Riociguat for the treatment of chronic thromboembolic pulmonary hypertension

Effect of balloon pulmonary angioplasty on cardio-ankle vascular index and biventricular remodeling in patients with chronic thromboembolic pulmonary hypertension

Background

Chronic thromboembolic pulmonary hypertension (CTEPH) is caused by organized pulmonary thrombi, and pulmonary endarterectomy is the only curative treatment. Since balloon pulmonary angioplasty (BPA) has become an established therapeutic option for inoperable CTEPH, prognosis has improved. Recent reports suggest that arterial stiffness evaluated using the cardio-ankle vascular index (CAVI) may play an important role in the cardio-vascular interaction in CTEPH; however, the details remain unclear. This study aimed to clarify the role of CAVI in CTEPH through hemodynamic changes and ventricular remodeling after BPA.

Methods and results

A total of 23 patients with CTEPH who had undergone BPA were enrolled in this study. The mean pulmonary artery pressure (mPAP) and CAVI significantly decreased after BPA [mPAP, 34 (26-45) mmHg to 20 (19-24) mmHg, p < 0.0001; CAVI, 9.4 (8.0-10.3) to 8.3 (7.5-9.6), p = 0.004]. The echocardiographic right ventricle was significantly decreased, and the left ventricular volume was significantly increased after BPA, indicating significant biventricular remodeling after BPA. Changes in CAVI (ΔCAVI) significantly correlated with changes in mPAP (r = 0.45, p = 0.03). Additionally, ΔCAVI was significantly correlated with changes in both right ventricular area and left ventricular volume.

Conclusions

Arterial stiffness, evaluated using the CAVI, improved after BPA. Changes in CAVI were significantly correlated with changes in pulmonary arterial pressure and biventricular remodeling. CAVI may play an important role in cardiovascular interactions in patients with CTEPH.

Development and validation of a nomogram for predicting hemodynamic response to balloon pulmonary angioplasty in patients with chronic thromboembolic pulmonary hypertension

BACKGROUND

Balloon pulmonary angioplasty (BPA) can effectively alleviate pulmonary hypertension in patients with chronic thromboembolic pulmonary hypertension (CTEPH). Identifying predictors of unfavorable hemodynamic response to BPA is essential to guide clinical practice. Therefore, our objective was to construct and validate a nomogram to facilitate clinicians predicting hemodynamic response to BPA.

METHODS

Patients with CTEPH and underwent BPA from May 2018 to April 2022 were retrospectively collected. Favorable hemodynamic response to BPA was defined as a mean pulmonary arterial pressure ≤30 mmHg and/or a reduction in pulmonary vascular resistance ≥30 % at follow-up.

RESULTS

A total of 155 patients were included. At baseline, patients with favorable hemodynamic response had significantly lower proportion of occlusive lesions (11.11 % vs. 26.32 %, P = 0.017), higher diffusing capacity of the lungs for carbon monoxide (63.77 % ± 14.10 % vs. 59.11 % ± 11.78 %, P = 0.039), and better cardiac morphology than counterparts. LASSO regression and random forest were used to construct prediction models respectively. The LASSO regression model demonstrated better predictive ability and accuracy than the random forest model, as evidenced by higher area under curve (0.745 vs. 0.740) and lower Brier score (0.192 vs. 0.195). A nomogram was constructed based on the LASSO regression model, consisting of right ventricular end-diastolic diameter/left ventricular end-diastolic diameter, number of treated pulmonary vessels and proportion of occlusion lesions. High predictive ability of the LASSO model was preserved in validation (C index 0.744).

CONCLUSIONS

The current study constructed a nomogram with high accuracy in predicting BPA hemodynamic outcome, which could facilitate decision-making in clinical practice.

Perioperative Management in Pulmonary Endarterectomy

Pulmonary endarterectomy (PEA) is the treatment of choice for patients with chronic thromboembolic pulmonary hypertension (PH), provided lesions are proximal enough in the pulmonary vasculature to be surgically accessible and the patient is well enough to benefit from the operation in the longer term. It is a major cardiothoracic operation, requiring specialized techniques and instruments developed over several decades to access and dissect out the intra-arterial fibrotic material. While in-hospital operative mortality is low (<5%), particularly in high-volume centers, careful perioperative management in the operating theater and intensive care is mandatory to balance ventricular performance, fluid balance, ventilation, and coagulation to avoid or treat complications. Reperfusion pulmonary edema, airway hemorrhage, and right ventricular failure are the most problematic complications, often requiring the use of extracorporeal membrane oxygenation to bridge to recovery. Successful PEA has been shown to improve both morbidity and mortality in large registries, with survival >70% at 10 years. For patients not suitable for PEA or with residual PH after PEA, balloon pulmonary angioplasty and/or PH medical therapy may prove beneficial. Here, we describe the indications for PEA, specific surgical and perioperative strategies, postoperative monitoring and management, and approaches for managing residual PH in the long term.

Revisiting Pulmonary Hypertension in the Era of Temporary Mechanical Circulatory Support - Literature Review and Case-Based Discussion

BACKGROUND

Pulmonary arterial hypertension (PAH) is characterized by persistently increased pressure in the pulmonary arteries. New defining criteria for the different hemodynamic types of pulmonary hypertension (PH) that occur with left heart disease have been proposed by the task force on PH. After consideration of the changes in the general definition of PH in left heart disease, the proposed hemodynamic definition was: (1) isolated postcapillary PH: pulmonary artery wedge pressure >15 mm Hg and mean pulmonary arterial pressure (mPAP) >20 mm Hg and pulmonary vascular resistance (PVR) <3 Woods units (WU); and (2) combined post- and precapillary PH: pulmonary artery wedge pressure >15 mm Hg, mPAP >20 mm Hg, and PVR ≥3 WU. Secondary PH is initially reversible, but eventually, it can become fixed because of the remodeling process of the pulmonary vascular system. Limitations in defining both the time for and amount of reversibility lack clarity. We discuss a case of PH as a framework to better understand these key principles in addressing patients' candidacy for heart or heart-lung transplantation.

