Cost Effectiveness of First-Line Oral Therapies for Pulmonary Arterial Hypertension: A Modelling Study

Population Health Model Predicting the Long-Term Impact of Sotatercept on Morbidity and Mortality in Patients with Pulmonary Arterial Hypertension (PAH)

INTRODUCTION

Pulmonary arterial hypertension (PAH) is a rare, progressive disease associated with significant morbidity and mortality. The phase 3 STELLAR trial tested sotatercept plus background therapy (BGT) versus placebo plus BGT. BGT was comprised of mono-, double-, or triple-PAH targeted therapy. Building on STELLAR findings, we employed a population health model to assess the potential long-term clinical impact of sotatercept.

METHODS

Based on the well-established ESC/ERS 4-strata risk assessment approach, we developed a six-state Markov-type model (low risk, intermediate-low risk, intermediate-high risk, high risk, lung/heart-lung transplant, and death) to compare the clinical outcomes of sotatercept plus BGT versus BGT alone over a lifetime horizon. State-transition probabilities were obtained from STELLAR. Risk stratum-adjusted mortality and lung/heart-lung transplant probabilities were based on COMPERA PAH registry data, and the post-transplant mortality probability was obtained from existing literature. Model outcomes were discounted at 3% annually. Sensitivity analyses were conducted to examine model robustness.

RESULTS

In the base case, sotatercept plus BGT was associated with longer life expectancy from model baseline (16.5 vs 5.1 years) versus BGT alone, leading to 11.5 years gained per patient. Compared with BGT alone, sotatercept plus BGT was further associated with a gain in infused prostacyclin-free life years per patient, along with 683 PAH hospitalizations and 4 lung/heart-lung transplant avoided per 1000 patients.

CONCLUSIONS

According to this model, adding sotatercept to BGT increased life expectancy by roughly threefold among patients with PAH while reducing utilization of infused prostacyclin, PAH hospitalizations, and lung/heart-lung transplants. Real-world data are needed to confirm these findings.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT04576988 (STELLAR).

Cost-effectiveness analysis of selexipag for the combined treatment of pulmonary arterial hypertension

Objective: Adding selexipag to the combined treatment of endothelin receptor antagonists (ERA) and phosphodiesterase 5 inhibitor (PDE5i) reduces the risk of clinical worsening events in patients with pulmonary arterial hypertension (PAH) but at a considerably higher cost. This study evaluated the cost-effectiveness of adding selexipag to the combined treatment of ERA and PDE5i in patients with PAH from a Chinese healthcare system perspective. Methods: A Markov model was developed to assess costs and quality-adjusted life years (QALYs) of macitentan + tadalafil + selexipag vs. macitentan + tadalafil for the treatment of PAH. Markov states included WHO Functional Class (FC) (I-IV) and death. Transition probabilities were based on data from the TRITON trial. Mortality rates, costs, and utilities were obtained from published literature and public databases. Results: In the base case analysis, compared with macitentan + tadalafil, selexipag + macitentan + tadalafil increased costs ($357,807.588 vs. $116,534.543, respectively) and QALYs (7.234 QALYs vs. 6.666 QALYs, respectively). The resulting incremental cost-effectiveness ratio was $424,746.070 per QALY, which was higher than the willingness-to-pay (WTP) of $38,223.339 per QALY. The results were most sensitive to HR for mortality of patients with FC IV relative to the general population, discount rate, and the cost of selexipag. The probability was greater than 50% for the selexipag + macitentan + tadalafil only if the WTP was more significant than $426,019.200 per QALY. Conclusion: In China, adding selexipag may not be cost-effective for patients with PAH who failed to control their condition after combined treatment of ERA and PDE5i. Results of the analysis can aid discussions on the value and position of selexipag for the combined treatment of PAH.

Cost-utility of ambrisentan and bosentan for pediatric pulmonary arterial hypertension

INTRODUCTION

Despite the increasing evidence supporting the efficacy of ambrisentan and bosentan in improving functional classes among pediatric patients with pulmonary arterial hypertension (PAH), there is a lack of information regarding their cost implications. Therefore, the objective of this study is to assess the cost-utility of bosentan compared to ambrisentan for the treatment of pediatric patients with PAH in Colombia.

