Treatment of pulmonary arterial hypertension: a preliminary decision analysis

Cost Effectiveness of Bosentan for Pulmonary Arterial Hypertension: A Systematic Review

Objectives

Although many studies have reported on the cost-effectiveness of bosentan for treating pulmonary arterial hypertension (PAH), a systematic review of economic evaluations of bosentan is currently lacking. Objective evaluation of current pharmacoeconomic evidence can assist decision makers in determining the appropriate place in therapy of a new medication.

Methods

Systematic literature searches were conducted in English-language databases (MEDLINE, EMBASE, EconLit databases, and the Cochrane Library) and Chinese-language databases (China National Knowledge Infrastructure, WanFang Data, and Chongqing VIP) to identify studies assessing the cost-effectiveness of bosentan for PAH treatments.

Results

A total of 8 published studies were selected for inclusion. Among them were two studies comparing bosentan with epoprostenol and treprostinil. Both results indicated that bosentan was more cost-effective than epoprostenol, while the results of bosentan and treprostinil were not consistent. Four studies compared bosentan with other endothelin receptor antagonists, which indicated ambrisentan might be the drug of choice for its economic advantages and improved safety profile. Only two economic evaluations provided data to compare bosentan versus sildenafil, and the results favored the use of sildenafil in PAH patients. Four studies compared bosentan with conventional, supportive, or palliative therapy, and whether bosentan was cost-effective was uncertain.

Conclusions

Bosentan may represent a more cost-effective option compared with epoprostenol and conventional or palliative therapy. There was unanimous agreement that bosentan was not a cost-effective front-line therapy compared with sildenafil and other endothelin receptor antagonists. However, high-quality cost-effectiveness analyses that utilize long-term follow-up data and have no conflicts of interest are still needed.

Resource utilization at the time of prostacyclin initiation in children in pulmonary arterial hypertension: a multicenter analysis

There are limited data investigating the epidemiology and resource utilization associated with parenteral prostacyclin use in children. We sought to examine national trends in treatment practices and resource utilization during prostacyclin initiation for pulmonary arterial hypertension (PAH) at children’s hospitals in the United States. Patients with PAH initiated on parenteral epoprostenol and treprostinil (2004–2014) were identified using a nationwide administrative database. Demographics, clinical characteristics, and resource utilization were compared between epoprostenol and treprostinil groups. Costs were indexed in 2014 US dollars. Among 1448 children admitted with a primary or secondary diagnosis of PAH, 280 (19%) were initiated on parenteral prostacyclins (epoprostenol n = 195 and treprostinil n = 85). Epoprostenol predominated early (97% of initiations in 2005); however, treprostinil predominated recently (52–67% of initiations/year). Children initiated on treprostinil had shorter ICU stays (1 [IQR = 0–4] vs. 4 [0–10] days, P < 0.001), shorter total lengths of stay (4 [2–9] vs. 8 [4–18] days, P = 0.001), and lower in-hospital mortality (1 vs. 12%, P = 0.001) with no difference in 30-day (13 vs. 19%, P = 0.19) or one-year readmission rates (56 vs. 61%, P = 0.41). Inpatient costs were lower for treprostinil initiation ($23,779 [11,830–39,535] vs. $32,976 [11,904–94,082], P = 0.03), with a greater difference in the recent era (2009–2013). Though significant variation exists regarding prostacyclin use for PAH across US centers, prostacyclins are common among children with PAH. Treprostinil initiation has been increasing and is associated with less resource utilization and lower cost compared to epoprostenol initiation. Post-discharge outcome data are needed to fully inform decision-making about the relative benefits of parental prostacyclin drug choice.

Systematic Review of the Economic Burden of Pulmonary Arterial Hypertension

BACKGROUND

Pulmonary arterial hypertension (PAH), as a life-threatening disease with no efficient cure, may impose a tremendous economic burden on patients and healthcare systems. However, most existing studies have mainly emphasised epidemiology and medications, while large observational studies reporting on the economic burden are currently lacking.

OBJECTIVES

To review and evaluate evidence on the costs of PAH and the cost effectiveness of PAH treatments, and to summarise the corresponding cost drivers.

METHODS

Systematic literature searches were conducted in English-language databases (PubMed, Web of Science, ScienceDirect) and Chinese-language databases (China National Knowledge Infrastructure, Wanfang Data, Chongqing VIP) to identify studies (published from 2000 to 2014) assessing the costs of PAH or the cost effectiveness of PAH treatments. The search results were independently reviewed and extracted by two reviewers. Costs were converted into 2014 US dollars.

RESULTS

Of 1959 citations identified in the initial search, 19 papers were finally included in this analysis: eight on the economic burden of PAH and 11 on economic evaluation of PAH treatments. The economic burden on patients with PAH was rather large, with direct healthcare costs per patient per month varying from $2476 to $11,875, but none of the studies reported indirect costs. Sildenafil was universally reported to be a cost-effective treatment, with lower costs and better efficacy than other medications. Medical costs were reported to be the key cost drivers.

CONCLUSION

The economic burden of patients with PAH is substantial, while the paucity of comprehensive country-specific evidence in this area and the lack of reports on indirect costs of PAH warrant researchers' concern, especially in China.

Cost-utility and budget impact analysis of drug treatments in pulmonary arterial hypertension associated with congenital heart diseases in Thailand

OBJECTIVE

This study aims to compare the lifetime costs and health outcomes of both first-line and sequential combination treatments with standard treatment for pulmonary arterial hypertension (PAH) associated with congenital heart disease (CHD) (PAH-CHD) patients.

METHODS

A cost-utility analysis was performed using a Markov model based on a societal perspective. One-way and probabilistic sensitivity analyses were performed to investigate the effect of parameter uncertainty.

RESULTS

As first-line treatments, both beraprost (incremental cost-effectiveness ratio (ICER) = 192,752 and 201,308 Thai baht (THB) per quality-adjusted life year (QALY) gained) and sildenafil (ICER = 249,770 and 226,802 THB per QALY gained) seemed cost-effective for PAH-CHD patients aged ≤30 years in functional classes II and III, respectively, while no treatment was cost-effective for the sequential combination therapy.

CONCLUSIONS

Sildenafil should be included in the National Drug List of Essential Medicines as the first-line treatment for PAH-CHD, and its price per dose should be negotiated to be reduced by 43-57%.

