Risk factors for hemoptysis in idiopathic and hereditary pulmonary arterial hypertension

The role of vasculature and angiogenesis in respiratory diseases

In European countries, nearly 10% of all hospital admissions are related to respiratory diseases, mainly chronic life-threatening diseases such as COPD, pulmonary hypertension, IPF or lung cancer. The contribution of blood vessels and angiogenesis to lung regeneration, remodeling and disease progression has been increasingly appreciated. The vascular supply of the lung shows the peculiarity of dual perfusion of the pulmonary circulation (vasa publica), which maintains a functional blood-gas barrier, and the bronchial circulation (vasa privata), which reveals a profiled capacity for angiogenesis (namely intussusceptive and sprouting angiogenesis) and alveolar-vascular remodeling by the recruitment of endothelial precursor cells. The aim of this review is to outline the importance of vascular remodeling and angiogenesis in a variety of non-neoplastic and neoplastic acute and chronic respiratory diseases such as lung infection, COPD, lung fibrosis, pulmonary hypertension and lung cancer.

Radiofrequency catheter ablation for pulmonary hypertension patients with atrial flutter

AIMS

We aimed to evaluate the effects of radiofrequency catheter ablation (RFCA) and the factors influencing mortality after RFCA in patients with pulmonary hypertension (PH) and atrial flutter (AFL).

METHODS AND RESULTS

Fifty-eight consecutive PH patients with AFL who underwent an electrophysiological study and RFCA between April 2013 and August 2021 were selected for this study. In the study population, pulmonary arterial hypertension associated with congenital heart disease (PAH-CHD) was the most common type of PH (n = 34, 59%), followed by idiopathic pulmonary arterial hypertension (IPAH) (n = 19, 33%). Typical atrial flutter was the most common type of atrial flutter (n = 50, 86.2%). Sinus rhythm was restored in 53 (91.4%) patients during RFCA. After a mean follow-up of 33.8 months, AFL recurred in a total of 22 patients. Nine of them underwent repeat RFCA, and the site of the repeat ablation was not exactly the same as the first. At a median follow-up of 34.6 months after the last ablation, none of the patients who underwent repeat RFCA experienced AFL recurrence, and all of these patients survived. There were no procedure-related complications during hospitalization or follow-up. Univariate Cox regression analysis suggested that AFL recurrence after the last ablation was not associated with all-cause mortality. NT-proBNP (HR: 1.00024, 95% CI: 1.00008-1.00041, P = 0.004), pulmonary artery systolic pressure (PASP) (HR: 1.048, 95% CI: 1.020-1.076, P = 0.001), and IPAH (vs.

PAH-CHD, HR

7.720, 95% CI: 1.437-41.483, P = 0.017) were independent predictors of all-cause mortality in PH patients with AFL after RFCA. Receiver operating characteristic (ROC) curve analysis revealed that the area under the curve (AUC) of PASP for predicting all-cause mortality was 0.708. There was no significant difference in the Kaplan-Meier curves for all-cause mortality between patients with AFL recurrence after the last ablation and those without recurrence (P = 0.851). Patients with higher PASP (≥110 mmHg) and IPAH showed the lower survival rate in Kaplan-Meier curves.

CONCLUSION

Repeat ablation was safe and feasible in patients with recurrent AFL and can maintain sinus rhythm. AFL recurrence was not associated with all-cause mortality, and patients with high PASP or IPAH were at higher risk for adverse outcomes.

Pulmonary apoplexy following severe mitral valve stenosis: A case report

Hemoptysis is a common clinical symptom in emergency patients. It is characterized by the discharge of bloody sputum, which originates from the lower respiratory tract. In the majority of cases, this event is self-limiting, and only in less than 5% of cases, it is massive. Mitral valve stenosis is an uncommon cause of hemoptysis, with a prevalence of 4.2%. In rare cases of this condition, massive and sudden hemoptysis occurs, which is called pulmonary apoplexy. Here, a 35-year-old woman with a history of mitral valve stenosis is introduced who was referred to the hospital with a complaint of massive hemoptysis and sudden shortness of breath. According to the history of mitral valve stenosis, the patient was diagnosed with pulmonary apoplexy. After treatment, both the imaging findings and the patient's symptoms resolved within a short period of time. Even though pulmonary apoplexy is often severe, it can still respond well to conservative treatments and may indicate a need for immediate attention to the stenosis of the mitral valve.