METHODS

We employed a Markov model to estimate the costs and quality-adjusted life-years (QALYs) associated with the use of ambrisentan or bosentan in pediatric patients diagnosed with pulmonary arterial hypertension (PAH). To ensure the reliability of our findings, we conducted sensitivity analyses to assess the robustness of the model. In our cost-effectiveness analysis, we evaluated the outcomes at a willingness-to-pay (WTP) threshold of US$5,180.

RESULTS

The expected annual cost per patient receiving ambrisentan was estimated to be $16,055 (95% CI 15,937 -16,172), while for bosentan it was $14,503 (95% CI 14,489 -14,615). The QALYs per person estimated for ambrisentan were 0.39 (95% CI 0.381-0.382), whereas for bosentan it was 0.40 (95% CI 0.401-0.403).

CONCLUSION

Our economic evaluation shows that ambrisentan is not cost-effective regarding bosentan to in treating pulmonary arterial hypertension in C.

Cost-Effectiveness Analysis of Macitentan in Comparison With Bosentan in the Treatment of Pulmonary Arterial Hypertension in Iran

OBJECTIVES

Pulmonary arterial hypertension (PAH) is a chronic and progressive disease that, if left untreated, shortens the life expectancy of patients. Endothelin receptor antagonists, such as macitentan and bosentan, play an essential role in improving the patient's symptoms, quality of life, and life expectancy. This study aimed to evaluate the cost-utility of macitentan compared with bosentan in treating PAH from the health system perspective in Iran.

METHODS

For evaluating the cost-effectiveness of macitentan, a Markov model consisting of 5 states, functional class (FC) I, FC II, FC III, FC IV, and death, was designed using the TreeAge software. The lifetime time horizon and a 3-month cycle length were set. Patients entered the model from FC II or FC III states based on the initial probabilities. Costs were measured in US dollars (USD), and outcomes were measured in terms of quality quality-adjusted life-years (QALYs). Consequently, the incremental cost-effectiveness ratio (ICER) was calculated. In addition, sensitivity analysis was performed to determine the robustness of the model by examining the possible effects of uncertainties on the final result.

RESULTS

The costs of treatment with macitentan and bosentan in PAH in Iran were calculated at 19 429 and 17 246 USD, and the outcomes were 4.02 and 3.04 QALYs, respectively. Therefore, ICER was calculated at 2233.46 USD/QALY. One-way sensitivity analysis demonstrates that the model is robust; nevertheless, it is most sensitive to the price of macitentan and bosentan.

CONCLUSION

Treatment with macitentan was associated with both higher costs and QALYs than bosentan. Nevertheless, it is considered the cost-effective treatment strategy in Iran given that the calculated ICER falls below the willingness to pay threshold.

Ambrisentan for in pediatric pulmonary arterial hypertension: A cost-utility analysis

INTRODUCTION

Despite the growing evidence of efficacy, little is known regarding the efficiency of ambrisentan to decrease cost and improve the functional classes of pediatric patients with pulmonary arterial hypertension. This study aims to determine the cost-utility of ambrisentan regarding sildenafil to treat pediatric patients with pulmonary arterial hypertension in Colombia.

METHODS

A decision tree model was used to estimate the cost and quality-adjusted life-years (QALYs) of ambrisentan, or sildenafil in pediatric patients with pulmonary arterial hypertension. Multiple sensitivity analyses were conducted to evaluate the robustness of the model. Cost-effectiveness was evaluated at a willingness-to-pay (WTP) value of US$5180.

RESULTS

The base-case analysis showed that compared with sildenafil, ambrisentan was associated with higher costs and higher QALYs. The expected annual cost per patient with ambrisentan was US$16,105 and with sildenafil was US$1431. The QALYs per person estimated with ambrisentan was 0.40 and for sildenafil was 0.39. The estimated improvement in quality of life and reduced costs results in an estimate of economic dominance for sildenafil over ambrisentan.

CONCLUSION

Our economic evaluation shows that ambrisentan is not cost-effective regarding sildenafil to treat pediatric patients with pulmonary arterial hypertension in Colombia. Our study provides evidence that should be used by decision-makers to improve clinical practice guidelines.

