Pulmonary arterial hypertension associated with connective tissue disease: meta-analysis of clinical trials

Pulmonary Hypertension in Connective Tissue Diseases Other than Systemic Sclerosis

Pulmonary hypertension (PH) is a known complication of certain connective tissue diseases (CTDs), with systemic sclerosis (SSc) being the most common in the Western world. However, PH in association with non-SSc CTD such as systemic lupus erythematous, mixed connective tissue disease, and primary Sjögren's syndrome constitutes a distinct subset of patients with inherently different epidemiologic profiles, pathophysiologic mechanisms, clinical features, therapeutic options, and prognostic implications. The purpose of this review is to inform a practical approach for clinicians evaluating patients with non-SSc CTD-associated PH.The development of PH in these patients involves a complex interplay between genetic factors, immune-mediated mechanisms, and endothelial cell dysfunction. Furthermore, the broad spectrum of CTD manifestations can contribute to the development of PH through various pathophysiologic mechanisms, including intrinsic pulmonary arteriolar vasculopathy (pulmonary arterial hypertension, Group 1 PH), left-heart disease (Group 2), chronic lung disease (Group 3), chronic pulmonary artery obstruction (Group 4), and unclear and/or multifactorial mechanisms (Group 5). The importance of diagnosing PH early in symptomatic patients with non-SSc CTD is highlighted, with a review of the relevant biomarkers, imaging, and diagnostic procedures required to establish a diagnosis.Therapeutic strategies for non-SSc PH associated with CTD are explored with an in-depth review of the medical, interventional, and surgical options available to these patients, emphasizing the CTD-specific considerations that guide treatment and aid in prognosis. By identifying gaps in the current literature, we offer insights into future research priorities that may prove valuable for patients with PH associated with non-SSc CTD.

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.

Long-Term Outcomes in Patients With Connective Tissue Disease-Associated Pulmonary Arterial Hypertension in the Modern Treatment Era: Meta-Analyses of Randomized, Controlled Trials and Observational Registries

Objective

Data on the magnitude of benefit of modern therapies for pulmonary arterial hypertension (PAH) in connective tissue disease (CTD)–associated PAH are limited. In this study, we performed meta‐analyses of randomized, controlled trials (RCTs) and registries to quantify the benefit of these modern therapies in patients with CTD‐PAH.

Methods

The PubMed and Embase databases were searched for articles reporting data from RCTs or registries published between January 1, 2000 and November 25, 2019. Eligibility criteria included multicenter studies with ≥30 CTD‐PAH patients. For an RCT to be included, the trial had to evaluate an approved PAH therapy, and long‐term risks of clinical morbidity and mortality or 6‐minute walk distance had to be reported. For a registry to be included, survival rates had to be reported. Random‐effects models were used to pool the data.

Results

Eleven RCTs (total of 4,329 patients; 1,267 with CTD‐PAH) and 19 registries (total of 9,739 patients; 4,008 with CTD‐PAH) were included. Investigational therapy resulted in a 36% reduction in the risk of clinical morbidity/mortality events both in the overall PAH population (hazard ratio [HR] 0.64, 95% confidence interval [95% CI] 0.54, 0.75; P < 0.001) and in CTD‐PAH patients (HR 0.64, 95% CI 0.51, 0.81; P < 0.001) as compared to control subjects. The survival rate was lower in CTD‐PAH patients compared to all PAH patients (survival rate 62%, 95% CI 57, 67% versus 72%, 95% CI 69, 75% at 3 years). The survival rate in CTD‐PAH patients treated primarily after 2010 was higher than that in CTD‐PAH patients treated before 2010 (survival rate 73%, 95% CI 62, 81% versus 65%, 95% CI 59, 71% at 3 years).

Conclusion

Modern therapy provides a similar reduction in morbidity/mortality risk in patients with CTD‐PAH when compared to the PAH population overall. Risk of death is higher in CTD‐PAH patients than in those with PAH overall, but survival has improved in the last 10 years, which may be related to increased screening and/or new treatment approaches. Early detection of PAH in patients with CTD and up‐front intensive treatment are warranted.