Medical Emergencies in Pulmonary Hypertension

The management of acute medical emergencies in patients with pulmonary hypertension (PH) can be challenging. Patients with preexisting PH can rapidly deteriorate due to right ventricular decompensation when faced with acute physiological challenges that would usually be considered low-risk scenarios. This review considers the assessment and management of acute medical emergencies in patients with PH, encompassing both pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH), acknowledging these comprise the more severe groups of PH. Management protocols are described in a systems-based approach. Respiratory emergencies include pulmonary embolism, airways disease, and pneumonia; cardiac emergencies including arrhythmia and chest pain with acute myocardial infarction are discussed, alongside PH-specific emergencies such as pulmonary artery dissection and extrinsic coronary artery compression by a dilated proximal pulmonary artery. Other emergencies including sepsis, severe gastroenteritis with dehydration, syncope, and liver failure are also considered. We propose management recommendations for medical emergencies based on available evidence, international guidelines, and expert consensus. We aim to provide advice to the specialist alongside the generalist, and emergency doctors, nurses, and acute physicians in nonspecialist centers. A multidisciplinary team approach is essential in the management of patients with PH, and communication with local and specialist PH centers is paramount. Close hemodynamic monitoring during medical emergencies in patients with preexisting PH is vital, with early referral to critical care recommended given the frequent deterioration and high mortality in this setting.

Which Is the Best Way to Treat Massive Hemoptysis? A Systematic Review and Meta-Analysis of Observational Studies

INTRODUCTION

Hemoptysis is one of the most common symptoms of respiratory system diseases. Common causes include bronchiectasis, tumors, tuberculosis, aspergilloma, and cystic fibrosis. The severity of hemoptysis varies from mild to moderate to massive hemoptysis and can easily lead to hemodynamic instability and death from suffocation or shock. Nevertheless, the most threatening hemoptysis that is presented to the emergency department and requires hospitalization is the massive one. In these cases, today, the most common way to manage hemoptysis is bronchial artery embolization (BAE).

METHODS

A systematic literature search was conducted in PubMed and Scopus from January 2017 (with the aim of selecting the newest possible reports in the literature) until May 2023 for studies reporting massive hemoptysis. All studies that included technical and clinical success rates of hemoptysis management, as well as rebleeding and mortality rates, were included. A proportional meta-analysis was conducted using a random-effects model.

RESULTS

Of the 30 studies included in this systematic review, 26 used bronchial artery embolization as a means of treating hemoptysis, with very high levels of both technical and clinical success (greater than 73.7% and 84.2%, respectively). However, in cases where it was not possible to use bronchial artery embolization, alternative methods were used, such as dual-vessel intervention (80% technical success rate and 66.7% clinical success rate), customized endobronchial silicone blockers (92.3% technical success rate and 92.3% clinical success rate), antifibrinolytic agents (50% clinical success rate), and percutaneous transthoracic embolization (93.1% technical success rate and 88.9% clinical success rate), which all had high success rates apart from antifibrinolytic agents. Of the 2467 patients included in these studies, 341 experienced rebleeding during the follow-up period, while 354 other complications occurred, including chest discomfort, fever, dysphagia, and paresis. A total of 89 patients died after an episode of massive hemoptysis or during the follow-up period. The results of the meta-analysis showed a pooled technical success of bronchial artery embolization equal to 97.22% and a pooled clinical success equal to 92.46%. The pooled recurrence was calculated to be 21.46%, while the mortality was 3.5%. These results confirm the ability of bronchial artery embolization in the treatment of massive hemoptysis but also emphasize the high rate of recurrence following the intervention, as well as the risk of death.

