95% CrI 0.57, 1.98). The probability that warfarin improves median survival by 6 months or more is 23.5% in SSc-PAH and 27.7% in IPAH. Conversely, there is a > 70% probability that warfarin provides no significant benefit or is harmful.

CONCLUSION

There is a low probability that warfarin improves survival in SSc-PAH and IPAH. Given the availability of other PAH therapies with demonstrable benefits, there is little reason to use warfarin to improve survival for these patients.

Pulmonary thromboendarterectomy after treatment with treprostenil in a chronic thromboembolic pulmonary hypertension patient: a case report

In recent years, there has been a major advance in the treatment of pulmonary hypertension. New medications are continually added to the therapeutic arsenal. The prostanoids are among the first agents used to treat pulmonary hypertension and are currently considered the most effective. This case study describes a 63-year-old man who was diagnosed with chronic thromboembolic pulmonary hypertension and successfully treated with subcutaneously administered treprostenil for 6 months before a successful pulmonary thromboendarterectomy. Treatment of chronic thromboembolic pulmonary hypertension often requires a multidisciplinary approach before surgery. Further evaluation of prostanoids is needed to define their role and time of initiation of medical therapy in these patients.

Pulmonary arterial hypertension: an update

Pulmonary arterial hypertension (PAH), defined as group 1 of the World Heart Organisation (WHO) classification of pulmonary hypertension, is an uncommon disorder of the pulmonary vascular system. It is characterised by an increased pulmonary artery pressure, increased pulmonary vascular resistance and specific histological changes. It is a progressive disease finally resulting in right heart failure and premature death. Typical symptoms are dyspnoea at exercise, chest pain and syncope; furthermore clinical signs of right heart failure develop with disease progression. Echocardiography is the key investigation when pulmonary hypertension is suspected, but a reliable diagnosis of PAH and associated conditions requires an intense work-up including invasive measurement by right heart catheterisation. Treatment includes general measures and drugs targeting the pulmonary artery tone and vascular remodelling. This advanced medical therapy has significantly improved morbidity and mortality in patients with PAH in the last decade. Combinations of these drugs are indicated when treatment goals of disease stabilisation are not met. In patients refractory to medical therapy lung transplantation should be considered an option.