Primary pulmonary hypertension: improved long-term effects and survival with continuous intravenous epoprostenol infusion

Echocardiographic diagnosis and clinical implications of wide-open tricuspid regurgitation for evaluating right ventricular dysfunction in the emergency department

The tricuspid regurgitation pressure gradient (TRPG) reflects the difference in pressure between the right ventricle and right atrium (ΔPRV-RA). Its estimation by echocardiography correlates well with that obtained using right-heart catheterization. An elevated TRPG is an important marker for identifying right ventricular dysfunction in both the acute and chronic settings. However, in the "wide-open" variant of TR, the TRPG counterintuitively falls. Failure to recognize this potential pitfall and underlying pathophysiology can cause underestimation of the severity of right ventricular dysfunction. This could lead to erroneous fluid tolerance assessments, and potentially harmful resuscitative and airway management strategies. In this manuscript, we illustrate the pathophysiology and potential pitfall of wide-open TR through a series of cases in which emergency physicians made the diagnosis using cardiac point-of-care ultrasound. To our knowledge, this clinical series is the first to demonstrate recognition of the paradoxically-low TRPG of wide-open TR, which guided appropriate management of critically ill patients in the emergency department.

The Role of Echocardiography in the Diagnosis and Prognosis of Pulmonary Hypertension

The right heart catheterisation constitutes the gold standard for pulmonary hypertension (PH) diagnosis. However, echocardiography remains a reliable, non-invasive, inexpensive, convenient, and easily reproducible modality not only for the preliminary screening of PH but also for PH prognosis. The aim of this review is to describe a cluster of echocardiographic parameters for the detection and prognosis of PH and analyse the challenges of echocardiography implementation in patients with suspected or established PH. The most important echocardiographic index is the calculation of pulmonary arterial systolic pressure (PASP) through the tricuspid regurgitation (TR). It has shown high correlation with invasive measurement of pulmonary pressure, but several drawbacks have questioned its accuracy. Besides this, the right ventricular outflow track acceleration time (RVOT-AT) has been proposed for PH diagnosis. A plethora of echocardiographic indices: right atrial area, pericardial effusion, the tricuspid annular plane systolic excursion (TAPSE), the TAPSE/PASP ratio, tricuspid annular systolic velocity (s'), can reflect the severity and prognosis of PH. Recent advances in echocardiography with 3-dimensional right ventricular (RV) ejection fraction, RV free wall strain and right atrial strain may further assist the prognosis of PH.

Epoprostenol for the treatment of pulmonary arterial hypertension

Introduction: Pulmonary arterial hypertension (PAH) is a rare, progressive, and severe disease. Since the first demonstration of survival benefit of intravenous epoprostenol in monotherapy in 1996, prostanoids remain the cornerstone for PAH patients at high risk. This review is essential to understand the current situation of this drug among all the therapeutic possibilities concerning this entity.Areas covered: The aim of this article is to review the pharmacological properties of epoprostenol and to update its clinical evidence in different specific clinical scenarios. A deep literature search was carried out on the MEDLINE database for published literature before March 2021.Expert opinion: Epoprostenol is still the best treatment option for high-risk PAH patients. Nevertheless, there are many unsolved questions: drug dosing, its use in combination therapy with other pulmonary vasodilators, and the utility in PAH associated with connective tissue disease, congenital heart disease, or pulmonary veno-occlusive disease are only a few examples. Its safety and efficacy are supported by clinical trials, observational work, and experience, both as monotherapy and in combination therapy. Epoprostenol should be considered a destination treatment in high-risk patients and not only as a bridge to pulmonary transplantation. However, it remains underused in clinical practice.

Intravenous prostacyclin-analogue therapy in pulmonary arterial hypertension - A review of the past, present and future

Therapy with intravenous prostacyclin analogues in patients with pulmonary arterial hypertension (PAH) has been established for decades and is an integral component of the current guidelines for the treatment of pulmonary hypertension. Initially, these drugs were infused by external pump systems via tunnelled right atrial catheters with the need for cooling and frequent exchange of drug reservoirs. Associated complications included, among others, catheter-related infections. More recently, fully implantable pump systems have been developed with drug reservoirs that are filled transcutaneously, allowing intervals between refills of several weeks. This technique results in a low rate of infections. Epoprostenol, iloprost and treprostinil have all been used intravenously in PAH, but titration, dosing and dose escalation in long-term therapy are not standardized. Intravenous prostacyclin analogues are still under-used, despite available data suggesting that early and broad application of these therapies as part of risk-oriented, guideline-directed combination therapy for patients with PAH may lead to a survival benefit. This review provides a detailed overview of the drugs, infusion systems and dosing strategies used for intravenous therapy in patients with PAH.

Prostanoids in pediatric pulmonary hypertension: clinical response, time-to-effect, and dose-response

For pediatric pulmonary arterial hypertension (PAH) patients treated with parenteral prostanoids, response predictors, and the dose-effect relationship are ill defined. We determined the following: (1) which pulmonary vascular hemodynamic variable, after initiating prostanoids, best correlates with a significant clinical response; (2) the time interval after treatment when if no pulmonary hemodynamic improvement has occurred, none is ever likely to; and (3) the relationship between the prostanoid dose and its hemodynamic effects. This is a retrospective cohort study of 31 pediatric patients with Group 1 PAH treated with parenteral prostanoids. We found the following: (1) A fall in mean pulmonary arterial pressure (mPAP) of ≥25% predicted freedom from adverse clinical events with 80.7% accuracy and was also associated with improved functional class. (2) Thirty-three percent of patients who avoided an adverse clinical event demonstrated a ≥25% reduction in mPAP after 1 year of treatment, and 65% by 2 years. (3) Lower mPAP was seldom seen with doses of epoprostenol >60 ng/kg/min (100 ng/kg/min for treprostinil). Cardiac index was positively correlated with the dose of epoprostenol but not treprostinil; cardiac index >4 l/min/m² was seen at modest as well as high doses. We conclude that a ≥25% fall in mPAP on prostanoids indicates a positive clinical response which, if validated in other studies, may be useful for patient management or clinical trials. Some patients take more than 2 years for this change. Exceptionally high doses were generally not more effective than lower, although we could not determine whether lower doses would have been as effective.

Pulmonary Arterial Hypertension: A Palliative Medicine Review of the Disease, Its Therapies, and Drug Interactions

Pulmonary arterial hypertension (PAH) is often a progressive and ultimately fatal disease. It is characterized by an elevated mean pulmonary arterial pressure because of disease of the small pulmonary arterioles. PAH leads to a constellation of symptoms, including dyspnea, fatigue, syncope, chest discomfort, and peripheral edema. Disease-targeted therapies for PAH produce symptomatic and functional improvement, but long-term survival remains uncommon without lung transplantation. Palliative care is appropriate to support patients with advanced PAH who typically have a high symptom burden. However, palliative care has historically focused on supporting patients with malignant disease, rather than progressive chronic disease such as PAH. Our aim is to provide palliative care clinicians with a background in the classification, pathophysiology, and modern treatment of PAH. This review describes disease-targeted therapies and their effects on symptoms, physical functioning, and health-related quality of life. We also review the unique physiology of PAH and its implication for palliative interventions. Pharmacological interactions with, and precautions related to commonly used palliative care medications, are discussed.

