Epidemiology of pulmonary hypertension: new data from the Swiss registry

BACKGROUND: since 1999 data from pulmonary hypertension (PH) patients from all PH centres in Switzerland were prospectively collected. We analyse the epidemiological aspects of these data. METHODS: PH was defined as a mean pulmonary artery pressure of >25 mm Hg at rest or >30 mm Hg during exercise. Patients with pulmonary arterial hypertension (PAH), PH associated with lung diseases, PH due to chronic thrombotic and/or embolic disease (CTEPH), or PH due to miscellaneous disorders were registered. Data from adult patients included between January 1999 and December 2004 were analysed. RESULTS: 250 patients were registered (age 58 +/- 16 years, 104 (41%) males). 152 patients (61%) had PAH, 73 (29%) had CTEPH and 18 (7%) had PH associated with lung disease. Patients <50 years (32%) were more likely to have PAH than patients >50 years (76% vs. 53%, p <0.005). Twenty-four patients (10%) were lost to followup, 58 patients (26%) died and 150 (66%) survived without transplantation or thrombendarterectomy. Survivors differed from patients who died in the baseline six-minute walking distance (400 m [300-459] vs. 273 m [174-415]), the functional impairment (NYHA class III/IV 86% vs. 98%), mixed venous saturation (63% [57-68] vs. 56% [50-61]) and right atrial pressure (7 mm Hg [4-11] vs. 11 mm Hg [4-18]). DISCUSSION: PH is a disease affecting adults of all ages. The management of these patients in specialised centres guarantees a high quality of care. Analysis of the registry data could be an instrument for quality control and might help identify weak points in assessment and treatment of these patients.     

A USA-based registry for pulmonary arterial hypertension: 1982-2006.

The aim of this study was to define the epidemiology of World Health Organization (WHO) Group I pulmonary arterial hypertension (PAH) in a large referral centre in the USA. The Pulmonary Hypertension Connection registry, initiated in 2004, evaluated all patients in a single USA practice from 1982-2006. For comparison, the authors divided the group by incident versus prevalent cohorts, aetiology and by treatment era. In total, 578 patients (77% female) aged 48+/-14 yrs were entered. Of these, 80% had class III or IV symptoms. Over time, connective tissue disease-associated PAH increased, while referrals for HIV remained low. One-third of patients were referred on calcium channel blocker therapy even though only 4.6% had an acute response to vasodilator challenge. When compared by treatment era, there were no differences in the severity of PAH. However, survival had improved over time, with a 1-yr survival of 85% in the incident cohort. In the USA, pulmonary arterial hypertension patients are still referred to tertiary centres too late. Referral of connective tissue disease is increasing, while referral of HIV remains low. Inappropriate calcium channel blocker treatment is common. Survival rates have increased but remain low suggesting that prognosis is improving but PAH is still a progressive, fatal disease.     

The bosentan patient registry: long‐term survival in pulmonary arterial hypertension

Background/Aims: The Bosentan Patient Registry (BPR) was a prospective, multicentre, Australian registry funded by Actelion Pharmaceuticals. The primary aim of the registry was to collect survival data in patients with pulmonary arterial hypertension (PAH) treated with bosentan. Methods: The BPR was initiated in 15 specialized PAH centres. All patients on or starting bosentan were invited to enrol. Treating physicians notified the registry if patients discontinued bosentan, because of either a change in therapy, transplantation, intervention or death. Survival data were validated against the Australian Institute of Health and Welfare National Death Index. Results: Between 2004 and 2007, a total of 528 patients (mean age 59 ± 17 years) were enrolled representing 69% of patients either previously taking or initiated on bosentan during that time. The BPR population was generally older with more advanced functional deficit than patients enrolled in randomized, placebo‐controlled trials. Aetiology was idiopathic (iPAH) in 58% and connective tissue disease related (scleroderma (SSc)‐PAH) in 42%. For iPAH patients, World Health Organisation functional classes II, III and IV at enrolment was 8.2%, 66.4% and 20.5%, and for the SSc‐PAH cohort, 3.2%, 75.8% and 17.9% respectively. The observed annual mortality was 11.8% in patients with iPAH and 16.6% in patients SSc‐PAH. Conclusion: This large Australian registry provides ‘real life’ information on the characteristics and management of PAH in clinical practice. Treatment with bosentan improved survival outcomes in both iPAH and SSc‐PAH compared with historical controls. Age, disease severity and aetiology were critical factors in determining clinical outcomes.     

Elderly patients diagnosed with idiopathic pulmonary arterial hypertension: Results from the COMPERA registry

Background

Originally reported to occur predominantly in younger women, idiopathic pulmonary arterial hypertension (IPAH) is increasingly diagnosed in elderly patients. We aimed to describe the characteristics of such patients and their survival under clinical practice conditions.

