Cost-Effectiveness of Combination Therapy for Patients With Systemic Sclerosis-Related Pulmonary Arterial Hypertension

The 'whole landscape' of research on systemic sclerosis over the past 73 years

OBJECTIVE

This study aimed to analyse existing research on systemic sclerosis (SSc) conducted over the past 73 years to develop an essential reference for a comprehensive and objective understanding of this field of inquiry.

METHODS

Using the Web of Science Core Collection, PubMed, and Scopus databases as data sources for the bibliometric analysis, we searched for published literature related to SSc over the past 73 years. The Bibliometrix package was used to analyse key bibliometric indicators, such as annual publication volume, countries, journals, author contributions, and research hotspots.

RESULTS

From 1970 to 2022, the number of SSc articles steadily increased, reaching its peak in 2020-2022, with approximately 1200 papers published in each of these three years. Matucci-Cerinic et al.'s team published the most articles (425). The United States (11,282), Italy (7027), and France (5226) were the most predominant contexts. The most influential scholars in the field were Denton, Leroy, Steen, and Khanna, with H-indices of 86, 84, and 83, respectively. Arthritis and Rheumatism was the most influential journal in this field (H-index 142). High-frequency keywords in the SSc field included fibrosis (738), inflammation (242), vasculopathy (145), fibroblasts (120), and autoantibodies (118) with respect to pathogenesis, and interstitial lung disease (ILD, 708), pulmonary arterial hypertension (PAH, 696), and Raynaud's phenomenon (326) with regards to clinical manifestations.

CONCLUSION

In the past three years, SSc research has entered a period of rapid development, mainly driven by research institutions in Europe and the United States. The most influential journal has been Arthritis and Rheumatism, and autoimmune aspects, vasculopathy, fibrogenesis, PAH, and ILD remain the focus of current research and indicate trends in future research.

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).

Ligustrazine alleviates pulmonary arterial hypertension in rats by promoting the formation of myocardin transcription complex in the nucleus of pulmonary artery smooth muscle cells

Pulmonary arterial hypertension (PAH) is a pathophysiological state of abnormally elevated pulmonary arterial pressure caused by drugs, inflammation, toxins, viruses, hypoxia, and other risk factors. We studied the therapeutic effect and target of tetramethylpyrazine (tetramethylpyrazine [TMP]; ligustrazine) in the treatment of PAH and we speculated that dramatic changes in myocardin levels can significantly affect the progression of PAH. In vivo, the results showed that administration of TMP significantly prolonged the survival of PAH rats by reducing the proliferative lesions, right ventricular systolic pressure (RVSP), mean pulmonary arterial pressure (mPAP), and the Fulton index in the heart and lung of PAH rats. In vitro, TMP can regulate the levels of smooth muscle protein 22-alpha (SM22-α), and myocardin as well as intracellular cytokines such as NO, transforming growth factor beta (TGF-β), and connective tissue growth factor (CTGF) in a dose-dependent manner (25, 50, or 100 μM). Transfection of myocardin small interfering RNA (siRNA) aggravated the proliferation of pulmonary artery smooth muscle cells (PSMCs), and the regulatory effect of TMP on α-smooth muscle actin (α-SMA) and osteopontin (OPN) disappeared. The application of 10 nM estrogen receptor alpha (ERα) inhibitor MPP promoted the proliferation of PSMCs, but it does not affect the inhibition of TMP on PSMCs proliferation. Finally, we found that TMP promoted the nucleation of myocardin-related transcription factor-A (MRTF-A) and combined it with myocardin. In conclusion, TMP can inhibit the transformation of PSMCs from the contractile phenotype to the proliferative phenotype by promoting the formation of the nuclear (MRTF-A/myocardin) transcription complex to treat PAH.

A claims-based, machine-learning algorithm to identify patients with pulmonary arterial hypertension

Many patients with pulmonary arterial hypertension (PAH) experience substantial delays in diagnosis, which is associated with worse outcomes and higher costs. Tools for diagnosing PAH sooner may lead to earlier treatment, which may delay disease progression and adverse outcomes including hospitalization and death. We developed a machine-learning (ML) algorithm to identify patients at risk for PAH earlier in their symptom journey and distinguish them from patients with similar early symptoms not at risk for developing PAH. Our supervised ML model analyzed retrospective, de-identified data from the US-based Optum® Clinformatics® Data Mart claims database (January 2015 to December 2019). Propensity score matched PAH and non-PAH (control) cohorts were established based on observed differences. Random forest models were used to classify patients as PAH or non-PAH at diagnosis and at 6 months prediagnosis. The PAH and non-PAH cohorts included 1339 and 4222 patients, respectively. At 6 months prediagnosis, the model performed well in distinguishing PAH and non-PAH patients, with area under the curve of the receiver operating characteristic of 0.84, recall (sensitivity) of 0.73, and precision of 0.50. Key features distinguishing PAH from non-PAH cohorts were a longer time between first symptom and the prediagnosis model date (i.e., 6 months before diagnosis); more diagnostic and prescription claims, circulatory claims, and imaging procedures, leading to higher overall healthcare resource utilization; and more hospitalizations. Our model distinguishes between patients with and without PAH at 6 months before diagnosis and illustrates the feasibility of using routine claims data to identify patients at a population level who might benefit from PAH-specific screening and/or earlier specialist referral.

Systemic sclerosis manifestations and clinical outcomes in Hispanics/Latinos of the American Southwest

Objective:

Certain Hispanic/Latino (Hispanic) populations have been reported to have higher rates and severity of systemic sclerosis; however, little is known of systemic sclerosis in the American Southwest. This study compared manifestations of systemic sclerosis in Hispanics with non-Hispanics of New Mexico.

