Riociguat for the treatment of chronic thromboembolic pulmonary hypertension

Is Pulmonary Embolism a Chronic Disease?

Pulmonary embolism (PE) is often regarded as an acute disorder, yet emerging evidence underscores its chronic trajectory. Many survivors endure long-term complications, including recurrent thrombosis, persistent dyspnoea, and psychosocial challenges. These sequelae impair functional capacity and quality of life long after the initial event. To address these issues, we suggest that clinicians should adopt an integrated, multidisciplinary model that includes risk stratification for recurrence, structured follow-up, exercise rehabilitation, and support for psychological challenges. Recognising the potential chronic sequalae of PE ultimately fosters comprehensive care aimed at reducing morbidity and improving long-term outcomes for surviv.

Recent Advances in Chronic Thromboembolic Pulmonary Hypertension: Expanding the Disease Concept and Treatment Options

Chronic thromboembolic pulmonary hypertension (CTEPH) is a progressive form of pulmonary hypertension characterized by unresolved thromboembolic occlusion of pulmonary arteries, leading to increased pulmonary arterial pressure and right heart failure. This review examines recent advances in the pathophysiology, diagnosis, and management of CTEPH, focusing on expanding disease concepts and evolving therapeutic approaches. The incidence of CTEPH has been revised upward with improved diagnostic techniques revealing a higher prevalence than previously recognized. Advances in surgical and interventional therapies, particularly pulmonary endarterectomy and balloon pulmonary angioplasty, have significantly improved outcomes. Emerging medical therapies, including pulmonary vasodilators like riociguat, have offered new hope for inoperable cases. The understanding of CTEPH has broadened, leading to better diagnostic strategies and more comprehensive treatment options that significantly enhance patient outcomes. Multidisciplinary team approaches are crucial in managing the disease effectively.

Exercise-induced oxyhemoglobin desaturation is an independent risk factor for sustained nocturnal hypoxemia in adults with precapillary pulmonary hypertension: A cross-sectional study

BACKGROUND

Nocturnal hypoxemia (NH) negatively impacts the prognosis of several chronic cardiopulmonary diseases.

OBJECTIVES

To assess the risk factors associated with sustained NH in adults with precapillary pulmonary hypertension (pPH).

METHODS

This cross-sectional study was performed between June 2021 and June 2024. Outpatients with a hemodynamic diagnosis of pPH (Groups 1 and 4) were consecutively recruited. Sustained NH was defined as ≥ 30 % of the percentage of time spent with oxygen saturation (SpO2) <90 % during a home sleep apnea test (HSAT). Clinical, laboratory, hemodynamic, echocardiographic, functional, and exercise-related variables were collected blindly regarding the HSAT data. We considered a difference in SpO2 [resting - final] (Δ SpO2) ≥ 3 % as indicative of exercise-induced oxyhemoglobin desaturation (EID) by the six-minute walk test. Multiple logistic regression analysis was used to identify possible predictive factors for the occurrence of NH.

RESULTS

Fifty-two pPH adults were included (71.2 % were females). Thirty-one patients (59.6 %) were classified as having NH. In the univariate logistic regression analysis, four parameters were identified as risk factors for the presence of NH: mean pulmonary artery pressure (p = 0.023), right atrial mean pressure (p = 0.037), systolic pulmonary arterial pressure (p = 0.042) and EID (p = 0.003). However, only EID was an independent predictor for detecting NH with an adjusted odds ratio of 10.590 (95 % confidence interval: 1.095-102.420); p = 0.042.

CONCLUSIONS

EID is an easily implementable risk factor for prolonged NH, suggesting that adults with pPH who experience EID have a high probability of also experiencing NH.

An overview of balloon pulmonary angioplasty for chronic thromboembolic pulmonary hypertension

INTRODUCTION

Chronic thromboembolic pulmonary hypertension (CTEPH) is a severe and progressive condition caused by unresolved pulmonary arterial obstructions, leading to secondary microvasculopathy and poor hemodynamics. Pulmonary endarterectomy (PEA) is the first-line treatment for operable patients. Balloon pulmonary angioplasty (BPA) has emerged as a promising treatment option for patients considered inoperable due to distal lesions, comorbidities, or residual pulmonary hypertension (PH) after PEA. Following the development of the BPA in safety and efficacy, it has been widely adopted and utilized across the globe.

AREAS COVERED

This review covers the historical development of BPA, its clinical role, and technical methodologies. Medical therapies as an adjunctive role in CTEPH management are also discussed. Finally, we present recent BPA experiences from our institution, highlighting hemodynamic outcomes and survival rates.

EXPERT OPINION

BPA is a transformative treatment for patients with CTEPH, particularly those ineligible for PEA. Procedural refinements have significantly improved safety and efficacy. However, challenges remain, including the standardization of decision-making processes for management and the establishment of optimal treatment goals. Ongoing research continues to refine the role of BPA to improve outcomes and enhance the quality of life for patients with CTEPH. [Figure: see text].

[Expert consensus on approaches to risk stratification and choice of therapy in patients with inoperable and residual chronic thromboembolic pulmonary hypertension]

On December 13, 2024, the final working group meeting was held, the purpose of which was to discuss the common position of experts on the problem of chronic thromboembolic pulmonary hypertension of various specialties: cardiologists, cardiac surgeons, pulmonologists, on issues of assessing the operability of patients, risk stratification and choice of therapy in patients with inoperable and residual forms of pathology. The discussion field included a wide range of issues that often arise in real clinical practice, but specific answers to them are not given in national and foreign guidelines. On November 8, 2024, at the preparatory stage, 16 experts under the leadership of Academician of the Russian Academy of Sciences I.E. Chazova (chairman) formulated questions for the preparation of a consensus document (without discussion), consistently discussing the feasibility of including each issue in the document and distributing tasks for the final session. Then, at the intermediate stage, experts searched and systematized scientific information on the formulated questions in the PubMed and eLIBRARY systems to prepare sections of the document in accordance with the established tasks. When finalizing the document, experts answered 28 questions: during anonymous voting an individual score was determined for each block from 1 - completely disagree, to 5 - completely agree. It was considered that a strong consensus was achieved with a mean score of M±m 2.5±2, and with a mean score below 2.5, consensus was not achieved. A strong consensus was reached on all issues.

Different Effects of Riociguat and Vericiguat on Pulmonary Vessels and Airways

Background/Objectives: Pulmonary hypertension is a progressive disease leading to right heart failure. One treatment strategy is to induce vasodilation via the nitric oxide-soluble guanylate cyclase-cyclic guanosine monophosphate (NO-sGC-cGMP) signaling pathway. There are currently two soluble guanylate cyclase stimulators on the market: Riociguat and vericiguat, with vericiguat having a longer half-life and needing to be taken only once a day. This study investigated whether the pharmacological differences between the drugs affect pulmonary vessels and airways. Methods: The effects of vericiguat and riociguat on pulmonary arteries, veins, and airways were studied using rat precision-cut lung slices (PCLS). Vessels were pretreated with endothelin-1 and airways with serotonin. In isolated perfused lungs (IPL), the effects of sGC stimulation on pulmonary artery pressure (PAP), airway resistance, inflammatory cytokine, and chemokine release were quantified. Results: Riociguat and vericiguat caused pulmonary artery dilation in PCLS. During IPL, riociguat was more effective than vericiguat in reducing PAP with a statistically significant reduction of 10%. Both drugs were potent bronchodilators in preconstricted airways (p < 0.001). Only vericiguat reduced airway resistance during IPL, as shown here for the first time. Both drugs significantly reduced IL-6 and IL-1ß levels, while riociguat also reduced VEGF-A and KC-GRO levels. Conclusions: Riociguat and vericiguat had three main effects in the two rat ex-vivo models: They dilated the pulmonary arteries, induced bronchodilation, and reduced inflammation. These properties could make sGC stimulators useful for treating diseases associated with endothelial dysfunction. In the future, vericiguat may provide an alternative treatment to induce bronchodilation in respiratory diseases.

Pulmonary Thromboendarterectomy: The Potentially Curative Treatment of Choice for Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a consequence of unresolved organized thromboembolic obstruction of the pulmonary arteries, which can cause pulmonary hypertension and right ventricular failure. Owing to its subtle signs, determining its exact incidence and prevalence is challenging. Furthermore, CTEPH may also present without any prior venous thromboembolic history, contributing to underdiagnosis and undertreatment. Diagnosis requires a high degree of suspicion and is ruled out by a normal ventilation/perfusion ratio scintigraphy. Additional imaging by computed tomography and/or conventional angiography, as well as right heart catheterization, are required to confirm CTEPH and formulate treatment plans. Pulmonary thromboendarterectomy is the treatment of choice for eligible patients and can be potentially curative. Pulmonary thromboendarterectomy has a low mortality rate of 1% to 2% at expert centers and offers excellent long-term survival. Furthermore, recent advances in the techniques allow distal endarterectomy with comparable outcomes. Alternative treatment options are available for those who may not be operable or have prohibitive risks, providing some benefit. However, CTEPH is a progressive disease with low long-term survival rates if left untreated. Given excellent short- and long-term outcomes of surgery, as well as the benefits seen with other treatment modalities in noncandidate patients, it is crucial that precapillary pulmonary hypertension and CTEPH are ruled out in any patient with dyspnea of unexplained etiology. These patients should be referred to expert centers where accurate operability assessment and appropriate treatment strategies can be offered by a multidisciplinary team.