The quality of economic evaluations of ultra-orphan drugs in Europe - a systematic review

An orphan disease is defined in the EU as a disorder affecting less than 1 in 2 000 individuals. The concept of ultra-orphan has been proposed for diseases with a prevalence of less than 1:50 000. Drugs for ultra-orphan diseases are amongst the most expensive medicines on a cost-per-patient basis. The extremely high prices have prompted initiatives to evaluate cost-effectiveness and cost-utility in EU-member states. The objective of this review was to evaluate the quality of cost-effectiveness and cost-utility studies on ultra-orphan drugs. We searched 2 databases and the reference lists of relevant systematic reviews. Studies reporting on full economic evaluations, or at least aiming at such evaluation, were eligible for inclusion. Quality was assessed with the use of the Consensus on Health Economic Criteria (CHEC)-list. Two-hundred-fifty-one studies were identified. Of these, 16 fitted our inclusion criteria. A study on enzyme replacement and substrate reduction therapies for lysosomal storage disorders did not perform a full economic evaluation due to the high drug costs and the lack of a measurable effect on either clinical or health-related quality of life outcomes. Likewise, a cost-effectiveness analysis of laronidase for mucopolysaccharidosis type 1 was considered unfeasible due to lack of clinical effectiveness data, while in the same study a crude model was used to estimate cost-utility of enzyme replacement therapy (ERT) for Fabry disease. Three additional studies, one on ERT for Fabry disease, one on ERT for Gaucher disease and one on eculizumab for paroxysmal nocturnal haemoglobinuria, used an approach that was too simplistic to lead to a realistic estimate of the incremental cost-effectiveness (ICER) or cost-utility ratio (ICUR). In all other studies (N = 11) more sophisticated pharmacoeconomic models were used to estimate cost-effectiveness and cost-utility of the specific drug, mostly ERT or drugs indicated for pulmonary arterial hypertension (PAH). Seven studies used a Markov-state-transition model. Other models used were patient-level simulation models (N = 3) and decision trees (N = 1). Only 4 studies adopted a societal perspective. All but 2 studies discounted costs and effects appropriately. Drugs for metabolic diseases appeared to be significantly less cost-effective than drugs indicated for PAH, with ICERs ranging from €43 532 (Gaucher disease) to €3 282 252 (Fabry disease). Quality of studies using a Markov-state-transition or patient-level simulation model is in general good with 14–19 points on the CHEC-list. We therefore conclude that economic evaluations of ultra-orphan drugs are feasible if pharmacoeconomic modelling is used. Considering the need for modelling of several disease states and the small patient groups, a Markov-state-transition model seems to be most suitable type of model. However, it should be realised that ultra-orphan drugs will usually not meet the conventional criteria for cost-effectiveness. Nevertheless, ultra-orphan drugs are often reimbursed. Further discussion on the use of economic evaluations and their consequences in case of ultra-orphan drugs is therefore warranted.

An official American Thoracic Society/American College of Chest Physicians policy statement: the Choosing Wisely top five list in adult pulmonary medicine

The American Board of Internal Medicine Foundation's Choosing Wisely campaign aims to curb health-care costs and improve patient care by soliciting lists from medical societies of the top five tests or treatments in their specialty that are used too frequently and inappropriately. The American Thoracic Society (ATS) and American College of Chest Physicians created a joint task force, which produced a top five list for adult pulmonary medicine. Our top five recommendations, which were approved by the executive committees of the ATS and American College of Chest Physicians and published by Choosing Wisely in October 2013, are as follows: (1) Do not perform CT scan surveillance for evaluation of indeterminate pulmonary nodules at more frequent intervals or for a longer period of time than recommended by established guidelines; (2) do not routinely offer pharmacologic treatment with advanced vasoactive agents approved only for the management of pulmonary arterial hypertension to patients with pulmonary hypertension resulting from left heart disease or hypoxemic lung diseases (groups II or III pulmonary hypertension); (3) for patients recently discharged on supplemental home oxygen following hospitalization for an acute illness, do not renew the prescription without assessing the patient for ongoing hypoxemia; (4) do not perform chest CT angiography to evaluate for possible pulmonary embolism in patients with a low clinical probability and negative results of a highly sensitive D-dimer assay; (5) do not perform CT scan screening for lung cancer among patients at low risk for lung cancer. We hope pulmonologists will use these recommendations to stimulate frank discussions with patients about when these tests and treatments are indicated--and when they are not.

Cost-effectiveness impact of rivaroxaban versus new and existing prophylaxis for the prevention of venous thromboembolism after total hip or knee replacement surgery in France, Italy and Spain

Venous thromboembolism (VTE) has a significant impact on healthcare costs but is largely preventable with anticoagulant prophylaxis using low-molecular-weight heparins (LMWHs), such as enoxaparin or dalteparin. Rivaroxaban and dabigatran etexilate are two new oral anticoagulants (NOACs) both compared with enoxaparin in separate trials. A decision analytic model with a healthcare and national payer perspective over a five-year time horizon was used to evaluate the cost-effectiveness of the NOACs for VTE prophylaxis after total hip replacement (THR) or total knee replacement (TKR) in France, Italy and Spain. Efficacy and safety data were obtained from randomised controlled trials of rivaroxaban vs enoxaparin and an indirect statistical comparison for rivaroxaban vs dabigatran. Rivaroxaban demonstrated dominance across all comparisons, indications and countries. In THR, total per-patient costs were reduced by up to €160 in the enoxaparin comparison and €115 in the dabigatran comparison, respectively. In addition, quality-adjusted life-years (QALYs) were increased by up to 0.0011 and 0.0012 in each comparison, respectively. Similarly, total costs were reduced in TKR by up to €137 and €28 in the enoxaparin and dabigatran comparisons, respectively. The total number of QALYs was increased by up to 0.0014 in the enoxaparin comparison and 0.0005 in the dabigatran comparison. The results were driven by costs since the incremental benefits were minimal. Rivaroxaban use could result in substantial healthcare cost savings and improved quality of life. The results are applicable across three European countries with differing healthcare systems so, potentially, could be generalised to a much wider population.

Cost effectiveness of prostacyclins in pulmonary arterial hypertension

BACKGROUND

Pulmonary arterial hypertension (PAH) is considered an orphan disease. Prostacyclins are the keystone for PAH treatment. Choosing between the three available prostacyclin therapies could be complicated because there are no comparison studies, so the final decision must be driven by factors such as efficacy, administration route, safety profile and economic aspects.