METHODS

We performed a literature search for all available contemporary data with the following terms: "pulmonary hypertension," "reversal," "Impella 5.5," "temporary mechanical support," and "LVAD" using the National Library of Medicine - PubMed and PubMed Central between 2019 and 2023. A total of 14 published papers were found with these search. From these, 3 addressed the issue of PH and reversibility in the setting of LHD after durable LVAD placement. No papers were found using Impella 5.5 and PH during this timeframe. Given the paucity of data in the field regarding temporary mechanical circulatory support and pulmonary hypertension, we present a case-based discussion to guide the reader in understanding the potential impact of this method in patients with WHO Class 2 Pulmonary hypertension.

CASE

A 49-year-old woman with a medical history of acute on chronic biventricular systolic and diastolic heart failure, American College of Cardiology stage D, Stevenson profile C, New York Heart Association class IV (ejection fraction 18%) secondary to nonischemic cardiomyopathy after cardiac resynchronization therapy, pulmonary hypertension, bilateral deep vein thrombosis, and segmental pulmonary embolism presented for heart transplant evaluation. Her cardiac output and central hemodynamics were measured, and she was found to have a pulmonary artery (PA) pressure of 78/38 with a mean PA pressure of 51, pulmonary capillary wedge pressure (PCWP) 30, transpulmonary pressure gradient (TPG) 21, thermodilution cardiac output (CO) 3.35 L/min, and cardiac input (CI) 1.75 L/min/m2. Her PVR was 6.2 WU. Provocative pharmacologic testing for reversibility of PH was performed using sodium nitroprusside, which resulted in a blood pressure of 83/57 (92), heart rate 92/min, and PA pressure of 71/31, with a mean PA pressure of 44 PCWP 22, TPG 22, CO 4.8 L/min, and CI of 2.48 L/min/m2 with a PVR of 4.5 WU. Following this, the patient underwent Impella 5.5 placement through the right axillary artery to optimize afterload reduction and improve end-organ perfusion. Post-Impella hemodynamics on milrinone 0.5 mcg/kg/min demonstrated the following: blood pressure 90/66 (74), heart rate 53/min, and PA pressure of 56/29, with a mean PA pressure of 38, PCWP 24, TPG 14, CO 6 L/min, and CI of 2.9 L/min/m2 with a PVR of 2.3 WU.

CONCLUSION

Left ventricular assist device support with Impella 5.5 is associated with a reduction in mPAP and PVR over weeks to months and thus plays a crucial role as a bridge to transplant. Our case and this review highlights the characteristics of PH resulting from heart failure with reduced ejection fraction and discusses the important clinical issues related to the treatment of these patients. We have shown that left ventricular assist device therapy with Impella 5.5 can effectively reduce left-sided filling pressures and lead to PH improvement. We demonstrate the potential benefits of Impella 5.5 in the management of patients with WHO 2 PH and cardiogenic shock with impaired hemodynamics.

Predictors of procedural complications in balloon pulmonary angioplasty for chronic thromboembolic pulmonary hypertension

BACKGROUND

Balloon pulmonary angioplasty (BPA) is an effective treatment for inoperable chronic thromboembolic pulmonary hypertension, with good results reported for residual pulmonary hypertension (PH) after pulmonary endarterectomy (PEA). However, BPA is associated with complications, such as pulmonary artery perforation and vascular injury, which can lead to critical pulmonary hemorrhage requiring embolization and mechanical ventilation. Furthermore, the risk factors for occurrence of complications in BPA are unclear; therefore, this study aimed to evaluate predictors of procedural complications in BPA.

METHODS

In this retrospective study, we collected clinical data (patient characteristics, details of medical therapy, hemodynamic parameters, and details of the BPA procedure) from 321 consecutive sessions involving 81 patients who underwent BPA. Procedural complications were evaluated as endpoints.

RESULTS

BPA for residual PH after PEA was performed in 141 sessions (43.9 %), which involved 37 patients. Procedural complications were observed in 79 sessions (24.6 %), including severe pulmonary hemorrhage requiring embolization in 29 sessions (9.0 % of all sessions). No patients experienced severe complications requiring intubation with mechanical ventilation or extracorporeal membrane oxygenation. Age ≥ 75 years and mean pulmonary artery pressure ≥ 30 mmHg were independent predictors of procedural complications. Residual PH after PEA was a significant predictor of severe pulmonary hemorrhage requiring embolization (adjusted odds ratio, 3.048; 95 % confidence interval, 1.042-8.914, p = 0.042).

CONCLUSIONS

Older age, high pulmonary artery pressure, and residual PH after PEA increase the risk of severe pulmonary hemorrhage requiring embolization in BPA.

Monographic Issue on Pulmonary Hypertension: Medical and Interventional Treatment for Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare complication of acute pulmonary embolism. The reasons why clots do not resorb are incompletely understood, but the result is partial or complete fibrothrombotic obstruction of pulmonary arteries. A secondary microvasculopathy aggravates the pulmonary hypertension (PH) as a consequence of high flow and shear stress in the nonoccluded arteries. The treatment of CTEPH has long been purely surgical, but many patients were inoperable because of inaccessible lesions or severe comorbidities. Alternatives were developed, including medical therapy and more recently balloon pulmonary angioplasty (BPA). Depending on the generation of the obstructed vessels, the treatment will be surgical, up to the (sub)segmental level, or by BPA for more distal vessels. PH drugs are used to treat the microvasculopathy. The current paper describes the therapeutic management of inoperable patients: the medical approach with PH drugs used in mono- or combination therapy; the proper use of anticoagulants in CTEPH; the technique, indications, and results at short- and long-term of BPA; the multimodal approach for inoperable patients combining PH drugs and BPA; and the effects of rehabilitation. It shows the importance of a multidisciplinary approach to the disease.