Patient-Reported Long-Term Outcome of Balloon Pulmonary Angioplasty for Inoperable CTEPH

BACKGROUND

 Balloon pulmonary angioplasty (BPA) is a promising interventional treatment for inoperable chronic thromboembolic pulmonary hypertension (CTEPH). Evidence in favor of BPA is growing, but long-term data remain scarce. The Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR) is validated for the assessment of patients with pulmonary hypertension within three domains: symptoms, activity, and quality of life (QoL). The aim of the present study was to evaluate the long-term effects of BPA on these domains in patients with inoperable CTEPH.

METHODS

 Between March 2014 and August 2019, technically inoperable patients with target lesions for BPA were included in this prospective, observational study. CAMPHOR scores were compared between baseline (before the first BPA) and 6 months after the last intervention and also for scores assessed at annual follow-ups.

RESULTS

 A total of 152 patients had completed a full series of BPA interventions and a 28 (interquartile range [IQR]: 26-32) week follow-up. Further follow-up assessments including the CAMPHOR score were performed 96 (IQR: 70-117) weeks, 178 (IQR: 156-200) weeks, and 250 (IQR: 237-275) weeks after the last intervention. From baseline to the last follow-up, CAMPHOR scores for symptoms, activity, and QoL improved from 9 (IQR: 6-14) to 3 (IQR: 0-9) (p < 0.001), 8 (IQR: 5-12) to 4 (IQR: 2-8) (p < 0.001), and 5 (IQR: 2-9) to 1 (IQR: 0-5) (p < 0.001).

CONCLUSION

 BPA leads to long-lasting, significant improvement of symptoms, physical capacity, and QoL in inoperable CTEPH patients.

Milestones in therapeutic and antithrombotic strategies for chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a condition caused by persistent thrombus obstructing the pulmonary arteries, resulting in pulmonary hypertension. Pulmonary endarterectomy remains the gold standard treatment and can provide dramatic improvement in eligible patients. However, approximately 40 % of patients are inoperable. Over the past years, several randomized controlled trials have explored pulmonary vasodilators and balloon pulmonary angioplasty. Based on these trials, a multimodal treatment approach has been established. Balloon pulmonary angioplasty has shown hemodynamic improvement rather than pulmonary vasodilators in randomized controlled trials. Similarly, lifelong anticoagulation therapy is the cornerstone of CTEPH management. While vitamin K antagonists such as warfarin have been the standard recommended by CTEPH guidelines, recent studies, including the CTEPH AC Registry and the KABUKI trial, suggest that direct oral anticoagulants may be safe and effective alternatives. Several ongoing randomized controlled trials aim to refine treatment strategies. The IMPACT-CTEPH trial is investigating whether the initial combination therapy (riociguat + macitentan) is superior to monotherapy before balloon pulmonary angioplasty. The GO-CTEPH trial compares the efficacy of pulmonary endarterectomy and balloon pulmonary angioplasty in eligible patients. The THERAPY-HYBRID-BPA trial is evaluating the need for continued riociguat after balloon pulmonary angioplasty. The FIND-DCR study is evaluating a new imaging modality for the early detection of CTEPH. As research advances, multimodal approaches combining surgical, interventional, and pharmacological treatments are expected to improve patient outcomes and shape the future of CTEPH management.

Long-Term Safety and Efficacy of Macitentan in Inoperable Chronic Thromboembolic Pulmonary Hypertension: Results from MERIT and its Open-Label Extension

INTRODUCTION

Evidence for use of pulmonary arterial hypertension targeted-therapies in patients with chronic thromboembolic pulmonary hypertension (CTEPH) is limited. In MERIT-1, the endothelin receptor antagonist macitentan improved hemodynamic and functional parameters versus placebo in patients with inoperable CTEPH over a 24-week double-blind (DB) period. Its open-label (OL) extension study (MERIT-2) provides long-term safety/efficacy data.

METHODS

MERIT-2 (NCT02060721) was a multicenter, single-arm, OL, phase 2 extension study of MERIT-1. Patients completing MERIT-1 were eligible to receive 10 mg macitentan once-daily in MERIT-2. Safety and efficacy (6-min walk distance [6MWD] and change in World Health Organization functional class [WHO FC]) were assessed in all patients in MERIT-2 regardless of treatment received in DB (All patients MERIT-2 OL macitentan 10 mg group) and the subgroup of patients receiving DB macitentan in MERIT-1 (Long-term [DB/OL] macitentan 10 mg subgroup).

RESULTS

Of the 80 patients randomized in MERIT-1, 76 entered MERIT-2 (All patients MERIT-2 OL macitentan 10 mg group): 40 who received DB macitentan (DB-macitentan patients) and 36 DB placebo (DB-placebo patients). Median (interquartile range) macitentan exposure in the All patients MERIT-2 OL macitentan 10 mg group was 45.5 (26.0, 66.1) months. During the OL period, treatment-emergent adverse events (AE) were reported in 72 (94.7%) patients; most frequent were worsening of pulmonary hypertension (19.7%), decreased hemoglobin (18.4%) and upper respiratory tract infection (15.8%). Fourteen (18.4%) patients died; none were assessed as macitentan-related. At Month 6 post-OL baseline, mean (standard deviation) change in 6MWD was - 0.4 m (43.62) for DB-macitentan patients and 10.7 m (45.63) for DB-placebo patients; the majority had unchanged (83.3%) or improved (12.5%) WHO FC. Safety/efficacy analyses were consistent in the Long-term (DB/OL) macitentan 10 mg subgroup.

CONCLUSION

These analyses provide long-term safety/efficacy data in patients with inoperable CTEPH treated with macitentan. No unexpected safety findings occurred; reported AEs were consistent with the known safety profile of macitentan. At 6 months post-OL baseline, DB-placebo patients modestly improved 6MWD; DB-macitentan patients maintained improvements observed in MERIT-1. WHO FC was largely unchanged.

TRIAL REGISTRATION

ClinicalTrials.gov Identifiers: NCT02021292; NCT02060721.

Assessment of Riociguat-related adverse events: a disproportionality analysis utilizing the FDA adverse event reporting system database

BACKGROUND

Riociguat is a novel soluble guanylate cyclase stimulator approved for the treatment of pulmonary arterial hypertension (PAH). Despite its widespread use, there has been a lack of large-scale studies assessing the adverse events (AEs) associated with this medication.

RESEARCH DESIGN AND METHODS

This study aimed to evaluate the AEs related to Riociguat by analyzing data from the FDA Adverse Event Reporting System (FAERS) from Q4 2013 to Q1 2024. A total of 12,149 AE reports were analyzed using four different disproportionality signal detection methodologies to identify significant AEs associated with Riociguat.

RESULTS

The analysis revealed 117 preferred terms (PTs) with significant disproportionality signals across all four methods. Among these, common AEs included 'headache,' 'dizziness,' 'hypotension,' 'nausea,' 'fall,' and 'loss of consciousness.' Notably, several unexpected AEs, such as 'fatigue,' 'malaise,' 'asthenia,' 'feeling abnormal,' and 'pain in extremity,' were identified, which were not highlighted in the product's package insert. Additionally, gender-specific differences were observed in certain adverse events.

CONCLUSIONS

This study offers insights into Riociguat's side effects. Clinicians should monitor patients closely for unexpected symptoms like limb pain and fatigue, paying particular attention to male patients, as some AEs occur more frequently in this group.

A Decadal Exploration of Cutaneous Adverse Effects of FDA-Approved Cardiovascular Medications: Insights From 2013 to 2023

ABSTRACT

Given the high prevalence of cardiovascular disease in the United States, there is a critical need for new medications to improve the outcomes of these diseases. The US Food and Drug Administration has approved numerous medications that are able to effectively do so. While these drugs have significantly beneficial effects, just like any other medication, they can come with a multitude of unwanted side effects. It has been noted that cardiovascular drugs have been associated with a considerable number of dermatologic reactions. This review examines current literature on the various cutaneous manifestations of these adverse reactions. It focuses on these newly Food and Drug Administration-approved cardiovascular medications from 2013 to 2023, detailing both common and rare effects in the past decade. As more medications continue to enter the market, the necessity for awareness of more systemic side effects will continue to grow. This comprehensive review aims to guide clinicians in identifying drug-induced reactions in patients on these therapies.

Meta-Analysis of Real-World Clinical Practice to Assess the Effectiveness of Riociguat in Treating Chronic Thromboembolic Pulmonary Hypertension

Riociguat is a drug that improves hemodynamic parameters and increases the exercise capacity of patients with chronic thromboembolic pulmonary hypertension (CTEPH). This meta-analysis evaluated cohort studies that measured changes in parameters such as the 6-minute walk distance (6MWD), mean pulmonary arterial pressure (mPAP), pulmonary vascular resistance (PVR), cardiac output (CO), and pulmonary arterial wedge pressure (PAWP). The study utilized cohort studies with a paired samples group design to measure the changes in these parameters. We searched for articles containing the keywords "Riociguat" and "Chronic thromboembolic pulmonary hypertension" in their titles in PubMed, Web of Science, Scopus, and ScienceDirect databases until May 2024. We conducted five meta-analyses to combine the mean difference values. We identified nine studies that examine the effects of Riociguat on patients. Analyzing data from 565 patients revealed that Riociguat increases the distance walked during the 6MWD test by an average of 35.86 m. After analyzing data from 717 patients, it was found that Riociguat reduces mPAP by an average of 9.23 mm Hg. Analyzing data from 586 patients, it was found that Riociguat reduces PVR by an average of 220.11 dyn . s . c m - 5 ${\mathrm{dyn}}.{\mathrm{s}}.{\mathrm{c}}{{{\mathrm{m}}}^{ - 5}}$ . Moreover, analyzing data from 643 patients showed that Riociguat increases CO by an average of 0.49 L/min. Finally, after analyzing data from 645 patients, it was concluded that Riociguat treatment did not have a statistically significant effect on PAWP. Our findings indicate that Riociguat improved certain hemodynamic parameters and exercise capacity in CTEPH patients.