Recent Advances in the Treatment of Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a disease in which stenosis or obstruction of the pulmonary arteries (PAs) causes an increase in PA pressure, leading to right-sided heart failure and death. Basic research has revealed a decrease in the levels of endogenous vasodilators, such as prostacyclin, and an increase in the levels of endogenous vasoconstrictors, such as endothelin, in patients with PAH, leading to the development of therapeutic agents. Currently, therapeutic agents for PAH target three pathways that are selective for PAs: the prostacyclin, endothelin, and nitric oxide pathways. These treatments improve the prognosis of PAH patients. In this review, we introduce new drug therapies and provide an overview of the current therapeutic agents.

Artemisinin and Its Derivate Alleviate Pulmonary Hypertension and Vasoconstriction in Rodent Models

Background

Pulmonary arterial hypertension (PAH) is a complex pulmonary vasculature disease characterized by progressive obliteration of small pulmonary arteries and persistent increase in pulmonary vascular resistance, resulting in right heart failure and death if left untreated. Artemisinin (ARS) and its derivatives, which are common antimalarial drugs, have been found to possess a broad range of biological effects. Here, we sought to determine the therapeutic benefit and mechanism of ARS and its derivatives treatment in experimental pulmonary hypertension (PH) models.

Methods

Isolated perfused/ventilated lung and isometric tension measurements in arteries were performed to test pulmonary vasoconstriction and relaxation. Monocrotaline (MCT) and hypoxia+Su5416 (SuHx) were administered to rats to induce severe PH. Evaluation methods of ARS treatment and its derivatives in animal models include echocardiography, hemodynamics measurement, and histological staining. In vitro, the effect of these drugs on proliferation, viability, and hypoxia-inducible factor 1α (HIF1α) was examined in human pulmonary arterial smooth muscle cells (hPASMCs).

Results

ARS treatment attenuated pulmonary vasoconstriction induced by high K⁺ solution or alveolar hypoxia, decreased pulmonary artery (PA) basal vascular tension, improved acetylcholine- (ACh-) induced endothelial-dependent relaxation, increased endothelial nitric oxide (NO) synthase (eNOS) activity and NO levels, and decreased levels of NAD(P)H oxidase subunits (NOX2 and NOX4) expression, NAD(P)H oxidase activity, and reactive oxygen species (ROS) levels of pulmonary arteries (PAs) in MCT-PH rats. NOS inhibitor, L-NAME, abrogated the effects of ARS on PA constriction and relaxation. Furthermore, chronic application of both ARS and its derivative dihydroartemisinin (DHA) attenuated right ventricular systolic pressure (RVSP), Fulton index (right ventricular hypertrophy), and vascular remodeling of PAs in the two rat PH models. In addition, DHA inhibited proliferation and migration of hypoxia-induced PASMCs.

Conclusions

In conclusion, these results indicate that treatment with ARS or DHA can inhibit PA vasoconstriction, PASMC proliferation and migration, and vascular remodeling, as well as improve PA endothelium-dependent relaxation, and eventually attenuate the development and progression of PH. These effects might be achieved by decreasing NAD(P)H oxidase generated ROS production and increasing eNOS activation to release NO in PAs. ARS and its derivatives might have the potential to be novel drugs for the treatment of PH.

Systematic review and cost-effectiveness of bosentan and sildenafil as therapeutic drugs for pediatric pulmonary arterial hypertension

BACKGROUND

Pulmonary arterial hypertension (PAH) is a rare disease in children, with significant mortality. Because of the limited research on pediatric PAH, first, systematic review of related drugs is conducted, and then economic evaluation of PAH drug treatment programs is conducted, which to provide a reference for the choice of more cost-effective treatment options.

METHODS

The search includes electronic databases such as Pubmed, ScienceDirect, and Embase. Through inclusion and exclusion criteria, screen high-quality randomized controlled trials. We used TreeAge Pro 2011 software to construct the markov model, that to simulate the total medical cost and quality-adjusted life years (QALYs), and to calculate the incremental cost-effectiveness ratio. Sensitivity analysis of transfer probability, utility, and cost was carried out.