Methods

Prospective registry in 28 centers in 6 European countries. Demographics, clinical characteristics, hemodynamics, treatment patterns and outcomes of younger (18–65 years) and elderly (> 65 years) patients with newly diagnosed IPAH (incident cases only) were compared.

Results

A total of 587 patients were eligible for analysis. The median (interquartile, [IQR]) age at diagnosis was 71 (16) years. Younger patients (n = 209; median age, 54 [16] years) showed a female-to-male ratio of 2.3:1 whereas the gender ratio in elderly patients (n = 378; median age, 75 [8] years) was almost even (1.2:1). Combinations of PAH drugs were widely used in both populations, albeit less frequently in older patients. Elderly patients were less likely to reach current treatment targets (6 min walking distance > 400 m, functional class I or II). The survival rates 1, 2, and 3 years after the diagnosis of IPAH were lower in elderly patients, even when adjusted for age- and gender-matched survival tables of the general population (p = 0.006 by log-rank analysis).

Conclusions

In countries with an aging population, IPAH is now frequently diagnosed in elderly patients. Compared to younger patients, elderly patients present with a balanced gender ratio and different clinical features, respond less well to medical therapy and have a higher age-adjusted mortality. Further characterization of these patients is required.Clinical trials registration: NCT01347216.     

Congenital heart disease-associated pulmonary arterial hypertension: preliminary results from a novel registry

Background/Aims: Pulmonary arterial hypertension (PAH) frequently accompanies childhood congenital heart disease (CHD) and may persist into adult life. The advent of specific PAH therapies for PAH prompted formation of a national Australian and New Zealand registry in 2010 to document the incidence, demographics, presentation and outcomes for these patients. Methods: This multicentre, prospective, web‐based registry enrols patients with CHD‐associated PAH being followed in a tertiary centre. The inclusion criteria stipulated patient age ≥16 years, a measured mean pulmonary arterial pressure >25 mmHg at rest or echocardiographical evidence of PAH or a diagnosis of Eisenmenger syndrome, and followed since 1 January 2000. A single observer collected standardised data during a series of site visits. Results: Of the first 50 patients enrolled, 30 (60%) were female. The mean age (standard deviation (SD)) at the time of PAH diagnosis or confirmation in an adult centre was 27.23 (10.07) years, and 32 (64%) patients are currently aged >30 years. Fourteen (28%) patients were in World Health Organization Functional Class II and 36 (72%) in Class III at the time of diagnosis. Forty‐seven of 50 (94%) had congenital systemic‐pulmonary shunts, and 36 (72%) never underwent intervention. Thirteen (26%) had Down syndrome. Confirmation of PAH by recent cardiac catheterisation was available in 30 (60%) subjects. During follow up, a total of 32 (64%) patients received a PAH‐specific therapy. Conclusions: CHD associated with PAH in adult life has resulted in a new population with unique needs. This registry will allow documentation of clinical course and long‐term outcomes for these patients.     

Bilateral lung transplantation for pediatric idiopathic pulmonary arterial hypertension: a multi-center experience

Many children with idiopathic pulmonary arterial hypertension (IPAH) experience disease progression despite advanced medical therapy. In these children, heart-lung or bilateral lung transplantation (BLTx) remain the only therapeutic options when other treatments fail. Data on functional outcome after BLTx in children with IPAH are limited. We report a multi-center experience of BLTx for pediatric IPAH. We performed a retrospective study including 25 centers within the International Pediatric Lung Transplant Collaborative. Children with IPAH who underwent BLTx were included (1996-2006). Twenty-three children underwent BLTx for IPAH, most of whom were in WHO class III or IV level of function pre-transplantation. At 6 months post-transplantation, 82% of children reported improvement in level of function to WHO class I. The median FEV(1) was 89% (12-126) of predicted at 12 months post-transplantation. Ten patients (44%) developed BOS at a median of 42 months (3-85), of whom five died at a median of 27 months (4-86) post-transplantation. Overall mortality was 4% at 3 months post-transplantation. The median survival for children in this cohort was 45 months (2-123). Our data suggest that BLTx is a valuable therapeutic option for children with end-stage IPAH with outcomes comparable to that after heart-lung transplantation in children with pulmonary arterial hypertension or those patients undergoing lung transplantation for other indications. In the majority of children, a good cardiopulmonary function is possible following BLTx, making BLTx a good therapeutic option and maximizing donor organ utilization by allowing more hearts to be available for children needing cardiac transplantation.     