Chronic thromboembolic pulmonary hypertension: A comprehensive review of pathogenesis, diagnosis, and treatment strategies

Chronic thromboembolic pulmonary hypertension (CTEPH) is part of group 4 of the pulmonary hypertension (PH) classification and generally affects more than a third of patients referred to PH centers. It is a three-compartment disease involving proximal (lobar-to-segmental) and distal (subsegmental) pulmonary arteries that are obstructed by persistent fibrothrombotic material, and precapillary pulmonary arteries that can be affected as in pulmonary arterial hypertension. It is a rare complication of pulmonary embolism (PE), with an incidence of around 3% in PE survivors. The observed incidence of CTEPH in the general population is around six cases per million but could be three times higher than this, as estimated from PE incidence. However, a previous venous thromboembolic episode is not always documented. With advances in multimodality imaging and therapeutic management, survival for CTEPH has improved for both operable and inoperable patients. Advanced imaging with pulmonary angiography helps distinguish proximal from distal obstructive disease. However, right heart catheterization is of utmost importance to establish the diagnosis and hemodynamic severity of PH. The therapeutic strategy relies on a stepwise approach, starting with an operability assessment. Pulmonary endarterectomy (PEA), also known as pulmonary thromboendarterectomy, is the first-line treatment for operable patients. Growing experience and advances in surgical technique have enabled expansion of the distal limits of PEA and significant improvements in perioperative and mid- to long-term mortality. In patients who are inoperable or who have persistent/recurrent PH after PEA, medical therapy and/or balloon pulmonary angioplasty (BPA) are effective treatment options with favorable outcomes that are increasingly used. All treatment decisions should be made with a multidisciplinary team that includes a PEA surgeon, a BPA expert, and a chest radiologist.

Effect of Balloon Pulmonary Angioplasty and Riociguat on Right Ventricular Afterload and Function in CTEPH: Insights From the RACE Trial

BACKGROUND

Riociguat and balloon pulmonary angioplasty (BPA) improve hemodynamics in inoperable chronic thromboembolic pulmonary hypertension. Importantly, comparative effects of riociguat and BPA on different components of right ventricular (RV) afterload and function remain not fully elucidated.

METHODS

We conducted a post hoc analysis including patients from the RACE trial (Riociguat Versus Balloon Pulmonary Angioplasty in Non-Operable Chronic Thromboembolic Pulmonary Hypertension) with complete data for the primary end point assessment (49 riociguat and 51 BPA). Symptomatic patients with a residual pulmonary vascular resistance >4 WU received add-on riociguat after BPA (n=18) or add-on BPA after riociguat (n=36) and were included in an ancillary 26-week follow-up study with hemodynamic reassessment at week 52.

RESULTS

Cardiac output, stroke volume, and RV afterload improved significantly with riociguat and BPA, and the relative changes in RV afterload from baseline to week 26 were more pronounced in the BPA group (all P<0.001). Change in RV afterload was primarily mediated by decreased mean pulmonary arterial pressure in the BPA group, while increased cardiac output was the main driver in the riociguat group. Key parameters of RV function (RV stroke work and right atrial pressure) improved only in the BPA group. The ancillary follow-up study confirmed that relative change in RV afterload from week 26 to week 52 was more pronounced with add-on BPA, and improved RV function was only observed in the add-on BPA group.

CONCLUSIONS

Both riociguat and BPA are effective in improving RV afterload in inoperable chronic thromboembolic pulmonary hypertension. However, BPA provided a more substantial impact on RV afterload reduction, and RV function only improved with BPA.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02634203.

Insights into balloon pulmonary angioplasty and the WHO functional class of chronic thromboembolic pulmonary hypertension patients: findings from the CTEPH AC registry

Advances in chronic thromboembolic pulmonary hypertension (CTEPH) treatment have improved prognosis, shifting focus towards symptom management. This study aimed to identify factors influencing the World Health Organization functional class (WHO-FC) in CTEPH patients. The CTEPH AC registry is a prospective, multicenter database from 35 Japanese institutions, analyzing data from August 2018 to July 2023. We examined factors associated with achieving WHO-FC I and WHO-FC changes over time in 1,270 patients. Significant factors for WHO-FC I achievement included male sex (odds ratio: 1.86, p = 0.019), age (0.98, p = 0.007), pulmonary vasodilator use (0.51, p = 0.001), post-balloon pulmonary angioplasty (BPA) (1.93, p = 0.010), lower mean pulmonary arterial pressure (0.94, p = 0.004), and lower pulmonary vascular resistance (PVR) (0.78, p = 0.006). Multivariate analysis showed that WHO-FC improvement correlated with male sex, baseline PVR, and BPA during follow-up. WHO-FC deterioration was associated with cancer, history of pulmonary endarterectomy and/or BPA at registration, bleeding risks, and thyroid disease or hormone therapy. BPA implementation is closely linked to symptomatic improvement and achieving WHO-FC I, while symptom worsening is often associated with patient-specific, difficult-to-control conditions.

Evolution and New Perspectives of Balloon Pulmonary Angioplasty in CTEPH

Chronic thromboembolic pulmonary disease (CTEPD) and chronic thromboembolic pulmonary hypertension (CTEPH) are debilitating complications of acute pulmonary embolism (PE) that are characterized by fibrosis and organization of the thrombotic material within pulmonary artery branches. This pathology leads to increased right ventricular afterload and dead space ventilation, posing a risk of progressive pulmonary hypertension, right-sided heart failure, and potentially death if left untreated. Pulmonary endarterectomy (PTE) is a technically complex open-heart surgery considered to be a first-line treatment as it is a potentially curative therapy. Although PTE is highly successful in proximal disease, it may not reach the very distal branches. On the other hand, pulmonary vasodilator therapy is very effective in improving microvasculopathy but does not address the obstructive fibrotic component of the larger vessels. Balloon pulmonary angioplasty (BPA) is a novel percutaneous revascularization therapy in which traditional angioplasty techniques are used to relieve obstruction in the pulmonary arteries. This review discusses the currently accepted indications, patient selection, technical considerations, outcomes, and complications of contemporary BPA. This review will address knowledge gaps and future perspectives in BPA research.

Soluble guanylyl cyclase stimulators and activators: Promising drugs for the treatment of hypertension?

Nitric oxide (NO)-stimulated cyclic guanosine monophosphate (cGMP) is a key regulator of cardiovascular health, as NO-cGMP signalling is impaired in diseases like pulmonary hypertension, heart failure and chronic kidney disease. The development of NO-independent sGC stimulators and activators provide a novel therapeutic option to restore altered NO signalling. sGC stimulators have been already approved for the treatment of pulmonary arterial hypertension (PAH), chronic thromboembolic pulmonary hypertension (CTEPH), and chronic heart failure (HFrEF), while sGC activators are currently in phase-2 clinical trials for CKD. The best characterized effect of increased cGMP via the NO-sGC-cGMP pathway is vasodilation. However, to date, none of the sGC agonists are in development for hypertension (HTN). According to WHO, the global prevalence of uncontrolled HTN continues to rise, contributing significantly to cardiovascular mortality. While there are effective antihypertensive treatments, many patients require multiple drugs, and some remain resistant to all therapies. Thus, in addition to improved diagnosis and lifestyle changes, new pharmacological strategies remain in high demand. In this review we explore the potential of sGC stimulators and activators as novel antihypertensive agents, starting with the overview of NO-sGC-cGMP signalling, followed by potential mechanisms by which the increase in cGMP may regulate vascular tone and BP. These effects may encompass not only acute vasodilation, but also mid-term and chronic effects, such as the regulation of salt and water balance, as well as mitigation of vascular ageing and remodelling. The main section summarizes the preclinical and clinical evidence supporting the BP-lowering efficacy of sGC agonists.

Balloon pulmonary angioplasty in patients with chronic thromboembolic pulmonary hypertension: short- and long-term results from a cohort in Brazil

OBJECTIVE

A significant number of patients with chronic thromboembolic pulmonary hypertension (CTEPH) are not eligible for pulmonary endarterectomy and may be treated with balloon pulmonary angioplasty (BPA). Although BPA programs have recently been developed in Brazil, no results have yet been published. The objective of this study was to assess the clinical and hemodynamic progression of the first patients treated with BPA at our center.

METHODS

This was an observational study of 23 patients with CTEPH enrolled in the BPA program of a specialized center in Brazil between 2015 and 2020.