OBJECTIVE

This study provides a cost-effectiveness and cost-utility comparison of initiating prostacyclin therapy with three different treatment alternatives (inhaled iloprost [ILO], intravenous epoprostenol [EPO] and subcutaneous treprostinil [TRE]) for patients with PAH. The goal of this work is to help physicians with their therapeutic decision-making.

METHODS

A Markov model was built to simulate a patient cohort with class III PAH according to the classification of the New York Heart Association (NYHA). Four health states corresponding with the NYHA classes plus death were allowed for patients in the model. Changing the treatment was possible when patients worsened from functional class III to IV. The time horizon was 3 years, allowing patients to transition between health states on a 12-week cycle basis. The study perspective was that of the National Health System (NHS) [only direct medical costs were included]. Unitary costs were obtained from the Drug Catalogue and e-Salud Database in 2009 and are given in euros (€). Data on health resources and treatment pathways were informed by a four-member expert panel. Efficacy was obtained from pivotal clinical trials of ILO, EPO and TRE, the latter used in Spain as a foreign medication. Utilities for each health state were obtained from the literature. The final efficacy measure was life-years gained (LYG), and utilities were used to obtain quality-adjusted life-years (QALYs). Costs and effects were discounted at a 3% rate. To check for the robustness of the results, sensitivity analyses were performed.

RESULTS

At the end of the 3 years, in the base case of the deterministic analysis, initiating prostacyclin therapy with iloprost was the less costly strategy (€132,840), followed by treprostinil (€359,869) and epoprostenol (€429,775). Epoprostenol has shown the best efficacy results with 2.73 LYG and 1.78 QALY, followed by iloprost (2.69 LYG and 1.74 QALY) and treprostinil (2.69 LYG and 1.73 QALY). Incremental cost-effectiveness ratios (ICER) and cost-utility ratios (ICUR) of epoprostenol versus iloprost and treprostinil were much above the €30,000 per LYG or QALY threshold commonly used in Spain. Iloprost was dominant compared with treprostinil. In the probabilistic analysis, epoprostenol, when compared with iloprost, was a dominant strategy in 15% of the simulations, but it was not a cost-effective option in 83% of the cases. When compared with treprostinil, epoprostenol was dominant in 43% of the simulations. Iloprost was dominant compared with treprostinil in 45% of the cases and it was a cost-effective alternative in 39% of the simulations.

CONCLUSIONS

Initiating prostacyclin treatment with iloprost in patients with PAH, functional class III of the NYHA, is the less costly alternative for the NHS in Spain, with a good efficacy profile when compared with the other alternatives.

Current practice for determining pulmonary capillary wedge pressure predisposes to serious errors in the classification of patients with pulmonary hypertension

BACKGROUND

Accurate measurement of left ventricular filling pressure is important to distinguish between category 1 pulmonary arterial hypertension (PAH) and category 2 pulmonary hypertension (PH) from left heart diseases (PH-HFpEF). We hypothesized that the common practice of relying on the digitized mean pulmonary capillary wedge pressure (PCWP-digital) results in erroneous recordings, whereas end-expiratory PCWP measurements (PCWP-end Exp) provide a reliable surrogate measurement for end-expiratory left ventricular end-diastolic pressure (LVEDP-end Exp-end Exp).

METHODS

We prospectively performed left and right cardiac catheterization on 61 patients referred for evaluation of PH and compared the LVEDP-end Exp to end-expiration to the (a) PCWP-end Exp and (b) PCWP-digital.

RESULTS

The PCWP-end Exp was a more reliable reflection of LVEDP-end Exp (mean 13.2 mm Hg vs 12.4 mm Hg; P, nonsignificant) than PCWP-digital (mean 8.0 mm Hg vs 12.4 mm Hg, P < .05). Bland-Altman analysis of PCWP-digital and LVEDP-end Exp revealed a mean bias of -4.4 mm Hg with 95% limits of agreement of -11.3 to 2.5 mm Hg. Bland-Altman analysis of PCWP-end Exp and LVEDP-end Exp revealed a mean bias of 0.9 mm Hg with 95% limits of agreement of -5.2 to 6.9 mm Hg. If PCWP-digital were used to define LVEDP-end Exp, 14 (27%) of 52 patients would have been misclassified as having PAH rather than PH-HFpEF. Patients with obesity and hypoxia were particularly more likely to be misclassified as PAH instead of PH-HFpEF if PCWP-digital was used to define LVEDP-end Exp (odds ratio 8.1, 95% CI 1.644-40.04, P = .01).

CONCLUSIONS

The common practice of using PCWP-digital instead of PCWP-end Exp results in a significant underestimation of LVEDP-end Exp. In our study, this translated to nearly 30% of patients being misclassified as having PAH rather than PH from HFpEF.

IVI epoprostenol as salvage therapy in pulmonary arterial hypertension: an Australian perspective

BACKGROUND

IVI epoprostenol is the only therapy for pulmonary arterial hypertension (PAH) with a randomized controlled trial demonstrating improved survival, when used as first-line monotherapy. In Australia it is used as salvage therapy for those failing treatment with other targeted therapies or presenting in World Health Organization functional class (FC) IV.

AIMS

Report experience with IVI epoprostenol, administered as salvage therapy for the treatment of adults with PAH in a single Australian PAH centre.

METHODS

Retrospective case series of all patients commenced on IVI epoprostenol for PAH, between 2002 and 2010. Review of case notes with collection of data at baseline and after treatment, including FC, 6-min walk test (6MWT), right ventricular systolic pressure (RVSP) on echocardiogram, patient survival and treatment complications. Change in indices was assessed using the Wilcoxon Sign Rank Test and is expressed as median (inter-quartile range).

RESULTS

A total of 23 patients was included. Treatment was generally well tolerated with few major complications. At the end of the study period, nine patients were successfully bridged to transplant, five had a sustained response to IVI epoprostenol, six had an incomplete response but were clinically stabilized, two died awaiting transplant and one died who was not a candidate for transplantation. Overall, when measured at best level post initiation of IVI epoprostenol, there were significant improvements in FC -1 [0 to -1] (P < 0.0001), 6MWT (m) +117 [70-264] (P= 0.002) and RVSP (mmHg) -7.0 [4.0 to -45] (P= 0.03).

CONCLUSION

Findings support efficacy of epoprostenol as salvage therapy for patients with PAH.