Review of Advances on Management of Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension is rare, underdiagnosed form of pulmonary hypertension. It is caused by intravascular obstruction of pulmonary arteries due to fibrotic transformation of thromboembolic material and microvasculopathy. It is important to diagnose this variant as potentially curative treatment in the form of pulmonary endarterectomy is available. Last two decades have seen rapid advances in targeted medical management and refinement in balloon pulmonary angioplasty technique, which have provided a viable therapeutic option for patients who deemed to be inoperable.

What changed after the 2022 guidelines for pulmonary hypertension?

With an estimated prevalence of around 1%, pulmonary hypertension (PH) presents a relevant burden worldwide. In this review, we aim to give an overview of the novelties from the revised European Society of Cardiology (ESC) /European Respiratory Society (ERS) guidelines for the diagnosis and treatment of PH and their implication for the everyday clinical practice.

Comparison of different treatment strategies in patients with chronic thromboembolic pulmonary hypertension: a single centre real-world experience

BACKGROUND

Pulmonary endarterectomy (PEA) has been the most effective therapy for chronic thromboembolic pulmonary hypertension (CTEPH). However, there is a substantial proportion of patients deemed not operable in whom other treatment strategies are available: medical therapy and balloon pulmonary angioplasty (BPA). We aimed to compare different CTEPH treatment strategies effect in a real-world setting.

METHODS

All patients with CTEPH referred to our centre were included. We compare the short-term clinical, functional, exercise and haemodynamic effect of medical therapy (irrespective of subsequent treatment strategies), PEA and BPA (irrespective of previous/subsequent treatment strategies); we also describe the long-term outcome of the different patient groups.

RESULTS

We included 467 patients (39% were treated only with medical therapy, 43% underwent PEA, 13% underwent BPA and 5% were not treated with any therapy). Patients treated only with medical therapy were the oldest; compared to patients undergoing PEA, they had a lower exercise capacity, a higher risk profile and gained a lower haemodynamic, functional and survival benefit from the treatment. Patients undergoing BPA had a lower haemodynamic improvement but a comparable functional, exercise and risk improvement and a similar survival compared to patients undergoing PEA; their survival is anyway better than patients undergoing only medical treatment. Untreated historical control patients had the worst survival.

CONCLUSIONS

We confirm the superiority of PEA compared to any alternative treatment in CTEPH patients and we observe that BPA, in patients deemed not operable or with persistent/recurrent PH after PEA, leads to a better outcome than medical therapy alone.

Balloon pulmonary angioplasty for chronic thromboembolic pulmonary hypertension:its history and development, and regional medical cooperation in Fukushima

Chronic thromboembolic pulmonary hypertension (CTEPH) is designated as an intractable disease by the Ministry of Health, Labour and Welfare of Japan, and has an extremely poor prognosis if untreated. Surgical pulmonary endarterectomy is the curative treatment for cases in which the organized thrombi are located in the central part of the pulmonary artery, but there had been no effective treatment for cases in which the thrombi are located in the peripheral part of the pulmonary artery. Recently, balloon pulmonary angioplasty (BPA), a transcatheter procedure to dilate stenotic or occluded lesions in the peripheral pulmonary artery, has been rapidly developed. Although BPA was once a globally abandoned procedure due to hemorrhagic complications, Japanese experts have improved the technique, and its safety and efficacy have been enhanced. As a result, BPA is now being reevaluated worldwide. This review describes the history and development of BPA in the treatment of CTEPH, as well as the status of this treatment in Fukushima Prefecture.

Changes in the management of chronic thromboembolic pulmonary hypertension over a 10-year period, in a French expert regional competence centre

Over the last few years, the advent of balloon pulmonary angioplasty (BPA) had led to changes in the management of chronic thromboembolic pulmonary hypertension (CTEPH). We reviewed data from 98 CTEPH patients diagnosed during the last decade in a pulmonary hypertension (PH) expert centre. The management modalities of 2 periods (Period A: 2011-15 and Period B: 2016-20) were compared. Age (period A: 72 [58-80] years; period B: 69 [62-79] years), clinical (New York Heart Association (NYHA) functional class III-IV: 25/41, 61% vs 39/57, 68%), and hemodynamic assessments (pulmonary vascular resistance: 7.5 [6.2-8.7] WU vs 8.0 [6.0-10.2] WU) at baseline were not significantly different. Pulmonary endarterectomy was performed in less than one third of patients (12, 29.3% vs 15, 26.3%). For patients not eligible for surgery, medical therapy was mostly prescribed alone during period A (medical therapy alone, patients diagnosed in period A: 61% vs in period B: 17.5%) while it was associated with BPA during period B (medical therapy + BPA, 12% vs 61.4%). The 5-year survival rate was excellent for patients who underwent surgery (96.3%) or BPA (95.2%), but was only 42.1% for patients under oral medication only (p < 0.0001). Patients diagnosed with CTEPH who cannot be operated should undergo BPA. The survival rate after BPA is as good as after surgery and significantly better than that of oral medication only.

[Chronic thromboembolic pulmonary hypertension]

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare disease, but an important late sequela after acute pulmonary embolism. Therefore, follow-up after at least three months of sufficient anticoagulation is recommended. Patients with suspected CTEPH should be referred to specialized CTEPH centers for further evaluation and treatment.Three treatment modalities are available: pulmonary endarterectomy (PEA), balloon pulmonary angioplasty (BPA) and pulmonary hypertension-targeted drugs. The indication for surgery depends mainly on the localization of the pulmonary arterial obstructions. Severe comorbidities as well as advanced age need individual evaluation, but do not present strict exclusion criteria. Multimodal treatments are common practice in inoperable CTEPH. However, treatment decision making in an experienced multidisciplinary team is mandatory.