RESULTS

After a mean of 5.6 ± 1.3 sessions and 11 ± 2.8 treated segments/patient (at a mean of 6.7 ± 2.9 months post-BPA), there was a 26% decrease in mean pulmonary artery pressure (51 ± 11 vs. 38 ± 11 mmHg; p < 0.0001), a 43% decrease in pulmonary vascular resistance (10 ± 3.7 vs. 5.7 ± 3.3 WU; p < 0.0001), and a 22.5% increase in the cardiac index (2.38 ± 0.6 vs. 2.95 ± 0.6 L/min/m2; p < 0.0001). There was an increase in the six-minute walk distance and an improvement in functional class. Acute lung injury with clinical manifestations was observed after 7% of the BPA sessions. None of the patients required intubation. During a mean outpatient follow-up period of 38 ± 22 months, two patients were referred for additional BPA sessions due to clinical worsening and new hospitalizations. Two deaths were recorded (due to CTEPH progression and gastrointestinal bleeding, respectively).

CONCLUSIONS

Among this first group of patients treated with BPA in Brazil, there was significant short- and long-term clinical improvement, together with a low frequency of complications.

Stimulating Soluble Guanylyl Cyclase with the Clinical Agonist Riociguat Restrains the Development and Progression of Castration-Resistant Prostate Cancer

Castration-resistant prostate cancer (CRPC) is incurable and fatal, making prostate cancer the second leading cancer-related cause of death for American men. CRPC results from therapeutic resistance to standard-of-care androgen deprivation (AD) treatments, through incompletely understood molecular mechanisms, and lacks durable therapeutic options. In this study, we identified enhanced soluble guanylyl cyclase (sGC) signaling as a mechanism that restrains CRPC initiation and growth. Patients with aggressive, fatal CRPC exhibited significantly lower serum levels of the sGC catalytic product cyclic GMP (cGMP) compared with the castration-sensitive stage. In emergent castration-resistant cells isolated from castration-sensitive prostate cancer populations, the obligate sGC heterodimer was repressed via methylation of its β subunit. Genetically abrogating sGC complex formation in castration-sensitive prostate cancer cells promoted evasion of AD-induced senescence and concomitant castration-resistant tumor growth. In established castration-resistant cells, the sGC complex was present but in a reversibly oxidized and inactive state. Subjecting CRPC cells to AD regenerated the functional complex, and cotreatment with riociguat, an FDA-approved sGC agonist, evoked redox stress-induced apoptosis. Riociguat decreased castration-resistant tumor growth and increased apoptotic markers, with elevated cGMP levels correlating significantly with lower tumor burden. Riociguat treatment reorganized the tumor vasculature and eliminated hypoxic tumor niches, decreasing CD44+ tumor progenitor cells and increasing the radiosensitivity of castration-resistant tumors. Thus, this study showed that enhancing sGC activity can inhibit CRPC emergence and progression through tumor cell-intrinsic and extrinsic effects. Riociguat can be repurposed to overcome CRPC, with noninvasive monitoring of cGMP levels as a marker for on-target efficacy. Significance: Soluble guanylyl cyclase signaling inhibits castration-resistant prostate cancer emergence and can be stimulated with FDA-approved riociguat to resensitize resistant tumors to androgen deprivation, providing a strategy to prevent and treat castration resistance.

Optimizing Medical Pretreatment for Balloon Pulmonary Angioplasty: Overshoot or Stride Toward Optimal Multimodal Treatment

In patients with chronic thromboembolic pulmonary hypertension (CTEPH) who undergo balloon pulmonary angioplasty (BPA), pretreatment with PH-targeted medical therapy may be beneficial to improve clinical parameters and pulmonary hemodynamics. This study aims to describe clinical results of PH-targeted therapy prior to BPA. All consecutive patients with CTEPH who underwent BPA treatment were selected from our CTEPH database. Medical treatment strategy, clinical parameters, and pulmonary hemodynamics at time of diagnosis and at the first BPA were analyzed. In total 92 CTEPH patients who started BPA treatment (64.1% women; 60.4 ± 14.1 years of age; 62.0% NYHA FC III/IV) were included. Most patients received dual oral PH-targeted medical therapy (68.5%) prior to BPA. Between diagnosis and first BPA (median time 13.9 [7.5-30.7] months) significant improvements were observed in patients treated with PH-targeted medical therapy for both clinical (6MWD: +28.2 m [5.1-51.3], log NTproBNP: -0.4 pg/ml [-0.8 to -0.1]) as well as pulmonary hemodynamic parameters (mPAP: -6.5 mmHg [-8.5 to -4.5], CO: +0.6 L/min [0.2-1.0] and PVR: -2.8 WU [-3.5 to -2.1]). The overall complication rate per BPA (out of a total of 441 procedures) was 15.0% for patients on monotherapy and 14.9% for those on dual/triple PH-targeted medical therapy. No severe complications occurred. In conclusion, pretreatment with PH-targeted medical therapy prior to BPA results in an improvement in clinical- and pulmonary hemodynamic parameters.

Treatment pathways in Finnish patients with pulmonary arterial hypertension (PAH) or chronic thromboembolic pulmonary hypertension (CTEPH)

Treatment patterns of pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) in Finland are unknown. Guidelines now recommend early escalation of treatment for PAH. We evaluated how well Finnish practice follows guidelines, and how treatment initiations and outcomes are related. The pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension patients in Finland cohort includes all PAH and CTEPH patients diagnosed between 2008 and 2020 in all Finnish university hospitals. Drug therapy was analysed in patients with medical/procedural history available, and changes in the 4-tier comparative, prospective registry of newly initiated therapies for pulmonary hypertension (COMPERA) 2.0 risk score were evaluated. PAH patients (n = 268) were initially treated with monotherapy (52%) or double therapy (24%). After year 2015, double therapy use increased to 39%. PAH treatment at 1 year after diagnosis included phosphodiesterase 5 inhibitors (71%), endothelin-receptor antagonist (48%), prostacyclin analogue (7%), calcium channel blocker (12%) and selexipag (1%). 35% achieved low risk at 1 year, increasing to 44% for patients diagnosed after 2015. Those remaining at intermediate-high (IH) or high risk (H) (28%) were not treated less aggressively than others but were older, had more comorbidities, and often history of smoking. CTEPH patients (n = 189) were treated with pulmonary endarterectomy (PEA) (27%), balloon pulmonary angioplasty (BPA) (11%) and medical therapy only (41%) within 1 year from diagnosis. 45% achieved low risk at 1 year. We present additional results on treatment of IH and H patients, patient characteristics preceding death, and treatment persistence. We found less treatment of PAH patients with double or triple therapies and of CTEPH patients with PEA and BPA than expected but with good results. Patients not reaching low or intermediate COMPERA 2.0 were old and had comorbidities.

[Chronic Thromboembolic Pulmonary Hypertension Drug Treatment]

The main treatment of patients with chronic thromboembolic pulmonary hypertension (CTEPH) is radical surgery, pulmonary thromboendarterectomy (PEA). However, about 40% of patients with CTEPH are inoperable due to distal pulmonary vascular lesions or the severity of hemodynamic disorders. Almost 30% of patients with CTEPH experience persistent or recurrent pulmonary hypertension after surgery, that requires a drug treatment with PAH-specific drugs. This review presents current data on the use of targeted therapy in patients with CTEPH. The review addresses the place, indications, and the evidence base for using the main groups of specific drugs, including stimulators of soluble guanylate cyclase, phosphodiesterase type 5 inhibitors, endothelin receptor antagonists, and prostacyclin analogues.

Shifting Paradigms in the Management of Pulmonary Hypertension

Pulmonary arterial hypertension (PAH) is a long-term condition characterised by increased resistance to blood flow in the pulmonary circulation. The disease has a progressive course and is associated with a poor prognosis. Without treatment, PAH is associated with mortality in <3 years. Over the past decade, many advances have been made in revising the haemodynamic definition, clinical classification, risk calculation score, treatment options etc. Suggestions from the Sixth World Symposium on Pulmonary Hypertension were incorporated into a literature review that was included in the European Society of Cardiology/European Respiratory Society (ESC/ERS)'s most recent iteration of their guidelines in 2022. The traditional cut-off for pulmonary hypertension (PH), i.e., mean pulmonary artery pressure (mPAP) >25 mm Hg, has been challenged by observational cohort studies, which have shown poor outcomes for values of 21-24 mmHg; the new consensus is that PH is defined at mPAP >20 mm Hg. Although the gold standard for diagnosis and the major source of therapy guidance continues to be right cardiac catheterisation, echocardiography remains the initial test of choice. A multidisciplinary approach is highly recommended when treating PH patients and careful evaluation of patients will aid in proper diagnosis and prognosis. Pharmacotherapy for PAH has seen a paradigm shift with the successful use of newer agents in more extensive, longer and more inclusive trials driven by hard endpoints. Macitentan, selexipag and riociguat are three oral agents that have shown astounding success in PAH randomised studies in the past decade. Upfront combination therapy with two agents is now becoming the norm (following the AMBITION, OPTIMA and ITALY trials) and the momentum is shifting towards triple therapy as for essential hypertension. More recently, inhaled treprostinil was shown to improve exercise capacity in PH associated with interstitial lung disease in the phase III INCREASE study and has been granted regulatory approval for World Health Organization group 3 PH. A new class of drug, sotatercept (a tumour growth factor-β signalling inhibitor), has also been recently approved by the Food and Drug Administration for management of PAH based on positive results from the phase III STELLAR study. Pulmonary artery denervation and balloon pulmonary angioplasty have emerged as viable alternatives in PH that are resistant to drug therapy. This article aims to summarise the key changes and recent advances in diagnosis and managing PH in general, with an emphasis on certain subgroups.