Effectiveness of epoprostenol in the management of pulmonary arterial hypertension: findings of an Australian retrospective chart review

BACKGROUND

Pulmonary arterial hypertension (PAH) is a progressively fatal disease. Parenteral prostanoids, including intravenous (IV) epoprostenol, are the most effective therapies for PAH. As epoprostenol requires continuous infusion, therapy is challenging and use is managed by specialist units.

AIMS

To describe the clinical outcomes for the use of IV epoprostenol in an Australian pulmonary vascular disease unit and identify opportunities to improve its use.

METHOD

We conducted a retrospective chart review of all adult patients who received IV epoprostenol for PAH at Prince Charles Hospital. Data were collected at baseline, initiation of epoprostenol and quarterly to the end of the audit period or the discontinuation of epoprostenol. Descriptive statistics were performed and comparisons made to epoprostenol initiation. Kaplan-Meier curves were used to estimate survival outcomes.

RESULTS

Thirty-nine patients received epoprostenol therapy. Most (87.2%) were female, had connective tissue disease (46.2%) or idiopathic PAH (35.9%) and had a World Health Organization functional Class of III or IV at initiation. The mean duration of epoprostenol therapy was 2.9 years. Intravenous epoprostenol was associated with favourable outcomes; 1, 3 and 5-year survival rates since initiation of 90.0, 75.8 and 68.2%; robust improvements in functional class; and improvements in 6-min walking distance of 160.4 m at 3 years; 94.9% patients experienced at least one drug-related adverse event and line complications were common.

CONCLUSION

Epoprostenol therapy was associated with impressive survival rates and durable improvements in functional outcomes. Epoprostenol therapy is challenging; however, it is manageable by the majority of patients with most experiencing positive, sustainable outcomes.

Improving Survival in Patients with Pulmonary Arterial Hypertension: Focus on Intravenous Epoprostenol

Pulmonary arterial hypertension represents a devastating disease, causing progressive increase of pulmonary vascular resistance leading to right ventricular dysfunction and death. Therapeutic management has rapidly advanced in recent years due to improved understanding of pathophysiology and new drugs have been developed; however, survival remains poor. Oral agents as phosphodiesterase type V inhibitors, the soluble guanylyl cyclase stimulator riociguat, the prostacyclin receptor agonist selexipag and the endothelin receptor antagonists have each achieved evidence-based validation and are recommended for pulmonary arterial hypertension. Initial oral monotherapy or combination therapy is recommended for patients with low or intermediate risk according to each patient's risk stratification. Intravenous epoprostenol is a synthetic prostacyclin and the first drug approved for the disease. Although it represents the only treatment shown to reduce mortality, it is underused. Survival rates for patients treated with oral combination drug therapies are lower than those for patients treated with initial combination therapies including intravenous epoprostenol. This raises the interesting question of whether intermediate risk pulmonary arterial hypertension patients should be routinely introduced to therapies including intravenous epoprostenol rather than combination oral therapies.

The burden of at-home preparation of lyophilized parenteral medications: an analysis of contributing factors and implications for chronic disease patients and caregivers

BACKGROUND

In the acute care setting, parenteral medication errors are well-studied. However, there is comparatively little research on how these issues translate to patient- or caregiver-prepared medications in the home, particularly with reconstituted medications.

METHODS

This was an ethnographic study designed to identify issues associated with four reconstitution use scenarios. Preparation burden was determined by measuring the time and manipulations required to prepare reconstituted medications across three preparation phases (assembly, reconstitution, and transfer). Deviations from product instructions for use, sterility breaches, self-reported preparation complications, and supply storage conditions were also analyzed.

RESULTS

A total of 14 participants completed the study. Overall, preparation burden was markedly higher when purpose-built reconstitution devices were not available. The majority of participants reported experiencing at least one complication associated with their medication preparation process; the reconstitution phase was the most significant source of both instructions for use deviations and breaches in sterility. Participants reported that the volume and variety of medication preparation supplies were a significant source of burden.

CONCLUSIONS

At-home preparation of reconstituted medications poses several challenges for patients and caregivers. As parenteral medications continue to shift towards self-administration, manufacturers should carefully consider the usability of such products and employ purpose-built reconstitution devices whenever possible.

Inhalation of repurposed drugs to treat pulmonary hypertension

Pulmonary arterial hypertension (PAH) is a rare, but severe and life-threatening disease characterized by vasoconstriction and remodeling of the pulmonary arterioles, leading to progressive increase in pulmonary vascular resistance and ultimately to right-heart failure. In the last two decades, significant progress in treatment of PAH has been made, with currently 12 drugs approved for targeted therapy. Among these, the stable prostacyclin analogues iloprost and treprostinil have been repurposed for inhalation. The paper highlights the development of the two drugs emphasizing the rationale and advantages of the inhalative approach. Despite substantial advances in the specific, mainly vasodilatory PAH therapy, disease progression is mostly inevitable and mortality remains unacceptably high. Thus, introduction of new drugs targeting the cancer-like remodeling of the diseased pulmonary arteries is urgently needed. Inhalation offers pulmonary selectivity and will hopefully pioneer the repurposing of novel highly potent drugs for effective aerosol therapy of PAH.

Current and Future Treatments for Persistent Pulmonary Hypertension in the Newborn

Persistent pulmonary hypertension in newborn (PPHN) is a serious and possibly fatal syndrome characterized by sustained foetal elevation of pulmonary vascular resistance at birth. PPHN may manifest secondary to other conditions as meconium aspiration syndrome, infection and congenital diaphragmatic hernia. This MiniReview provides the reader with an overview of current and future treatment options for patients with PPHN without congenital diaphragmatic hernia. The study is based on systematic searches in the databases PubMed and Cochrane Library and registered studies on Clinicaltrials.gov investigating PPHN. Inhaled nitric oxide (iNO) is well documented for treatment of PPHN, but 30% fail to respond to iNO. Other current treatment options could be sildenafil, milrinone, prostaglandin analogues and bosentan. There are several ongoing trials with sildenafil, but evidence is lacking for the other treatments and/or for the combination with iNO. Currently, there is no evidence for effect in PPHN of other treatments, for example tadalafil, macitentan, ambrisentan, riociguat and selexipag used for pulmonary arterial hypertension in adults. Experimental studies in animal models for PPHN suggest effect of a series of approaches including recombinant human superoxide dismutase, L-citrulline, Rho-kinase inhibitors and peroxisome proliferator-activated receptor-γ agonists. We conclude that iNO is the most investigated and the only approved pulmonary vasodilator for infants with PPHN. In the iNO non-responders, sildenafil currently seems to be the best alternative either alone or in combination with iNO. Systematic and larger clinical studies are required for testing the other potential treatments of PPHN.