Riociguat in patients with early diffuse cutaneous systemic sclerosis (RISE-SSc): open-label, long-term extension of a phase 2b, randomised, placebo-controlled trial

BACKGROUND

The phase 2b Riociguat Safety and Efficacy in Patients with Diffuse Cutaneous Systemic Sclerosis (RISE-SSc) trial investigated riociguat versus placebo in early diffuse cutaneous systemic sclerosis. The long-term extension evaluated safety and exploratory treatment effects for an additional year.

METHODS

Patients were enrolled to RISE-SSc between Jan 15, 2015, and Dec 8, 2016. Those who completed the 52-week, randomised, parallel-group, placebo-controlled, double-blind phase were eligible for the long-term extension. Patients originally assigned to riociguat continued therapy (riociguat-riociguat group). Those originally assigned to placebo were switched to riociguat (placebo-riociguat group), adjusted up to 2·5 mg three times daily in a 10-week, double-blind dose-adjustment phase, followed by an open-label phase. Statistical analyses were descriptive. Safety including adverse events and serious adverse events was assessed in the long-term safety analysis set (all patients randomly assigned and treated with study medication in the double-blind phase who continued study medication in the long-term extension). The RISE-SSc trial is registered with ClinicalTrials.gov, NCT02283762.

FINDINGS

In total, 87 (72%) of 121 patients in the main RISE-SSc study entered the long-term extension (riociguat-riociguat, n=42; placebo-riociguat, n=45). 65 (75%) of 87 patients were women, 22 (25%) were men, and 62 (71%) were White. Overall, 82 (94%) of 87 patients in the long-term extension had an adverse event; most (66 [76%] of 87) were of mild to moderate severity, with no increase in pulmonary-related serious adverse events in patients with interstitial lung disease.

INTERPRETATION

No new safety signals were observed with long-term riociguat in patients with early diffuse cutaneous systemic sclerosis. Study limitations include the absence of a comparator group in this open-label extension study.

FUNDING

Bayer and Merck Sharp & Dohme.

Post-Pulmonary Embolism Syndrome and Functional Outcomes after Acute Pulmonary Embolism

Survivors of acute pulmonary embolism (PE) are at risk of developing persistent, sometimes disabling symptoms of dyspnea and/or functional limitations despite adequate anticoagulant treatment, fulfilling the criteria of the post-PE syndrome (PPES). PPES includes chronic thromboembolic pulmonary hypertension (CTEPH), chronic thromboembolic pulmonary disease, post-PE cardiac impairment (characterized as persistent right ventricle impairment after PE), and post-PE functional impairment. To improve the overall health outcomes of patients with acute PE, adequate measures to diagnose PPES and strategies to prevent and treat PPES are essential. Patient-reported outcome measures are very helpful to identify patients with persistent symptoms and functional impairment. The primary concern is to identify and adequately treat patients with CTEPH as early as possible. After CTEPH is ruled out, additional diagnostic tests including cardiopulmonary exercise tests, echocardiography, and imaging of the pulmonary vasculature may be helpful to rule out non-PE-related comorbidities and confirm the ultimate diagnosis. Most PPES patients will show signs of physical deconditioning as main explanation for their clinical presentation. Therefore, cardiopulmonary rehabilitation provides a good potential treatment option for this patient category, which warrants testing in adequately designed and executed randomized trials. In this review, we describe the definition and characteristics of PPES and its diagnosis and management.

Long-term safety of macitentan in patients with pulmonary hypertension: A meta-analysis of randomised controlled trials

BACKGROUND

Macitentan has demonstrated its effectiveness in patients with pulmonary hypertension (PH), but its safety, especially for long-term use, needs to be further explored. This systematic review and meta-analysis aimed to determine the safety of long-term use of macitentan in patients with PH.

METHODS

A systematic search was made of PubMed, Embase, Cochrane Library and clinicaltrials.gov, without language restrictions. Randomised controlled trials (RCTs) on treatment of PH with macitentan, compared with placebo, were reviewed. Estimated effects of included studies were pooled as risk ratios (RRs), with 95% confidence intervals (CIs).

RESULTS

Six RCTs (enrolling 1003 participants) met the inclusion criteria. Anaemia (RR 3.86, 95% CI 2.05-7.30), headache (RR 1.52, 95% CI 1.02-2.26) and bronchitis (RR 2.24, 95% CI 1.30-3.87) were more frequent in the macitentan groups. There was no statistically significant difference in the proportion of patients with at least one adverse event (AE) or serious adverse event (SAE), AEs leading to discontinuation of study treatment, all-cause death, right ventricular failure (RVF) and peripheral oedema between the two groups.

CONCLUSIONS

The long-term use of macitentan is safe for patients with PH, although with a higher risk of anaemia, headache and bronchitis.

Anticoagulation in chronic thromboembolic pulmonary hypertension: A systematic review and meta-analysis

INTRODUCTION

Life-long anticoagulation is the recommended management for chronic thromboembolic pulmonary hypertension (CTEPH). Evidence regarding the use of direct oral anticoagulants (DOAC) for CTEPH is yet to be established. We performed a systematic review and meta-analysis to clarify the outcomes of CTEPH in patients who used DOAC or vitamin K antagonists (VKA).

METHODS

We reviewed literature in PubMed and EMBASE through March 2023. We included studies involving patients with CTEPH where DOAC and VKA were compared. We collected data including intervention history for CTEPH, bleeding events, recurrence of VTE (venous thromboembolism), and mortality. We performed a meta-analysis using the Mantel-Haenszel method with a fixed-effects model.

