Efficacy and Safety of Pulmonary Arterial Hypertension-specific Therapy in Pulmonary Arterial Hypertension: A Meta-analysis of Randomized Controlled Trials

Liver injury associated with endothelin receptor antagonists: a pharmacovigilance study based on FDA adverse event reporting system data

BACKGROUND

Endothelin receptor antagonists are commonly used in clinical practice, with concerns about their hepatotoxicity.

AIM

This study aimed to conduct a comprehensive pharmacovigilance study based on FDA adverse event reporting system data to evaluate the possible association between endothelin receptor antagonists and drug-induced liver injury.

METHOD

Adverse event reports from FDA adverse event reporting system between January 2004 and December 2022 were analyzed. Disproportionality algorithms, including reporting odds ratio and information component, were used to evaluate the association between endothelin receptor antagonists and liver injury. Sex- and age-stratified analyses of drug-induced liver injury events were also conducted in relation to endothelin receptor antagonists.

RESULTS

Significant associations between bosentan, macitentan, and liver injury were identified. Bosentan showed a strong link with liver injury, with reporting odds ratios for cholestatic injury at 7.59 (95% confidence interval: 6.90-8.35), hepatocellular injury at 5.63 (5.29-6.00), and serious drug-related hepatic disorders events at 1.33 (1.24-1.43). Drug-induced liver injury signals associated with bosentan were detected in all age groups. Macitentan was associated with liver injury, with reporting odds ratios for hepatic failure at 1.64 (1.39-1.94), cholestatic injury at 1.62 (1.43-1.83), and serious drug-related hepatic disorders events at 1.40 (1.29-1.51). No drug-induced liver injury signal was detected for ambrisentan, and no significant sex differences were observed in drug-induced liver injury events.

CONCLUSION

Both bosentan and macitentan are associated with liver injury. Routine monitoring of serum aminotransferase levels is recommended, especially in patients at higher risk of liver injury. Further research into drug-drug interactions involving endothelin receptor antagonists is warranted.

Treatment of pulmonary arterial hypertension in patients with connective tissue diseases: a systematic review and meta-analysis

The evidence for the treatment of connective tissue disease-associated pulmonary arterial hypertension (CTD-PAH) mostly depends on subgroup or post hoc analysis of randomized controlled trials (RCTs). Thus, we performed a meta-analysis of RCTs that reported outcomes for CTD-PAH. PubMed and EMBASE were searched for CTD-PAH treatment. The selected outcomes were functional class (FC) change, survival rates, 6-min walk distance (6-MWD), clinical worsening (CW), N-terminal prohormone BNP (NT-proBNP), pulmonary vascular resistance (PVR), mean pulmonary arterial pressure (mPAP), right atrial pressure (RAP), and cardiac index (CI). The meta-analysis was conducted according to the PRISMA guidelines and registered in PROSPERO (CRD42020153560). Twelve RCTs conducted with 1837 patients were included. The diagnoses were systemic sclerosis in 59%, SLE in 20%, and other CTDs in 21%. The pharmacological interventions were epoprostenol, treprostinil, sildenafil, tadalafil, bosentan, macitentan, ambrisentan, riociguat, and selexipag. There was a significant difference between interventions and placebo in FC, 6MWD, CW, PVR, RAP, and CI that favored intervention. Our analysis showed a 39% reduction in the CW risk with PAH treatment. The short-term survival rates and mean serum NT-proBNP changes were similar between the study and control groups. Treatment for CTD-PAH had favorable effects on clinical and hemodynamic outcomes but not on survival and NT-proBNP levels. Different from the previous meta-analyses that focused on 6-MWD, time to clinical worsening, and CW as outcomes, this meta-analysis additionally reports the pooled analysis of change in FC, hemodynamic measurements (RAP, PVR, CI), and NT-proBNP, some of which have prognostic value for PAH.

Retrospective cohort study of pulmonary arterial hypertension associated with connective tissue disease effect on patients' prognosis

OBJECTIVE

The objectives of this study are to clarify clinical characteristics and recognize prognostic factors of CTD-PAH patients.

METHODS

A retrospective cohort study of consecutive patients with documented CTD-PAH diagnosis from Jan 2014 to Dec 2019 was conducted, the ones who have other comorbid conditions that cause PH were excluded. Survival functions were plotted using the Kaplan-Meier method. Univariable and multivariable Cox regression analysis was applied to determine the survival-related factors.

RESULTS

In 144 patients with CTD-PAH analyzed, the median sPAP value was 52.5 (44.0, 71.0) mmHg, the overall targeted drug usage rate was 55.6%, and only 27.5% patients were given combination. Twenty-four non-PAH-CTD patients with sPAP value were included as the control group. Compared with non-PAH-CTD groups, CTD-PAH patients had worse cardiac function, higher NT-pro BNP and γ-globulin level, and lower PaCO2 level. Compared with the mild PAH group, the moderate-severe PAH group had worse cardiac function; increased Hb, HCT, and NP-pro BNP level; and decreased PaO2. Kaplan-Meier analysis showed significant difference for survival among non-PAH-CTD, mild CTD-PAH, and moderate-severe CTD-PAH groups. The univariate analyses showed that Hb, pH, and Ln (NT-pro BNP) were identified as factors significantly associated with survival, and Hb and pH showed significant association with risk of death in the multivariate model. Kaplan-Meier analysis also showed that Hb > 109.0 g/L and pH > 7.457 affected CTD-PAH patients' survival significantly.

CONCLUSIONS

PAH is not rare in CTDs patients; PAH affects CTD patients' prognosis significantly. Higher Hb and pH were associated with an increased risk of death. Key Points • Pulmonary arterial hypertension affects connective tissue disease patients' prognosis significantly. • The significantly factors associated with survival is hemoglobin, pH, and Ln (NT-pro BNP).

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.

Minimal Clinically Important Difference in the 6-minute-walk Distance for Patients with Pulmonary Arterial Hypertension

Rationale: The 6-minute-walk distance (6MWD) is an important clinical and research metric in pulmonary arterial hypertension (PAH); however, there is no consensus about what minimal change in 6MWD is clinically significant. Objectives: We aimed to determine the minimal clinically important difference in the 6MWD. Methods: We performed a meta-analysis using individual participant data from eight randomized clinical trials of therapy for PAH submitted to the U.S. Food and Drug Administration to derive minimal clinically important differences in the 6MWD. The estimates were externally validated using the Pulmonary Hypertension Association Registry. We anchored the change in 6MWD to the change in the Medical Outcomes Survey Short Form physical component score. Measurements and Main Results: The derivation (clinical trial) and validation (Pulmonary Hypertension Association Registry) samples were comprised of 2,404 and 537 adult patients with PAH, respectively. The mean ± standard deviation age of the derivation sample was 50.5 ± 15.2 years, and 1,849 (77%) were female, similar to the validation sample. The minimal clinically important difference in the derivation sample was 33 meters (95% confidence interval, 27-38), which was almost identical to that in the validation sample (36 m [95% confidence interval, 29-43]). The minimal clinically important difference did not differ by age, sex, race, pulmonary hypertension etiology, body mass index, use of background therapy, or World Health Organization functional class. Conclusions: We estimated a 6MWD minimal clinically important difference of approximately 33 meters for adults with PAH. Our findings can be applied to the design of clinical trials of therapies for PAH.