Noninvasive pulmonary arterial pressure estimation using a logistic-based systolic model

RATIONALE

A hemodynamic relationship of pulmonary artery pressure (PAP) to pulmonary acceleration time (PAcT) has not yet been explicitly presented.

OBJECTIVE

We employed a logistic-based systolic model with a subtle modification for pulmonary circulation and provided a logical ground for the relationship between systolic PAP and PAcT using transthoracic echocardiography. Additionally, the logistic-based PAP estimation equation was deduced from the model to relate systolic PAP and PAcT.

METHODS AND RESULTS

This equation was statistically tested in comparison to existing PAP estimation equations. Results showed that the logistic-based PAP estimation equation was at least as accurate as previous equations with respect to previously published mean PAP versus PAcT values. After the subtle pulmonary modification of the model, the pulmonary blood flow velocity and pressure not only well reflected the underlying pulmonary circulation physiology, but could also be presented in harmony with systemic circulation physiology.

CONCLUSIONS

A future clinical study with actual systolic PAP versus PAcT measurements is needed to test the application of the logistic-based PAP estimation equation.

Selexipag Active Metabolite ACT-333679 Displays Strong Anticontractile and Antiremodeling Effects but Low β-Arrestin Recruitment and Desensitization Potential

Prostacyclin (PGI₂) receptor (IP receptor) agonists, which are indicated for the treatment of pulmonary arterial hypertension (PAH), increase cytosolic cAMP levels and thereby inhibit pulmonary vasoconstriction, pulmonary arterial smooth muscle cell (PASMC) proliferation, and extracellular matrix synthesis. Selexipag (Uptravi, 2-{4-[(5,6-diphenylpyrazin-2-yl)(isopropyl)amino]butoxy}-N-(methylsulfonyl)acetamide) is the first nonprostanoid IP receptor agonist, it is available orally and was recently approved for the treatment of PAH. In this study we show that the active metabolite of selexipag and the main contributor to clinical efficacy ACT-333679 (previously known as MRE-269) behaved as a full agonist in multiple PAH-relevant receptor-distal-or downstream-cellular assays with a maximal efficacy (E_max) comparable to that of the prototypic PGI₂ analog iloprost. In PASMC, ACT-333679 potently induced cellular relaxation (EC₅₀ 4.3 nM) and inhibited cell proliferation (IC₅₀ 4.0 nM) as well as extracellular matrix synthesis (IC₅₀ 8.3 nM). In contrast, ACT-333679 displayed partial agonism in receptor-proximal-or upstream-cAMP accumulation assays (E_max 56%) when compared with iloprost and the PGI₂ analogs beraprost and treprostinil (E_max ∼100%). Partial agonism of ACT-333679 also resulted in limited β-arrestin recruitment (E_max 40%) and lack of sustained IP receptor internalization, whereas all tested PGI₂ analogs behaved as full agonists in these desensitization-related assays. In line with these in vitro findings, selexipag, but not treprostinil, displayed sustained efficacy in rat models of pulmonary and systemic hypertension. Thus, the partial agonism of ACT-333679 allows for full efficacy in amplified receptor-distal PAH-relevant readouts while causing limited activity in desensitization-related receptor-proximal readouts.

Transition From Subcutaneous or Inhaled Treprostinil to Oral Treprostinil at Home in Patients With Pulmonary Arterial Hypertension: A Retrospective Case Series

Pulmonary arterial hypertension (PAH) is a progressive condition that can lead to right ventricular failure and death. Treprostinil is a prostacyclin analogue that has proven clinical efficacy in patients with PAH. Difficulties in the administration of inhaled and parenteral prostacyclins led to the development of extended-release treprostinil diolamine for oral use. Limited data exist on the transition to oral treprostinil. The purpose of this case series is to describe the transition from subcutaneous or inhaled treprostinil to oral treprostinil in the outpatient setting. With the current availability of oral prostacyclins and prostacyclins analogues, most transitions to oral therapy are done in the hospital setting resulting in increased cost and risk of hospital-acquired infections. Four patients on background phosphodiesterase type 5 therapy with baseline World Health Organization functional class (WHO FC) II PAH were transitioned at home. Three of the 4 patients were safely transitioned as outpatients and maintained WHO FC II status at 10 and 12 months. The fourth patient had worsening right heart failure and was admitted within 2 months of the transition and started back on parenteral prostacyclin therapy. The 6-minute walk distance (6MWD) increased in patients transitioning from inhaled therapy and decreased in the patient transitioning from subcutaneous therapy. The most common adverse event was nausea.

An advanced protocol-driven transition from parenteral prostanoids to inhaled trepostinil in pulmonary arterial hypertension

Patients with pulmonary arterial hypertension (PAH) often require parenteral prostanoids to improve symptoms and signs of PAH. Complications of parenteral prostanoids-such as catheter-related infections and intolerable adverse effects-may develop, prompting transition to inhaled prostanoids. We report a prospective, protocol-driven transition from parenteral prostanoids to inhaled prostanoids with monitoring of exercise gas exchange and acute hemodynamics. Three PAH centers recruited patients transitioning from parenteral prostanoids to inhaled trepostinil. Rigid inclusion criteria were used, including parenteral prostanoid dose < 30 ng/kg/min, New York Heart Association functional class (FC) < 3, and pulmonary vascular resistance (PVR) < 6 Wood units. Of the 9 patients meeting initial inclusion criteria, 3 were excluded. In the remaining patients, the parenteral prostanoid was reduced and the inhaled prostanoid was increased over 24-36 hours with continuous hemodynamic monitoring. Exercise capacity and FC were measured at baseline and weeks 1, 4, and 12. All patients were successfully weaned from parenteral prostanoids. An acute PVR decrease was seen with most inhaled prostanoid doses, but PVR varied throughout the transition. Patients tolerated inhaled prostanoids for 9-12 breaths 4 times a day with no treatment-limiting adverse events. At week 12, FC was unchanged, and all patients continued to receive inhaled prostanoids without serious adverse events or additional PAH therapy. In 5 of 6 patients, 6-minute walk distance and peak [Formula: see text] were within 10% of baseline. Using a strict transition protocol and rigid patient selection criteria, the parenteral prostanoid to inhaled prostanoid transition appeared safe and well tolerated and did not result in clinical deterioration over 12 weeks. Hemodynamic variability noted acutely during transition in our study did not adversely affect successful transition. (Trial registration: ClinicalTrials.gov identifier: NCT01268553).

Epoprostenol and pulmonary arterial hypertension: 20 years of clinical experience

Epoprostenol was the first therapy to be approved for the treatment of pulmonary arterial hypertension (PAH). In the 20 years since the introduction of this prostacyclin analogue, the outlook for patients with PAH has improved, with survival rates now double those from the era before the development of disease-specific treatments. Today, there are a large amount of data on the clinical role of prostacyclin treatments and a body of evidence attesting the efficacy of epoprostenol in improving exercise capacity, key haemodynamic parameters and PAH symptoms, as well as in reducing mortality. The place of epoprostenol in the therapeutic management of PAH continues to evolve, with the development of new formulations and use in combination with other drug classes. In this review, we provide a historical perspective on the first 20 years of epoprostenol, a therapy that led to evidence-based study of PAH-specific treatments and the subsequent expansion of treatment options for PAH.