RESULTS

Incorporate two studies that meet the criteria, one compared the therapeutic effects of bosentan and placebo on pediatric PAH, the other compared therapeutic effects of sildenafil and placebo on pediatric PAH, both articles were of good quality. Compared with the sildenafil group (3.38QALYs and $161,120.14), the QALY of the bosentan treatment group (3.33QALYs and $257,411.29) was reduced by 0.05, and the cost increased by $96,291.15. The estimated improvement to quality of life and reduced costs result in an estimate of economic dominance for sildenafil over bosentan. This dominant result persisted probabilistic analyses.

CONCLUSIONS

Based on this model, a more cost-effective treatment drug for PAH in children is sildenafil.

Cost-effectiveness microsimulation of catheter-directed thrombolysis in submassive pulmonary embolism using a right ventricular function model

Approximately 30-50% of hemodynamically stable patients presenting with acute pulmonary embolism (PE) have evidence of right ventricular (RV) dysfunction. These patients are classified as submassive PE and the role of reperfusion therapy remains unclear. We sought to identify the circumstances under which catheter-directed thrombolysis (CDT) would represent high-value care for submassive PE. We used a computer-based, individual-level, state-transition model with one million simulated patients to perform a cost-effectiveness analysis comparing the treatment of submassive PE with CDT followed by anticoagulation to treatment with anticoagulation alone. Because RV function impacts prognosis and is commonly used in PE outcomes research, our model used RV dysfunction to differentiate health states. One-way, two-way, and probabilistic sensitivity analyses were used to quantify model uncertainty. Our base case analysis generated an incremental cost-effectiveness ratio (ICER) of $119,326 per quality adjusted life year. Sensitivity analyses resulted in ICERs consistent with high-value care when CDT conferred a reduction in the absolute probability of RV dysfunction of 3.5% or more. CDT yielded low-value ICERs if the absolute reduction was less than 1.56%. Our model suggests that catheter-directed thrombolytics represents high-value care compared to anticoagulation alone when CDT offers an absolute improvement in RV dysfunction of 3.5% or more, but there is substantial uncertainly around these results. We estimated the monetary value of clarifying the costs and consequences surrounding RV dysfunction after submassive PE to be approximately $268 million annually, suggesting further research in this area could be highly valuable.

The Nitric Oxide Pathway in Pulmonary Arterial Hypertension: Pathomechanism, Biomarkers and Drug Targets

The altered Nitric Oxide (NO) pathway in the pulmonary endothelium leads to increased vascular smooth muscle tone and vascular remodelling, and thus contributes to the development and progression of pulmonary arterial hypertension (PAH). The pulmonary NO signalling is abrogated by the decreased expression and dysfunction of the endothelial NO synthase (eNOS) and the accumulation of factors blocking eNOS functionality. The NO deficiency of the pulmonary vasculature can be assessed by detecting nitric oxide in the exhaled breath or measuring the degradation products of NO (nitrite, nitrate, S-nitrosothiol) in blood or urine. These non-invasive biomarkers might show the potential to correlate with changes in pulmonary haemodynamics and predict response to therapies. Current pharmacological therapies aim to stimulate pulmonary NO signalling by suppressing the degradation of NO (phosphodiesterase- 5 inhibitors) or increasing the formation of the endothelial cyclic guanosine monophosphate, which mediates the downstream effects of the pathway (soluble guanylate cyclase sensitizers). Recent data support that nitrite compounds and dietary supplements rich in nitrate might increase pulmonary NO availability and lessen vascular resistance. This review summarizes current knowledge on the involvement of the NO pathway in the pathomechanism of PAH, explores novel and easy-to-detect biomarkers of the pulmonary NO.

The cost-effectiveness of schistosomiasis screening and treatment among recently resettled refugees to Canada: an economic evaluation

BACKGROUND

Many refugees and asylum seekers from countries where schistosomiasis is endemic are infected with the Schistosoma parasite when they arrive in Canada. We assessed, from a systemic perspective, which of the following management strategies by health care providers is cost-effective: testing for schistosomiasis and treating if the individual is infected, treating presumptively or waiting for symptoms to emerge.

METHODS

We constructed a decision-tree model to examine the cost-effectiveness of 3 management strategies: watchful waiting, screening and treatment, and presumptive treatment. We obtained data for the model from the literature and other sources, to predict deaths and chronic complications caused by schistosomiasis, as well as costs and net monetary benefit.