Strategizing Drug Therapies in Pulmonary Hypertension for Improved Outcomes

Pulmonary hypertension (PH) is characterized by a resting mean pulmonary artery pressure (PAP) of 20 mmHg or more and is a disease of multiple etiologies. Of the various types of PH, pulmonary arterial hypertension (PAH) is characterized by elevated resistance in the pulmonary arterial tree. It is a rare but deadly disease characterized by vascular remodeling of the distal pulmonary arteries. This paper focuses on PAH diagnosis and management including current and future treatment options. Over the last 15 years, our understanding of this progressive disease has expanded from the concept of vasoconstrictive/vasodilatory mismatch in the pulmonary arterioles to now a better appreciation of the role of genetic determinants, numerous cell signaling pathways, cell proliferation and apoptosis, fibrosis, thrombosis, and metabolic abnormalities. While knowledge of its pathophysiology has expanded, the majority of the treatments available today still modulate the same three vasodilatory pathways that have been targeted for over 30 years (endothelin, nitric oxide, and prostacyclin). While modifying these pathways may help improve symptoms and quality of life, none of these directly modify the underlying disease pathogenesis. However, there are now studies ongoing with new drugs that can prevent or reverse these underlying causes of PAH. This review discusses the evidence base for the current treatment algorithms for PAH, as well as discusses novel therapies in development.

Efficacy and safety of sequential combination therapy for pulmonary arterial hypertension: A meta-analysis of Randomized-Controlled Trials

BACKGROUND

Previous meta-analyses of pulmonary arterial hypertension (PAH) combination therapy pooled sequential and initial combination together, which might threaten their authenticity and clinical significance for the difference between two strategies.

METHODS

PubMed, Embase, and the Cochrane Library were searched for randomized controlled trials (RCTs) that compared sequential combination therapy (SCT) with background therapy (BT) in PAH patients. Raw data were extracted to calculate risk ratio (RR) or weighted mean difference (WMD) for predefined efficacy and safety outcomes. Mantel-Haenszel fixed or random effects model was used based on heterogeneity.

RESULTS

17 RCTs involving 4343 patients (97.2% of patients with WHO-FC II-III) were included. SCT decreased clinical worsening (RR 0.66, 95% CI 0.58 to 0.76), nonfatal clinical worsening (RR 0.61, 95% CI 0.52 to 0.71), functional class (decrease of 28% in the portion of patients with WHO-FC worsening and increase of 33% in the portion of patients with WHO-FC improvement), and increased 6-min walk distance (WMD 17.68 m, 95% CI 10.16 to 25.20), but didn't reduce mortality, lung transplantation, admission to hospital, and treatment escalation compared with BT. Although any adverse event and serious adverse event were similar between SCT and BT, SCT increased all-cause treatment discontinuation (RR 1.49, 95% CI 1.30 to 1.71) and drug-related treatment discontinuation (RR 2.30, 95% CI 1.86 to 2.84) with higher incidence of headache, flushing, nausea, diarrhoea and jaw pain.

CONCLUSIONS

For WHO-FC II-III PAH patients who have established BT, our study reinforced the recommendation of SCT to improve clinical worsening, functional status, and exercise capacity, although with higher incidence of side-effects and withdrawal.

Dynamics of 6-Minute Walk Distance as a Predictor of Efficiency Specific Pulmonary Vasodilators

Pulmonary hypertension is a severe and often rapidly progressive disease with a fatal outcome. Approved specific therapy with five classes of drugs – prostanoids, endothelin receptor antagonists, phosphodiesterase-5 inhibitors, soluble guanylate cyclase stimulators and prostacyclin receptor agonists has significantly improved the prognosis of patients. An accessible and reproducible criterion of exercise tolerance – a distance walked in six-minute walk test (6MXD) – occupies one of the central places among the performance indicators (clinical, echocardiographic and hemodynamic) of specific pulmonary vasodilators. Reflecting the clinical severity of pulmonary hypertension and, according to some data, its long-term prognosis, the dynamics of 6MXD is an integral component of the combined primary endpoints of randomized controlled trials. In the CHEST-2019 recommendations, the dynamics of the 6MXD was used to standardize the randomized controlled trials. The 6MXD is indispensable for dynamic observation and decisionmaking on further treatment tactics 

Secular and Regional Trends among Pulmonary Arterial Hypertension Clinical Trial Participants

Rationale: The population of patients with pulmonary arterial hypertension (PAH) has evolved over time from predominantly young White women to an older, more racially diverse and obese population. Whether these changes are reflected in clinical trials is not known. Objectives: To determine secular and regional trends among PAH trial participants. Methods: We performed a pooled cohort analysis using harmonized data from phase III clinical trials of PAH therapies submitted to the U.S. Food and Drug Administration. We used mixed-effects linear and logistic regression to assess regional differences in participant age, sex, body habitus, and hemodynamics over time. Results: A total of 6,599 participants were enrolled in 18 trials between 1998 and 2013; 78% were female. The mean age of participants in North America, Europe, and Latin America at the time of study start increased by 2.09 (95% confidence interval [CI], 0.67-3.51), 1.62 (95% CI, 0.24-3.00), and 4.75 (95% CI, 2.29-7.21) years per 5 years, respectively (P = 0.01). Body mass index at the time of study start increased by 0.72 kg/m2 per 5 years (95% CI, 0.44-0.99; P < 0.001) across all regions. Eighty-five percent of participants in early studies were non-Hispanic White, but this decreased over time to 70%. Ninety-seven percent of Asians and 74% of Hispanics in the sample were recruited from Asia and Latin America. Conclusions: Patients enrolled in more recent PAH therapy trials are older and more obese, mirroring the changing epidemiology of observational cohorts. However, these trends varied by geographic region. PAH cohorts remain predominantly female, presenting challenges for generalizability to male patients. Although the proportion of non-White participants increased over time, this was primarily through recruitment in Asia and Latin America.