CONCLUSION

In conclusion, massive hemoptysis can be treated with great clinical and technical success using bronchial artery embolization, reducing mortality. Mortality has now been reduced to a small percentage of cases.

Bronchial artery hypertrophy-associated perioperative pulmonary hemorrhage in cardiovascular surgery: a case report

Background

Pulmonary hemorrhage is a life-threatening complication of cardiovascular surgery. Bronchial artery hypertrophy, a rare pathology associated with inflammatory and ischemic respiratory diseases, increases the risk of pulmonary hemorrhage; however, its involvement in cardiovascular surgery is not well known. We present two cardiovascular surgical cases in which embolization of the hypertrophied bronchial artery was effective in controlling perioperative pulmonary hemorrhage.

Case presentation

The first case was a 51-year-old man with chronic obstructive pulmonary disease who developed acute type A aortic dissection. After emergent surgery, his blood pressure suddenly dropped in the intensive care unit; computed tomography revealed a right hemothorax. Because a 4-mm dilated bronchial artery was identified on preoperative computed tomography, the hemothorax was suspected to be associated with bronchial artery hypertrophy. Selective bronchial arteriography was emergently performed and revealed a right pulmonary parenchymal blush. After subsequent coil embolization of the bronchial artery, the parenchymal blush disappeared, and his hemodynamic condition stabilized. The second case was a 66-year-old man with bronchiectasis who was referred for redo aortic valve replacement due to structural valve deterioration. A bioprosthesis was previously implanted to avoid permanent anticoagulation because the patient had repeated episodes of hemoptysis; however, he still had persistent hemosputum during admission for the redo aortic valve replacement. A dilated bronchial artery 3.7 mm in size was incidentally identified on preoperative computed tomography, and hence, the repeated hemosputum was suspected to be associated with bronchial artery hypertrophy. Bronchial arteriography revealed a right pulmonary parenchymal blush, and prophylactic embolization of the bronchial artery was performed. The hemosputum disappeared after the procedure, and redo aortic valve replacement was performed uneventfully 8 days later.

Conclusion

In cardiovascular surgery, the risk of pulmonary hemorrhage associated with bronchial artery hypertrophy should be considered, especially in patients with inflammatory and ischemic respiratory diseases.

Haemoptysis in Pulmonary Arterial Hypertension Associated with Congenital Heart Disease: Insights on Pathophysiology, Diagnosis and Management

Haemoptysis represents one of the most severe major bleeding manifestations in the clinical course of pulmonary arterial hypertension (PAH) associated with congenital heart disease (CHD). Accumulating evidence indicates that dysfunction of the pulmonary vascular bed in the setting of PAH predisposes patients to increased hemorrhagic diathesis, resulting in mild to massive and life-threatening episodes of haemoptysis. Despite major advances in PAH targeted treatment strategies, haemoptysis is still correlated with substantial morbidity and impaired quality of life, requiring a multidisciplinary approach by adult CHD experts in tertiary centres. Technological innovations in the field of diagnostic and interventional radiology enabled the application of bronchial artery embolization (BAE), a valuable tool to efficiently control haemoptysis in modern clinical practice. However, bleeding recurrences are still prevalent, implying that the optimum management of haemoptysis and its implications remain obscure. Moreover, regarding the use of oral anticoagulation in patients with haemoptysis, current guidelines do not provide a clear therapeutic strategy due to the lack of evidence. This review aims to discuss the main pathophysiological mechanisms of haemoptysis in PAH-CHD, present the clinical spectrum and the available diagnostic tools, summarize current therapeutic challenges, and propose directions for future research in this group of patients.