Advanced Management of Patients Undergoing Transcatheter Treatment for Pulmonary Embolism: Evidence-Based Strategies for Optimized Patient Care

Pulmonary embolism (PE) is a life-threatening medical condition caused by the thrombotic occlusion of one or more branches of the lung vasculature, which represents the third most common cause of cardiovascular mortality after myocardial infarction and stroke. PE treatment requires a tailored approach based on accurate risk stratification and personalized treatment decision-making. Anticoagulation is the cornerstone of PE management, yet patients at higher clinical risk may require more rapid reperfusion therapies. In recent years, transcatheter treatment has emerged as a valuable option for patients with intermediate-high or high-risk PE who have contraindications to systemic thrombolysis. Recent advancements in catheter-directed therapies, such as catheter-directed thrombolysis (CDT) and catheter-directed mechanical thrombectomy (CDMT), provide minimally invasive options for swift symptom relief and hemodynamic stabilization. This review aims to provide a practical approach for optimal patient selection and management for PE percutaneous therapies, supported by a thorough evaluation of the current evidence base supporting these procedures. A focus on post-procedural management, the prevention of recurrence, and monitoring for long-term complications such as chronic pulmonary hypertension and post-PE syndrome is also specifically tackled.

Pulmonary sarcoidosis: A comprehensive review: Past to present

Sarcoidosis is a sterile non-necrotizing granulomatous disease without known causes that can involve multiple organs with a predilection for the lung and thoracic lymph nodes. Worldwide it is estimated to affect 2-160/100,000 people and has a mortality rate over 5 years of approximately 7%. For sarcoidosis patients, the cause of death is due to sarcoid in 60% of the cases, of which up to 80% are from advanced cardiopulmonary failure (pulmonary hypertension and respiratory microbial infections) in all races except in Japan were greater than 70% of the sarcoidosis deaths are due to cardiac sarcoidosis. Scadding stages for pulmonary sarcoidosis associates with clinical outcomes. Stages I and II have radiographic remission in approximately 30%-80% of cases. Stage III only has a 10%-40% chance of resolution, while stage IV has no change of resolution. Up to 40% of pulmonary sarcoidosis patients progress to stage IV disease with lung parenchyma fibroplasia, bronchiectasis with hilar retraction and fibrocystic disease. These patients are at highest risk for the development of precapillary pulmonary hypertension, which may occur in up to 70% of these patients. Sarcoid patients with pre-capillary pulmonary hypertension can respond to targeted pulmonary arterial hypertension medications. Stage IV fibrocytic sarcoidosis with significant pulmonary physiologic impairment, >20% fibrosis on HRCT or pre-capillary pulmonary hypertension have the highest risk of mortality, which can be >40% at 5-years. First line treatment for patients who are symptomatic (cough and dyspnea) with parenchymal infiltrates and abnormal pulmonary function testing (PFT) is oral glucocorticoids, such as prednisone with a typical starting dose of 20-40 mg daily for 2 weeks to 2 months. Prednisone can be tapered over 6-18 months if symptoms, spirometry, PFTs, and radiographs improve. Prolonged prednisone may be required to stabilize disease. Patients requiring prolonged prednisone ≥10 mg/day or those with adverse effects due to glucocorticoids may be prescribed second and third line treatements. Second and third line treatments include immunosuppressive agents (e.g., methotrexate and azathioprine) and anti-tumor necrosis factor (TNF) medication; respectively. Effective treatments for advanced fibrocystic pulmonary disease are being explored. Despite different treatments, relapse rates range from 13% to 75% depending on the stage of sarcoid, number of organs involved, socioeconomic status, and geography. CONCLUSION: The mortality rate for sarcoidosis over a 5 year follow up is approximately 7%. Unfortunately, 10%-40% of patients with sarcoidosis develop progressive pulmonary disease, and >60% of deaths resulting from sarcoidosis are due to advance cardiopulmonary disease. Oral glucocorticoids are the first line treatment, while methotrexate and azathioprine are considered second and anti-TNF agents are third line treatments that are used solely or as glucocorticoid sparing agents for symptomatic extrapulmonary or pulmonary sarcoidosis with infiltrates on chest radiographs and abnormal PFT. Relapse rates have ranged from 13% to 75% depending on the population studied.

Post-Pulmonary Embolism Syndrome-A Diagnostic Dilemma and Challenging Management

Historically, research on pulmonary embolism (PE) management has focused on short-term outcomes, such as acute cardiovascular collapse, change in right ventricular function, and in-hospital mortality. However, long-standing functional impairments from acute PE occur in up to half of all patients. This chronic syndrome has been termed the post-PE syndrome, which describes patients who have persistent or worsening symptoms, functional limitations, and cardiorespiratory impairment not explained by a comorbid condition. Diagnosis and management are challenging, and post-PE syndrome remains an underrecognized and undertreated condition. This review seeks to increase awareness of the syndrome that affects a significant portion of PE survivors. The epidemiology, pathophysiology, and clinical features are discussed, followed by a description of imaging findings and management options across the entire spectrum of post-PE syndrome.

The Role of Lung Ventilation/Perfusion Scan in the Management of Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH), which is classified as a group 4 pulmonary hypertension (PH), is a life-threatening complication of acute pulmonary embolism (PE). With the introduction of multidisciplinary approaches and innovative treatment strategies for CTEPH, it is currently regarded not as a fatal disease, but as a curable form of PH. Ventilation/perfusion (V/Q) scan is the preferred imaging method for screening for CTEPH, with superior sensitivity to CT pulmonary angiography. The findings and interpretations of V/Q scan in CTEPH may differ from those observed in acute PE. The use of V/Q scan in combination with SPECT or SPECT/CT is becoming more popular than planar scan alone. Comprehensive understanding of the role of V/Q scan in CTEPH will assist in providing early diagnosis, proper therapeutic decision making, and improved prognosis. This review outlines the current roles and potential clinical applications of V/Q scan in the diagnosis and evaluation of CTEPH.

A pulmonary hypertension targeted algorithm to improve referral to right heart catheterization: A machine learning approach

Background

Pulmonary hypertension (PH) is a pathophysiological problem that may involve several clinical symptoms and be linked to various respiratory and cardiovascular illnesses. Its diagnosis is made invasively by Right Cardiac Catheterization (RHC), which is difficult to perform routinely. Aim of the current study was to develop a Machine Learning (ML) algorithm based on the analysis of anamnestic data to predict the presence of an invasively measured PH.

Methods

226 patients with clinical indication of RHC for suspected PH were enrolled between October 2017 and October 2020. All patients underwent a protocol of diagnostic techniques for PH according to the recommended guidelines. Machine learning (ML) approaches were considered to develop classifiers aiming to automatically detect patients affected by PH, based on the patient's characteristics, anamnestic data, and non-invasive parameters, transthoracic echocardiography (TTE) results and spirometry outcomes.

Results

Out of 51 variables of patients undergoing RHC collected, 12 resulted significantly different between patients who resulted positive and those who resulted negative at RHC. Among them 8 were selected and utilized to both train and validate an Elastic-Net Regularized Generalized Linear Model, from which a risk score was developed. The AUC of the identification model is of 83 % with an overall accuracy of 74 % [95 % CI (61 %, 84 %)], indicating very good discrimination between patients with and without the pathology.

Conclusions

The PH-targeted ML models could streamline routine screening for PH, facilitating earlier identification and better RHC referrals.

Clonal Hematopoiesis in Chronic Thromboembolic Pulmonary Hypertension

BACKGROUND

The cause of chronic thromboembolic pulmonary hypertension (CTEPH) remains largely unknown. Recently, clonal hematopoiesis (CH) has been reported to be associated with cardiovascular and thromboembolic diseases. Here, we investigated the prevalence and clinical impact of CH in patients with CTEPH.

METHODS AND RESULTS

Whole-exome sequencing and deep-panel sequencing were performed in 214 patients with CTEPH. Clinical data before and after treatment were compared between patients with and without CH. RNA sequencing and serum analysis were performed to explore the pathogenesis that CH contributes to CTEPH. Among the enrolled patients, 20.1%, notably 44.4% who were 80 to 89 years old, had variants in CH-associated genes. In regard to clinical impact, B-type natriuretic peptide levels and home oxygen therapy rate were significantly higher, and 6-minute walk distance was significantly shorter after treatment in patients with CH than in those without CH. Moreover, novel clot reformation in the pulmonary artery despite the use of anticoagulants and additional angioplasty events after treatment completion were more frequent in patients with CH. RNA sequencing analysis revealed that blood coagulation and neutrophil extracellular trap formation pathways were enriched in patients with CH. Additionally, serum citrullinated histone H3 levels were higher in patients with CH than those without CH. These results were consistent in the subgroup of patients who did not have the history of hematological disorders.

CONCLUSIONS

The findings in this study raise the possibility that CH will induce a more prothrombotic state through neutrophil activation and neutrophil extracellular trap formation, contributing to pathogenesis and poor treatment response in patients with CTEPH.