An open‐label, dose‐escalation study to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of single doses of GSK2586881 in participants with pulmonary arterial hypertension

Preclinical and early clinical studies suggest that angiotensin‐converting enzyme type 2 activity may be impaired in patients with pulmonary arterial hypertension (PAH); therefore, administration of exogenous angiotensin‐converting enzyme type 2 (ACE2) may be beneficial. This Phase IIa, multi‐center, open‐label, exploratory, single‐dose, dose‐escalation study (NCT03177603) assessed the potential vasodilatory effects of single doses of GSK2586881 (a recombinant human ACE2) on acute cardiopulmonary hemodynamics in hemodynamically stable adults with documented PAH who were receiving background PAH therapy. Successive cohorts of participants were administered a single intravenous dose of GSK2586881 of 0.1, 0.2, 0.4, or 0.8 mg/kg. Dose escalation occurred after four or more participants per cohort were dosed and a review of safety, tolerability, pharmacokinetics, and hemodynamic data up to 24 h postdose was undertaken. The primary endpoint was a change in cardiopulmonary hemodynamics (pulmonary vascular resistance, cardiac index, and mean pulmonary artery pressure) from baseline. Secondary/exploratory objectives included safety and tolerability, effect on renin‐angiotensin system peptides, and pharmacokinetics. GSK2586881 demonstrated no consistent or sustained effect on acute cardiopulmonary hemodynamics in participants with PAH receiving background PAH therapy (N = 23). All doses of GSK2586881 were well tolerated. GSK2586881 was quantifiable in plasma for up to 4 h poststart of infusion in all participants and caused a consistent and sustained reduction in angiotensin II and a corresponding increase in angiotensin (1–7) and angiotensin (1–5). While there does not appear to be a consistent acute vasodilatory response to single doses of GSK2586881 in participants with PAH, the potential benefits in terms of chronic vascular remodeling remain to be determined.

The therapeutic effect and mechanism of Rapamycin combined with HO-3867 on monocrotaline-induced pulmonary hypertension in rats

This study test was designed to investigate the possible modulatory effect of rapamycin combined with HO-3867 in monocrotaline(MCT)-induced pulmonary arterial hypertension in rats. We hypothesized that combined treatment with rapamycin and HO-3867 is superior to either alone in attenuating MCT-induced rat pulmonary arterial hypertension (PAH). Pulmonary arterial hypertension was induced by a single intraperitoneal injection of monocrotaline (60 mg/kg). 2 weeks later, rapamycin (2 mg/kg i.p.) and HO3867 (10 mg/kg i.h.) were administered daily, alone and in combination, for 2 weeks. Right ventricular systolic pressure, echocardiography were recorded and then rats were sacrificed. Histological analysis of pulmonary arteries medial wall thickness, right ventricular hypertrophy index (RVHI), the ratio of right ventricular to body weight, and collagen volume fraction (CVF) of right ventricular were performed. Moreover, the expression of t-STAT3, p-STAT3, t-Akt, p-Akt in lung and t-STAT3, p-STAT3, t-S6, p-S6 in right ventricular were examined. The result showed that combined treatment provided a considerable improvement toward maintaining hemodynamic changes, lung vascular remodeling as well as amending RV remodeling and function. Furthermore, Combined treatment can normalize the protein levels of two signal pathways in lung and heart tissue, where p-S6 or p-Akt significantly decreased compared to HO-3867 alone, or p-STAT3 significantly reduced compared to rapamycin alone. In conclusion, combined treatment with rapamycin and HO-3867 is superior to either alone in attenuating MCT-induced PAH in rats.

Optimization of specific therapy for pulmonary hypertension: the possibilities of riociguat

Pulmonary hypertension (PH) is a severe and often rapidly progressive disease with fatal outcome. Endothelial dysfunction in PH is associated with decreased nitric oxide production. After reviewing the mechanisms of action and the evidence base for specific therapy with phosphodiesterase 5 inhibitors (PDE-5) and soluble guanylate cyclase stimulators, a reseach review on switching from PDE-5 to riociguat is conducted. A potential advantage of riociguat is its independence from endogenous nitric oxide and from the other (besides PDE-5) isoenzymes of phosphodiesterases. The favorable efficacy profile of sildenafil has been proven for the main forms of pulmonary arterial hypertension, of riociguat for the main forms of pulmonary arterial hypertension and chronic thromboembolic PH. The clinical efficacy of replacing PDE-5 with riociguat has been demonstrated in uncontrolled trials and in the randomized controlled study REPLACE. The possibility of therapy optimization by switching from IFDE-5 to riociguat is fixed in the Russian (class and level of evidence B-3) and Eurasian (class and level of evidence IIb-B) clinical guidelines, as well as in the materials of the Cologne Expert Consensus. An additional argument for switching is the lower cost as compared to combination therapy in the Russian Federation. According to the Russian and Eurasian guidelines for PH and the Russian instructions for the use of riociguat, the drug should be taken at least 24 hours after sildenafil discontinuation.

Standardized exercise training is feasible, safe, and effective in pulmonary arterial and chronic thromboembolic pulmonary hypertension: results from a large European multicentre randomized controlled trial

AIMS

This prospective, randomized, controlled, multicentre study aimed to evaluate efficacy and safety of exercise training in patients with pulmonary arterial (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH).

METHODS AND RESULTS

For the first time a specialized PAH/CTEPH rehabilitation programme was implemented in 11 centres across 10 European countries. Out of 129 enrolled patients, 116 patients (58 vs. 58 randomized into a training or usual care control group) on disease-targeted medication completed the study [85 female; mean age 53.6 ± 12.5 years; mean pulmonary arterial pressure 46.6 ± 15.1 mmHg; World Health Organization (WHO) functional class II 53%, III 46%; PAH n = 98; CTEPH n = 18]. Patients of the training group performed a standardized in-hospital rehabilitation with mean duration of 25 days [95% confidence interval (CI) 17-33 days], which was continued at home. The primary endpoint, change of 6-min walking distance, significantly improved by 34.1 ± 8.3 m in the training compared with the control group (95% CI, 18-51 m; P < 0.0001). Exercise training was feasible, safe, and well-tolerated. Secondary endpoints showed improvements in quality of life (short-form health survey 36 mental health 7.3 ± 2.5, P = 0.004), WHO-functional class (training vs. control: improvement 9:1, worsening 4:3; χ2P = 0.027) and peak oxygen consumption (0.9 ± 0.5 mL/min/kg, P = 0.048) compared with the control group.

CONCLUSION

This is the first multicentre and so far the largest randomized, controlled study on feasibility, safety, and efficacy of exercise training as add-on to medical therapy in PAH and CTEPH. Within this study, a standardized specialized training programme with in-hospital start was successfully established in 10 European countries.