Predictive value of chest HRCT for survival in idiopathic pulmonary arterial hypertension

Background

Little attention has been paid to chest high resolution computed tomography (HRCT) findings in idiopathic pulmonary arterial hypertension (IPAH) patients so far, while a couple of small studies suggested that presence of centrilobular ground-glass opacifications (GGO) on lung scans could have a significant negative prognostic value. Therefore, the aims of the present study were: to assess frequency and clinical significance of GGO in IPAH, and to verify if it carries an add-on prognostic value in reference to multidimensional risk assessment tool recommended by the 2015 European pulmonary hypertension guidelines.

Methods

Chest HRCT scans of 110 IPAH patients were retrospectively analysed. Patients were divided into three groups: with panlobular (p)GGO, centrilobular (c)GGO, and normal lung pattern. Association of different GGO patterns with demographic, functional, haemodynamic, and biochemical parameters was tested. Survival analysis was also performed.

Results

GGO were found in 46% of the IPAH patients: pGGO in 24% and cGGO in 22%. Independent predictors of pGGO were: positive history of haemoptysis, higher number of low-risk factors, and lower cardiac output. Independent predictors of cGGO were: positive history of haemoptysis, younger age, higher right atrial pressure, and higher mixed venous blood oxygen saturation. CGGO had a negative prognostic value for outcome in a 2-year perspective. This effect was not seen in the longer term, probably due to short survival of cGGO patients.

Conclusions

Lung HRCT carries a significant independent prognostic information in IPAH, and in patients with cGGO present on the scans an early referral to lung transplantation centres should be considered.

Intimal Sarcoma of the Great Vessels

Intimal sarcomas of the pulmonary artery and aorta are rare entities with a poor prognosis. In many instances, pulmonary artery sarcomas are misinterpreted as acute or chronic pulmonary thromboembolism, whereas aortic intimal sarcomas are often misdiagnosed as protuberant atherosclerotic disease or intimal thrombus. Discernment of intimal sarcomas from these and other common benign entities is essential for the timely initiation of aggressive therapy. The most useful imaging modalities for assessment of a suspected intimal sarcoma include CT angiography, fluorine 18-fluorodeoxyglucose PET, and MRI. The authors discuss the clinical features, current treatment options, characteristic imaging findings, and underlying pathologic features of intimal sarcomas. The authors emphasize imaging discernment of intimal sarcomas and how their differential diagnosis is informed by knowledge of radiologic-pathologic correlation. The most reliable distinguishing imaging features are also emphasized to improve accurate and timely diagnosis. Online supplemental material is available for this article. ^©RSNA, 2021.

Beyond the Lungs: Systemic Manifestations of Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a disease characterized by progressive loss and remodeling of the pulmonary arteries, resulting in right heart failure and death. Until recently, PAH was seen as a disease restricted to the pulmonary circulation. However, there is growing evidence that patients with PAH also exhibit systemic vascular dysfunction, as evidenced by impaired brachial artery flow-mediated dilation, abnormal cerebral blood flow, skeletal myopathy, and intrinsic kidney disease. Although some of these anomalies are partially due to right ventricular insufficiency, recent data support a mechanistic link to the genetic and molecular events behind PAH pathogenesis. This review serves as an introduction to the major systemic findings in PAH and the evidence that supports a common mechanistic link with PAH pathophysiology. In addition, it discusses recent studies describing morphological changes in systemic vessels and the possible role of bronchopulmonary anastomoses in the development of plexogenic arteriopathy. On the basis of available evidence, we propose a paradigm in which metabolic abnormalities, genetic injury, and systemic vascular dysfunction contribute to systemic manifestations in PAH. This concept not only opens exciting research possibilities but also encourages clinicians to consider extrapulmonary manifestations in their management of patients with PAH.

Clinical heterogeneity of Pulmonary Arterial Hypertension associated with variants in TBX4

Background

The knowledge of hereditary predisposition has changed our understanding of Pulmonary Arterial Hypertension. Genetic testing has been widely extended and the application of Pulmonary Arterial Hypertension specific gene panels has allowed its inclusion in the diagnostic workup and increase the diagnostic ratio compared to the traditional sequencing techniques. This is particularly important in the differential diagnosis between Pulmonary Arterial Hypertension and Pulmonary Venoocclusive Disease.