Tailoring oral anticoagulant treatment in the era of multi-drug therapies for PAH and CTEPH

The use of oral anticoagulants in the management of pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) presents distinct therapeutic challenges and benefits. In PAH, the benefits of oral anticoagulation are uncertain, with studies yielding mixed results on their efficacy and safety. Conversely, oral anticoagulants are a cornerstone in the treatment of CTEPH, where their use is consistently recommended to prevent recurrent thromboembolic events. The choice between vitamin K antagonists (VKAs) and direct oral anticoagulants (DOACs) remains a significant clinical question, as each type presents advantages and potential drawbacks. Furthermore, drug-drug interactions (DDIs) with concomitant PAH and CTEPH treatments complicate anticoagulant management, necessitating careful consideration of individual patient regimens. This review examines the current evidence on oral anticoagulant use in PAH and CTEPH and discusses the implications of DDIs within a context of multi-drug treatments, including targeted drugs in PAH.

Computed tomography identifies sex-specific differences in surgical chronic thromboembolic pulmonary hypertension

Background

Registry data suggest women are less likely than men to undergo pulmonary thromboendarterectomy for chronic thromboembolic pulmonary hypertension despite a similar proportion of proximal vs distal disease. We hypothesized that sex-specific differences could be elicited with a computed tomography pulmonary angiography analysis beyond proximal vs distal.

Methods

Preoperative computed tomography pulmonary angiography of patients who underwent pulmonary thromboendarterectomy for chronic thromboembolic pulmonary hypertension from January 2017 to September 2021 was analyzed. The pulmonary vascular tree was divided into 32 named vessels with chronic thromboembolism presence and lesion type recorded for each vessel. If no lesion was identified in a segmental vessel, subsegmental disease was recorded when present.

Results

One hundred forty-four patients (mean age 57 ± 15 years, 78 women) were included. There were no sex differences in baseline hemodynamics. Men had more vessels involved than women (mean 20.3 vs 17.1, p = 0.004) and had fewer disease-free pulmonary segments (mean 4.9 ± 4.3 vs 7.6 ± 5.5, p = 0.001). Men had a greater number of webs, eccentric thickening, and occlusions. The distribution of lesion type did not significantly differ between sexes at the main or lobar level but men had significantly more lesions in the segmental vasculature while women had a higher proportion of subsegmental lesions (p < 0.001).

Conclusions

Sex-specific differences in chronic thromboembolic pulmonary hypertension are demonstrated on computed tomography pulmonary angiography in overall distribution and lesion type at the segmental and subsegmental level with women having fewer and more distal lesions despite similar hemodynamics.

MK-5475, an inhaled soluble guanylate cyclase stimulator, for treatment of pulmonary arterial hypertension: the INSIGNIA-PAH study

BACKGROUND

MK-5475 is an investigational inhaled soluble guanylate cyclase stimulator hypothesised to avoid most side-effects of systemic vasodilation.

METHODS

The phase 2 INSIGNIA-PAH (NCT04732221) trial randomised adults with pulmonary arterial hypertension (PAH) on stable background therapy 1:1:1:1 to once-daily dosing with placebo, MK-5475 32 µg, 100 µg or 380 µg via dry powder inhalation for 12 weeks.

OBJECTIVES

The objectives were to evaluate pulmonary vascular resistance (PVR; primary), 6-min walk distance (6MWD; secondary), additional selected haemodynamic parameters, and safety and tolerability in participants with PAH.

RESULTS

168 participants were randomised to placebo (n=41), MK-5475 32 µg (n=42), 100 µg (n=44), and 380 µg (n=41). Median age was 51 years. Most participants were female (73.8%), diagnosed with idiopathic PAH (63.7%), receiving concomitant phosphodiesterase type 5 inhibitors (PDE5i; 93.5%), and treated with double or triple combination therapy (85.1%). At week 12, the placebo-corrected changes in PVR by least-squares means were -9.2% (95% CI -21.3%, 2.9%; p=0.068) with 32 µg, -22.0% (95% CI -33.7%, -10.3%; p<0.001) with 100 µg, and -19.9% (95% CI -33.4%, -6.4%; p=0.002) with 380 µg MK-5475. No treatment differences versus placebo were observed in 6MWD. Treatment-related adverse events and serious adverse events were similar across treatment groups. Three participants died: two on placebo and one on MK-5475 100 µg. One participant had symptomatic hypotension and one had haemoptysis (both on MK-5475 100 µg).

CONCLUSIONS

In participants with PAH on stable background therapy, including PDE5i, inhaled MK-5475 reduced PVR and was well tolerated, without evidence of systemic side-effects such as hypotension, suggesting a pulmonary selective pharmacodynamic effect.

Non-invasive prediction of pulmonary vascular disease-related exercise intolerance and survival in non-group 1 pulmonary hypertension

AIMS

The clinical utility of pulmonary hypertension (PH) risk scores in non-group 1 PH with pulmonary vascular disease (PVD) remains unresolved.

METHODS AND RESULTS

We utilized the prospective multicenter PVDOMICS cohort with group 2, 3, 4 or 5 PH-related PVD and calculated group 1 PH risk scores (REVEAL 2.0, REVEAL Lite 2, French registry score and COMPERA 2). The c-statistic to predict death was compared separately in (i) pre-capillary PH groups 3/4/5, and (ii) combined post- and pre-capillary PH group 2. Exercise right heart catheterization reserve, ventricular interdependence and right ventricular-pulmonary artery (RV-PA) coupling were compared across risk categories. Among 449 individuals with group 3/4/5 PH, the REVEAL 2.0 risk score had the highest c-statistic for predicting death (0.699, 95% confidence interval [CI] 0.660-0.737, p < 0.0001) with comparable performance using the simpler REVEAL Lite 2 score (0.695, 95% CI 0.656-0.734, p < 0.0001). The French and COMPERA 2 risk scores were also predictive of mortality, but performance of both was statistically inferior to REVEAL 2.0 (c-statistic difference -0.072, 95% CI -0.123 to -0.020, p = 0.006, and -0.043, 95% CI -0.067 to -0.018, p = 0.0007, respectively). RV function and RV-PA coupling measures were prognostic in isolation, but did not add incremental value to REVEAL (p > 0.50 for all). Findings were similar in patients with group 2 PH (n = 239). Stratification by the REVEAL Lite 2 score non-invasively identified non-group 1 PH with more advanced PVD with worse exercise capacity, RV-PA uncoupling, ventricular interdependence and impaired cardiac output reserve (p < 0.05 for all).

CONCLUSIONS

Non-invasive REVEAL risk predicts mortality in non-group 1 PH without incremental prognostic value from detailed RV function or RV-PA coupling assessment. Baseline REVEAL Lite 2 risk stratification non-invasively identifies greater pulmonary vascular dysfunction and right heart-related exercise limitation, which may help guide patient selection for targeted pulmonary vascular therapies in non-group 1 PH.

Soluble GC stimulators and activators: Past, present and future

The discovery of soluble GC (sGC) stimulators and sGC activators provided valuable tools to elucidate NO-sGC signalling and opened novel pharmacological opportunities for cardiovascular indications and beyond. The first-in-class sGC stimulator riociguat was approved for pulmonary hypertension in 2013 and vericiguat very recently for heart failure. sGC stimulators enhance sGC activity independent of NO and also act synergistically with endogenous NO. The sGC activators specifically bind to, and activate, the oxidised haem-free form of sGC. Substantial research efforts improved on the first-generation sGC activators such as cinaciguat, culminating in the discovery of runcaciguat, currently in clinical Phase II trials for chronic kidney disease and diabetic retinopathy. Here, we highlight the discovery and development of sGC stimulators and sGC activators, their unique modes of action, their preclinical characteristics and the clinical studies. In the future, we expect to see more sGC agonists in new indications, reflecting their unique therapeutic potential.

Sequelae of Acute Pulmonary Embolism: From Post-Pulmonary Embolism Functional Impairment to Chronic Thromboembolic Disease

Among survivors of acute pulmonary embolism (PE), roughly half report persistent dyspnea, impaired functional status, and decreased quality of life. Post-pulmonary embolism syndrome (PPES) is a broad condition which has been increasingly recognized in recent years and may be due to post-pulmonary embolism functional impairment, chronic thromboembolic disease, or the most severe long-term complication of PE, chronic thromboembolic pulmonary hypertension. Despite guideline recommendations for appropriate follow-up for post-pulmonary embolism patients, PPES remains underrecognized and diagnostic testing underutilized. Patients with symptoms suggestive of PPES at follow-up should undergo a transthoracic echocardiogram to screen for the presence of pulmonary hypertension; additional testing, such as a ventilation/perfusion scan, right heart catheterization, and cardiopulmonary exercise testing may be indicated. The pathophysiology of post-pulmonary embolism syndrome is complex and heterogeneous. In chronic thromboembolic pulmonary hypertension, the pathophysiology reflects persistent pulmonary arterial thrombi and a progressive small vessel vasculopathy. In patients with chronic thromboembolic disease or chronic thromboembolic pulmonary hypertension, medical therapy, balloon pulmonary angioplasty, or pulmonary thromboendarterectomy should be considered, and in cases of chronic thromboembolic pulmonary hypertension, pulmonary thromboendarterectomy significantly improves mortality. In all causes of post-pulmonary embolism syndrome, rehabilitation is a safe treatment option that may improve quality of life.