Methods:

This cross-sectional longitudinal study included 109 systemic sclerosis patients followed over a mean of 12.6 ± 8.9 years. Subjects were repetitively evaluated including physical examination, echocardiography, chest imaging, and serologic testing and observed for complications. Disease characteristics and long-term outcomes were statistically compared between self-identified Hispanic and non-Hispanic subjects.

Results:

A total of 73 (67%) systemic sclerosis subjects were Hispanic and 36 (33%) were non-Hispanic. The cohorts were similar in mean age, age of systemic sclerosis onset, limited versus diffuse cutaneous systemic sclerosis, telangiectases, gastroesophageal reflux disease, Raynaud’s phenomenon, autoantibody profile, interstitial lung disease, pulmonary hypertension, scleroderma renal crisis, mortality, and comorbid malignancy (all p > 0.05). However, the standardized mortality ratio was increased in both cohorts relative to age-adjusted mortality: Hispanic: 2.08, confidence interval (1.94–2.24); non-Hispanic: 1.56, confidence interval (1.46–1.68). Furthermore, the standardized incidence ratio for malignancy was increased in both cohorts: Hispanic: 1.45, confidence interval (1.35–1.56); non-Hispanic: 1.24, confidence interval (1.16–1.34). The mean age of cancer diagnosis occurred at a significantly younger age in Hispanics (Hispanics: 53.1 ± 9.7 years; non-Hispanics 63.7 ± 7.9 years; 95% confidence interval: −19 ⩽ 10.6 ⩽ 2.2; p = 0.016).

Conclusion:

Systemic sclerosis phenotype, autoantibodies, complications, outcomes, malignancy rates, and mortality are generally similar between Hispanics and non-Hispanics with systemic sclerosis in the American Southwest. However, age-adjusted comorbid malignancy and mortality rates are significantly increased in both groups.

Healthcare utilization and economic burden in systemic sclerosis: a systematic review

OBJECTIVE

Systemic Sclerosis (SSc) is characterized by vasculopathy, fibrosis of skin and internal organs, and autoimmunity with complications including interstitial lung disease, pulmonary hypertension, and digital ulcers with substantial morbidity and disability. Patients with SSc may require considerable healthcare resources with economic impact. The purpose of this systematic review was to provide a narrative synthesis of the economic impact and healthcare resource utilization associated with SSc.

METHODS

MEDLINE and EMBASE were searched from inception to January 20th, 2021. Studies were included if they provided information regarding the total, direct and indirect cost of SSc. The cost of SSc subtypes and associated complications was determined. Risk of bias assessments through the Joanna Briggs Institute cross-sectional and case series checklists, and the Newcastle-Ottawa Cohort and Case-Control study scales were performed. A narrative synthesis of included studies was planned.

RESULTS

1777 publications were retrieved, of which 33 were included representing 20 cross-sectional, 10 cohort, and 3 case-control studies. Studies used various methods of calculating cost including prevalence-based cost-of-illness approach and health resource units cost analysis. Overall SSc total annual cost ranged from USD$14 959-$23 268 in USA, CAD$10 673-$18 453 in Canada, €4,607-€30 797 in Europe, and AUD$7,060-$11 607 in Oceania. Annual cost for SSc-associated interstitial lung disease and pulmonary hypertension was USD$31 285-$55 446 and $44 454-$63 320, respectively.

CONCLUSION

Cost-calculation methodology varied greatly between included studies. SSc represents significant patient and health resource economic burden. SSc-associated complications increase economic burden and are variable depending on geographical location, and access.

Cost-Effectiveness of Combination Therapy for Patients With Systemic Sclerosis-Related Pulmonary Arterial Hypertension

Background

To evaluate the cost‐effectiveness of combination pulmonary arterial hypertension specific therapy in systemic sclerosis–related PAH.

Methods and Results

Health outcomes and costs were captured through data linkage. Health utility was derived from Medical Outcomes Study Short Form‐36 scores. A probabilistic discrete‐time model was developed to simulate lifetime changes in costs and health utility. Mortality was predicted using a Gompertz parametric survival model. For both treatment arms, the simulations were started using the same cohort of 10 000 patients. Probabilistic sensitivity analysis was performed using the Monte Carlo simulation with 1000 sets of sampled parameter values. Of 143 patients with systemic sclerosis–related pulmonary arterial hypertension, 89 were on monotherapy and 54 on combination therapy. Mean simulated costs per patient per year in monotherapy and combination therapy groups were AU$23 411 (US$16 080) and AU$29 129 (US$19 982), respectively. Mean life years and quality‐adjusted life years from pulmonary arterial hypertension diagnosis to death of patients receiving monotherapy were 7.1 and 3.0, respectively, and of those receiving combination therapy were 9.2 and 3.9, respectively. Incremental costs per life year and quality‐adjusted life year gained of combination therapy compared with monotherapy were AU$47 989 (US$32 920) and AU$113 823 (US$78 082), respectively. At a willingness‐to‐pay threshold of AU$102 000 (US$69 972) per life year gained, and of AU$177 222 (US$121 574) per quality‐adjusted life year gained, the probability of combination therapy being cost‐effective was 0.95.

Conclusions

The incremental cost per quality‐adjusted life year gained of combination therapy compared with monotherapy was substantial in the base case analysis. Given the fatal prognosis of systemic sclerosis–related pulmonary arterial hypertension and the incremental cost per life year of AU$47 989 (US$32 920), combination therapy could be considered cost‐effective in systemic sclerosis–related pulmonary arterial hypertension.