RESULTS

We included one randomized clinical trial and six observational studies, with a total of 2969 patients. Six studies investigated major bleeding outcomes, and seven investigated all bleeding outcomes. There were no differences in major bleeding (RR 0.59, 95 % CI [0.34-1.02], I2 = 0 %) and all-bleeding (RR 0.87, 95 % CI [0.67-1.13], I2 = 0 %). Based on the five studies we included, DOAC was associated with a lower risk of mortality (RR 0.54, 95 % CI: 0.37-0.79, I2 = 5 %). However, a higher risk of recurrent pulmonary embolism (PE) was seen in three studies (RR 3.80, 95 % CI: [1.93-7.50], I2 = 11 %). No significant differences were noted in terms of VTE.

CONCLUSION

DOAC compared to VKA was associated with a significantly lower mortality and higher risk of recurrent PE. Since most of the included studies are observational, we must consider the existence of multiple biases and confounding factors.

[Chronic thromboembolic pulmonary hypertension]

Chronic thromboembolic pulmonary disease (CTEPD) is an important late complication of acute pulmonary embolism, in which the thrombi transform into fibrous tissue, become integrated into the vessel wall, and lead to chronic obstructions. CTEPD is differentiated into cases without pulmonary hypertension (PH), characterized by a mean pulmonary arterial pressure up to 20 mmHg and a form with PH. Then, it is still referred to as chronic thromboembolic pulmonary hypertension (CTEPH).When there is suspicion of CTEPH, initial diagnostic tests should include echocardiography and ventilation/perfusion scan to detect perfusion defects. Subsequently, referral to a CTEPH center is recommended, where further imaging diagnostics and right heart catheterization are performed to determine the appropriate treatment.Currently, three treatment modalities are available. The treatment of choice is pulmonary endarterectomy (PEA). For non-operable patients or patients with residual PH after PEA, PH-targeted medical therapy, and the interventional procedure of balloon pulmonary angioplasty (BPA) are available. Increasingly, PEA, BPA, and pharmacological therapy are combined in multimodal concepts.Patients require post-treatment follow-up, preferably at (CTE)PH centers. These centers are required to perform a minimum number of PEA surgeries (50/year) and BPA interventions (100/year).

Observational cohort study to validate SEARCH, a novel hierarchical algorithm to define long-term outcomes after pulmonary embolism

BACKGROUND

Chronic dyspnoea and exercise impairment are common after acute pulmonary embolism (PE) but are not defined and quantified sufficiently to serve as outcomes in clinical trials. The planned project will clinically validate a novel method to determine discrete, clinically meaningful diagnoses after acute PE. The method uses an algorithm entitled SEARCH, for symptom screen, exercise testing, arterial perfusion, resting echocardiography, confirmatory imaging and haemodynamic measurements. SEARCH is a stepwise algorithm that sorts patients by a hierarchical series of dichotomous tests into discreet categories of long-term outcomes after PE: asymptomatic, post-PE deconditioning, symptoms from other causes, chronic thromboembolism with ventilatory inefficiency, chronic thromboembolism with small stroke volume augmentation, chronic thromboembolic disease and chronic thromboembolic pulmonary hypertension.

METHODS

The project will test the inter-rater reliability of the SEARCH algorithm by determining whether it will yield concordant post-PE diagnoses when six independent reviewers review the same diagnostic data on 150 patients evaluated at two time points after PE. The project will also determine whether the post-PE diagnoses are stable, according to the SEARCH algorithm, between the first evaluation and the subsequent one 6 months later.

IMPLICATIONS

Validation of the SEARCH algorithm would offer clinicians a straightforward method to diagnose post-PE conditions that are rarely distinguished clinically. Their categorisation and definition will allow post-PE conditions to be used as endpoints in clinical trials of acute PE treatment.

TRIAL REGISTRATION NUMBER

NCT05568927.

Pharmacological management of connective tissue disease-associated pulmonary arterial hypertension

INTRODUCTION

Pulmonary arterial hypertension (PAH) is a severe, progressive pulmonary vasculopathy (Group 1 Pulmonary Hypertension (PH)) that complicates the course of many connective tissue diseases (CTD). Detailed testing is required to differentiate PAH from other types of PH caused by CTD such as left heart disease (Group 2 PH), pulmonary parenchymal disease (Group 3 PH), and chronic thromboembolic pulmonary hypertension (Group 4 PH). PAH is most frequently seen in systemic sclerosis but can also be seen with systemic lupus erythematosus, mixed CTD, and primary Sjogren's syndrome.

AREAS COVERED

This review discusses the epidemiology of CTD-associated PAH, outlines the complex diagnosis approach, and finishes with an in-depth discussion on the current treatment paradigm. Focus is placed on challenges faced in the treatment of CTD-associated PAH, (decreased efficacy and poorer tolerance of pharmacological therapies) and includes a discussion on the future investigational treatments.

EXPERT OPINION

Despite significant advances over the past decades with more aggressive treatment algorithms, CTD-associated PAH patients continue to have poorer survival compared to those with idiopathic PAH. This review highlights factors leading to disparate outcomes compared to other forms of PAH, and discusses on further improvements that may increase quality of life and survival for CTD-associated PAH patients.

Pulmonary hypertension - the latest updates for physicians

Pulmonary hypertension (PH) is common, with an estimated prevalence of approximately 1% that increases with age. Prompt and accurate diagnosis is key to institute timely and appropriate therapy to improve symptoms and prognosis. The international guidelines for the diagnosis and management of PH have recently been updated, with a lowering of the haemodynamic threshold for diagnosis to a mean pulmonary artery pressure >20 mmHg. New diagnostic algorithms and revised indications for screening in at-risk groups have been developed to facilitate early referral to specialist PH centres. This includes fast-track referral pathways for patients who are either clinically high-risk or are at-risk for pulmonary arterial hypertension (PAH) or chronic thromboembolic pulmonary hypertension (CTEPH). This review summarises key changes in the PH guidelines for general physicians who are, most often, the first healthcare professionals to encounter these patients and consequently have a key role as referrers into specialist PH services.