Pharmacoeconomic evidence of bosentan for pulmonary arterial hypertension

In this article, we review randomized controlled trials, open-label trials and pharmacoeconomic models of bosentan for the management of patients with pulmonary arterial hypertension. Bosentan consistently improves WHO functional class and quality of life, slows clinical worsening and is associated with improved survival compared with historical treatment. Although head-to-head trials are scarce, data directly comparing bosentan with sildenafil indicate no clinically significant differences between treatments as measured by the 6-min walk distance alone. Compared with historical care, bosentan treatment, over a 15-30-year period, increases the number of quality-adjusted life years (3.49 years). Economic modeling suggests that the cost-effectiveness of bosentan is similar to that of ambrisentan (US$43,725-57,778 per quality-adjusted life year), not as cost effective as sildenafil (at 20 mg three-times daily) and more cost effective than iloprost. More randomized controlled trials of longer duration are required to confirm the results from these economic models.

Pharmacoeconomic analysis in Saudi Arabia: an overdue agenda item for action

Pharmacoeconomics is a branch of health economics related to the most economical and efficient use of pharmaceuticals. Pharmacoeconomic research identifies, measures and compares the costs and outcomes (clinical, economic and humanistic) of pharmaceutical products and services. Pharmacoeconomic evaluation can play a significant role in the efficient allocation of resources in healthcare systems with constrained budgets. Countries are trying to control the rising costs of health care in their aging population. They are all asking the same question: Is the new drug good value for money; and if so, what is the society willing to pay for it? This article reviews the importance of, and the need for, adaptation of pharmacoeconomic analysis to the conditions in Saudi Arabia. It will shed some light on the important steps for converting the concept into practice, including the need for identifying the willing-to-pay (WTP) or the threshold cutoff, the existence of a real cost for each utility, the nonexistence of an pharmacoeconomic advisory forum, pharmaceutical budget allocation, and the impact of pharmaceutical marketing. It will also provide recommendations for easing any challenges that might jeopardize the conduct of such analysis in Saudi Arabia.

Bosentan for the treatment of adult pulmonary hypertension

Pulmonary hypertension is a severe progressive disease with a marked morbidity and a high mortality attributed to right heart failure. Bosentan, a dual endothelin receptor antagonist, is an effective and well-tolerated oral therapy for the management of pulmonary arterial hypertension (PAH; WHO group 1 pulmonary hypertension). Bosentan improves cardiopulmonary hemodynamics, exercise capacity, WHO functional class and quality of life, as well as delaying time to clinical worsening in patients with PAH. This article reviews the role of endothelin-1 in the pathogenesis and progression of PAH, the diagnosis of PAH and the pharmacology of bosentan, and summarizes the current available evidence for the safety and efficacy of bosentan for the treatment of PAH as a monotherapy and combination therapy, as well as its role in the management of other forms of pulmonary hypertension.

Idiopathic- and scleroderma-related pulmonary arterial hypertension: outcomes and QOL on bosentan

Idiopathic pulmonary arterial hypertension (previously known as primary pulmonary hypertension) is a devastating disease of insidious onset, late diagnosis, progressive functional disability and poor prognosis. However, treatment with pulmonary arterial hypertension-specific agents has already changed the outlook wherever these agents are accessible. The process of economic evaluation of treatment for idiopathic pulmonary arterial hypertension is challenging due to limitations common to clinical studies in rare diseases, such as small patient numbers limiting survival information, lack of directly comparable trials for the efficacy of different drugs and a paucity of quality of life measurements. Bosentan (Tracleer), Actelion), has proven effective in clinical trials, and is the most frequently used pulmonary arterial hypertension-specific agent worldwide. It has additionally undergone a comprehensive quality of life trial and economic evaluation as therapy for idiopathic pulmonary arterial hypertension and pulmonary arterial hypertension associated with scleroderma. This review explores the role of bosentan in providing cost-effective therapy compared with alternative treatments, and addresses the future considerations required to ensure accessible patient care for idiopathic pulmonary arterial hypertension and pulmonary arterial hypertension associated with scleroderma.

Burden of pulmonary arterial hypertension in Germany

This study aimed to describe health care provision, resource consumption and related costs, as well as treatment patterns and quality of life in adult patients with pulmonary arterial hypertension (PAH) in Germany. Data for this retrospective and prospective cost-of-illness-study were derived from hospitals, general practitioners and patients. Costs were evaluated from the perspective of third party payer and patient. Quality of life data were collected by using three validated instruments. A total of 167 patients were enrolled at 10 hospitals. Time period from first occurrence of symptoms to confirmed diagnosis of PAH was 2.3 years on average. Mean number of GP visits was 1.5 per patient per month, and within 15 months, inpatient stays were reported for 50% of patients. The ratio of combination therapy to single-drug therapy for endothelin receptor antagonists, phosphodiesterase-5-inhibitor and prostacyclin analogues increased significantly during 15 months. Treatment costs were, on average, euro47,400 per patient per year, arising mainly from drugs. Compared to the general population, quality of life of PAH patients was considerably impaired. This is the first study which evaluated aspects of the medical and economic consequences of PAH based on a large cohort of PAH patients in Germany.

Treatment patterns and resource utilization and costs among patients with pulmonary arterial hypertension in the United States

OBJECTIVE

To explore treatment patterns and resource utilization and cost for subjects with pulmonary arterial hypertension (PAH).

RESEARCH DESIGN

Retrospective claims database analysis of 706 patients with PAH enrolled in a large, geographically diverse US managed-care organization.

RESULTS

In the final sample of PAH patients treated with bosentan (n=251) or sildenafil (n=455), average age was 57 years, 86% of patients were commercially insured, and 52% of patients were male. Gender distribution varied significantly across subgroups, with a lower proportion of males in the bosentan (30%) subgroup compared with the sildenafil group (64%) (p<0.001). Average baseline Charlson comorbidity score was 2.4. Average numbers of fills per month were 0.8 and 0.4 for bosentan and sildenafil patients, respectively (p<0.001). Over 80% of patients received only one PAH treatment in the first 90 days following the index date, with 28% of bosentan and 13% of sildenafil patients receiving combination therapy (p<0.001). Over one-third of bosentan patients and one-quarter of sildenafil patients experienced a dose increase in the follow-up period (p=0.009). Sixteen percent of sildenafil patients experienced a dose decrease in the follow-up period, while a smaller proportion of patients receiving bosentan (4%) experienced a dose decrease (p<0.001). On average, number of PAH-related per subject per month (PSPM) inpatient stays and emergency department visits and PSPM length of inpatient stays were statistically similar between the subgroups. PAH-related PSPM healthcare costs were high for both subgroups, with average monthly costs of $5,332 and $3,632 among bosentan and sildenafil patients, respectively (p=0.003). Differences in total costs were driven mainly by differences in pharmacy expenditures.