RESULTS

Presumptive treatment was cost-saving if the prevalence of schistosomiasis in the target population was greater than 2.1%. In our baseline analysis, presumptive treatment was associated with an increase of 0.156 quality-adjusted life years and a cost saving of $405 per person, compared with watchful waiting. It was also more effective and less costly than screening and treatment.

INTERPRETATION

Among recently resettled refugees and asylum claimants in Canada, from countries where schistosomiasis is endemic, presumptive treatment was predicted to be less costly and more effective than watchful waiting or screening and treatment. Our results support a revision of the current Canadian recommendations.

Repurposing of medications for pulmonary arterial hypertension

This manuscript on drug repurposing incorporates the broad experience of members of the Pulmonary Vascular Research Institute's Innovative Drug Development Initiative as an open debate platform for academia, the pharmaceutical industry and regulatory experts surrounding the future design of clinical trials in pulmonary hypertension. Drug repurposing, use of a drug in a disease for which it was not originally developed, in pulmonary arterial hypertension has been a remarkable success story, as highlighted by positive large phase 3 clinical trials using epoprostenol, bosentan, iloprost, and sildenafil. Despite the availability of multiple therapies for pulmonary arterial hypertension, mortality rates have modestly changed. Moreover, pulmonary arterial hypertension patients are highly symptomatic and frequently end up on parental therapy and lung transplant waiting lists. Therefore, an unmet need for new treatments exists and drug repurposing may be an important avenue to address this problem.

Cost-utility analysis of Macitentan Vs. Bosentan in pulmonary atrial hypertension

Objective:

Endothelin (ET) receptor antagonists (ERAs) have considerable improvements in pulmonary arterial hypertension (PAH) patients’ symptoms. Macitentan, a novel ERA, has more significant positive effects like reduction of morbidity and mortality in PAH patients by 45% and decreases PAH hospitalization. Besides, macitentan was able to improve both the physical and mental aspects of patients’ lives. This study aimed to evaluate an incremental cost-utility analysis of macitentan compared with bosentan in PAH patients in the Iranian health care system.

Methods:

We developed a hybrid model consisting of a decision tree in which PAH patients would take and continue either macitentan or bosentan with different probabilities. Subsequently, each patient would enter one of the 4 Markov's, each consisting of 5 states, PAH fraction I, PAH fraction II, PAH fraction III, PAH fraction IV, and death. The cycles and time horizon were considered 3 months and lifetime, respectively. We assessed the impact of each medicine on patients’ quality-adjusted life-years (QALYs) and costs, consequently calculated the ICER (Incremental Cost-Effectiveness Ratio). The costs were measured in the dollar (1 dollar is equal to 42000 rials) with the perspective of the payer. The discount rates were assumed 3% for utility and 5% for costs. In addition, a sensitivity analysis was conducted.

Results:

The costs are about 14163 dollars for bosentan and 13876 dollars for macitentan for each patient in a lifetime. The QALY produced per patient by macitentan was 0.81 more than that of bosentan. The calculated ICER was -357.47 which means that for each incremental QALY, the payer is charged less.

Conclusion:

Macitentan is preferable to and dominant over bosentan in both effectiveness and expenditure. Thus, the therapeutic regimen containing macitentan is introduced as a favorable treatment strategy.

Factors Associated With Potentially Inappropriate Phosphodiesterase-5 Inhibitor Use for Pulmonary Hypertension in the United States, 2006 to 2015

BACKGROUND

Use of phosphodiesterase-5 inhibitors (PDE5i) for groups 2 and 3 pulmonary hypertension (PH) is rising nationally, despite guidelines recommending against this low-value practice. Although receiving care across healthcare systems is encouraged to increase veterans' access to specialists critical for PH management, receiving care in 2 systems may increase risk of guideline-discordant prescribing. We sought to identify factors associated with prescribing of PDE5i for group 2/3 PH, particularly, to test the hypothesis that veterans prescribed PDE5i for PH in the community (through Medicare) will have increased risk of subsequently receiving potentially inappropriate treatment in Veterans Health Administration (VA).