The evolution of the place of epoprostenol in the management of pulmonary arterial hypertensionhttp://ow.ly/OkY3303N2CX

Management of the patient with pulmonary arterial hypertension receiving intravenous prostacyclin: an expert nurse practical guide

Pulmonary arterial hypertension (PAH) is a severely disabling disorder characterized by elevated pulmonary artery pressure ultimately leading to right heart failure and death. Treatment options have significantly increased over the past decade. Intravenous prostacyclins remain the treatment of choice for advanced PAH, leading to long-term clinical benefits and improved survival. Their administration requires a high level of nursing competency and presents considerable challenges for patients and caregivers. This article reviews the characteristics of currently available intravenous prostacyclins and provides a practical guide for nurses who may have had limited exposure to intravenous prostacyclins and their unique dosing, side effects, and titration characteristics.

Pulmonary hypertension in patients with heart failure and preserved ejection fraction: differential diagnosis and management

The most common cause of pulmonary hypertension (PH) due to left heart disease (LHD) was previously rheumatic mitral valve disease. However, with the disappearance of rheumatic fever and an aging population, nonvalvular LHD is now the most common cause of group 2 PH in the developed world. In this review, we examine the challenge of investigating patients who have PH and heart failure with preserved ejection fraction (HF-pEF), where differentiating between pulmonary arterial hypertension (PAH) and PH-LHD can be difficult, and also discuss the entity of combined precapillary and postcapillary PH. Given the proven efficacy of targeted therapy for the treatment of PAH, there is increasing interest in whether these treatments may benefit selected patients with PH associated with HF-pEF, and we review current trial data.

Present and future treatment strategies for pulmonary arterial hypertension : focus on phosphodiesterase-5 inhibitors

Idiopathic pulmonary arterial hypertension (IPAH) is a rare progressive disorder historically associated with mortality in <3 years post-diagnosis. The etiology of PAH is complex, multifactorial, and likely involves the interplay between genetic and environmental factors. These are reviewed with emphasis on the nitric oxide pathway. Use of treatment modalities including vasodilator therapy have resulted in improved symptoms, hemodynamics, and survival in these patients. Vasodilators, including the calcium channel antagonists, prostanoids, and endothelin receptor antagonists, have been used to counteract potential imbalances in vasoactive mediators in PAH patients; all have produced improved long-term symptomatology and hemodynamics. Only the prostanoid epoprostenol has improved survival in IPAH patients. Although these medications have worked well in many patients with PAH, each of them has limitations. The phosphodiesterase-5 (PDE-5) inhibitors are a relatively new form of treatment for PAH. They are designed to potentiate the effects of cyclic guanosine monophosphate, thereby mimicking endogenous nitric oxide within the vasculature. PDE-5 inhibitors are selective pulmonary vasodilators effective in animal models of pulmonary hypertension. The published clinical studies evaluating their use have been small in size to date but appear to demonstrate benefit. The recently completed 12-week randomized placebo-controlled Sildenafil Use in Pulmonary Hypertension (SUPER-1) trial demonstrated improvement in 6-minute walk distance and hemodynamics in patients receiving sildenafil. These data suggest that the PDE-5 inhibitors are effective in treating PAH and that it is likely that their usage will increase over time. The purpose of this review is to present a current view of the pathogenesis and treatment of PAH, with an emphasis on the use of PDE-5 inhibitors in these patients.

Parenteral Prostanoid Use at a Tertiary Referral Center: A Retrospective Cohort Study

BACKGROUND

Evidence-based guidelines recommend the use of parenteral prostaglandin (PP) therapy in patients with advanced pulmonary arterial hypertension (PAH). Despite this, many patients with PAH die without PP therapy. We sought to examine the frequency of PP use at a large referral center and characterize patients with PAH who died without receiving PP.

METHODS

We conducted a single-center retrospective cohort analysis of consecutive patients with PAH between 2008 and 2012. Clinical data and cause of death were compared between patients with PAH treated with PP (PAH-PP) and those who were not but were not documented as poor PP candidates (PAH-nonPP).

RESULTS

Of the 101 patients who received a diagnosis of PAH and died, 61 received PP therapy. Of the 40 patients not treated with PP, 10 did not have documented evaluations for PP therapy (PAH-nonPP) whereas 30 were not considered candidates or refused PP therapy. Compared with PAH-PP, PAH-nonPP had a longer 6-min walk distance, had a longer duration between time of diagnosis and date of worse functional class visit, were less likely to be diagnosed as functional class IV, and had significantly lower right atrial pressure. None of the PAH-nonPP died of progressive PAH.

CONCLUSIONS

We found that most patients who die with PAH are evaluated for PP therapy at a large referral center and the small minority of PAH-nonPP tended to have less severe disease and die of non-PAH-related causes. Our data suggest that at large pulmonary hypertension (PH) centers, the vast majority of patients who are appropriate candidates receive PP therapy.

The limits of oral therapy in pulmonary arterial hypertension management

Pulmonary arterial hypertension (PAH) is a devastating disease in which remodeling of the small pulmonary arteries leads to a progressive increase in pulmonary vascular resistance and right-sided heart failure. Over the past decade, new treatments for PAH, such as the use of ERAs, PDE-5 inhibitors and prostacyclin analogs, have brought about dramatic improvements in clinical outcomes. Epoprostenol infusion therapy has been shown to improve hemodynamics, functional status, and survival, and it remains the gold standard for treatment of patients with severe PAH. Many agents, approved for PAH are always delivered in pill form. Although oral therapy occupies an important position, it has some drawbacks and limitations in PAH management. For patients in World Health Organization functional class IV and with severe right heart failure, there are few data on the long-term survival of patients treated with oral medications. Further research, exploration, and clinical experience with oral therapy in severe PAH and combination therapy will redefine its position in PAH management.

Use of outcome measures in pulmonary hypertension clinical trials

OBJECTIVES

To evaluate the use of surrogate measures in pulmonary hypertension (PH) clinical trials and how it relates to clinical practice.

BACKGROUND

Studies of pulmonary arterial hypertension (PAH) employ a variety of surrogate measures in addition to clinical events because of a small patient population, participant burden, and costs. The use of these measures in PH drug trials is poorly defined.

METHODS

We searched PubMed/MEDLINE/Embase for randomized or prospective cohort PAH clinical treatment trials from 1985 to 2013. Extracted data included intervention, trial duration, study design, patient characteristics, and primary and secondary outcome measures. To compare with clinical practice, we assessed the use of surrogate measures in a clinical sample of patients on PH medications at Duke University Medical Center between 2003 and 2014.