Real-time imaging of cGMP signaling shows pronounced differences between glomerular endothelial cells and podocytes

Recent clinical trials of drugs enhancing cyclic guanosine monophosphate (cGMP) signaling for cardiovascular diseases have renewed interest in cGMP biology within the kidney. However, the role of cGMP signaling in glomerular endothelial cells (GECs) and podocytes remains largely unexplored. Using acute kidney slices from mice expressing the FRET-based cGMP biosensor cGi500 in endothelial cells or podocytes enabled real-time visualization of cGMP. Stimulation with atrial natriuretic peptide (ANP) or SNAP (NO donor) and various phosphodiesterase (PDE) inhibitors elevated intracellular cGMP in both cell types. GECs showed a transient cGMP response upon particulate or soluble guanylyl cyclase activation, while the cGMP response in podocytes reached a plateau following ANP administration. Co-stimulation (ANP + SNAP) led to an additive response in GECs. The administration of PDE inhibitors revealed a broader basal PDE activity in GECs dominated by PDE2a. In podocytes, basal PDE activity was mainly restricted to PDE3 and PDE5 activity. Our data demonstrate the existence of both guanylyl cyclase pathways in GECs and podocytes with cell-specific differences in cGMP synthesis and degradation, potentially suggesting new therapeutic options for kidney diseases.

Worldwide CTEPH Registry: Long-Term Outcomes With Pulmonary Endarterectomy, Balloon Pulmonary Angioplasty, and Medical Therapy

BACKGROUND

The European Chronic Thromboembolic Pulmonary Hypertension (CTEPH) registry, conducted between 2007 and 2012, reported the major impact of pulmonary endarterectomy (PEA) on the long-term survival of patients with CTEPH. Since then, 2 additional treatments for inoperable CTEPH have become available: balloon pulmonary angioplasty (BPA), and an approved oral drug therapy with the guanylate cyclase stimulator riociguat. The current registry aimed to evaluate the effect of these new therapeutic approaches in a worldwide context.

METHODS

Participation in this international global registry included 34 centers in 20 countries. Between February 2015 and September 2016, 1009 newly diagnosed, consecutive patients were included and followed until September 2019.

RESULTS

Overall, 605 patients (60%) underwent PEA and 185 (18%) underwent BPA; 76% of the 219 remaining patients not receiving mechanical intervention (ie, neither PEA nor BPA) were treated with pulmonary hypertension drugs. Of patients undergoing PEA and BPA, 38% and 78% also received drugs for pulmonary hypertension, respectively. Median age at diagnosis was higher in the BPA and No PEA/BPA groups than in the PEA group: 66 and 69, respectively, versus 60 years. Pulmonary vascular resistance (PVR) was similar in all groups, with an average of 643 dynes.s.cm-5. During the observation period (>3 years; ≤5.6 years), death was reported in 7%, 11%, and 27% of patients treated by PEA and BPA, and those receiving no mechanical intervention (P<0.001). In Kaplan-Meier analysis, 3-year survival was 94%, 92%, and 71% in the 3 groups, respectively. PEA 3-year survival improved by 5% from that observed between 2007 and 2012. There was no survival difference in patients receiving vitamin K antagonists and non-vitamin K oral anticoagulants (P=0.756). In Cox regression, reduced mortality was associated with: PEA and BPA in the global cohort; history of venous thromboembolism and lower PVR in the PEA group; lower right atrial pressure in the BPA group; and use of pulmonary hypertension drugs, oxygen therapy, and lower right atrial pressure, as well as functional class in the group receiving no mechanical intervention.

CONCLUSIONS

This second international CTEPH registry reveals important improvement in patient survival since the introduction of BPA and an approved drug for pulmonary hypertension. The type of anticoagulation regimen did not influence survival.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02656238.

Pulmonary Hypertension: Pharmacological and Non-Pharmacological Therapies

Pulmonary hypertension (PH) is a severe and chronic disease characterized by increased pulmonary vascular resistance and remodeling, often precipitating right-sided heart dysfunction and death. Although the condition is progressive and incurable, current therapies for the disease focus on multiple different drugs and general supportive therapies to manage symptoms and prolong survival, ranging from medications more specific to pulmonary arterial hypertension (PAH) to exercise training. Moreover, there are multiple studies exploring novel experimental drugs and therapies including unique neurostimulation, to help better manage the disease. Here, we provide a narrative review focusing on current PH treatments that target multiple underlying biochemical mechanisms, including imbalances in vasoconstrictor-vasodilator and autonomic nervous system function, inflammation, and bone morphogenic protein (BMP) signaling. We also focus on the potential of novel therapies for managing PH, focusing on multiple types of neurostimulation including acupuncture. Lastly, we also touch upon the disease's different subgroups, clinical presentations and prognosis, diagnostics, demographics, and cost.

Chronic thromboembolic pulmonary disease

Chronic thromboembolic pulmonary hypertension is a complication of pulmonary embolism and a treatable cause of pulmonary hypertension. The pathology is a unique combination of mechanical obstruction due to failure of clot resolution, and a variable degree of microvascular disease, that both contribute to pulmonary vascular resistance. Accordingly, multiple treatments have been developed to target the disease components. However, accurate diagnosis is often delayed. Evaluation includes high-quality imaging modalities, necessary for disease confirmation and for appropriate treatment planning. All patients with chronic thromboembolic pulmonary disease, and especially those with pulmonary hypertension, should be referred to expert centres for multidisciplinary team decision on treatment. The first decision remains assessment of operability, and the best improvement in symptoms and survival is achieved by the mechanical therapies, pulmonary endarterectomy and balloon pulmonary angioplasty. With the advances in multimodal therapies, excellent outcomes can be achieved with 3-year survival of >90%.

Current surgical management of chronic thromboembolic pulmonary disease

Chronic thromboembolic pulmonary disease (CTEPD) with or without pulmonary hypertension (PH) is an important potential consequence of venous thromboembolic disease. Untreated CTEPD with pulmonary hypertension (CTEPH) is associated with high rates of morbidity and mortality. Several treatment options are now available for patients with CTEPD and CTEPH, including pulmonary endarterectomy (PEA), balloon pulmonary angioplasty, medical therapy or a combination of therapies. Choice of treatment depends on the location of the thromboembolic disease burden, presence and severity of PH and patient factors, including frailty, parenchymal lung disease and other comorbidities. PEA is a complex surgery that can result in excellent outcomes and resolution of disease, but also comes with the risk of serious perioperative complications. This manuscript examines the history of PEA and its place in Australasia, and reports on outcomes from the main Australasian CTEPH expert centre. It provides a summary of up-to-date guidance on how PEA should be utilised in the overall management of these patients and describes opportunities and challenges for the future diagnosis and management of this disease, particularly in the Australasian setting.

Prostacyclin pathway vasodilators in patients with chronic thromboembolic pulmonary hypertension (CTEPH): A systemic review and meta-analysis of randomized controlled trials

Although surgical and interventional therapy has emerged as the primary treatment for patients with chronic thromboembolic pulmonary hypertension (CTEPH), there remains a subset of patients who need medication therapy. This study aimed to evaluate the efficacy and safety outcomes of prostacyclin pathway vasodilators, providing further insight for clinical decision-making. A literature search was conducted in PubMed, Embase, and CENTRAL databases from inception to December 2023. Literature screening and quality assessment were carried out with the Cochrane Risk of Bias Tool. Data analysis was conducted using RevMan 5.4 software. We included 6 randomized controlled trials with 387 patients. Prostacyclin pathway vasodilators demonstrated a significant improvement in PVR (-125.26 dynes·sec·cm-5, 95%CI: -219.29 to -31.23, Z = 2.61, and p < 0.009), RAP (-0.78 mmHg, 95%CI: -1.52 to -0.04, Z = 2.06, and p = 0.04), cardiac index (0.62, 95%CI: 0.54 to 0.69, Z = 16.13, and p < 0.00001), and the number of patients showing improvement in WHO functional class (3.86, 95%CI: 1,92 to 7.77, Z = 3.79, and p = 0.0002) compared to controls, moreover, a trend towards improvement was observed in mPAP, 6MWD, and NT-proBNP. Regarding the safety endpoints, no significant difference was found in both groups in terms of serious adverse events and all-cause deaths. The prostacyclin pathway vasodilators present therapeutic potential for CTEPH patients with inoperable or persistent/recurrent PH after PEA/BPA primarily characterized by distal small-vessel and microvasculopathy. However, the current clinical evidence remains insufficient and controversial, necessitating further validation.

An in-depth evaluation of the efficacy and safety of various treatment modalities for chronic thromboembolic pulmonary hypertension: A systematic review and network meta-analysis

Background

Chronic thromboembolic pulmonary hypertension (CTEPH) is a major risk for pulmonary hypertension with poor prognosis. Limited data is available on the optimal treatment of choice. We aimed to comprehensively assess the efficacy and safety of CTEPH targeted therapies and update the evidence.

Methods

We searched PubMed, Scopus, and the Cochrane library up to December 2023 to include randomized controlled trials comparing different therapies in patients with CTEPH. Primary outcomes were 6-minute walk distance (6 MWD), pulmonary vascular resistance (PVR), and mean pulmonary artery pressure (mPAP). While secondary outcomes were the mean right atrial pressure (mRAP), Borg dyspnea score, cardiac output (CO), cardiac index, adverse events, and all-cause mortality.