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.

Pulmonary arterial hypertension associated with connective tissue diseases: A review focusing on distinctive clinical aspects

Recent studies have clarified that pulmonary arterial hypertension associated with connective tissue diseases (CTD-PAH) has some distinctive clinical aspects from other PAH, such as high prevalence, venous and cardiac involvement, less favourable outcome, helpfulness of detection algorithm, response to immunosuppression, pre-PAH conditions in borderline pulmonary arterial pressure and coexistence of interstitial lung disease. In this review, by focusing on these distinctive aspects, we discuss how to provide an efficacious and safe management of CTD-PAH and garner attention to areas where further evidence is desired.

Complex Pathophysiology of Pulmonary Hypertension Associated with Systemic Sclerosis: Potential Unfavorable Effects of Vasodilators

Therapeutic advance by pulmonary vasodilators has provided huge impacts on prognosis in patients with pulmonary arterial hypertension (PAH), but outcomes of systemic sclerosis (SSc)-associated PAH still remain unsatisfactory. One of the major reasons is a series of potential unfavorable effects triggered by pulmonary vasodilators, which result from the complex pathophysiology of SSc-PAH. We herein present and discuss five representative conditions potentially induced by pulmonary vasodilators, including (i) emergence of latent pulmonary veno-occlusive disease, (ii) emergence of latent left-heart disease, (iii) worsening of pulmonary gas change in the presence of interstitial lung disease, (iv) ischemic limb gangrene by stealing of blood flow, and (v) uncontrolled hemorrhage from gastrointestinal telangiectasia. The former three conditions are common causes for worsening of dyspnea or oxygenation during treatment with pulmonary vasodilators, whereas the latter two are rare, but have significant negative impacts on patients’ quality of life and survival. These unfavorable conditions are pitfalls in clinical practice, and interfere with optimizing therapies in patients with SSc-PAH. Therefore, pre-assessment of pathophysiology of pulmonary hypertension and cautious monitoring during the treatment are necessary to achieve better outcomes in patients with SSc-PAH.

Current Approaches to the Treatment of Systemic-Sclerosis-Associated Pulmonary Arterial Hypertension (SSc-PAH)

Pulmonary arterial hypertension (PAH) is a severe condition causing significant morbidity and mortality in patients with systemic sclerosis (SSc). Despite the use of specific treatments, SSc-PAH survival remains poorer than in idiopathic PAH (IPAH). Recent therapeutic advances in PAH show a lower magnitude of response in SSc-PAH and a higher risk of adverse events, as compared to IPAH. The multifaceted underlying mechanisms and the multisystem nature of SSc probably explain part of the worse outcomes in SSc-PAH compared to IPAH. This review describes the current management of SSc-PAH with an emphasis on the impact of the different organ involvements in the prognosis and treatment response. An earlier detection of PAH and a better characterization of the clinical phenotypes of SSc-PAH are warranted in clinical practice and future trials. Determinants of prognosis, surrogate markers of clinical improvement or worsening, and relevance of the common endpoints used in clinical trials should be evaluated in this specific population. A multidisciplinary approach in expert referral centers is mandatory for SSc-PAH management.

Comparative Effectiveness of Oral Medications for Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a disease that imposes a significant burden on patients. Although multiple treatment options for PAH are available, head-to-head comparisons are difficult to conduct. Network meta-analysis (NMA) can be a useful alternative for direct comparison to estimate the relative effectiveness of multiple treatments. The objective of the present study was to conduct a systematic review and NMA to evaluate the relative effectiveness among oral PAH medications.Data collection was performed by searching the Cochrane Central Register of Controlled Trials (CENTRAL) and Ichushi-Web. Randomized controlled trials (RCTs) assessing at least 1 of the following 3 outcome measurements; 6-minute walk distance test (6MWD), WHO functional class (WHOFC), and mean pulmonary artery pressure (mPAP) were included (PROSPERO registration number: CRD42015016557). Outcomes were evaluated by estimating the differences in the mean change from baseline or by estimating the odds ratios. Analyses were performed using WinBUGS 1.4.3.Seven double-blind RCTs were eligible. NMA results showed similar improvements in 6MWD for all medications assessed. Bosentan and sildenafil caused a statistically significant improvement in WHOFC compared to other medications.The relative effectiveness of oral PAH medications could be compared using NMA, which suggested the superiority of bosentan and sildenafil in the improvement of WHOFC.