RESULTS

Between 1985 and 2013, 126 PAH trials were identified and analyzed. Surrogate measures served as primary endpoints in 119 trials (94.0%). Inclusion of invasive hemodynamics decreased over time (78.6%, 75.0%, 52.2%; P for trend = .02), while functional testing (7.1%, 60.0%, 81.5%; P for trend < .0001) and functional status or quality of life (0%, 47.6%, 62.8%; P for trend < .0001) increased in PAH trials over the same time periods. Echocardiography data were reported as a primary or secondary outcome in 32 trials (25.4%) with increased use from 1985-1994 to 1995-2004 (7.1% vs 35.0%, P = .04), but the trend did not continue to 2005-2013 (25.0%). In comparison, among 450 patients on PAH therapies at our institution between 2003 and 2013, clinical assessments regularly incorporated serial echocardiography and 6-minute walk distance tests (92% and 95% of patients, respectively) and repeat measurement of invasive hemodynamics (46% of patients).

CONCLUSIONS

The majority of PAH trials have utilized surrogate measures as primary endpoints. The use of these surrogate endpoints has evolved significantly over time with increasing use of patient-centered endpoints and decreasing or stable use of imaging and invasive measures. In contrast, imaging and invasive measures are commonly used in contemporary clinical practice. Further research is needed to validate and standardize currently used measures.

Correlation between Pulmonary Artery Pressure Measured by Echocardiography and Right Heart Catheterization in Patients with Rheumatic Mitral Valve Stenosis (A Prospective Study)

INTRODUCTION

Right heart catheterization (RHC) remains the gold standard for hemodynamic assessment of the right heart and pulmonary artery. However, this is an invasive tool, and noninvasive alternatives such as transthoracic echocardiography (TTE) are preferable. Nonetheless, the correlation between measurements by TTE and RHC are debated. In this study, we prospectively examined the correlation between systolic and mean pulmonary artery pressures (sPAP and mPAP) measured by RHC and TTE in patients with hemodynamically significant rheumatic mitral stenosis (MS).

MATERIAL AND METHODS

Three hundred patients with hemodynamically significant MS undergoing TTE who were scheduled to undergo RHC within 24 hours were analyzed. PAP measurements were taken for all patients by RHC (sPAP(RHC), mPAP(RHC)). Maximum velocity of tricuspid regurgitation (TR) jet obtained by continuous-wave Doppler with adding right atrial (RA) pressure was used for measuring sPAP by TTE (sPAP(TRVmax)). Mean PAP was measured using either pulmonary artery acceleration time (mPAP(PAAT)) method or by adding RA pressure to velocity-time integral of TR jet (mPAP(TRVTI)).

RESULTS

A good correlation between sPAP(RHC) and sPAP(TRVmax) (r = 0.89, P < 0.001), between mPAP(RHC) and mPAP(PAAT) (r = 0.9, P < 0.001), and between mPAP(RHC) and mPAP(TRVTI) (r = 0.92, P < 0.001) was found. Sensitivity and specificity of sPAP(TRV) max in detecting pulmonary hypertension (PH) were 92.8% and 86.6% and of mPAP(PAAT) were 94.1% and 73.3%, respectively.

CONCLUSION

The noninvasive assessment of sPAP and mPAP by TTE correlates well with invasive measurements and has an acceptable specificity and sensitivity in detecting PH in patients with hemodynamically significant MS.

Hospitalization and survival in patients using epoprostenol for injection in the PROSPECT observational study

BACKGROUND:

Few studies have prospectively reported outcomes in patients with pulmonary arterial hypertension (PAH) treated with epoprostenol in the modern-day era of oral therapy and combination treatments. The Registry to Prospectively Describe Use of Epoprostenol for Injection (Veletri, prolonged room temperature stable-epoprostenol [RTS-Epo]) in Patients with Pulmonary Arterial Hypertension (PROSPECT) was established to prospectively describe the course of PAH in patients prescribed RTS-Epo.

METHODS:

PROSPECT is a multicenter, US-based drug registry of primarily group 1 patients with PAH treated with RTS-Epo who were parenteral-naive or parenteral-transitioned at enrollment. Patients were followed until discontinuation of RTS-Epo, withdrawal, loss to follow-up, death, or end of study (maximum 1 year). One-year freedom from hospitalization (FH) and survival estimates were summarized by prostacyclin history (parenteral-naive or parenteral-transitioned), sex, and chronic renal insufficiency (CRI).

RESULTS:

A total of 336 patients were included. The overall 1-year FH estimate was 51.0% ± 2.8% and was lower in parenteral-naive patients than parenteral-transitioned patients (42.8% ± 4.3% vs 57.1% ± 3.7%, respectively; P = .002). FH estimates were lower in male patients than female patients (38.3% ± 5.9% vs 54.6% ± 3.2%, respectively; P < .015) and in patients with CRI than patients without CRI (17.0% ± 8.4% vs 53.7% ± 2.9%, respectively; P < .001). The overall 1-year survival estimate was 84.0% ± 2.1%. Survival was poorer in parenteral-naive patients, male patients, and patients with CRI.

CONCLUSIONS:

Risk of hospitalization and mortality remain high in patients with PAH. In particular, patients who are parenteral-naive at initiation of RTS-Epo therapy, male patients, and patients with CRI require close monitoring and aggressive clinical management.

Balloon dilation atrial septostomy for advanced pulmonary hypertension in patients on prostanoid therapy

BACKGROUND

Prostanoid therapy improves quality of life and may increase survival in patients with advanced pulmonary hypertension (PH). Balloon dilated atrial septostomy (BDAS) can palliate or bridge to transplantation for patients resistant to medical therapy. The safety and efficacy of BDAS in the prostanoid era has not previously been reported.

METHODS

All patients had progressive symptoms despite prostanoid therapy at the time of their first BDAS. Sixteen patients who underwent a total of 23 septostomies between 2004 and 2014 were included in this retrospective case series.

RESULTS

Patients were aged 47.6 years ± 11.3 with 12/16 women. Etiologies included idiopathic (7), methamphetamine (6), scleroderma (1), and anorexigen (2). One patient died within 24 hr post-procedure. Thirty-day and 1-year survival were 75% and 64%, respectively. Six of the septostomies were revisions, including two which were ultimately stented. Three subjects were successfully bridged to transplant. Pulmonary capillary wedge pressure (PCWP) increased from a mean of 13 to 17 mm Hg, cardiac index increased from 2.1 to 2.4 L/min/m(2) , and arterial saturation decreased from 90.7 ± 4.3 to 82.5 ± 5.6%. All non-survivors at 30 days were male and had higher baseline serum creatinine, mean RAP, right ventricular end diastolic pressure (RVEDP), and left ventricle (LV) filling pressures, and lower right ventricle (RV) ejection fraction. Mortality was associated with unchanged post-septostomy cardiac output despite an increase in left ventricular end diastolic pressure (LVEDP).

CONCLUSIONS

BDAS may be an alternate therapy for select PH patients who have symptomatic progression despite prostanoid therapy. Survival is comparable to prior reports of BDAS in the pre-prostanoid era.