Outcomes of pulmonary vasodilator use in Veterans with pulmonary hypertension associated with left heart disease and lung disease

Randomized trials of pulmonary vasodilators in pulmonary hypertension due to left heart disease (Group 2) and lung disease (Group 3) have demonstrated potential for harm. Yet these therapies are commonly used in practice. Little is known of the effects of treatment outside of clinical trials. We aimed to establish outcomes of vasodilator treatment for Groups 2/3 pulmonary hypertension in real-world practice. We conducted a retrospective cohort study of 132,552 Medicare-eligible Veterans with incident Groups 2/3 pulmonary hypertension between 2006 and 2016, and a secondary nested case-control study. Our primary outcome was a composite of death by any cause or selected acute organ failures. In our cohort analysis, we calculated adjusted risks of time to our outcome using Cox proportional hazards models with facility-specific random effects. In our case-control analysis, we used logistic mixed-effects models to estimate the effect of any past, recent, and cumulative exposure on our outcome. From our cohort study, 3249 (2.5%) Veterans were exposed to pulmonary vasodilators. Exposure to vasodilators was associated with increased risk of our primary outcome, in both Group 3 (HR: 1.58 (95% CI: 1.37-1.82)) and Group 2 (HR: 1.26 (95% CI: 1.12-1.41)) pulmonary hypertension patients. The case-control study determined odds of our outcome increased by 11% per year of exposure (OR: 1.11 (95% CI: 1.07-1.16)). Treating Groups 2/3 pulmonary hypertension with vasodilators in clinical practice is associated with increased risk of harm. This extension of trial findings to a real-world setting offers further evidence to limit use of vasodilators in Groups 2/3 pulmonary hypertension outside of clinical trials.

Critical Care of Patients With Cardiopulmonary Complications of Sarcoidosis

Sarcoidosis is a systemic inflammatory disease defined by the presence of aberrant granulomas affecting various organs. Due to its multisystem involvement, care of patients with established sarcoidosis becomes challenging, especially in the intensive care setting. While the lungs are typically involved, extrapulmonary manifestations also occur either concurrently or exclusively within a significant proportion of patients, complicating diagnostic and management decisions. The scope of this review is to focus on what considerations are necessary in the evaluation and management of patients with known sarcoidosis and their associated complications within a cardiopulmonary and critical care perspective.

[Advantages and limitations of initial combination therapy in pulmonary arterial hypertension patients in Russia]

Pulmonary arterial hypertension (PAH) is severe and often times rapidly progressive disease with fatal outcome. The concept of initial combination of PAH-specific therapies in high risk patients at baseline was first described in the European guidelines on pulmonary hypertension (PH) in 2009, and in low or intermediate risk patients at baseline in 2015. Interestingly, that in Cologne Experts Consensus, and then in the 6th World Symposium on PH medical community started considering initial combination therapy as one of the most important pillars in PAH treatment algorithms in 2018. As of August 2020, as many as 8 formulations of 7 reference PAH-specific drugs are licensed for medical use in the Russian Federation. On top of that, 6 abbreviated drugs (generics) have also become available few years ago. Unfortunately, intravenous and subcutaneous prostacyclin analogs (PCA) and tadalafil are not approved for PH patients treatment in the Russian Federation. In this narrative review paper we attempted to describe studies on initial dual combination therapy with PAH-specific drugs registered in Russia, i.e. ambrisentan and riociguat, macitentan and riociguat, macitentan and sildenafil in low or intermediate risk patients at baseline, as well as iloprost inhaled and sildenafil, iloprost inhaled and bosentan in high risk patients. Some beneficial pharmacological effects due to the synergy between ambrisentan plus riociguat, and inhaled iloprost plus sildenafil appear to be interesting and require further clinical confirmation. Other initial combinations of PAH-specific agents require large-scale clinical trials as well.

Evidence synthesis in pulmonary arterial hypertension: a systematic review and critical appraisal

BACKGROUND

The clinical landscape of pulmonary arterial hypertension (PAH) has evolved in terms of disease definition and classification, trial designs, available therapies and treatment strategies as well as clinical guidelines. This study critically appraises published evidence synthesis studies, i.e. meta-analyses (MA) and network-meta-analyses (NMA), to better understand their quality, validity and discuss the impact of the findings from these studies on current decision-making in PAH.

METHODS

A systematic literature review to identify MA/NMA studies considering approved and available therapies for treatment of PAH was conducted. Embase, Medline and the Cochrane's Database of Systematic Reviews were searched from database inception to April 22, 2020, supplemented by searches in health technology assessment websites. The International Society for Pharmacoeconomics and Outcomes Research (ISPOR) checklist covering six domains (relevance, credibility, analysis, reporting quality and transparency, interpretation and conflict of interest) was selected for appraisal of the included MA/NMA studies.

RESULTS

Fifty-two full publications (36 MAs, 15 NMAs, and 1 MA/NMA) in PAH met the inclusion criteria. The majority of studies were of low quality, with none of the studies being scored as 'strong' across all checklist domains. Key limitations included the lack of a clearly defined, relevant decision problem, shortcomings in assessing and addressing between-study heterogeneity, and an incomplete or misleading interpretation of results.

CONCLUSIONS

This is the first critical appraisal of published MA/NMA studies in PAH, suggesting low quality and validity of published evidence synthesis studies in this therapeutic area. Besides the need for direct treatment comparisons assessed in long-term randomized controlled trials, future efforts in evidence synthesis in PAH should improve analysis quality and scrutiny in order to meaningfully address challenges arising from an evolving therapeutic landscape.

Treatment Discontinuation or Interruption in Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a progressive disease, which can be potentially fatal. The management of a complex disease like PAH requires a multidisciplinary approach from a team consisting of physicians, nurses, social workers, and pharmacists. Adherence to PAH-specific therapy is one of the key factors in the management of this disease. Poor adherence to treatment is a common problem in PAH as it is in many chronic diseases. Management of medication interruptions is a challenge in patients with PAH that can lead to negative consequences. However, for most PAH-specific drugs, there are no clear guidelines on how to manage temporary or abrupt medication discontinuations. In this review, we summarized the available literature and provide suggestions on how to manage interruptions of PAH-specific therapies.

Aloperine suppresses human pulmonary vascular smooth muscle cell proliferation via inhibiting inflammatory response

Abnormal pulmonary arterial vascular smooth muscle cells (PASMCs) proliferation is critical pathological feature of pulmonary vascular remodeling that acts as driving force in the initiation and development of pulmonary arterial hypertension (PAH), ultimately leading to pulmonary hypertension. Aloperine is a main active alkaloid extracted from the traditional Chinese herbal Sophora alopecuroides and possesses outstanding antioxidation and anti-inflammatory effects. Our group found Aloperine has protective effects on monocroline-induced pulmonary hypertension in rats by inhibiting oxidative stress in previous researches. However, the anti-inflammation effects of Aloperine on PAH remain unclear. Therefore, to further explore whether the beneficial role of Aloperine on PAH was connected with its anti-inflammatory effects, we performed experiments in vitro. Aloperine significantly inhibited the proliferation and DNA synthesis of human pulmonary artery smooth muscle cells (HPASMCs) induced by platelet-derived growth factor-BB, blocked progression through G₀/G₁to S phase of the cell cycle and promoted total ratio of apoptosis. In summary, these results suggested that Aloperine negatively regulated nuclear factor-κB signaling pathway activity to exert protective effects on PAH and suppressed HPASMCs proliferation therefore has a potential value in the treatment of pulmonary hypertension by negatively modulating pulmonary vascular remodeling.