CONCLUSIONS

Of the oral agents approved for treating PAH at the time of this study, sildenafil was most commonly prescribed as index therapy and was also associated with the lowest costs, largely due to significantly lower pharmacy costs. This study is characterized by limitations inherent to claims database analyses, such as the potential for coding errors and lack of information on whether a drug was taken as prescribed. Furthermore, PAH severity (WHO functional class) was not assessed.

Cost-utility of treatments for pulmonary arterial hypertension: a Markov state-transition decision analysis model

BACKGROUND AND OBJECTIVE

Clinicians must choose between an increasing number of medications for the treatment of pulmonary arterial hypertension (PAH) with different routes of administration, adverse effects, costs and efficacies. We constructed a decision analysis to help inform treatment choices in PAH.

METHODS

We created a Markov-type model to evaluate 1-year treatment with bosentan, treprostinil, epoprostenol, inhaled iloprost, sildenafil, sitaxentan and ambrisentan. Transition probabilities were based on observed transitions between WHO functional classes, adjusted by relative risk of improvement in a 6-minute walk test. Utilities were based on reported values for each functional class, adjusted for burden of treatment administration. Costs were estimated from Medicare and Medicaid reimbursement data. Sensitivity analyses evaluated changes in efficacy, utilities and costs.

RESULTS

Treatment with sildenafil was less costly and resulted in a greater gain in quality-adjusted life-years (QALYs) compared with other treatments. Treatment with ambrisentan and bosentan resulted in the same gain in QALYs as sildenafil, but at a higher cost. Sensitivity analyses had minimal impact on these results.

CONCLUSIONS

Based on this model, sildenafil is a cost-effective treatment for PAH with a low price and a net increase in QALYs. The results from this analysis are a tool to help guide clinicians in deciding which PAH medications to use; however, the final decisions should be individualized because the effectiveness of therapy, resulting utilities and acceptable costs will differ with each patient.

The cost-effectiveness of bosentan in the United Kingdom for patients with pulmonary arterial hypertension of WHO functional class III

OBJECTIVES

To assess whether bosentan or no active intervention, in addition to palliative care, is the more cost-effective first-line treatment option for patients with idiopathic pulmonary arterial hypertension (iPAH) or PAH associated with connective tissue disease (PAH-CTD) of WHO functional classification (FC) III in the United Kingdom.

METHODS

A cost-utility model simulated the treatment of patients with PAH of FC III. Patients remained on the selected intervention until death or clinical deterioration to FC IV, which would trigger initiation of epoprostenol treatment. The initial first-line treatment choice was assumed to not affect survival, but to affect the time until clinical deterioration, with this assumption being relaxed in sensitivity analyses. The distribution of time to clinical deterioration was estimated from long-term clinical trial databases of bosentan and from published literature. Utility associated with FC was taken from published literature. Costs were sourced from published literature and from specialist PAH centers. The time horizon was that of patients' lifetimes, with costs and benefits discounted at 3.5% per annum.

RESULTS

In the base case, bosentan dominated no active intervention because of the longer time to clinical deterioration and therefore the reduced time, per patient, spent in FC IV, which was associated with high costs of epoprostenol and reduced utility. In sensitivity analyses, bosentan was estimated to be more cost-effective than no active intervention, provided that any survival benefit was not greater than 2 years for patients with iPAH and 1 year for those with PAH-CTD.

CONCLUSIONS

Bosentan is likely to be a more cost-effective first-line therapy for patients with PAH FC III in the UK than no active intervention.

Dosing considerations in the use of intravenous prostanoids in pulmonary arterial hypertension: an experience-based review

BACKGROUND

Intravenous (IV) prostanoid therapy remains arguably the most effective treatment of advanced pulmonary arterial hypertension (PAH) despite the introduction of newer molecules from different drug classes.

METHODS

Literature regarding the properties, efficacy, safety, dosing, and cost of IV prostanoids was reviewed. In addition, a survey of physicians who treat PAH in the United States was conducted to assess IV prostanoid use in clinical practice.

RESULTS

Clinical studies have demonstrated that the 2 prostanoids available for IV administration in the United States, epoprostenol and treprostinil, improve exercise capacity, dyspnea, and cardiopulmonary hemodynamics in patients with PAH. Furthermore, epoprostenol has been shown to improve quality of life, functional class, and survival. The safety profiles of epoprostenol and IV treprostinil during short-term therapy appear comparable. Potential differences in the biochemical properties of these 2 drugs may have clinical implications. Whereas long-term data with subcutaneous treprostinil have been published, such data for IV treprostinil are not currently available. The physician survey revealed differences in the common maintenance doses used for both drugs, with IV treprostinil dosing approximately twice that of epoprostenol. These differences in dose have a direct bearing on the cost of therapy.

CONCLUSIONS

The unique properties of epoprostenol and treprostinil translate into clinical differences, which can influence the amount of drug used to achieve satisfactory patient improvement in the acute and long-term settings.

Oral therapies for the treatment of pulmonary arterial hypertension: a population-based cost-minimization analysis

BACKGROUND AND OBJECTIVE

Pulmonary arterial hypertension (PAH) is a rare but life-threatening condition that is characterized by progressive elevation of pulmonary artery pressure and pulmonary vascular resistance, leading to right-sided heart failure and frequently death. Orally administered agents used for the treatment of symptomatic, moderate-to-severe PAH include sildenafil and the endothelin (ET) receptor antagonists (ERAs), bosentan and sitaxentan (sitaxsentan). Ambrisentan is a new oral ET(A) receptor-selective ERA, with higher ET receptor affinity than bosentan. Placebo-controlled, randomized clinical trials (RCTs) have demonstrated that ambrisentan (5 or 10 mg/day) is safe and effective. To provide health economic data on the multiple oral PAH therapies currently available, a population-based cost-minimization analysis (CMA) was conducted for Canada.