Methods

Since November 2011, genetic testing is offered to all patients with idiopathic, hereditable and associated forms of Pulmonary Arterial Hypertension or Pulmonary Venoocclusive Disease included in the Spanish Registry of Pulmonary Arterial Hypertension. Herein, we present the clinical phenotype and prognosis of all Pulmonary Arterial Hypertension patients with disease-associated variants in TBX4.

Results

Out of 579 adults and 45 children, we found in eight patients from seven families, disease-causing associated variants in TBX4. All adult patients had a moderate-severe reduction in diffusion capacity. However, we observed a wide spectrum of clinical presentations, including Pulmonary Venoocclusive Disease suspicion, interstitial lung disease, pulmonary vascular abnormalities and congenital heart disease.

Conclusions

Genetic testing is now essential for a correct diagnosis work-up in Pulmonary Arterial Hypertension. TBX4-associated Pulmonary Arterial Hypertension has marked clinical heterogeneity. In this regard, a genetic study is extremely useful to obtain an accurate diagnosis and provide appropriate management.

EXPRESS: Statement on imaging and pulmonary hypertension from the Pulmonary Vascular Research Institute (PVRI)

Pulmonary hypertension (PH) is highly heterogeneous and despite treatment advances it remains a life-shortening condition. There have been significant advances in imaging technologies, but despite evidence of their potential clinical utility, practice remains variable, dependent in part on imaging availability and expertise. This statement summarizes current and emerging imaging modalities and their potential role in the diagnosis and assessment of suspected PH. It also includes a review of commonly encountered clinical and radiological scenarios, and imaging and modeling-based biomarkers. An expert panel was formed including clinicians, radiologists, imaging scientists, and computational modelers. Section editors generated a series of summary statements based on a review of the literature and professional experience and, following consensus review, a diagnostic algorithm and 55 statements were agreed. The diagnostic algorithm and summary statements emphasize the key role and added value of imaging in the diagnosis and assessment of PH and highlight areas requiring further research.

Riociguat for pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension: Results from a phase II long-term extension study

BACKGROUND

Riociguat was well tolerated and improved exercise and functional capacity in patients with pulmonary arterial hypertension (PAH) and inoperable chronic thromboembolic pulmonary hypertension (CTEPH) in a 12-week Phase II trial. We present final data from the long-term extension phase of this study.

METHODS

During this multicenter, open-label, uncontrolled long-term extension study, riociguat dose could be changed at the physician's discretion (range 0.5-2.5 mg three times daily). The primary outcome was long-term safety and tolerability of riociguat; secondary outcomes included 6-minute walking distance, World Health Organization functional class, survival, and clinical worsening-free survival.

RESULTS

Sixty-eight patients (inoperable CTEPH, n = 41; PAH, n = 27) entered the long-term extension. Median treatment duration at the final data cut-off was 77 months. The most common adverse events were nasopharyngitis (57%) and peripheral edema (37%). Three patients (4%) experienced serious adverse events of hemoptysis: two moderate, one severe, none fatal or considered drug-related. At Month 48, 6-minute walking distance increased from baseline by 69 ± 105 m, and World Health Organization functional class improved/stabilized/worsened versus baseline in 50/45/5% of patients. Three-year survival and clinical worsening-free survival were 91% and 49%, respectively (with patients censored if they withdrew without experiencing an event). Starting a new PAH treatment was the most frequent clinical worsening event.

CONCLUSIONS

Improvements in exercise and functional capacity were maintained at 4 years in patients remaining on treatment, with no new safety signals identified. These data support riociguat as a long-term treatment option for PAH and inoperable CTEPH.

TRIAL REGISTERED AT

ClinicalTrials.gov.

REGISTRATION NUMBER

NCT00454558.