Clinical Outcomes and Treatment Options in Patients With Pulmonary Hypertension Who Received Pulmonary Hypertension-Specific Drugs - Single-Center Case Series

Background: Recent progress in the development of pulmonary hypertension (PH)-specific pharmaceutical agents has improved mortality and morbidity remarkably. Today, these PH-specific drugs have become a standard treatment for PH. Methods and Results: We herein summarize the treatment options and longitudinal clinical outcomes of 21 patients with PH who received PH-specific drugs at the present institution. Sixteen patients began treatment with a single PH-specific drug; 9 of them needed additional PH-specific drugs, but the other 7 were still taking the same drug at the last follow-up. Five patients began treatment with a combination of 2 or 3 PH-specific drugs, and their drugs were not discontinued. Most patients (17/21) were taking a phosphodiesterase type 5 (PDE5) inhibitor at the last follow-up. During the 6.5±4.4 years' follow-up, 5 patients died, but only 1 death was related to PH. At 5 and 10 years, the estimated PH-related death-free and lung transplantation-free survival rate was 100% (95% CI: 100-100%) and 87.5% (95% CI: 38.7-98.1%), respectively. The estimated 5- and 10-year estimated overall survival rates were 77.9% (95% CI: 50.8-91.3%) and 68.2% (95% CI: 37.4-86.2%), respectively. Conclusions: PDE5 inhibitors played a central role in the treatment options. The long-term prognosis of PH was favorable at the present institution.

The Efficacy and Safety of Aerosolized Iloprost in Pulmonary Arterial Hypertension: A Systematic Review and Meta-Analysis

BACKGROUND

This systematic review and meta-analysis was conducted to investigate the efficacy and safety of the chronic administration of aerosolized iloprost for pulmonary arterial hypertension (PAH).

METHODS

All the relevant studies were obtained from three databases, namely, PubMed, Web of Science and the Cochrane Library, from the inception of each database to June 1, 2018. In our study, chronic treatment was defined as a period lasting at least 3 months. The rate of each event was analyzed by SPSS as a percentage with 95% confidence intervals (CIs). For the meta-analysis, a randomized effect model or a fixed effect model was applied according to the results of the heterogeneity test.

RESULTS

Ten studies were included in this study, with a total of 370 patients treated with inhaled iloprost, including 214 in five randomized controlled trials and 156 in five prospective clinical trials. Among the patients who received inhaled iloprost, there was a significant improvement in the 6-min walk distance (6MWD) in the short-medium and prolonged treatment groups. Notably, the functionality improved by at least 1 class in 48.7% of the treated patients. In all the pooled studies, the estimated 3-month, 6-month, 1-year and 2-year event-free survival rates were 96.6%, 92.3%, 62.6% and 39.6%, respectively. In addition, there were eight adverse drug responses.

CONCLUSION

In this systematic review and meta-analysis, inhaled iloprost has been shown to be a safe and well-tolerated agent for PAH in the first 3 months after diagnosis. If used for a prolonged period, aerosol iloprost monotherapy could contribute to an unsatisfactory improvement in vascular remodeling and even a decreased event-free survival rate.

NPS2390, a Selective Calcium-sensing Receptor Antagonist Controls the Phenotypic Modulation of Hypoxic Human Pulmonary Arterial Smooth Muscle Cells by Regulating Autophagy

Background and Objectives

Calcium-sensing receptor (CaSR) is known to regulate hypoxia-induced pulmonary hypertension (HPH) and vascular remodeling via the phenotypic modulation of pulmonary arterial smooth muscle cells (PASMCs) in small pulmonary arteries. Moreover, autophagy is an essential modulator of VSMC phenotype. But it is not clear whether CaSR can regulate autophagy involving the phenotypic modulation under hypoxia.

Methods

The viability of human PASMCs was detected by cell cycle and BrdU. The expressions of proliferation protein, phenotypic marker protein, and autophagy protein in human PASMCs were determined by western blot.

Results

Our results showed that hypoxia-induced autophagy was considerable at 24 h. The addition of NPS2390 decreased the expression of autophagy protein and synthetic phenotype marker protein osteopontin and increased the expression of contractile phenotype marker protein SMA-ɑ and calponin via suppressing downstream PI3K/Akt/mTOR signal pathways.

Conclusions

Our study demonstrates that treatment of NPS2390 was conducive to inhibit the proliferation and reverse phenotypic modulation of PASMCs by regulating autophagy levels.

Adverse Events of Prostacyclin Mimetics in Pulmonary Arterial Hypertension: A Systematic Review and Meta-Analysis

Prostacyclin mimetics (PMs) are effective for the treatment of pulmonary arterial hypertension (PAH). However, their clinical use may be limited by their adverse events. This study aims to quantify the different PM adverse events (AEs) with regard to their selectivity towards the prostacyclin (IP) receptor and their administrative routes. The study included randomised, placebo-controlled trials comparing iloprost, beraprost, treprostinil, and selexipag to placebo (published 2002–2016). We report the group efficacy differences between treatment and placebo by weighted and standardised mean difference. The probability of adverse events was determined by the odds ratio (OR). Of the 14 randomised clinical trials involving 3518 PAH patients, outcome and adverse event data were meta-analysed by drug type and route of administration. Prostacyclin mimetics comparison demonstrated a more significant discontinuation of the IP-selective agonist, selexipag, due to an adverse event (OR = 2.2; 95% CI: 1.5, 3.3). Compared to placebo, site pain associated with subcutaneously administered treprostinil was the most significant likely adverse event (OR = 17.5; 95% CI: 11.1, 27.1). Parenteral PMs were associated with fewer adverse effects overall. The overall efficacy of PMs to improve 6-minute walk distance by 16.3 meters was significant (95% CI: 13.0, 19.7). Decreases in pulmonary vascular resistance index (SMD = -5.5; 95% CI: -10.1, -0.9; I² = 98%) and mean pulmonary arterial pressure (SMD = -1.0; 95% CI: -2.6, -0.7; I² = 99%) in treatment groups were found to be significant. Adverse event profiles varied in response to administration route and PM type but were not negated by use of a selective IP agonist. Prostacyclin mimetics exposure to non-target IP receptors may underpin some AEs reported.