Chronic thromboembolic pulmonary hypertension: realising the potential of multimodal management

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare complication of acute pulmonary embolism. Important advances have enabled better understanding, characterisation, and treatment of this condition. Guidelines recommending systematic follow-up after acute pulmonary embolism, and the insight that CTEPH can mimic acute pulmonary embolism on initial presentation, have led to the definition of CTEPH imaging characteristics, the introduction of artificial intelligence diagnosis pathways, and thus the prospect of easier and earlier CTEPH diagnosis. In this Series paper, we show how the understanding of CTEPH as a sequela of inflammatory thrombosis has driven successful multidisciplinary management that integrates surgical, interventional, and medical treatments. We provide imaging examples of classical major vessel targets, describe microvascular targets, define available tools, and depict an algorithm facilitating the initial treatment strategy in people with newly diagnosed CTEPH based on a multidisciplinary team discussion at a CTEPH centre. Further work is needed to optimise the use and combination of multimodal therapeutic options in CTEPH to improve long-term outcomes for patients.

Health Care Disparities in Pulmonary Arterial Hypertension

The current approach for the management of pulmonary arterial hypertension (PAH) relies on data gathered from clinical trials and large registries. However, there is concern that minorities including Black, Indigenous, and People of Color are underrepresented in these trials and registries, making current data not generalizable to these groups of patients. Hence, it is important to discuss the significance of race/ethnicity and socioeconomic factors in patients with PAH. Here, we review the current knowledge on health care disparities in PAH. We also propose future steps in the global task of assuring justice and equality in access to pulmonary hypertension health care.

One-Step Synthesis of Functionalized Pyrazolo[3,4-b]pyridines via Ring Opening of the Pyrrolinium Ion

Herein, we report a highly regioselective one-pot synthesis of pyrazolo[3,4-b]pyridines via the reaction of 3-arylidene-1-pyrrolines with aminopyrazoles. The reaction proceeds through the sequential nucleophilic addition/electrophilic substitution/C-N bond cleavage and provides easy access to pyrazolo[3,4-b]pyridine derivatives featuring a primary amino group. Moreover, the reaction can be terminated at the electrophilic substitution stage, thus providing convenient entry to the hardly accessible pyrazolopyrrolopyridine scaffold.

Chronic thromboembolic pulmonary hypertension-medical, interventional, and surgical therapy

Chronic thromboembolic pulmonary hypertension (CTEPH) is an important late sequela of pulmonary embolism and a common form of pulmonary hypertension. Currently, three specific treatment modalities are available: pulmonary endarterectomy, balloon pulmonary angioplasty, and targeted medical therapy. The treatment decision depends mainly on the exact localization of the underlying pulmonary arterial obstructions. Pulmonary endarterectomy is the gold standard treatment of CTEPH. For inoperable patients, riociguat and treprostinil are approved. In addition, interventional therapy is recommended if appropriate target lesions are proven. Evaluation and treatment of patients with CTEPH in experienced centers are mandatory.

Single-Center Experience of Pulmonary Endarterectomy for Chronic Thromboembolic Pulmonary Hypertension: The Results from the Tabriz University Medical Sciences (TUMS) CTEPH Program

INTRODUCTION

Pulmonary endarterectomy (PEA) remains the preferred and potentially curative option for patients with chronic thromboembolic pulmonary hypertension (CTEPH). This study aimed to report the results of PEA for CTEPH in a tertiary center in Tabriz, Iran.

METHODS

We analyzed the results of 42 CTEPH patients undergoing PEA, who were enrolled in the Tabriz University of Medical Sciences (TUMS-CTEPH) from January 2016 to October 2020. The main outcome measures included the New York Heart Association (NYHA) functional classification, the 6-Minute Walk Distance, hemodynamic measures in right heart catheterization, morbidity, and mortality.

RESULTS

There was a significant improvement in the NYHA function class (2.6 ± 0.5 vs 1.1 ± 0.34), mean pulmonary arterial pressure (47.1 ± 13 vs 27.9 ± 8 mm Hg), cardiac output (4.3 ± 1.06 vs 5.9 ± 1.2 L/min), and pulmonary vascular resistance (709.4 ± 297.5 vs 214 ± 77 dyn s/cm5). Fifteen patients (35%) developed complications. The most common complication (10 [23%]) was reperfusion injury. Also, postsurgical mortality was 4% during hospital admission and 1-year follow-up.

CONCLUSION

This is the first single-center report of PEA from Iran. Post-PEA and 1-year survival were acceptable as a referral center. PEA can be performed safe with low mortality. Greater awareness of PEA and patients' access to experienced CTEPH centers are important issues.

Chronic thromboembolic pulmonary hypertension and the post-pulmonary embolism (PE) syndrome

Over a third of patients surviving acute pulmonary embolism (PE) will experience long-term cardiopulmonary limitations. Persistent thrombi, impaired gas exchange, and altered hemodynamics account for aspects of the postpulmonary embolism syndrome that spans mild functional limitations to debilitating chronic thromboembolic pulmonary hypertension (CTEPH), the most worrisome long-term consequence. Though pulmonary endarterectomy is potentially curative for the latter, less is understood surrounding chronic thromboembolic disease (CTED) and post-PE dyspnea. Advances in pulmonary vasodilator therapies and growing expertise in balloon pulmonary angioplasty provide options for a large group of patients ineligible for surgery, or those with persistent postoperative pulmonary hypertension. In this clinical review, we discuss epidemiology and pathophysiology as well as advances in diagnostics and therapeutics surrounding the spectrum of disease that may follow months after acute PE.