Pharmacologic therapy for pulmonary arterial hypertension in adults: CHEST guideline and expert panel report

OBJECTIVE

Choices of pharmacologic therapies for pulmonary arterial hypertension (PAH) are ideally guided by high-level evidence. The objective of this guideline is to provide clinicians advice regarding pharmacologic therapy for adult patients with PAH as informed by available evidence.

METHODS

This guideline was based on systematic reviews of English language evidence published between 1990 and November 2013, identified using the MEDLINE and Cochrane Library databases. The strength of available evidence was graded using the Grades of Recommendations, Assessment, Development, and Evaluation methodology. Guideline recommendations, or consensus statements when available evidence was insufficient to support recommendations, were developed using a modified Delphi technique to achieve consensus.

RESULTS

Available evidence is limited in its ability to support high-level recommendations. Therefore, we drafted consensus statements to address many clinical questions regarding pharmacotherapy for patients with PAH. A total of 79 recommendations or consensus statements were adopted and graded.

CONCLUSIONS

Clinical decisions regarding pharmacotherapy for PAH should be guided by high-level recommendations when sufficient evidence is available. Absent higher level evidence, consensus statements based upon available information must be used. Further studies are needed to address the gaps in available knowledge regarding optimal pharmacotherapy for PAH.

Prognostic value of echocardiographic changes in patients with pulmonary arterial hypertension receiving parenteral prostacyclin therapy

BACKGROUND

It is unknown whether the echocardiographic changes observed after treatment of patients with pulmonary arterial hypertension have prognostic value.

METHODS

Subjects with pulmonary arterial hypertension, confirmed by right heart catheterization, who underwent Doppler echocardiography before (baseline) and after 1 year of treatment (follow-up) with parenteral prostacyclin analogues were retrospectively identified. Echocardiographic parameters were measured offline by two investigators.

RESULTS

A total of 48 patients were included (mean age, 45 ± 14 years; 83% women). Compared with baseline, follow-up echocardiography showed reductions in right atrial area (mean percentage change, 12 ± 25%; P < .001), right ventricular (RV) basal and middle cavity dimensions (mean percentage change, 8.5 ± 14% [P < .001] and 6.8 ± 17% [P = .005], respectively), and peak tricuspid regurgitant velocity (mean percentage change, 10 ± 14%; P < .001). Tricuspid annular plane systolic excursion (mean percentage change, 36 ± 43%; P < .001) and RV outflow tract time-velocity integral (mean percentage change, 48 ± 66%; P < .001) increased. During a median follow-up period of 52.5 months (interquartile range, 20.5-80 months), 18 patients (37.5%) died, mostly (n = 15 [83%]) from progression of pulmonary arterial hypertension. The changes in RV end-diastolic area (hazard ratio [HR per 10% decrease, 0.73; 95% confidence interval [CI], 0.57-0.93), tricuspid valve regurgitation velocity (HR per 10 cm/sec decrease, 0.58; 95% CI, 0.37-0.89), RV outflow tract velocity-time integral (HR per 10% increase, 0.90; 95% CI, 0.83-0.98), and subjective RV function (HR per 1 unit of improvement [e.g., from moderate to mild], 0.55; 95% CI, 0.31-0.96) were associated with overall mortality.

CONCLUSIONS

Echocardiographic parameters that estimate RV systolic pressure and assess RV morphology and function improve after 1 year of prostacyclin analogue treatment, and the degree of change has prognostic implications.

Long-term sildenafil added to intravenous epoprostenol in patients with pulmonary arterial hypertension

BACKGROUND

In pulmonary arterial hypertension (PAH), adding oral sildenafil to intravenous epoprostenol improved 6-minute walk distance (6MWD) and hemodynamics and delayed time to clinical worsening in a 16-week randomized, placebo-controlled trial (Pulmonary Arterial Hypertension Combination Study of Epoprostenol and Sildenafil [PACES-1]).

METHODS

Patients completing PACES-1 could receive sildenafil (titrated to 80 mg, three times daily, as tolerated) in an open-label extension study (PACES-2) for ≥ 3 years; additional therapy was added according to investigator judgment. Survival and changes from PACES-1 baseline in World Health Organization Functional Class and 6MWD were captured.

RESULTS

In an open-label setting, 6MWD, an effort-dependent outcome measure, was known to have improved or to have been maintained in 59%, 44%, and 33% of patients at 1, 2, and 3 years, respectively; functional class was known to have improved or to have been maintained in 73%, 59%, and 46%. At 3 years, 66% of patients were known to be alive, 24% were known to have died, and 10% were lost to follow-up. Patients with PACES-1 baseline 6MWD < 325 meters without 6MWD improvement during the first 20 weeks of sildenafil treatment subsequently had poorer survival.

CONCLUSIONS

Although reliable assessments of safety and efficacy require a long-term randomized trial, the addition of sildenafil to background intravenous epoprostenol therapy appeared generally to be well tolerated in PAH patients.

Medical therapeutics for pulmonary arterial hypertension: from basic science and clinical trial design to evidence-based medicine

Pulmonary arterial hypertension is a severe disease with poor prognosis, caused by obliteration of the pulmonary vasculature as a result of pulmonary-vascular remodeling, active vasoconstriction and in situ thrombosis. Left untreated, pulmonary arterial hypertension results in right-ventricular failure and death. There has been dramatic progress in the treatment of pulmonary arterial hypertension during recent years. A remarkable number of randomized-controlled trials with agents known to target specific abnormalities present in pulmonary arterial hypertension have been completed. Most commonly, therapeutic efficacy was judged by the ability of the drug under study to improve exercise capacity and to decrease the rate of severe complications. Completed clinical trials have mainly evaluated patients with relatively advanced disease. Despite these advances, responses to therapy in pulmonary arterial hypertension are not uniformly favorable and frequently incomplete. In addition, the methods of delivery and the adverse effect profile of the currently available pulmonary arterial hypertension-specific drugs create further management difficulties. Based on newly identified pathobiologic abnormalities in the pulmonary vasculature, future studies are likely to focus on the discovery of new therapeutic targets. Clinical trial design will continue to evolve in an attempt to enable inclusion of patients with less advanced disease and evaluation of treatment combinations or comparisons of the currently approved drugs.

Lung transplantation and atrial septostomy in pulmonary arterial hypertension

This article summarizes the current literature regarding surgical interventions in pulmonary hypertension, excluding chronic thromboembolic pulmonary hypertension. The article discusses the use of atrial septostomy in patients meeting criteria as well as single, double, and heart-lung transplantation.

Parenteral and inhaled prostanoid therapy in the treatment of pulmonary arterial hypertension

Since continuous IV epoprostenol was approved in the U.S., parenteral prostanoid therapy has remained the gold standard for the treatment of patients with advanced pulmonary arterial hypertension (PAH). Prostanoid agents can be administered as continuous intravenous infusions, as continuous subcutaneous infusions and by intermittent nebulization therapy. This article presents data from clinical trials of available prostanoid agents, and their varied routes of administration. The varied routes of administration allow for the incremental use of this class of agents in advanced PAH, and if PAH progresses. Prostanoids will remain a major component of PAH therapy for the foreseeable future.