Inhaled combination of sildenafil and rosiglitazone improves pulmonary hemodynamics, cardiac function, and arterial remodeling

Currently, dual- or triple-drug combinations comprising different vasodilators are the mainstay for the treatment of pulmonary arterial hypertension (PAH). However, the patient outcome continues to be disappointing because the existing combination therapy cannot restrain progression of the disease. Previously, we have shown that when given as a monotherapy, long-acting inhaled formulations of sildenafil (a phosphodiesterase-5 inhibitor) and rosiglitazone (a peroxisome proliferator receptor-γ agonist) ameliorate PAH in rats. Thus, with a goal to develop a new combination therapy, we prepared and characterized poly(lactic-co-glycolic acid) (PLGA)-based long-acting inhalable particles of sildenafil and rosiglitazone. We then assessed the efficacy of the combinations of sildenafil and rosiglitazone, given in plain forms or as PLGA particles, in reducing mean pulmonary arterial pressure (mPAP) and improving pulmonary arterial remodeling and right ventricular hypertrophy (RVH) in Sugen 5416 plus hypoxia-induced PAH rats. After intratracheal administration of the formulations, we catheterized the rats and measured mPAP, cardiac output, total pulmonary resistance, and RVH. We also conducted morphometric studies using lung tissue samples and assessed the degree of muscularization, the arterial medial wall thickening, and the extent of collagen deposition. Compared with the plain drugs, given via the pulmonary or oral route as a single or dual combination, PLGA particles of the drugs, although given at a longer dosing interval compared with the plain drugs, caused more pronounced reduction in mPAP without affecting mean systemic pressure, improved cardiac function, slowed down right heart remodeling, and reduced arterial muscularization. Overall, PLGA particles of sildenafil and rosiglitazone, given as an inhaled combination, could be a viable alternative to currently available vasodilator-based combination therapy for PAH.

Mechanism of anti-remodelling action of treprostinil in human pulmonary arterial smooth muscle cells

Treprostinil is applied for pulmonary arterial hypertension (PAH) therapy. However, the mechanism by which the drug achieves its beneficial effects in PAH vessels is not fully understood. This study investigated the effects of treprostinil on PDGF-BB induced remodelling parameters in isolated human pulmonary arterial smooth muscle cells (PASMC) of four PAH patients. The production of TGF-β1, CTGF, collagen type-I and -IV, and of fibronectin were determined by ELISA and PCR. The role of cAMP was determined by ELISA and di-deoxyadenosine treatment. Proliferation was determined by direct cell count. Treprostinil increased cAMP levels dose and time dependently, which was not affected by PDGF-BB. Treprostinil significantly reduced PDGF-BB induced secretion of TGF-β1 and CTGF, both was counteracted when cAMP generation was blocked. Similarly, the PDGF-BB induced proliferation of PASMC was dose dependently reduced by treprostinil through signalling via cAMP—C/EBP-α p42 –p21^(WAf1/Cip1). In regards to extracellular matrix remodelling, treprostinil significantly reduced PDGF-BB—TGF-β1—CTGF induced synthesis and deposition of collagen type I and fibronectin, in a cAMP sensitive manner. In contrast, the deposition of collagen IV was not affected. The data suggest that this action of treprostinil in vessel wall remodelling may benefit patients with PAH and may reduce arterial wall remodelling.

A disease looking for innovative drugs: The case of pulmonary arterial hypertension

BACKGROUND

Pulmonary arterial hypertension (PAH) is a life-threatening rare disease. Between 2001 and 2016 the European Medicines Agency (EMA) approved nine drugs to treat PAH. Considering the poor prognosis of patients with PAH it would be useful to understand whether the approved therapies can change the natural history of the disease. We assessed the therapeutic value and the quality of the evidence on medicines that have been authorized by the EMA in the 2000s.

METHODS

Information about drug approval was obtained from the EMA website and the European Public Assessment Reports. MedLine, Embase, and Cochrane databases were systematically searched for published randomized clinical trials and meta-analyses of the selected drugs and their combinations.

RESULTS

At the time of approval no medicine had been proved to reduce mortality or slow the progression of the disease or to improve patients' quality of life. Recent meta-analyses concluded that, compared to placebo, active treatments reduced mortality but there was no conclusion on any preferred therapeutic option. Approvals of monotherapies in the absence of best evidence of their efficacy, have prompted the search for better efficacy of their combinations. Three meta-analyses found no advantage in survival from combinations as opposed to monotherapies.

CONCLUSIONS

This model case confirms previous analyses that marketing authorizations granted in spite of low evidence of therapeutic efficacy not only expose patients to treatments with unknown benefit-risk profiles but also hamper post-marketing research aimed at filling the information gap.

Efficacy and safety of oral targeted therapies in pulmonary arterial hypertension: a meta-analysis of randomized clinical trials

Oral targeted therapies play an important role in the treatment of pulmonary arterial hypertension (PAH). Several new oral agents have emerged for PAH in recent years. However, whether they provide a survival advantage is still not clear. This meta-analysis aimed to assess the efficacy and safety of oral targeted therapies, especially on predefined clinical worsening events. Trials were searched in the Cochrane Library, EMBASE, and PUBMED databases through June 2018. We calculated risk ratios for dichotomous data and weighted mean differences with 95% confidence intervals (CI) for continuous data. Twenty-five trials with a total of 6847 participants were included in the meta-analysis. Oral targeted therapies were associated with significant risk reduction in clinical worsening compared with placebo (relative risk [RR] 0.64; 95% CI = 0.58–0.70; P < 0.001). This reduction in risk was driven by reduction in non-fatal endpoints, including PAH-related admissions to hospital (RR = 0.66; 95% CI = 0.56–0.76; P < 0.001), treatment escalation (RR = 0.43; 95% CI = 0.28–0.66; P < 0.001), and symptomatic progression (RR = 0.55; 95% CI = 0.48–0.64; P < 0.001), but not by reduction of mortality (RR = 0.87; 95% CI = 0.68–1.12; P = 0.215). Oral targeted therapies were also associated with improvement in 6-min walk distance (26.62 m; 95% CI = 20.54–32.71; P < 0.001) and World Health Organization functional class (RR = 1.36; 95% CI = 1.20–1.54; P < 0.001). The results of this meta-analysis showed the benefits of oral treatments on clinical worsening events in PAH. However, these oral agents did not show any survival benefit in the short-term follow-up.