Distal vessel pulmonary thromboendarterectomy: Results from a single institution

BACKGROUND

Chronic thromboembolic pulmonary hypertension (CTEPH) is primarily managed by pulmonary thromboendarterectomy (PTE). As advanced surgical techniques permit resection at the segmental and subsegmental level, PTE can now be curative for CTEPH mostly involving the distal pulmonary arteries.

METHODS

Between January 2017 and June 2021, consecutive patients undergoing PTE were categorized according to the most proximal level of chronic thrombus resection: Level I (main pulmonary artery), Level II (lobar), Level III (segmental) and Level IV (subsegmental). Proximal disease patients (any Level I or II) were compared to distal disease (Level III or IV bilaterally) patients. Demographics, medical history, preoperative pulmonary hemodynamics, and immediate postoperative outcomes were obtained for each group.

RESULTS

During the study period, 794 patients underwent PTE, 563 with proximal disease and 231 with distal disease. Patients with distal disease more frequently had a history of an indwelling intravenous device, splenectomy, upper extremity thrombosis or use thyroid replacement and less often had prior lower extremity thrombosis or hypercoagulable state. Despite more use of PAH-targeted medications in the distal disease group (63.2% vs 50.1%, p < 0.001), preoperative hemodynamics were similar. Both patient groups exhibited significant improvements in pulmonary hemodynamics postoperatively with comparable in-hospital mortality rates. Compared to proximal disease, a lower percentage of patients with distal disease showed residual pulmonary hypertension (3.1% vs 6.9%, p = 0.039) and airway hemorrhage (3.0% vs 6.6%, p = 0.047) postoperatively.

CONCLUSIONS

Thromboendarterectomy for distal (segmental and subsegmental) CTEPH is technically feasible and may result in favorable pulmonary hemodynamic outcomes, without increased mortality or morbidity.

Evaluation and Management of Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a treatable form of pulmonary hypertension and right heart failure. CTEPH (group 4 pulmonary hypertension) is caused by persistent organized thromboembolic obstruction of the pulmonary arteries from incompletely resolved acute pulmonary embolism. CTEPH also may present without prior VTE history, which can contribute to its underrecognition. The true incidence of CTEPH is unclear, but is estimated to be approximately 3% after acute pulmonary embolism. V˙/Q˙ scintigraphy is the best screening test for CTEPH, with CT scan imaging and other advanced imaging methods now playing a larger role in disease detection and confirmation. Perfusion defects on V˙/Q˙ scintigraphy in the setting of pulmonary hypertension are suggestive of CTEPH, but pulmonary angiography and right heart catheterization are required for confirmation and treatment planning. CTEPH potentially is curative with pulmonary thromboendarterectomy surgery, with mortality rates of approximately 2% at expert centers. Advances in operative techniques are allowing more distal endarterectomies to be performed successfully with favorable outcomes. However, more than one-third of patients may be considered inoperable. Although these patients previously had minimal therapeutic options, effective treatments now are available with pharmacotherapy and balloon pulmonary angioplasty. Diagnosis of CTEPH should be considered in all patients with suspicion of pulmonary hypertension. Treatments for CTEPH have advanced with improvements in outcomes for both operable and inoperable patients. Therapy should be tailored based on multidisciplinary team evaluation to ensure optimal treatment response.

Intravenous Treprostinil in Severe Inoperable Chronic Thromboembolic Pulmonary Hypertension Using Implantable Pumps-Single-Center Experience over More Than a Decade

The management of chronic thromboembolic pulmonary hypertension has significantly changed over the last decade with the availability of both specific therapies and interventional treatments. In parallel, implantable pumps for intravenous administration of treprostinil have broadened the spectrum of continuous prostanoid infusion. We evaluated the course of 17 consecutive patients with inoperable chronic thromboembolic pulmonary hypertension treated with treprostinil by means of an implantable infusion pump between 2011 and 2023 at our center. Complications associated with the infusion system were rare, leading to 0.4 unplanned surgical interventions during 17,160 patient days. No additional safety signals were detected, and clinical benefits achieved with subcutaneous treprostinil before pump implantation could be maintained in all patients. No catheter-related infections or thromboembolic events were observed. Implantable infusion pumps offer an attractive alternative to subcutaneous treprostinil for patients intolerant to the subcutaneous route, including those with chronic thromboembolic pulmonary hypertension.

Targeting Soluble Guanylyl Cyclase during Ischemia and Reperfusion

Ischemia and reperfusion (IR) damage organs and contribute to many disease states. Few effective treatments exist that attenuate IR injury. The augmentation of nitric oxide (NO) signaling remains a promising therapeutic target for IR injury. NO binds to soluble guanylyl cyclase (sGC) to regulate vasodilation, maintain endothelial barrier integrity, and modulate inflammation through the production of cyclic-GMP in vascular smooth muscle. Pharmacologic sGC stimulators and activators have recently been developed. In preclinical studies, sGC stimulators, which augment the reduced form of sGC, and activators, which activate the oxidized non-NO binding form of sGC, increase vasodilation and decrease cardiac, cerebral, renal, pulmonary, and hepatic injury following IR. These effects may be a result of the improved regulation of perfusion and decreased oxidative injury during IR. sGC stimulators are now used clinically to treat some chronic conditions such as heart failure and pulmonary hypertension. Clinical trials of sGC activators have been terminated secondary to adverse side effects including hypotension. Additional clinical studies to investigate the effects of sGC stimulation and activation during acute conditions, such as IR, are warranted.