Real-world experience of selexipag titration in pulmonary arterial hypertension

Selexipag is an oral selective prostacyclin-receptor agonist that was approved for use in patients with World Health Organisation (WHO) functional class II–III pulmonary arterial hypertension (PAH). Treatment with individualised doses of selexipag resulted in significant reductions in the composite end point of death or a complication related to PAH in the phase III GRIPHON (Prostacyclin [PGI2] Receptor Agonist In Pulmonary Arterial Hypertension) study. In order to better understand the real-world approach to selexipag titration and to establish the individualised maintenance regimens used in our centre, we performed this retrospective study of the first 20 patients prescribed selexipag. Baseline characteristics differed from the GRIPHON study, with more combination therapy and comorbidities at drug initiation. Maintenance doses were stratified as low-dose in 10% (n=2), medium-dose in 70% (n=14) and high-dose in 20% (n=4). This study highlights that selexipag can be safely initiated, titrated and transitioned in an outpatient setting to achieve an individualised dosing regimen.Key words: prostacyclin, pulmonary circulation, pulmonary hypertension, selexipag     

Treatments for pulmonary arterial hypertension

PURPOSE: Pulmonary arterial hypertension (PAH) is characterized by vasoconstriction, in situ thrombosis and vascular remodeling of small pulmonary arteries inducing a fixed pulmonary arterial obstruction and persistent elevation of pulmonary arterial resistance. Conventional treatment is based on simple measures (exercise limitation) and non-specific drugs (warfarine, diuretics, oxygen). CURRENT KNOWLEDGE AND KEY POINTS: Pure vasodilators like calcium channel antagonists have little or no effect on the vast majority of patients, presumably because fixed pulmonary arteriopathy predominate over vasoconstriction. Intravenous prostacyclin (epoprostenol) and endothelin receptor antagonists have vasodilator and antiproliferative properties. Epoprostenol therapy has resulted in significant improvements in prognosis of this disease and this drug remains the first-line treatment of the most severe patients. Bosentan is an interesting first-line treatment for NYHA functional class III patients. Availability of novel specific drugs (endothelin receptor type A antagonists, prostacyclin analogues, type 5 phosphodiesterase inhibitors) open new perspectives in treatment of PAH. The long-term benefit of these drugs remains to be evaluated and their respective place in treatment of these patients is still uncertain. We here present the different therapeutic alternatives available in the PAH and propose an algorithm for treatment of these patients. FUTURE PROSPECTS AND PROJECTS: The evolution of therapy from vasodilators to antiproliferative agents reflects the advancement in our understanding of the mechanisms mediating pulmonary arterial hypertension.     

Treatments for pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a devastating disease that leads to right heart failure and premature death. Historically, we are restricted by limited options for drug treatment. Over the past decade, with advances in our understanding of pathophysiological and molecular mechanisms, many new therapeutic strategies (synthetic prostacyclin and prostacyclin analogues, endothelin receptor antagonists and sildenafil) have been developed for the treatment of PAH, and the clinical efficacy has been tested in many randomized-controlled trials (RCTs). In this overview, we review the evidence for the use of historical and new treatments that arises from the Cochrane Collaboration of Systematic Reviews and from recent RCTs.     

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.     

Pharmacotherapy for pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a disabling, progressive disease. The past decade has seen an explosion in the available therapies for the management of PAH. Choosing appropriate pharmacotherapy can be a daunting task for the practitioner, as no head-to-head comparisons between drugs have been published. This article aims to assist the practitioner in developing an evidence-based, rational pharmacologic treatment algorithm for the management of patients with PAH. Currently approved pharmacotherapy and the pivotal trials that led to approval for the respective agents are reviewed. Common dilemmas in the treatment of PAH for which strong evidence is lacking are discussed.     

Current epoprostenol use in patients with severe idiopathic,heritable or anorexigen-associated pulmonary arterial hypertension: Data from the French pulmonary hypertension registry

Objectives

The current use of intravenous epoprostenol in patients with severe idiopathic, heritable or anorexigen-use associated pulmonary arterial hypertension (IHA-PAH) was investigated.

Methods

This observational study evaluated newly diagnosed (≤ 1 year) patients with IHA-PAH, enrolled in the French pulmonary hypertension (PH) registry between 2006 and 2010 and treated with epoprostenol. Among 209 consecutive patients receiving epoprostenol for the treatment of severe PH, 78 had IHA-PAH, including 43 patients naïve of previous PAH-specific treatment.