Comparison of Treatment Response in Idiopathic and Connective Tissue Disease-associated Pulmonary Arterial Hypertension

RATIONALE

Studies suggest that patients with connective tissue disease-associated pulmonary arterial hypertension (CTD-PAH) have a poorer treatment response to therapies for PAH compared with patients with idiopathic PAH (IPAH), but individual randomized controlled trials (RCTs) have been underpowered to examine differences within these subgroups.

OBJECTIVES

To compare the effect of therapy for PAH in CTD-PAH versus IPAH.

METHODS

We obtained individual participant data from phase III placebo-controlled RCTs of therapies for PAH submitted to the U.S. Food and Drug Administration for drug approval. A treatment-by-diagnosis interaction term evaluated differences in treatment response between CTD-PAH and IPAH. Outcomes included change in 6-minute-walk distance (∆6MWD) from baseline to 12 weeks, clinical worsening, and all-cause mortality.

MEASUREMENTS AND MAIN RESULTS

The study sample included 827 participants with CTD-PAH and 1,935 with IPAH from 11 RCTs. Patients with CTD-PAH had less improvement in 6MWD when assigned to active treatment versus placebo compared with patients with IPAH (difference in treatment effect on ∆6MWD in CTD-PAH vs. IPAH, -17.3 m; 90% confidence interval, -31.3 to -3.3; P for interaction = 0.043). Treatment was less effective in reducing the occurrence of clinical worsening in CTD-PAH versus IPAH (P for interaction = 0.012), but there was no difference in the placebo-adjusted effect of treatment on mortality (P for interaction = 0.65).

CONCLUSIONS

Treatment for PAH was less effective in CTD-PAH compared with IPAH in terms of increasing 6MWD and preventing clinical worsening. The heterogeneity of treatment response supports the need for identifying therapies that are more effective for CTD-PAH.

Adverse Events in Connective Tissue Disease-Associated Pulmonary Arterial Hypertension

OBJECTIVE

Patients with connective tissue disease (CTD)-associated pulmonary arterial hypertension (PAH) have a poorer prognosis compared to those with idiopathic PAH, but little is known about the differences in treatment-related adverse events (AEs) and serious adverse events (SAEs) between these groups. This study was undertaken to characterize these differences.

METHODS

Individual patient-level data from 10 randomized controlled trials of therapies for PAH were obtained from the US Food and Drug Administration. Patients diagnosed as having either CTD-associated PAH or idiopathic PAH were included. A treatment-by-diagnosis interaction term was used to examine whether the effect of treatment on occurrence of AEs differed between patients with CTD-associated PAH and those with idiopathic PAH. Studies were pooled using fixed-effect models.

RESULTS

The study sample included 2,370 participants: 716 with CTD-associated PAH and 1,654 with idiopathic PAH. In the active treatment group compared to the placebo group, the risk of AEs was higher among patients with CTD-associated PAH than among those with idiopathic PAH (odds ratio [OR] 1.57, 95% confidence interval [95% CI] 1.00-2.47 versus OR 0.94, 95% CI 0.69-1.26; P for interaction = 0.061), but there was no difference in the risk of SAEs in analyses adjusted for age, race, sex, hemodynamic findings, and laboratory values. Despite the higher occurrence of AEs in patients with CTD-associated PAH assigned to active therapy compared to those receiving placebo, the risk of drug discontinuation due to an AE was similar to that in patients with idiopathic PAH assigned to active therapy (P for interaction = 0.27).