Electrocardiography-Gated Computed Tomography of the Bronchial Arteries With Iterative Image Reconstruction: Clinical Evaluation and Image Quality

BACKGROUND

The aim of this study was to apply electrocardiography (ECG)-gated prospective-triggered multidetector row computed tomography angiography with iterative model reconstruction (IMR) to optimize imaging of the bronchial arteries in patients with the chief complaint of hemoptysis.

METHODS

This was a prospective observational study. Between August 2015 and June 2016, we enrolled 31 consecutive patients with the chief complaint of hemoptysis who were scheduled to undergo computed tomography of the bronchial artery. Patients were randomly divided into 3 groups: group A, with filtered back-projection reconstruction; group B, with iDose reconstruction; and group C, with ECG-gated prospective-triggered multidetector row computed tomography angiography with IMR. Image quality, visibility, and traceability were compared.

RESULTS

Image quality, including signal-to-noise and contrast-to-noise ratios, visibility, and traceability, was best in group C.

CONCLUSIONS

With the help of IMR and ECG-synchronized prospective-triggered technology, the bronchial artery anatomy can be accurately depicted in patients with massive hemoptysis.

Bronchial artery embolization for the treatment of haemoptysis in pulmonary hypertension

PURPOSE

To test the efficacy of bronchial artery embolization (BAE) to treat haemoptysis in pulmonary hypertension (PH).

METHODS

33 patients were treated by BAE for haemoptysis associated with PH (PH group = 21) or non-associated with PH (control group = 12). The details of procedure, outcome, and rate of relapse were compared between the two groups. Within the PH group, the comparison was operated between subjects with congenital heart disease-associated pulmonary artery hypertension (CHD-APAH subgroup = 12) and non-CHD (non-CHD-APAH subgroup = 9).

RESULTS

The rate of relapse at 30 and 90-days was similar between the PH group and control group. BAE in the PH group was more challenging (median 2 arteries embolized per procedure) compared to the control group (median 1 artery embolized per procedure; p = 0.001). Bleeding arteries were more heterogeneous in the PH group, while a single right bronchial artery was the only clinical finding in 66.7% of controls (p = 0.001). Within the PH group, the CHD subgroup showed higher survival rate compared to the non-CHD-APAH group (p = 0.007).

CONCLUSION

BAE is effective and safe for the treatment of haemoptysis in PH, yet more challenging than other conditions. In PH-associated haemoptysis, BAE provides higher survival rate for subjects with PH associated with CHD.

BMPR2 mutation status influences bronchial vascular changes in pulmonary arterial hypertension

The impact of bone morphogenetic protein receptor 2 (BMPR2) gene mutations on vascular remodelling in pulmonary arterial hypertension (PAH) is unknown. We sought to identify a histological profile of BMPR2 mutation carriers.Clinical data and lung histology from 44 PAH patients were subjected to systematic analysis and morphometry.Bronchial artery hypertrophy/dilatation and bronchial angiogenesis, as well as muscular remodelling of septal veins were significantly increased in PAH lungs carrying BMPR2 mutations. We found that patients displaying increased bronchial artery remodelling and bronchial microvessel density, irrespective of the mutation status, were more likely to suffer from severe haemoptysis. History of substantial haemoptysis (>50 mL) was significantly more frequent in BMPR2 mutation carriers. 43.5% of BMPR2 mutation carriers, as opposed to 9.5% of noncarriers, displayed singular large fibrovascular lesions, which appear to be closely related to the systemic lung vasculature.Our analysis provides evidence for the involvement of the pulmonary systemic circulation in BMPR2 mutation-related PAH. We show that BMPR2 mutation carriers are more prone to haemoptysis and that haemoptysis is closely correlated to bronchial arterial remodelling and angiogenesis; in turn, pronounced changes in the systemic vasculature correlate with increased pulmonary venous remodelling, creating a distinctive profile in PAH patients harbouring a BMPR2 mutation.