METHODS AND RESULTS

We constructed a retrospective cohort of 34 775 Medicare-eligible veterans with group 2/3 PH by linking national patient-level data from VA and Medicare from 2006 to 2015. We calculated adjusted odds ratios (ORs) of receiving daily PDE5i treatment for PH in VA using multivariable models with facility-specific random effects. In this cohort, 1556 veterans received VA prescriptions for PDE5i treatment for group 2/3 PH. Supporting our primary hypothesis, the variable most strongly associated with PDE5i treatment in VA for group 2/3 PH was prior treatment through Medicare (OR, 6.5 [95% CI, 4.9-8.7]). Other variables strongly associated with increased likelihood of VA treatment included more severe disease as indicated by recent right heart failure (OR, 3.3 [95% CI, 2.8-3.9]) or respiratory failure (OR, 3.7 [95% CI, 3.1-4.4]) and prior right heart catheterization (OR, 3.8 [95% CI, 3.4-4.3]).

CONCLUSIONS

Our data suggest a missed opportunity to reassess treatment appropriateness when pulmonary hypertension patients seek prescriptions from VA-a relevant finding given policies promoting shared care across VA and community settings. Interventions are needed to reinforce awareness that pulmonary vasodilators are unlikely to benefit group 2/3 pulmonary hypertension patients and may cause harm.

Tetramethylpyrazine: A promising drug for the treatment of pulmonary hypertension

BACKGROUND AND PURPOSE

Tetramethylpyrazine (TMP) was originally isolated from the traditional Chinese herb ligusticum and the fermented Japanese food natto and has since been synthesized. TMP has a long history of beneficial effects in the treatment of many cardiovascular diseases. Here we have evaluated the therapeutic effects of TMP on pulmonary hypertension (PH) in animal models and in patients with pulmonary arterial hypertension (PAH) or chronic thromboembolic pulmonary hypertension (CTEPH).

EXPERIMENTAL APPROACH

Three well-defined models of PH -chronic hypoxia (10% O₂ )-induced PH (HPH), monocrotaline-induced PH (MCT-PH) and Sugen 5416/hypoxia-induced PH (SuHx-PH) - were used in Sprague-Dawley rats, and assessed by echocardiography, along with haemodynamic and histological techniques. Primary cultures of rat distal pulmonary arterial smooth muscle cells (PASMCs) were used to study intracellular calcium levels. Western blots and RT-qPCR assays were also used. In the clinical cohort, patients with PAH or CTEPH were recruited. The effects of TMP were evaluated in all systems.

KEY RESULTS

TMP (100 mg·kg^-1 ·day^-1 ) prevented rats from developing experimental PH and ameliorated three models of established PH: HPH, MCT-PH and SuHx-PH. The therapeutic effects of TMP were accompanied by inhibition of intracellular calcium homeostasis in PASMCs. In a small cohort of patients with PAH or CTEPH, oral administration of TMP (100 mg, t.i.d. for 16 weeks) increased the 6-min walk distance and improved the 1-min heart rate recovery.

CONCLUSION AND IMPLICATIONS

Our results suggest that TMP is a novel and inexpensive medication for treatment of PH. Clinical trial is registered with www.chictr.org.cn (ChiCTR-IPR-14005379).

Lifetime patient outcomes and healthcare utilization for Bronchopulmonary dysplasia (BPD) and extreme preterm infants: a microsimulation study

BACKGROUND

Bronchopulmonary dysplasia (BPD) is among the most severe chronic lung diseases and predominantly affects premature infants. There is a general understanding of BPD's significant impact on the short-term outcomes however there is little evidence on long-term outcomes. Our study estimates the lifetime clinical outcomes, quality of life, and healthcare costs of BPD and associated complications.

METHODS

We developed a microsimulation model to estimate lifetime clinical and economic burden of BPD among extreme preterm infants (≤28 weeks gestational age at birth) and validated it against the best available Canadian data. We further estimate the cumulative incidence of major complications associated with BPD, differentiated by BPD severity and gestational age category.

RESULTS

We find, on average, patients with BPD and resulting complications will incur over CAD$700,000 in lifetime health systems costs. We also find the average life expectancy of BPD patients to be moderately less than that of the general population and significant reductions in quality-adjusted life year due to major complications. Healthcare utilization and quality of life measures vary dramatically according to BPD severity, suggesting significant therapeutic headroom for interventions that can prevent or mitigate the effects of BPD for patients.