Results

Fourteen RCTs comprising 1047 patients were included in this network meta-analysis. Regarding 6 MWD, PADN (MD=113.59, 95% CI: 53.80; 173.39), BPA (MD=48.84, 95% CI: 27.99; 69.69), riociguat (MD=42.59, 95% CI: 22.01; 63.18), treprostinil (MD=41.60, 95% CI: 17.07; 66.13), and macitentan (MD=34.00, 95% CI: 3.50; 64.50) were favored compared to placebo. In terms of PVR, BPA (MD=-392.19, 95% CI: -571.77; -212.62), treprostinil (MD=-287.20, 95% CI: -475.63; -98.77), PADN (MD=-280.61, 95% CI: -506.69; -54.52), bosentan (MD=-176.00, 95% CI: -340.91; -11.09), and riociguat (MD=-171.61, 95% CI: -298.40; -44.81) displayed statistically significant results.

Conclusion

Current therapeutic modalities are effective in terms of improving exercise capacity, pulmonary hemodynamics, and reducing adverse events and all-cause mortality. Overall, BPA and PADN were superior to all other targeted medications in the studied outcomes.

Efficacy and safety of selexipag in patients with inoperable or persistent/recurrent CTEPH (SELECT randomised trial)

BACKGROUND

SELECT was the first global randomised controlled trial of selexipag with standard of care in patients with inoperable or persistent/recurrent chronic thromboembolic pulmonary hypertension.

METHODS

SELECT was a multicentre, randomised, double-blind, placebo-controlled, parallel-group, group-sequential, phase 3 study (ClinicalTrials.gov: NCT03689244). Adults aged ≤85 years in World Health Organization Functional Class I-IV, with a 6-min walk distance of 100-450 m, were randomised (1:1) to receive selexipag (200-1600 µg twice daily titration until individual maximum tolerated dose)+standard of care or placebo+standard of care. Patients were recruited into the haemodynamic set (first 91 randomised patients to undergo right heart catheterisation (RHC); week 20) or non-haemodynamic cohort (remaining patients, no RHC required). The primary end-point was percent of baseline pulmonary vascular resistance (PVR; week 20). Safety was also assessed.

RESULTS

Of 321 patients screened, 128 were randomised (haemodynamic set n=91 (selexipag n=47; placebo n=44)). In the haemodynamic set, 29 (31.9%) patients had previous pulmonary endarterectomy (PEA), 20 (22.0%) balloon pulmonary angioplasty (BPA), and 14 (15.4%) both PEA and BPA; 28 (30.8%) were inoperable. The independent data monitoring committee recommended to stop the study for futility as no statistically significant difference was observed for the primary end-point (between-treatment geometric least squares mean ratio of PVR: 0.95, 95% CI 0.84-1.07; p=0.412). Adverse events were reported in 63 (98.4%) and 53 (82.8%) patients for selexipag and placebo, respectively.

CONCLUSIONS

SELECT was discontinued for futility, as no treatment effect on the primary end-point (PVR) was observed. Safety data were consistent with the established safety profile of selexipag, with no new safety signals identified.

Chronic thromboembolic pulmonary hypertension treatment and sex: Systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

Chronic thromboembolic pulmonary hypertension (CTEPH) is a complication of pulmonary embolism and a major cause of chronic pulmonary hypertension leading to right heart failure and death. While pulmonary endarterectomy is the treatment of choice, some patients might benefit from medical therapy or balloon pulmonary angioplasty. Sex differences in outcomes of these therapies are not well characterized.

MATERIAL AND METHODS

We conducted a systematic review and meta-analysis to investigate sex differences in outcomes of various therapies for CTEPH. We searched MEDLINE, PubMed, Embase, CINAHL and the Cochrane Library databases between January 1, 2010 and April 30, 2021, published in English. We pooled incidence estimates using random-effects meta-analyses. We evaluated heterogeneity using the I2 statistic. We assessed publication bias using Begg's and Egger's tests. This study is registered in PROSPERO, CRD42021268504.

RESULTS

A total of 19 studies met the eligibility criteria, but only 3 trials provided separate outcomes for women and men. Two studies evaluated the efficacy of BPA, and one study evaluated the efficacy of riociguat (129 patients). Overall, 57.3% of patients were women and 62.6% were in functional class III. Mean time of follow-up was 55.5 (SD 26.1) weeks. Women showed a significantly better response in cardiac index (mean difference [MD], 0.10L/min/m2; 95% confidence interval [CI], 0.04-0.16; I2=0%; P=0.001). Alternatively, the reduction of pulmonary vascular resistances was significantly higher for men than for women (MD, 161.17dynscm-5; 95% CI, 67.99-254.35; I2=0%; P=0.0007).

CONCLUSIONS

Women and men might show different hemodynamic responses to riociguat or BPA for CTEPH.

DYZY01 alleviates pulmonary hypertension via inhibiting endothelial cell pyroptosis and rescuing endothelial dysfunction

Pulmonary hypertension (PH) is a malignant pulmonary vascular disease with a poor prognosis. Although the development of targeted drugs for this disease has made some breakthroughs in recent decades, PH remains incurable. Therefore, innovative clinical treatment methods and drugs for PH are still urgently needed. DYZY01 is a new drug whose main ingredient is high-purity cannabidiol, a non-psychoactive constituent of cannabinoids that was demonstrated to have anti-inflammatory and anti-pyroptosis properties. Several recent studies have found cannabidiol could improve experimental PH, whereas the mechanistic effect of it warrants further investigation. Thus, this study aimed to investigate whether DYZY01 can treat PH by inhibiting inflammation and pyroptosis and to reveal its underlying mechanism. We established hypoxia and monocrotaline (MCT)-induced PH rat models in vivo and treated them with either DYZY01 (10,50 mg/kg/d) or Riociguat (10 mg/kg/d) by oral administration. The mean pulmonary arterial pressure (mPAP), right ventricular hypertrophy index (RVHI), and extent of vascular remodeling were measured. Meanwhile, the effect of DYZY01 on human pulmonary arterial endothelial cells (HPAECs) was assessed in vitro. The results indicated that DYZY01 significantly reduced mPAP and RVHI in PH rats and reversed the extent of pulmonary vascular remodeling. This improvement may have been achieved by reducing endothelial cell pyroptosis via inhibiting the NF-κB/NLRP3/Caspase-1 pathway. Furthermore, DYZY01 could improve endothelial vascular function, possibly by regulating the secretion of vasodilator factors and inhibiting the proliferation and migration of pulmonary endothelial cells.

An exploration into CTEPH medications: Combining natural language processing, embedding learning, in vitro models, and real-world evidence for drug repurposing

BACKGROUND

In the modern era, the growth of scientific literature presents a daunting challenge for researchers to keep informed of advancements across multiple disciplines.

OBJECTIVE

We apply natural language processing (NLP) and embedding learning concepts to design PubDigest, a tool that combs PubMed literature, aiming to pinpoint potential drugs that could be repurposed.

METHODS

Using NLP, especially term associations through word embeddings, we explored unrecognized relationships between drugs and diseases. To illustrate the utility of PubDigest, we focused on chronic thromboembolic pulmonary hypertension (CTEPH), a rare disease with an overall limited number of scientific publications.

RESULTS

Our literature analysis identified key clinical features linked to CTEPH by applying term frequency-inverse document frequency (TF-IDF) scoring, a technique measuring a term's significance in a text corpus. This allowed us to map related diseases. One standout was venous thrombosis (VT), which showed strong semantic links with CTEPH. Looking deeper, we discovered potential repurposing candidates for CTEPH through large-scale neural network-based contextualization of literature and predictive modeling on both the CTEPH and the VT literature corpora to find novel, yet unrecognized associations between the two diseases. Alongside the anti-thrombotic agent caplacizumab, benzofuran derivatives were an intriguing find. In particular, the benzofuran derivative amiodarone displayed potential anti-thrombotic properties in the literature. Our in vitro tests confirmed amiodarone's ability to reduce platelet aggregation significantly by 68% (p = 0.02). However, real-world clinical data indicated that CTEPH patients receiving amiodarone treatment faced a significant 15.9% higher mortality risk (p<0.001).

CONCLUSIONS

While NLP offers an innovative approach to interpreting scientific literature, especially for drug repurposing, it is crucial to combine it with complementary methods like in vitro testing and real-world evidence. Our exploration with benzofuran derivatives and CTEPH underscores this point. Thus, blending NLP with hands-on experiments and real-world clinical data can pave the way for faster and safer drug repurposing approaches, especially for rare diseases like CTEPH.

New Therapies in Outpatient Pulmonary Medicine

Newer medications and devices, as well as greater understanding of the benefits and limitations of existing treatments, have led to expanded treatment options for patients with lung disease. Treatment advances have led to improved outcomes for patients with asthma, chronic obstructive pulmonary disease, interstitial lung disease, pulmonary hypertension, and cystic fibrosis. The risks and benefits of available treatments are substantially variable within these heterogeneous disease groups. Defining the role of newer therapies mandates both an understanding of these disorders and overall treatment approaches. This section will review general treatment approaches in addition to focusing on newer therapies for these conditions..