Pulmonary Hypertension in the Intensive Care Unit

Pulmonary hypertension occurs as the result of disease processes increasing pressure within the pulmonary circulation, eventually leading to right ventricular failure. Patients may become critically ill from complications of pulmonary hypertension and right ventricular failure or may develop pulmonary hypertension as the result of critical illness. Diagnostic testing should evaluate for common causes such as left heart failure, hypoxemic lung disease and pulmonary embolism. Relatively few patients with pulmonary hypertension encountered in clinical practice require specific pharmacologic treatment of pulmonary hypertension targeting the pulmonary vasculature. Management of right ventricular failure involves optimization of preload, maintenance of systemic blood pressure and augmentation of inotropy to restore systemic perfusion. Selected patients may require pharmacologic therapy to reduce right ventricular afterload by directly targeting the pulmonary vasculature, but only after excluding elevated left heart filling pressures and confirming increased pulmonary vascular resistance. Critically-ill patients with pulmonary hypertension remain at high risk of adverse outcomes, requiring a diligent and thoughtful approach to diagnosis and treatment.

Riociguat for the treatment of pulmonary arterial hypertension: a long-term extension study (PATENT-2)

Riociguat is a soluble, guanylate cyclase stimulator, approved for pulmonary arterial hypertension. In the 12-week PATENT-1 study, riociguat was well tolerated and improved several clinically relevant end-points in patients with pulmonary arterial hypertension who were treatment naïve or had been pretreated with endothelin-receptor antagonists or prostanoids. The PATENT-2 open-label extension evaluated the long-term safety and efficacy of riociguat. Eligible patients from the PATENT-1 study received riociguat individually adjusted up to a maximum dose of 2.5 mg three times daily. The primary objective was to assess the safety and tolerability of riociguat; exploratory efficacy assessments included 6-min walking distance and World Health Organization (WHO) functional class. Overall, 396 patients entered the PATENT-2 study and 324 (82%) were ongoing at this interim analysis (March 2013). The safety profile of riociguat in PATENT-2 was similar to that observed in PATENT-1, with cases of haemoptysis and pulmonary haemorrhage also being observed in PATENT-2. Improvements in the patients', 6-min walking distance and WHO functional class observed in PATENT-1 persisted for up to 1 year in PATENT-2. In the observed population at the 1-year time point, mean±sd 6-min walking distance had changed by 51±74 m and WHO functional class had improved in 33%, stabilised in 61% and worsened in 6% of the patients versus the PATENT-1 baseline. Long-term riociguat was well tolerated in patients with pulmonary arterial hypertension, and led to sustained improvements in exercise capacity and functional capacity for up to 1 year.

Riociguat for the treatment of chronic thromboembolic pulmonary hypertension: a long-term extension study (CHEST-2)

Riociguat is a soluble guanylate cyclase stimulator approved for the treatment of inoperable and persistent/recurrent chronic thromboembolic pulmonary hypertension (CTEPH). In the 16-week CHEST-1 study, riociguat showed a favourable benefit-risk profile and improved several clinically relevant end-points in patients with CTEPH. The CHEST-2 open-label extension evaluated the long-term safety and efficacy of riociguat. Eligible patients from CHEST-1 received riociguat individually adjusted up to a maximum dose of 2.5 mg three times daily. The primary objective was the safety and tolerability of riociguat; exploratory efficacy end-points included 6-min walking distance (6MWD) and World Health Organization (WHO) functional class (FC). Overall, 237 patients entered CHEST-2 and 211 (89%) were ongoing at this interim analysis (March 2013). The safety profile of riociguat in CHEST-2 was similar to CHEST-1, with no new safety signals. Improvements in 6MWD and WHO FC observed in CHEST-1 persisted for up to 1 year in CHEST-2. In the observed population at 1 year, mean±sd 6MWD had changed by +51±62 m (n=172) versus CHEST-1 baseline (n=237), and WHO FC had improved/stabilised/worsened in 47/50/3% of patients (n=176) versus CHEST-1 baseline (n=236). Long-term riociguat had a favourable benefit-risk profile and apparently showed sustained benefits in exercise and functional capacity for up to 1 year.