CONCLUSIONS

Our study adds a significant expansion of existing evidence by presenting the lifetime burden of BPD based on key patient characteristics. Given the extreme cost burden at the earliest stage of life and lifetime negative impact on quality of life, there is larger headroom for investment in prevention and mitigation of severe BPD than is currently available.

Pharmacological Treatment of Pulmonary Arterial Hypertension in Australia: Current Trends and Challenges

BACKGROUND

Combination drug therapy for pulmonary arterial hypertension (PAH) is the international standard of care for most patients, however in Australia there are barriers to drug access. This study evaluates current treatment of PAH patients in Australia and the consistency of therapy with international guidelines.

METHODS

Cross-sectional analysis of patients with Group 1 PAH enrolled in the Pulmonary Hypertension Society of Australia and New Zealand Registry (PHSANZ) at 31 December 2017. Drug treatment was classified as monotherapy or combination therapy and adequacy of treatment was determined by risk status assessment using the Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL) 2.0 risk calculator. Predictors of monotherapy were assessed using a generalised linear model with Poisson distribution and logarithmic link function.

RESULTS

1,046 patients met the criteria for analysis. Treatment was classified as monotherapy in 536 (51%) and combination therapy in 510 (49%) cases. Based on REVEAL 2.0, 184 (34%) patients on monotherapy failed to meet low-risk criteria and should be considered inadequately treated. Independent predictors of monotherapy included age greater than 60 years (risk ratio [RR] 1.23, 95% confidence interval [CI] 1.09-1.38; p=0.001), prevalent enrolment in the registry (RR 1.21 [95%CI 1.08-1.36]; p=0.001) and comorbid systemic hypertension (RR 1.17 [95%CI 1.03-1.32]; p=0.014), while idiopathic/heritable/drug-induced PAH subtype (RR 0.85 [95%CI 0.76-0.96]; p=0.006), functional class IV (RR 0.50 [95%CI 0.29-0.86]; p=0.012), increased right ventricular systolic pressure (RR 0.99 [95%CI 0.99-1.00]; p<0.001) and increased pulmonary vascular resistance (RR 0.96 [95%CI 0.95-0.98]; p<0.001) were less likely to be associated with monotherapy.

CONCLUSIONS

Most Australian PAH patients are treated with monotherapy and a significant proportion remain at risk of poor outcomes. This is below the standard of care recommended by international guidelines and at risk patients should be escalated to combination therapy.

Anticoagulation in pulmonary arterial hypertension: a decision analysis

Systemic anticoagulation may be beneficial in pulmonary arterial hypertension, but there is no randomized clinical trial data to guide therapeutic decision making, and current guidelines do not account for patient preferences or quality of life. Decision analytic models to evaluate the potential risks and benefits of systemic anticoagulation in pulmonary arterial hypertension patients, focusing on the benefit in quality-adjusted life years, may be helpful in clarifying this uncertainty. We constructed a 31-state Markov decision analytic model to explore anticoagulation and no anticoagulation strategies. Modeled patient characteristics included gender, use of central catheter-based pulmonary arterial hypertension therapy, type of pulmonary arterial hypertension (idiopathic, idiopathic pulmonary arterial hypertension, or connective-tissue associated, connective tissue disease-pulmonary arterial hypertension), and use of oral contraceptive medication by females. Modeled events included mortality, thromboembolic complications, atrial fibrillation, stroke, and anticoagulation bleeding. Deterministic and probabilistic sensitivity analyses were performed. Anticoagulation was favored in all idiopathic pulmonary arterial hypertension cases, with a gain of 0.43-0.51 quality-adjusted life years, and detrimental in all connective tissue disease-pulmonary arterial hypertension cases, with a loss of 0.66-1.89 quality-adjusted life years. Anticoagulation would need to demonstrate a hazard ratio for pulmonary arterial hypertension mortality of 0.95 or better to be favored. In our model, idiopathic pulmonary arterial hypertension patients benefit from anticoagulation in terms of quality-adjusted life years, and connective tissue disease-pulmonary arterial hypertension patients were harmed, with a hazard ratio for pulmonary arterial hypertension mortality of 0.95 or better being required to favorably impact quality-adjusted life years. These results suggest that anticoagulation significantly improves quality adjusted life years and should be offered to all idiopathic pulmonary arterial hypertension patients. Shared decision models based on these results may help clarify therapeutic decision-making uncertainty in pulmonary arterial hypertension patients.