CONCLUSION

Patients with CTD-associated PAH experienced more treatment-related AEs compared to those with idiopathic PAH in therapeutic clinical trials. These findings suggest that the overall benefit of advanced therapies for PAH may be attenuated by the greater frequency of AEs.

Connective tissue disease-associated pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is characterized by vascular remodeling of pulmonary arterioles that leads to increased pulmonary vascular resistance, right heart failure, and death. It is associated with connective tissue diseases, including systemic sclerosis, systemic lupus erythematosus, and mixed connective tissue disease. PAH is characterized by dyspnea on exertion and fatigue. Syncopal events suggest severe disease. Patients may present with signs of right heart failure. One- and 3-year survival rates are approximately 81% and 52%, respectively. Given the high prevalence and mortality, algorithms for screening are currently under investigation and will hopefully lead to earlier diagnosis and improved survival.

Bosentan Improves Exercise Capacity in Adolescents and Adults After Fontan Operation

Background—

The Fontan procedure has improved survival in children with functionally univentricular hearts. With time, however, complications such as reduced exercise capacity are seen more frequently. Exercise intolerance is multifactorial, but pulmonary vascular resistance probably plays a crucial role. Elevated pulmonary vascular resistance has been associated with raised levels of endothelin-1, which are common both before and after Fontan operations. Treatment with endothelin-1 receptor antagonists could theoretically improve cardiopulmonary hemodynamics and exercise capacity. The aim of this study was therefore to examine the efficacy and safety of bosentan in Fontan patients.

Methods and Results—

Seventy-five adolescents and adults were randomized 1:1 to 14 weeks of treatment with bosentan or placebo. Cardiopulmonary exercise test, functional class, blood samples, and quality-of-life questionnaires were evaluated at baseline and at the end of treatment. Sixty-nine patients (92%) completed the study. Peak oxygen consumption increased 2.0 mL·kg −1 ·min −1 (from 28.7 to 30.7 mL·kg −1 ·min −1 ) in the bosentan group compared with 0.6 mL·kg −1 ·min −1 (from 28.4 to 29.0 mL·kg −1 ·min −1 ) in the placebo group ( P =0.02). Cardiopulmonary exercise test time increased by 0.48 minute (from 6.79 to 7.27 minutes) versus 0.08 minute (from 6.94 to 7.02 minutes; P =0.04). Nine bosentan-treated patients improved 1 functional class, whereas none improved in the placebo group ( P =0.0085). Side effects were mild and occurred equally in both groups. No serious adverse effects were seen, and no patients had liver enzyme levels above the 3-fold upper limit.

Conclusions—

Bosentan improves exercise capacity, exercise time, and functional class in Fontan patients without serious adverse events or hepatotoxicity.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT01292551.

Effect of Th17 and Treg axis disorder on outcomes of pulmonary arterial hypertension in connective tissue diseases

This prospective cohort study is to verify the hypothesis that the balance of Th17 and Treg cells frequencies in the peripheral circulation is disturbed in patients with varying degrees of connective tissue diseases-associated pulmonary arterial hypertension (CTD-aPAH) and to prove the influence of Th17/Treg imbalance on prognosis. We detected the frequencies and absolute counts of Th17 and Treg cells and related serum cytokines secretion and expressions of key transcription factors in 117 patients with connective tissue diseases (CTD), 53 patients with CTD-aPAH, and 48 healthy volunteers. Moreover, the median value according to levels of Th17/Treg ratios in patients with CTD-aPAH was chosen as basis of group division for survival analysis. CTD-aPAH patients revealed significant increase in peripheral Th17 cells, Th17-related cytokines, and ROR γt mRNA levels. They also presented a significant decrease in Treg cells, Treg-related cytokines, and Foxp3 mRNA levels as compared with CTD patients and healthy controls. More importantly, the Th17/Treg ratio was significantly related to the severity and prognosis of CTD-aPAH. This study indicated that the Th17/Treg axis disorder plays a critical role in CTD-aPAH. Furthermore, the dynamic balance between Th17 and Treg cells was likely to influence prognosis of patients with CTD-aPAH.