Berberine attenuates pulmonary arterial hypertension via protein phosphatase 2A signaling pathway both in vivo and in vitro

Excessive proliferation, migration, and antiapoptosis of pulmonary artery (PA) smooth muscle cells (PASMCs) underlies the development of pulmonary vascular remodeling. The innervation of the PA is predominantly sympathetic, and increased levels of circulating catecholamines have been detected in pulmonary arterial hypertension (PAH), suggesting that neurotransmitters released by sympathetic overactivation may play an essential role in PAH. However, the responsible mechanism remains unclear. Here, to investigate the effects of norepinephrine (NE) on PASMCs and the related mechanism, we used 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide, the proliferating cell nuclear antigen and the cell counting kit-8 assay to evaluate the proliferation of PASMCs, Boyden chamber migration, and wound-healing assays to assess migration and western blot analysis to investigate protein expression. We demonstrated that the phosphorylation level of the protein phosphatase 2A (PP2A) catalytic subunit (Y307) was higher in PAH patients and PAH models than in controls, both in vivo and in vitro. In addition, NE induced the proliferation and migration of PASMCs, which was attenuated by berberine (BBR), a Chinese herbal medicine, and/or PP2A overexpression. PP2A inhibition worsened NE-induced PAH and could not be reversed by BBR. Thus, PP2A is critical in driving PAH, and BBR may alleviate PAH via PP2A signaling pathways, thereby offering a potential therapeutic option for PAH.

Atrial arrhythmias are associated with increased mortality in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a deadly vascular disease, characterized by increased pulmonary arterial pressures and right heart failure. Considering prior non-US studies of atrial arrhythmias in PAH, this retrospective, regional multi-center US study sought to define more completely the risk factors and impact of paroxysmal and non-paroxysmal forms of atrial fibrillation and flutter (AF/AFL) on mortality in this disease. We identified patients seen between 2010 and 2014 at UPMC (Pittsburgh) hospitals with hemodynamic and clinical criteria for PAH or chronic thromboembolic pulmonary hypertension (CTEPH) and determined those meeting electrocardiographic criteria for AF/AFL. We used Cox proportional hazards regression with time-varying covariates to analyze the association between AF/AFL occurrence and survival with adjustments for potential cofounders and hemodynamic severity. Of 297 patients with PAH/CTEPH, 79 (26.5%) suffered from AF/AFL at some point. AF/AFL was first identified after PAH diagnosis in 42 (53.2%), identified prior to PAH diagnosis in 27 (34.2%), and had unclear timing in the remainder. AF/AFL patients were older, more often male, had lower left ventricular ejection fractions, and greater left atrial volume indices and right atrial areas than patients without AF/AFL. AF/AFL (whether diagnosed before or after PAH) was associated with a 3.81-fold increase in the hazard of death (95% CI 2.64-5.52, p < 0.001). This finding was consistent with multivariable adjustment of hemodynamic, cardiac structural, and heart rate indices as well as in sensitivity analyses of patients with paroxysmal versus non-paroxysmal arrhythmias. In these PAH/CTEPH patients, presence of AF/AFL significantly increased mortality risk. Mortality remained elevated in the absence of a high burden of uncontrolled or persistent arrhythmias, thus suggesting additional etiologies beyond rapid heart rate as an explanation. Future studies are warranted to confirm this observation and interrogate whether other therapies beyond rate and rhythm control are necessary to mitigate this risk.

The efficiency of endothelin receptor antagonist bosentan for pulmonary arterial hypertension associated with congenital heart disease: A systematic review and meta-analysis

BACKGROUND

Oral bosentan has been widely applied in pulmonary arterial hypertension associated with congenital heart disease (PAH-CHD). A systemic review and meta-analysis was conducted for a therapeutic evaluation of oral bosentan in both adult and pediatric patients with PAH-CHD. The acute responses and a long-term effect were respectively assessed in a comparison with baseline characteristics, and the improvement of exercise tolerance was analyzed.

METHODS

PubMed, Medline, Embase, and Cochrane Central Register of clinical controlled trails or observational studies have been searched for a recording of bosentan effects on the PAH-CHD participants. For mortality and rate of adverse events (AEs), it was described in detail. Randomized-effects model or fixed-effects model was used to calculate different effective values with a sensitivity analysis.

RESULTS

Seventeen studies were pooled in this review, and 3 studies enrolled the pediatric patients. Among all studies, 456 patients were diagnosed with PAH-CHD, and 91.7% were treated with oral bosentan. With a term less than 6 months of bosentan therapy, there existed a significant improvement in 6-minute walk distance (6MWD) and the World Health Organization functional class (WHO-FC), but no such differences in Borg dyspnea index scores (BDIs) and the resting oxygen saturation (SpO2). Although with a prolonged treatment, not only 6MWD and FC, but also the resting SpO2 and heart rate were changed for a better exercise capability. Additionally, compared with the basic cardiopulmonary hemodynamics, it showed a statistically significant difference in mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance index (PVRi). Although a limitation of pooled studies with comparative outcomes of different terms, outcomes presented a lower WHO-FC which contributes to a success in a prolonged treatment.

CONCLUSIONS

Bosentan in PAH-CHD is well established and still requires clinical trials for an identification of its efficiency on CHD patients for an optimized period lessening a serious complication and the common AEs.

Validation of claims-based algorithms for pulmonary arterial hypertension

Administrative claims studies do not adequately distinguish pulmonary arterial hypertension (PAH) from other forms of pulmonary hypertension (PH). Our aim is to develop and validate a set of algorithms using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes and electronic medical records (EMR), to identify patients with PAH. From January 2012 to August 2015, the EMRs of patients with ICD-9-CM codes for PH with an outpatient visit at the University of Texas Medical Branch were reviewed. Patients were divided into PAH or non-PAH groups according to EMR encounter diagnosis. Patient demographics, echocardiography, right heart catheterization (RHC) results, and PAH-specific therapies were assessed. RHC measurements were reviewed to categorize cases as hemodynamically determined PAH or not PAH. Weighted sensitivity, specificity, and positive and negative predictive values were calculated for the developed algorithms. A logistic regression analysis was conducted to determine how well the algorithms performed. External validation was performed at the University of Virginia Health System. The cohort for the development algorithms consisted of 683 patients with PH, PAH group (n = 191) and non-PAH group (n = 492). A hemodynamic diagnosis of PAH determined by RHC was recorded in the PAH (26%) and non-PAH (3%) groups. The positive predictive value for the algorithm that included ICD-9-CM and PAH-specific medications was 66.9% and sensitivity was 28.2% with a c-statistic of 0.66. The positive predictive value for the EMR-based algorithm that included ICD-9-CM, EMR encounter diagnosis, echocardiography, RHC, and PAH-specific medication was 69.4% and a c-statistic of 0.87. A validation cohort of 177 patients with PH examined from August 2015 to August 2016 using EMR-based algorithms yielded a similar positive predictive value of 62.5%. In conclusion, claims-based algorithms that included ICD-9-CM codes, EMR encounter diagnosis, echocardiography, RHC, and PAH-specific medications better-identified patients with PAH than ICD-9-CM codes alone.