METHODS

The primary requirement for a CMA is that all clinical outcomes be equivalent between comparator treatments. To provide such supporting data, a literature search was conducted for RCTs of oral agents used to treat symptomatic PAH. This was followed by application of direct and indirect statistical methods to support the hypothesis of clinical equivalence between the oral agents. Estimates for PAH prevalence, incidence and death rates were then used to build a population-based CMA model. The base-case analysis considered costs for drug therapy, outpatient pharmacy costs, medical consultations and visits, laboratory and diagnostic procedures and other healthcare-related resources. In addition, costs for secondary pharmacotherapy in cases where the primary agent had to be discontinued because of adverse effects were also included. The time horizon for evaluating pharmacotherapy was 3 years, all costs were in 2008 Canadian dollars ($Can) and the costs were discounted at a rate of 3% annually. The study perspective was the Canadian healthcare system.

RESULTS

There were no double-blind RCTs comparing ambrisentan with any of the other oral agents. Therefore, an indirect comparison of placebo-controlled trials of PAH drugs had to be used to support the clinical equivalence. This included a calculation of standardized mean differences (SMD) between agents (vs placebo) and a meta-regression analysis on the primary and secondary trial endpoints. Keeping in mind the caveats associated with indirect trial comparisons, the data suggested similar clinical efficacy over 12-16 weeks between agents, as indicated by the identical magnitude of the SMD between the active agent and placebo and the non-significant differences between drugs as determined by the meta-regression analysis. The population-based model projected that the number of PAH patients clinically suitable for these drugs in Canada would be 931 in the first full-budget year (i.e. 2009) with an increase to 1114 by the third full year. The CMA revealed the following rank order of the least to most costly agent; sildenafil, ambrisentan, sitaxentan and bosentan. Sildenafil was the least costly, primarily because of the lower daily drug-acquisition cost. Of the three ERAs, ambrisentan would be associated with annual cost savings of $Can3.4 and $Can5.6 million when used as an alternative to sitaxentan or bosentan, respectively.

CONCLUSIONS

Ambrisentan is less costly than other available ERAs, including bosentan and sitaxentan, but is more costly than sildenafil. In PAH patients in whom an ERA is the preferred agent, ambrisentan may be the drug of choice because of its economic advantages and improved safety profile.

Evidence-based pharmacologic management of pulmonary arterial hypertension

BACKGROUND

Pulmonary arterial hypertension (PAH) is a debilitating chronic disorder of the pulmonary vasculature characterized by elevated mean pulmonary arterial pressure, right-sided heart failure, and early mortality.

OBJECTIVES

This paper reviews the available information on PAH, including its pathophysiology, classification of its severity, current treatment options, drug interactions, pharmacokinetics, and cost considerations. The results of clinical trials of the available treatments are summarized, and a suggested treatment algorithm is provided as a guide to the medical management of PAH.

METHODS

Pertinent articles were identified by a search of MEDLINE through May 2007 using the terms primary pulmonary hypertension, pulmonary arterial hypertension, prostacyclin, pulmonary vasodilators, endothelin-receptor antagonists, and phosphodiesterase inhibitors. Trials with prospective, randomized designs were given precedence, and prospective studies having nonrandomized, open-label designs or using historical controls were included if they contributed useful knowledge. Retrospective studies were not included.

RESULTS

In two 12-week, randomized, open-label trials in patients with moderate to severe PAH (N = 81 and N = 111), exercise capacity, measured on the 6-minute walk test (6-MWT), was significantly improved with intravenous epoprostenol compared with conventional therapy (+31 vs -29 m, respectively, in one study [P = 0.002]; +46 vs -48 m in the other [P < 0.001]). In one of these trials, intravenous epoprostenol also was associated with a significant survival benefit (P < 0.003). In a 12-week, randomized, doubleblind, placebo-controlled trial in 470 patients with moderate to severe PAH, subcutaneous treprostinil plus conventional therapy was associated with a significant improvement on the 6-MWT compared with conventional therapy alone (+10 vs 0 m, respectively; P = 0.006). In a 16-week, randomized, double-blind, placebo-controlled trial in 213 patients with mild to moderate symptoms, the oral endothelin-receptor antagonist bosentan was associated with a significant improvement on the 6-MWT compared with placebo (+36 vs -8 m, respectively; P </= 0.001) and significantly less clinical worsening at 28 weeks (9/144 vs 14/69; P = 0.002). In a 12-week, prospective, randomized, double-blind, placebo-controlled trial in 277 patients with PAH, sildenafil 20, 40, and 80 mg TID were associated with significant improvements on the 6-MWT compared with placebo (all, P < 0.001). In a prospective trial in 76 patients with idiopathic PAH, the inhaled prostacyclin iloprost was associated with overall survival rates of 93%, 79%, 70%, 59%, 59%, and 49% at 3 months and 1, 2, 3, 4, and 5 years, respectively. In an early trial in 64 patients receiving highdose calcium channel blockers, those who had responded to initial drug challenge (defined as a > 20% decrease in pulmonary arterial pressure and pulmonary vascular resistance immediately after challenge) had a survival rate of 94% at 1, 3, and 5 years.

CONCLUSIONS

Patients who respond to an acute trial of a vasodilator may be treated with an oral calcium channel blocker, whereas oral therapies such as sildenafil and bosentan have been effective in patients with mild to moderate symptoms. Infusions of the prostacyclin analogues epoprostenol and treprostinil appear to be the treatment of choice for moderate to severe PAH, and agents with alternate routes of delivery such as inhaled iloprost may be advantageous in adjunctive roles. Future trials that focus on the long-term effects of currently available agents, as well as on combination therapy, are needed.

Epidemiology of Pulmonary Arterial Hypertension

Progress in understanding the basic biology and the development of new therapies for pulmonary arterial hypertension have led to improvements in survival. This article reviews clinically important changes in the classification of the pulmonary hypertensive diseases, as well as the epidemiology of various forms of pulmonary hypertension. The risk factors for the development of pulmonary arterial hypertension, prognostic markers, and the effects of current therapies on survival are discussed.

Low-dose oral sildenafil for patients with pulmonary hypertension: a cost-effective solution in countries with limited resources

INTRODUCTION

Pulmonary arterial hypertension, both primary and secondary, continues to pose a therapeutic problem. In this study, we evaluate the efficacy and safety of a low-dose of oral sildenafil in 10 patients with pulmonary arterial hypertension.