Results

After 4 months of epoprostenol therapy, improvement was observed for treatment naïve patients (n = 43) and for patients who had received previous PAH-specific therapy (n = 35): NYHA functional class improved in 79% and 44% of these patients, respectively, 6-minute walk distance increased by 146 (p < 0.0001) and 41 m (p = 0.03), cardiac index increased by 1.2 (p < 0.0001) and 0.5 L·min^− 1·m^− 2 (p = 0.006), and pulmonary vascular resistance decreased by 700 (p < 0.0001) and 299 dyn·s·cm^− 5 (p = 0.009). In the treatment-naïve patient group, upfront combination of epoprostenol and oral PAH therapy tended to be more beneficial compared with epoprostenol monotherapy and was associated with improvement in cardiac index (p = 0.03).The observed 1- and 3-year survival estimates from epoprostenol initiation were 84% and 69%, respectively. The highest survival rates were observed for treatment-naïve patients receiving upfront combination of epoprostenol and oral PAH therapy (92% and 88% at 1 and 3 years, respectively).

Conclusions

First-line therapy with epoprostenol, especially when combined with oral PAH treatment, was associated with a substantial improvement in clinical and hemodynamic status and favorable survival estimates in patients with severe IHA-PAH.     

Prevalence and outcome in systemic sclerosis associated pulmonary arterial hypertension: application of a registry approach

OBJECTIVE: To determine the prevalence of systemic sclerosis associated pulmonary arterial hypertension (SScPAH), evaluate outcome, and identify predictors of mortality in a large patient cohort. METHODS: A prospective four year follow up study of 794 patients (722 from our own unit and 72 referrals). All patients screened for PAH using a combination of echocardiography, lung function testing, and clinical assessment. Patients with suspected raised pulmonary artery systolic pressures of >35 mm Hg, carbon monoxide transfer factor (TLCO) <50% predicted, or a precipitous fall in TLCO >20% over a one year period with no pulmonary fibrosis, and patients with SSc with breathlessness with no pulmonary fibrosis found were investigated with right heart catheterisation. All patients with SScPAH were treated in accordance with current best practice. RESULTS: The prevalence of PAH was 12% (89/722) by right heart catheter. The survival was 81%, 63%, and 56% at 1, 2, and 3 years from the diagnosis (in 89 patients from our own cohort and 59/72 referrals). Haemodynamic indices of right ventricular failure--raised mRAP (hazard ratio 21), raised mPAP (hazard ratio 20), and low CI (hazard ratio 11) predicted an adverse outcome There was no significant difference in survival between patients with SScPAH with (n=40) and without (n=108) pulmonary fibrosis (p=0.3). CONCLUSIONS: The prevalence of SScPAH in this cohort was similar to that of other catheter based studies and lower than that of previous echo based studies. The 148 patients with SScPAH actively treated had comparable outcomes to those of the cohorts with primary pulmonary hypertension. A high mRAP was the strongest haemodynamic predictor of mortality. To improve prognosis, future treatments need to be implemented at an earlier disease stage to prevent right ventricular decompensation.     

Ambrisentan therapy for pulmonary arterial hypertension

OBJECTIVES: The purpose of this study was to examine the efficacy and safety of four doses of ambrisentan, an oral endothelin type A receptor-selective antagonist, in patients with pulmonary arterial hypertension (PAH). BACKGROUND: Pulmonary arterial hypertension is a life-threatening and progressive disease with limited treatment options. Endothelin is a vasoconstrictor and smooth muscle cell mitogen that plays a critical role in the pathogenesis and progression of PAH. METHODS: In this double-blind, dose-ranging study, 64 patients with idiopathic PAH or PAH associated with collagen vascular disease, anorexigen use, or human immunodeficiency virus infection were randomized to receive 1, 2.5, 5, or 10 mg of ambrisentan once daily for 12 weeks followed by 12 weeks of open-label ambrisentan. The primary end point was an improvement from baseline in 6-min walk distance (6MWD); secondary end points included Borg dyspnea index, World Health Organization (WHO) functional class, a subject global assessment, and cardiopulmonary hemodynamics. RESULTS: At 12 weeks, ambrisentan increased 6MWD (+36.1 m, p < 0.0001) with similar and statistically significant increases for each dose group (range, +33.9 to +38.1 m). Improvements were also observed in Borg dyspnea index, WHO functional class, subject global assessment, mean pulmonary arterial pressure (-5.2 mm Hg, p < 0.0001), and cardiac index (+0.33 l/min/m2, p < 0.0008). Adverse events were mild and unrelated to dose, including the incidence of elevated serum aminotransferase concentrations >3 times the upper limit of normal (3.1%). CONCLUSIONS: Ambrisentan appears to improve exercise capacity, symptoms, and hemodynamics in patients with PAH. The incidence and severity of liver enzyme abnormalities appear to be low.