Early intervention in the management of pulmonary arterial hypertension: clinical and economic outcomes

Pulmonary arterial hypertension (PAH) has a high morbidity rate and is fatal if left untreated. Increasing evidence supports early intervention, possibly with initial combination therapy. PAH-specific pharmaceuticals, however, are expensive and may have serious adverse effects, particularly when used in combination. The currently dynamic health care economy reinforces the need for a review of early intervention from both outcomes and economic perspectives. We aimed to review the clinical and economic impact of PAH therapy, particularly examining drug cost, hospitalization burden, and health care economics impact, and the effect of early intervention on clinical outcomes. We searched PubMed, Scopus, Ovid, and MEDLINE databases from 2005 to 2017 for studies comparing drug cost, clinical outcomes, and hospitalization burden associated with therapy for PAH. Emerging data indicate that early therapy is effective, but drug therapy is expensive, particularly with combination therapy. Efficacy studies also generally show benefit of combination therapy for patients in World Health Organization functional class II, with a consistent decrease in hospitalization. Pharmacoeconomic studies are limited but indicate that increased pharmacy costs are at least partially offset by decreased health care utilization, particularly inpatient care. Modeling also shows a cost benefit with combination therapy at 2 years. Nonetheless, more rigorously collected health care economic data should be incorporated into future drug efficacy trials to provide a clearer understanding of the impact and the associated cost benefit of early PAH therapy. Increasing evidence in support of early intervention and combination therapy for PAH is associated with rising medication costs that are largely offset by reduced hospitalization, on the basis of the currently available literature. Nonetheless, the studies performed to date have methodologic limitations that highlight the need for prospective studies using more robust economic modeling.

Incidence and risk of respiratory tract infection associated with specific drug therapy in pulmonary arterial hypertension: a systematic review

Specific drug therapy has been proven to improve functional capacity and slow disease progression in pulmonary arterial hypertension (PAH), regretfully with the data on the risk of respiratory tract infection (RTI) associated with specific drug therapy being limited. Databases of Medline, Embase, Cochrane Library and the ClinicalTrials.gov Website were searched for randomized controlled trials (RCTs) that reported the RTI data of PAH-specific drug therapy in patients. The primacy outcome was assessed by employing a fixed-effects model. Totally, 24 trials involving 6307 patients were included in the analysis. PAH-specific drug therapy was not significantly associated with the increased risk of both RTI (19.4% vs. 21.1% RR 1.02, 95%CI 0.92-1.14, P = 0.69) and serious RTI (4.3% vs. 5.0% RR 0.99, 95%CI 0.77-1.26, P = 0.93) compared to placebo. The results were consistent across the key subgroups. No heterogeneity between the studies (I2 = 35.8% for RTI, and I2 = 0.0% for serious RTI) and no publication bias was identified. In conclusion, no significant increase in RTI had been found in PAH-specific drug therapy when compared with placebo. Whereas, RTI in PAH patients is still worthy of clinical attention.

Cumulative subgroup analysis to reduce waste in clinical research for individualised medicine

BACKGROUND

Although subgroup analyses in clinical trials may provide evidence for individualised medicine, their conduct and interpretation remain controversial.

METHODS

Subgroup effect can be defined as the difference in treatment effect across patient subgroups. Cumulative subgroup analysis refers to a series of repeated pooling of subgroup effects after adding data from each of related trials chronologically, to investigate the accumulating evidence for subgroup effects. We illustrated the clinical relevance of cumulative subgroup analysis in two case studies using data from published individual patient data (IPD) meta-analyses. Computer simulations were also conducted to examine the statistical properties of cumulative subgroup analysis.

RESULTS

In case study 1, an IPD meta-analysis of 10 randomised trials (RCTs) on beta blockers for heart failure reported significant interaction of treatment effects with baseline rhythm. Cumulative subgroup analysis could have detected the subgroup effect 15 years earlier, with five fewer trials and 71% less patients, than the IPD meta-analysis which first reported it. Case study 2 involved an IPD meta-analysis of 11 RCTs on treatments for pulmonary arterial hypertension that reported significant subgroup effect by aetiology. Cumulative subgroup analysis could have detected the subgroup effect 6 years earlier, with three fewer trials and 40% less patients than the IPD meta-analysis. Computer simulations have indicated that cumulative subgroup analysis increases the statistical power and is not associated with inflated false positives.

CONCLUSIONS

To reduce waste of research data, subgroup analyses in clinical trials should be more widely conducted and adequately reported so that cumulative subgroup analyses could be timely performed to inform clinical practice and further research.

Comparative Effectiveness of Pharmacologic Interventions for Pulmonary Arterial Hypertension: A Systematic Review and Network Meta-Analysis

BACKGROUND

We conducted a systematic review and network meta-analysis to examine comparative efficacy and tolerability of pharmacologic interventions for pulmonary arterial hypertension (PAH).

METHODS

MEDLINE, the Cochrane Register, EMBASE, CINAHL, and clinicaltrials.gov were searched (January 1, 1990 to March 3, 2016). Randomized controlled trials (RCTs) studying the approved pharmacologic agents endothelin receptor antagonists (ERA), phosphodiesterase inhibitors (PDE5i), the oral/inhaled (PO/INH) and IV/subcutaneous (SC) prostanoids, and riociguat and selexipag, alone or in combination, for pulmonary arterial hypertension (PAH) and reporting at least one efficacy outcome were selected.

RESULTS

Thirty-one RCTs with 6,565 patients were selected. In network meta-analysis, when compared with a median placebo rate of 14.5%, clinical worsening was estimated at 2.8% with riociguat (risk ratio [RR], 0.19; 95% CI, 0.05-0.76); at 3.9% with ERA + PDE5i (RR, 0.27; 95% CI, 0.14-0.52), and at 5.7% with PDE5i (RR, 0.39; 95% CI, 0.24-0.62). For improvement in functional status, when compared with 16.2% in the placebo group, improvement in at least one New York Heart Association/World Health Organization (NYHA/WHO) functional class was estimated at 81.8% with IV/SC prostanoids (RR, 5.06; 95% CI, 2.3211.04), at 28.3% with ERA + PDE5i (RR, 1.75; 95% CI, 1.05-2.92), and at 25.2% with ERA (RR, 1.56; 95% CI, 1.22-2.00). Differences in mortality were not significant. Adverse events leading to discontinuation of therapy were highest with the PO/INH prostanoids (RR, 2.92; 95% CI, 1.68-5.06) and selexipag (RR, 2.06; 95% CI, 1.04-3.88) compared with placebo.

CONCLUSIONS

Currently approved pharmacologic agents have varying effects on morbidity and functional status in patients with PAH. Future comparative effectiveness trials are warranted with a focus on a patient-centered approach to therapy.

REGISTRATION

PROSPERO CRD42016036803.