METHODS

We administered a single daily dose of 0.5 milligrams per kilogram of sildenafil for 3 months to 10 patients with pulmonary arterial hypertension. Their average age was 26.8 years. Diagnoses were primary pulmonary arterial hypertension in 3 patients, and secondary pulmonary arterial hypertension due to congenital cardiac disease in the remaining 7 patients. Outcome measures included the clinical state, the mean pulmonary arterial pressure, and the indexed pulmonary vascular resistance; the latter two assessed at the beginning and at the end of the treatment period by cardiac catheterization. We also analysed the cost of the treatment.

RESULTS

Oral treatment was well tolerated, and resulted in an improvement of the functional capacity in 9 of the 10 patients. Pulmonary arterial pressure decreased from 70 to 60 millimetres of mercury (p equal to 0.05), and indexed pulmonary vascular resistance decreased from 21.8 to 15.8 Wood units per square metre (p equal to 0.006). The mean cost per patient for 3 months on oral treatment with sildenafil was 120.99 American dollars.

CONCLUSIONS

A low dose of 0.5 milligrams per kilogram per day of oral sildenafil, instead of 1 to 4 milligrams per kilogram per day, provided early clinical and haemodynamic improvements, and proved less expensive. Additional experience is now required to define more reliably the true long-term benefits of this therapy.

Bosentan therapy of pulmonary arterial hypertension in connective tissue diseases

BACKGROUND

Pulmonary arterial hypertension (PAH) is a life-threatening and debilitating complication of several connective tissue diseases. We aimed to evaluate the effects of long-term treatment with bosentan, an oral dual endothelin ET(A)/ET(B) receptor antagonist, in a cohort of patients with PAH related to connective tissue diseases.

MATERIALS AND METHODS

In the present prospective, noncontrolled study, 13 patients (nine with systemic sclerosis, two with systemic lupus erythematosus, one with mixed connective tissue disease and one with overlap syndrome including scleroderma and myositis), mostly nonresponders to prostanoids therapy, were treated for 1 year with bosentan. Cardiac haemodynamics and the diagnosis of PAH were performed by Doppler ultrasound examination. Exercise capacity was assessed by 6-min walking test at baseline and at 3, 6 and 12 months of therapy.

RESULTS

During bosentan treatment, progressive improvement of exercise capacity was observed. Walk distance increased in seven patients, remained unchanged in three and slightly decreased in three patients. A progressive significant decrease of right ventricular systolic pressure was also observed, whereas pulmonary artery mean pressure remained unchanged. Adverse effects related to bosentan (elevation of hepatic aminotransferases) were noted in two patients.

CONCLUSION

Long-term treatment with bosentan was effective in improving exercise capacity and pulmonary haemodynamics in patients with PAH related to connective tissue diseases.

Cognitive, emotional, and quality of life outcomes in patients with pulmonary arterial hypertension

Background

The effects of pulmonary arterial hypertension on cardiovascular and physical function are well documented. Limited information exists regarding the effects of pulmonary arterial hypertension on cognitive function despite patient reports of problems with memory and attention. Our primary purpose was to determine if a prospectively identified cohort of pulmonary arterial hypertension patients had cognitive sequelae. Our secondary purpose was to determine the relationships between cognitive sequelae and neuropsychological test scores with depression, anxiety, and quality of life.

Methods

Forty-six adults with pulmonary arterial hypertension underwent assessment of cognitive function, depression, anxiety, and quality of life using standardized neuropsychological tests and questionnaires. The patients' scores were compared to normal population data. Medical, affective, neuropsychological, and quality of life data for patients with and without cognitive sequelae were compared using analysis of variance, Chi-square, or Fisher exact tests for categorical data. Correlations assessed relationships between neuropsychological test scores, depression, anxiety, quality of life, and medical data.

Results

Cognitive sequelae occurred in 58% (27/46) of the pulmonary arterial hypertension patients. Patients with cognitive sequelae had worse verbal learning, delayed verbal memory, executive function, and fine motor scores compared to patients without cognitive sequelae. Twenty-six percent of patients had moderate to severe depression and 19% had moderate to severe anxiety. Depression, anxiety and quality of life were not different for patients with or without cognitive sequelae. Our patients had decreased quality of life, which was associated with worse working memory.

Conclusion

Patients with pulmonary arterial hypertension have cognitive impairments, depression, anxiety, and decreased quality of life. Depression, anxiety, and quality of life were similar for patients with cognitive sequelae compared to those without cognitive sequelae. Decreased quality of life was associated with worse verbal and working memory. Clinicians should be aware of adverse brain related outcomes in PAH patients. Attention to proximal determinants and possible interventions to prevent or reduce cognitive and emotional morbidity and decreased quality of life are warranted and should be an emphasis in outcomes research.

Public funding of bosentan for the treatment of pulmonary artery hypertension in Australia: cost effectiveness and risk sharing

OBJECTIVES

In Australia, no therapeutic agents were subsidised for the treatment of idiopathic pulmonary artery hypertension (iPAH), a rare progressive and severe disease with short life expectancy, until 1 March 2004, when bosentan (a dual endothelin receptor antagonist of high cost) was listed on the Pharmaceutical Benefits Scheme (PBS). Bosentan, in addition to conventional therapy, has been shown to slow iPAH progression and improve clinical and haemodynamic status and symptomatology, compared with placebo and conventional therapy. The objective of this paper is to describe the process of the Australian Pharmaceutical Benefits Scheme listing for bosentan (Tracleer), which included a health economic model assessing the cost effectiveness of bosentan from a healthcare payer perspective, and a risk-sharing arrangement based on the establishment of a patient registry.

METHODS

The health economic model predicted the cost, hospitalisation and mortality rates of a population of iPAH patients treated with either the conventional therapy regimen used in Australia or bosentan plus the conventional therapy regimen. The model was implemented as a first-order Monte Carlo simulation with mortality modelled directly as the main clinical outcome. The impacts of proposed continuation criteria, restricting the ongoing use of the drug, were evaluated. Costs and outcomes were discounted at 5% and a sensitivity analysis examined the robustness of the key assumptions.

RESULTS

The model predicted that after 5, 10 and 15 years, the difference in average cumulative costs between bosentan plus conventional therapy and conventional therapy alone would be 116,929 Australian dollars (A dollars), A181,808 dollars and A216,331 dollars for each patient, respectively. There would be an associated increase in average life expectancy of 1.39, 2.93 and 3.87 years at 5, 10 and 15 years, respectively, with an incremental cost-effectiveness ratio at 15 years of A55,927 dollars for each life-year gained. Removing the continuation criteria from the model increased the incremental cost-effectiveness ratio to A62,267 dollars (1996-2002 values).