Preoperative cardiac variables of diastolic dysfunction and clinical outcomes in lung transplant recipients

Background. Orthotopic lung transplantation is now widely performed in patients with advanced lung disease. Patients with moderate or severe ventricular systolic dysfunction are typically excluded from lung transplantation; however, there is a paucity of data regarding the prognostic significance of abnormal left ventricular diastolic function and elevated pretransplant pulmonary pressures. Methods. We reviewed the characteristics of 111 patients who underwent bilateral and unilateral lung transplants from 200 to 2009 in order to evaluate the prognostic significance of preoperative markers of diastolic function, including invasively measured pulmonary capillary wedge pressure (PCWP) and echocardiographic variables of diastolic dysfunction including mitral A > E and A′ > E′. Results. Out of 111 patients, 62 were male (56%) and average age was 54.0 ± 10.5 years. Traditional echocardiographic Doppler variables of abnormal diastolic function, including A′ > E′ and A > E, did not predict adverse events (P = 0.49). Mildly elevated pretransplant PCWP (16–20 mmHg) and moderately/severely elevated PCWP (>20 mmHg) were not associated with adverse clinical events after transplant (P = 0.30). Additionally, all clinical endpoints did not show any statistical significance between the two groups. Conclusions. Pre-lung transplant invasive and echocardiographic findings of elevated pulmonary pressures and abnormal left ventricular diastolic function are not predictive of adverse posttransplant clinical events.

Pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a chronic and progressive disease leading to right heart failure and ultimately death if untreated. The first classification of PH was proposed in 1973. In 2008, the fourth World Symposium on PH held in Dana Point (California, USA) revised previous classifications. Currently, PH is devided into five subgroups. Group 1 includes patients suffering from idiopathic or familial PAH with or without germline mutations. Patients with a diagnosis of PAH should systematically been screened regarding to underlying mutations of BMPR2 gene (bone morphogenetic protein receptor type 2) or more rarely of ACVRL1 (activine receptor-like kinase type 1), ENG (endogline) or Smad8 genes. Pulmonary veno occusive disease and pulmonary capillary hemagiomatosis are individualized and designated as clinical group 1'. Group 2 'Pulmonary hypertension due to left heart diseases' is divided into three sub-groups: systolic dysfonction, diastolic dysfonction and valvular dysfonction. Group 3 'Pulmonary hypertension due to respiratory diseases' includes a heterogenous subgroup of respiratory diseases like PH due to pulmonary fibrosis, COPD, lung emphysema or interstitial lung disease for exemple. Group 4 includes chronic thromboembolic pulmonary hypertension without any distinction of proximal or distal forms. Group 5 regroup PH patients with unclear multifactorial mechanisms. Invasive hemodynamic assessment with right heart catheterization is requested to confirm the definite diagnosis of PH showing a resting mean pulmonary artery pressure (mPAP) of ≥ 25 mmHg and a normal pulmonary capillary wedge pressure (PCWP) of ≤ 15 mmHg. The assessment of PCWP may allow the distinction between pre-capillary and post-capillary PH (PCWP > 15 mmHg). Echocardiography is an important tool in the management of patients with underlying suspicion of PH. The European Society of Cardiology and the European Respiratory Society (ESC-ERS) guidelines specify its role, essentially in the screening proposing criteria for estimating the presence of PH mainly based on tricuspid regurgitation peak velocity and systolic artery pressure (sPAP). The therapy of PAH consists of non-specific drugs including oral anticoagulation and diuretics as well as PAH specific therapy. Diuretics are one of the most important treatment in the setting of PH because right heart failure leads to fluid retention, hepatic congestion, ascites and peripheral edema. Current recommendations propose oral anticoagulation aiming for targeting an International Normalized Ratio (INR) between 1.5-2.5. Target INR for patients displaying chronic thromboembolic PH is between 2–3. Better understanding in pathophysiological mechanisms of PH over the past quarter of a century has led to the development of medical therapeutics, even though no cure for PAH exists. Several specific therapeutic agents were developed for the medical management of PAH including prostanoids (epoprostenol, trepoprostenil, iloprost), endothelin receptor antagonists (bosentan, ambrisentan) and phosphodiesterase type 5 inhibitors (sildenafil, tadalafil). This review discusses the current state of art regarding to epidemiologic aspects of PH, diagnostic approaches and the current classification of PH. In addition, currently available specific PAH therapy is discussed as well as future treatments.

Pulmonary artery pressure, gender, menopause, and pregnancy in schistosomiasis-associated pulmonary hypertension

Background

Schistosomiasis-associated pulmonary arterial hypertension (SPAH) is a major concern worldwide. However, the role of gender specific contributing factors in SPAH is unknown.

Objective

We investigated how systolic pulmonary artery pressure (SPAP) values and the presence of severe SPAP relate to gender, menopausal status, and pregnancy history in SPAH patients.

Methods

Seventy-nine patients diagnosed with SPAH from 2000 to 2009 were assessed and 66 were enrolled in the study. Information about age, menopausal status, pregnancy, echocardiography-derived SPAP, and invasive mean pulmonary artery pressure (mPAP) was collected from medical records. The relation between values of SPAP and mPAP and their agreement for severe disease were assessed. Regression models assessed the association of gender, menopausal status, and pregnancy history with SPAP values and the presence of severe SPAP.

Results

Moderate correlation and good agreement for severe disease were found between mPAP and SPAP. Mean SPAP values were similar for men and women. A trend toward higher values of SPAP was found for non-menopausal women compared to men. Higher SPAP values were found for menopausal compared to non-menopausal women; the values were non-significant after adjustment for age. Pregnancy history had no association with SPAP. Menopause and positive pregnancy had no association with severe SPAP.

Conclusion

In SPAH patients, neither gender, nor menopausal status, nor pregnancy history showed independent correlation with SPAP values assessed by echocardiography.

Chryseomonas luteola bloodstream infection in a pediatric patient with pulmonary arterial hypertension receiving intravenous treprostinil therapy

Treprostinil is a prostacyclin analogue approved for the treatment of pulmonary arterial hypertension (PAH). It is commonly administered through a central venous catheter (CVC). Treprostinil is associated with the incidence of Gram-negative bacterial bloodstream infections (BSI), a susceptibility that has been associated with a diluent used for treprostinil. We report the case of a 14-year-old boy with idiopathic PAH on continuous intravenous treprostinil therapy who presented with fever and fatigue. A blood culture drawn from his CVC was positive for the rare Gram-negative organism Chryseomonas luteola. The patient made a complete recovery with antibacterial treatment. This is the only documented case of a C. luteola BSI in a PAH patient receiving continuous intravenous treprostinil. We recommend maintaining a high index of suspicion for both common and rare Gram-negative pathogens and the early administration of appropriate antibiotic therapy in this population. The use of an alternate diluent solution, such as Sterile Diluent for Flolan, further decreases the infection risk.

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.