Phosphodiesterase-5 Inhibitor Therapy for Pulmonary Hypertension in the United States. Actual versus Recommended Use

RATIONALE

Care of patients with pulmonary hypertension is complex. Although pulmonary vasodilators are effective for Group 1 pulmonary hypertension, clinical guidelines and the Choosing Wisely Campaign recommend against routine use for Groups 2 and 3 pulmonary hypertension (the most common types of pulmonary hypertension) because of a lack of benefit, potential for harm, and high cost ($10,000-$13,000 per patient per year treated). Little is known about how these medications are used in practice.

OBJECTIVES

To determine national patterns of phosphodiesterase-5 inhibitor prescribing for pulmonary hypertension in the Veterans Health Administration.

METHODS

Retrospective analysis of Veterans prescribed phosphodiesterase-5 inhibitor for pulmonary hypertension between 2005 and 2012 at any Veterans Health Administration site. Patients were identified by presence of an International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis code for pulmonary hypertension and one or more outpatient prescriptions for daily phosphodiesterase-5 inhibitor therapy. We developed and validated, using gold-standard chart abstraction, an International Classification of Diseases, Ninth Revision, Clinical Modification-based algorithm to assign pulmonary hypertension group. Our primary outcome was the proportion of patients who received potentially inappropriate phosphodiesterase-5 inhibitor, as determined by guideline recommendations (Group 1 pulmonary hypertension: appropriate; Groups 2/3: potentially inappropriate; Groups 4/5: uncertain value), among all patients prescribed phosphodiesterase-5 inhibitor for pulmonary hypertension. Secondary outcomes included proportion of treated patients who received guideline-recommended right heart catheterization.

RESULTS

Among 108,777 Veterans with pulmonary hypertension, 2,790 (2.6% [95% confidence interval, 2.5-2.7%]) received daily phosphodiesterase-5 inhibitor therapy. Among treated patients, 541 (19.4% [95% confidence interval, 18.0-20.9%]) received appropriate treatment, 1,711 (61.3% [95% confidence interval, 59.5-63.1%]) potentially inappropriate treatment, and 358 (12.8% [95% confidence interval, 11.6-14.1%]) treatment of uncertain value. The number of potentially inappropriately treated patients per year increased substantially over the study period (53 in 2005, 748 in 2012). On the basis of chart abstraction in a randomly selected subset of patients treated with phosphodiesterase-5 inhibitor, half (110 of 230, 47.8% [95% confidence interval, 41.3-54.5%]) had documented right heart catheterization to confirm presence or type of pulmonary hypertension. After factoring presence of and data from right heart catheterization into our treatment appropriateness algorithm, only 11.7% (95% confidence interval, 8.0-16.8%) received clearly appropriate treatment.

CONCLUSIONS

Most Veterans with pulmonary hypertension do not receive phosphodiesterase-5 inhibitor therapy. However, among treated Veterans, almost two-thirds of phosphodiesterase-5 inhibitor prescriptions are inconsistent with pulmonary hypertension guidelines, exposing patients to potential harm and creating a financial burden on the healthcare system. Further study is warranted to clarify the effects of these prescription patterns on pulmonary hypertension outcomes.

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.

Treatment Selection in Pulmonary Arterial Hypertension: Phosphodiesterase Type 5 Inhibitors versus Soluble Guanylate Cyclase Stimulator

Pulmonary arterial hypertension is a chronic and life-threatening disease that if left untreated is fatal. Current therapies include stimulating the nitric oxide-soluble guanylate cyclase (sGC)-cyclic guanosine monophosphate axis, improving the prostacyclin pathway and inhibiting the endothelin pathway. Phosphodiesterase type 5 inhibitors, such as sildenafil, and the sGC stimulator riociguat are currently used in the treatment of pulmonary arterial hypertension. This article discusses the similarities and differences between phosphodiesterase type 5 inhibitors and sGC stimulator based on pharmacological action and clinical trials, and considers which is better for the treatment of pulmonary arterial hypertension.