CONCLUSIONS

Economic modelling based on improved survival suggests bosentan to be a potentially cost-effective treatment for iPAH. However, the structure of the model and its inputs should be reviewed and updated as more data become available.

Cost-minimization analysis of treprostinil vs. epoprostenol as an alternate to oral therapy non-responders for the treatment of pulmonary arterial hypertension

INTRODUCTION

Idiopathic pulmonary arterial hypertension (IPAH) is associated with substantial morbidity and mortality. Treprostinil was compared to epoprostenol for the economic impact of treating IPAH patients who failed or were not candidates for bosentan.

METHODS

The model was a cost-minimization analysis, assuming clinical equivalence was achieved by proper dosing of both drugs, in terms of survival and surrogate measures. Two theoretical cohorts of 270 patients were treated with subcutaneous treprostinil and intravenous epoprostenol, and were evaluated over 3 years using a spreadsheet model. Annual survival rates were estimated for the cohorts so that at endpoint 114 (42%) patients survived in both groups. The model utilized resource valuation data for medication and supply costs from Medicare; hospital, consultation, surgical, and diagnostic procedural fees from North Carolina hospitals; and costs to treat adverse events from published sources. Costs were obtained from standard lists and were presented as 2003 US dollars, discounted at 3%. Sensitivity analyses were performed testing all model uncertainties.

RESULTS

In the base case analysis, treprostinil demonstrated savings of 22,701 US dollars and 37,433 US dollars per patient over 1- and 3-year time horizons, respectively. The greatest savings came from reduced or minimal hospitalizations attributed to the dose titration and treatment of adverse events, such as sepsis, associated with epoprostenol and its delivery system. Probabilistic sensitivity analyses resulted in average 3-year cost-savings of 41,051 US dollars (Standard Deviation = 13,902 US dollars) per patient.

CONCLUSIONS

By initiating and continuing treatment with treprostinil over a 3-year period, the economic burden associated with IPAH may be reduced compared to treatment with epoprostenol. The greatest saving with treprostinil was attributed to decreased sepsis.

The evolving use of cost-effectiveness analysis in formulary management within the Department of Veterans Affairs

The Veterans Health Administration (VHA) runs the largest integrated healthcare system in the nation. Formulary management within VHA primarily involves 3 national groups: the Medical Advisory Panel, the Veterans Integrated Service Network Formulary Leaders, and the Pharmacy Benefits Management Strategic Healthcare Group. Together, these groups manage the VHA national drug formulary with a goal of providing a comprehensive, safe, and cost-effective pharmacy benefit for veterans. Traditionally, VHA has relied on cost-minimization analyses in formulary decisions. More recently, VHA has emphasized the use of cost-effectiveness data, especially for newer, costly drugs. In addition to including this data in drug monographs, the VHA has begun requiring formal cost-effectiveness analysis from manufacturers of selected pharmaceuticals. VHA has also requested that clinically relevant information such as quality of life plus mortality benefit be made available from industry so that internal cost analyses can be performed. It is hoped that by setting the expectation that cost-effectiveness will be formally considered in all VHA formulary decisions, the pharmaceutical industry and others will be stimulated to collect and report data that enables these analyses. We believe that if other organizations also place an emphasis on economic evaluations, industry and the public will be more accepting of decisions that incorporate cost considerations.

Health-related quality of life in patients with pulmonary arterial hypertension

Background

Improved outcomes with expanding treatment options for patients with pulmonary arterial hypertension present the opportunity to consider additional end-points in approaching therapy, including factors that influence health-related quality of life. However, comparatively little is known about health-related quality of life and its determinants in patients with pulmonary arterial hypertension.

Methods

Health-related quality of life was evaluated in a cross sectional study of 155 outpatients with pulmonary arterial hypertension using generic and respiratory-disease specific measurement tools. Most patients had either World Health Organization functional Class II or III symptoms. Demographic, hemodynamic and treatment variables were assessed for association with health-related quality of life scores.

Results

Patients with pulmonary arterial hypertension suffered severe impairments in both physical and emotional domains of health-related quality of life. Patients with idiopathic ("primary") pulmonary arterial hypertension had the best, and those with systemic sclerosis the worst health-related quality of life. Greater six-minute walk distance correlated with better health-related quality of life scores, as did functional Class II versus Class III symptoms. Hemodynamic measurements, however, did not correlate with health-related quality of life scores. No differences in health-related quality of life were found between patients who were being treated with calcium channel antagonists, bosentan or continuously infused epoprostenol at the time of quality of life assessment.

Conclusion

Health-related quality of life is severely impaired in patients with pulmonary arterial hypertension and is associated with measures of functional status. Specific associations with impaired health-related quality of life suggest potential areas for targeted intervention.

Inhaled Iloprost in Pulmonary Arterial Hypertension

OBJECTIVE

To review the pharmacology, pharmacodynamics, and clinical trials evaluating inhaled iloprost in pulmonary arterial hypertension (PAH).

DATA SOURCES

A MEDLINE search (1996–February 2005) was performed using the key words pulmonary hypertension, iloprost, and epoprostenol. Information regarding Food and Drug Administration approval was obtained via the Internet.

STUDY SELECTION AND DATA EXTRACTION

All clinical trials using inhaled iloprost in PAH published in English were identified. Additionally, references from the identified articles were reviewed.

DATA SYNTHESIS

A stable analog of prostacyclin, inhaled iloprost is thought to promote benefit in PAH through vasodilation, antiproliferative effects, and inhibition of platelet aggregation. In a placebo-controlled trial of 203 patients, inhaled iloprost significantly improved the combined endpoint of change in New York Heart Association functional class and 10% improvement in 6-minute walk distance (p = 0.007). Small, short-term clinical trials demonstrated hemodynamic benefits for inhaled iloprost alone and in combination with other pulmonary vasodilating agents. The aerosolized delivery route and low incidence of adverse events are positive attributes for inhaled iloprost, while the frequency of administration and lack of comparative data limit its role in PAH.

CONCLUSIONS

Currently, inhaled iloprost offers potential benefit for patients with contraindications to bosentan, preference for non-parenteral products, ineligibility for parenteral therapy, or as adjunctive therapy with other pulmonary vasodilators. Larger, long-term clinical trials are needed to solidify the role for inhaled iloprost in the management of PAH.

Prostacyclin for pulmonary hypertension in adults

BACKGROUND

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

OBJECTIVES

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

SEARCH STRATEGY

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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