The diagnostic accuracy of Doppler echocardiography in assessment of pulmonary artery systolic pressure: a meta-analysis

BACKGROUND

Transthoracic echocardiography is commonly used to estimate pulmonary arterial systolic pressure (PASP) and to diagnose pulmonary hypertension (PH). However, some recent studies have questioned the accuracy of Doppler echocardiography (DE) in the assessment of PASP. The present meta-analysis was performed to estimate the accuracy, sensitivity, and specificity of DE in the assessment of PASP.

METHODS

A literature search and data extraction of English and non-English articles reported from May 1984 to January 2009 was performed independently by 2 investigators using MEDLINE and EMBASE databases. Articles were included if they compared DE with right heart catheterization (RHC) in the assessment of PASP. Nine articles met our criteria and were included in our meta-analysis. We conducted a meta-analysis of the results of these articles using fixed- and random-effect models to estimate the accuracy, sensitivity, and specificity of DE in the assessment of PASP.

RESULTS

The correlation between PASP estimated by DE and RHC ranged from (r = 0.65, P < 0.001) to (r = 0.97, P < 0.001). The pooled sensitivity, specificity, and accuracy of DE for the diagnosis of PH were 88% (95% confidence interval [CI], 84-92%), 56% (95% CI, 46-66%), and 63% (95% CI, 53-73%), respectively.

CONCLUSION

DE is a useful noninvasive modality to screen for PH and can reliably determine whether PASP is normal, mildly elevated, or markedly elevated. However, abnormal results from DE need to be confirmed by RHC.

Prognostic factors and outcomes of patients with pulmonary hypertension admitted to the intensive care unit

PURPOSE

Patients with pulmonary hypertension (PH) can decompensate to the point where they require care in the intensive care unit (ICU). Our objective is to examine the outcomes and characteristics of patients with PH admitted to the ICU.

METHODS

This is a retrospective study of 99 patients with PH who were admitted to the medical ICU of a single tertiary care center. Baseline characteristics, interventions during ICU admission, and ICU and 6-month outcome were documented. Univariate and multivariate logistic regressions were used to evaluate association of patient characteristics with mortality.

RESULTS

Intensive care unit mortality was 30%, and 6-month mortality was 40%. Acute Physiology and Chronic Health Evaluation II score, World Health Organization Group 3 PH, and preexisting treatment with a prostacyclin at time of ICU admission were associated with worse outcome. Patients who received cardiopulmonary resuscitation had 100% mortality. The requirement for mechanical ventilation and dialysis was also associated with increased mortality. Pulmonary artery catheter placement was associated with reduced mortality, specifically if it was placed early during ICU admission and if associated with a change in the present management.

CONCLUSIONS

Mortality is high in critically ill patients with PH. The identification of prognostic baseline characteristics and interventions in the ICU is important and warrants further investigation.

Prostanoids for Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a severe condition that markedly reduces exercise capacity and survival in the affected patient population. PAH includes primary pulmonary hypertension (PPH) and pulmonary hypertension associated with collagen vascular diseases, congenital systemic-to-pulmonary shunts, portal hypertension and HIV infection. All these conditions share virtually identical obstructive pathologic changes of the pulmonary microcirculation and probably similar pathobiologic processes. The pathophysiology is characterized by a progressive increase in pulmonary vascular resistance, leading to right ventricular failure and death. Prostacyclin is an endogenous substance that is produced by vascular endothelial cells and induces vasodilatation, inhibition of platelet activity, and antiproliferative effects. A dysregulation of prostacyclin metabolic pathways has been shown in patients with PAH and this represents the rationale for the exogenous therapeutic administration of this substance. The clinical use of prostacyclin in patients with PAH has been made possible by the synthesis of stable analogs that possess different pharmacokinetic properties but share similar pharmacodynamic effects. Experience in humans has been initially collected with epoprostenol, which is a synthetic salt of prostacyclin. Epoprostenol has a short half-life in the circulation and requires continuous administration by the intravenous route by means of infusion pumps and permanent tunnelized catheters. In addition, epoprostenol is unstable at room temperature, and the complex delivery system required is associated with several adverse effects and potentially serious complications. For these reasons, alternatives to intravenous epoprostenol have been sought and this has led to the development of analogs that can be administered subcutaneously (treprostinil), orally (beraprost sodium) or by inhalation (iloprost). Three unblinded clinical trials and several uncontrolled trials have shown that treatment with epoprostenol improved symptoms and exercise capacity in New York Heart Association (NYHA) class III and IV PAH patients and also survival in patients with PPH. Subcutaneous treprostinil improved symptoms, exercise, hemodynamics and clinical events in the largest clinical trial ever performed in PAH, but local infusion site reactions limited efficacy in a proportion of patients. Oral beraprost sodium improved exercise capacity only in patients with PPH and is the only prostacyclin analog that has also been tested in NYHA class II patients. Inhaled iloprost has improved symptoms, exercise capacity and clinical events in patients with PAH and inoperable chronic thromboembolic pulmonary hypertension. The favorable effects of prostanoids observed in all studies coupled with different profiles of adverse events and tolerability for each prostacyclin analog allow the unique opportunity to select the most appropriate compound for the individual patient with PAH.

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.

Dual therapy in IPAH and SSc-PAH. A qualitative systematic review

BACKGROUND

Use of endothelin receptor antagonists (ERA), phosphodiesterase type-5 (PDE-5) inhibitors and prostaglandin analogues has resulted in improved outcomes in idiopathic pulmonary arterial hypertension (IPAH) and systemic sclerosis-associated PAH (SSc-PAH) patients. However, patients often deteriorate on monotherapy. The objective of this study is to evaluate the effect of dual therapy on outcomes in IPAH and SSc-PAH.

METHODS

A systematic review of MEDLINE (1950-2011), EMBASE (1980-2011) and CINAHL (inception-2011) was conducted to identify studies that evaluated the effect of any dual combination of ERA, PDE-5 inhibitors or prostaglandin analogues on 6-min walk distance (6MWD), functional class (FC), haemodynamics, quality-of-life (QoL) or time-to-clinical-worsening in IPAH or SSc-PAH. A standardized form was used to abstract design, sample size, aetiology, outcome and treatment effect.

RESULTS

Twenty-six observational studies and 6 randomized trials were identified. Using combination PDE-5 inhibitor and prostaglandin analogues, 6/7 studies reported improvement in 6MWD, 6/8 studies reported improvement in FC, 6/6 studies reported improvement in haemodynamics and 1 trial demonstrated improvement in QoL and time-to-clinical-worsening. Using combination ERA and prostaglandin analogues, 4/6 studies and 1 trial reported improvement in 6MWD, 3/3 studies and 1 trial reported improvement in FC, 4/5 studies and 1 trial reported improvement in PAP. Using combination ERA and PDE-5 inhibitor, 4/7 studies reported an improvement in 6MWD, and 2/6 report improvement in FC.

CONCLUSION

The evidence suggests a beneficial effect of dual therapy in IPAH and SSc-PAH, particularly those who are deteriorating on monotherapy. Research should focus on subsets of patients to identify the optimal timing and combination of dual therapy.