Pulmonary hypertension inhaled therapies: An updated review

Treatments of pulmonary hypertension (PH) continue to evolve with approval of new therapies. The currently FDA approved inhaled PH therapies include inhaled iloprost for group 1 pulmonary arterial hypertension (PAH), inhaled treprostinil solution and treprostinil dry powder inhaler for both group 1 PAH and group 3 PH associated with interstitial lung disease (PH-ILD). Inhaled treprostinil was recently approved for group 3 PH-ILD based on the results of INCREASE trial and the newer formulation of treprostinil dry powder that comes with a new inhaler was recently approved for both group 1 PAH and group 3 PH-ILD based on BREEZE study. The pipeline for inhaled PH therapies includes several promising molecules that can enrich the current PH therapeutic era and mitigate several systemic side effects by directly delivering the drug to the target organ. In this review article we summarize the evidence for the currently approved inhaled PAH/PH therapies, discuss the available inhalation devices, present a roadmap for successful treatment strategy, and present several inhaled PAH/PH therapies in the pipeline.

The Evolution of Pulmonary Artery Denervation for Treatment of Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a progressive, life-limiting disease. Despite significant medical progress over the last three decades, the prognosis of PAH remains poor. PAH is associated with sympathetic nervous system over-stimulation and baroreceptor-mediated vasoconstriction, leading to pathologic pulmonary artery (PA) and right ventricular remodeling. PA denervation is a minimally-invasive intervention that ablates local sympathetic nerve fibers and baroreceptors to modulate pathologic vasoconstriction. Preliminary animal and clinical studies have shown improvements in short-term pulmonary hemodynamics and PA remodeling. However, future studies are needed to elucidate appropriate patient selection, timing of intervention, and long-term efficacy before integration into standard of care.

Evolving Role and Clinical Evidence in the Global Practice of Balloon Pulmonary Angioplasty

Balloon pulmonary angioplasty (BPA) was first described in 2001 and now has evolved into a class I indication for inoperable or residual chronic thromboembolic pulmonary hypertension. This review article aims to describe evidence from studies performed at various pulmonary hypertension (PH) centers across the globe, to better understand the role of BPA in chronic thromboembolic pulmonary disease with and without PH. Additionally, we hope to highlight innovations and the ever-changing safety and efficacy profile of BPA.

Technical Considerations for Performing Safe and Effective Balloon Pulmonary Angioplasty in Patients with Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is a late complication of acute pulmonary thromboembolism owing to incomplete clot dissolution in pulmonary artery. Pulmonary endarterectomy is the first-line treatment for CTEPH. However, 40% of patients are not candidates for surgery because of distal lesions or age. Balloon pulmonary angioplasty (BPA), a catheter-based intervention, is increasingly being used worldwide for treating inoperable CTEPH. Previous BPA strategy had a major concern of reperfusion pulmonary edema as a complication. However, recent refined strategies promise safe and effective BPA. Five-year survival rate after BPA is 90% for inoperable CTEPH, comparable with that of operable CTEPH.

Drug repurposing-a promising approach for patients with angina but non-obstructive coronary artery disease (ANOCA)

In today's era of individualized precision medicine drug repurposing represents a promising approach to offer patients fast access to novel treatments. Apart from drug repurposing in cancer treatments, cardiovascular pharmacology is another attractive field for this approach. Patients with angina pectoris without obstructive coronary artery disease (ANOCA) report refractory angina despite standard medications in up to 40% of cases. Drug repurposing also appears to be an auspicious option for this indication. From a pathophysiological point of view ANOCA patients frequently suffer from vasomotor disorders such as coronary spasm and/or impaired microvascular vasodilatation. Consequently, we carefully screened the literature and identified two potential therapeutic targets: the blockade of the endothelin-1 (ET-1) receptor and the stimulation of soluble guanylate cyclase (sGC). Genetically increased endothelin expression results in elevated levels of ET-1, justifying ET-1 receptor blockers as drug candidates to treat coronary spasm. sGC stimulators may be beneficial as they stimulate the NO-sGC-cGMP pathway leading to GMP-mediated vasodilatation.

Myeloid-derived suppressor cells and pulmonary hypertension

Pulmonary hypertension (PH) is a chronic pulmonary vascular disorder characterized by an increase in pulmonary vascular resistance and pulmonary arterial pressure. The detailed molecular mechanisms remain unclear. In recent decades, increasing evidence shows that altered immune microenvironment, comprised of immune cells, mesenchymal cells, extra-cellular matrix and signaling molecules, might induce the development of PH. Myeloid-derived suppressor cells (MDSCs) have been proposed over 30 years, and the functional importance of MDSCs in the immune system is appreciated recently. MDSCs are a heterogeneous group of cells that expand during cancer, chronic inflammation and infection, which have a remarkable ability to suppress T-cell responses and may exacerbate the development of diseases. Thus, targeting MDSCs has become a novel strategy to overcome immune evasion, especially in tumor immunotherapy. Nowadays, severe PH is accepted as a cancer-like disease, and MDSCs are closely related to the development and prognosis of PH. Here, we review the relationship between MDSCs and PH with respect to immune cells, cytokines, chemokines and metabolism, hoping that the key therapeutic targets of MDSCs can be identified in the treatment of PH, especially in severe PH.

Medical Management of Pulmonary Arterial Hypertension: Current Approaches and Investigational Drugs

Pulmonary arterial hypertension (PAH) is a malignant pulmonary vascular syndrome characterized by a progressive increase in pulmonary vascular resistance and pulmonary arterial pressure, which eventually leads to right heart failure and even death. Although the exact mechanism of PAH is not fully understood, pulmonary vasoconstriction, vascular remodeling, immune and inflammatory responses, and thrombosis are thought to be involved in the development and progression of PAH. In the era of non-targeted agents, PAH had a very dismal prognosis with a median survival time of only 2.8 years. With the deep understanding of the pathophysiological mechanism of PAH as well as advances in drug research, PAH-specific therapeutic drugs have developed rapidly in the past 30 years, but they primarily focus on the three classical signaling pathways, namely the endothelin pathway, nitric oxide pathway, and prostacyclin pathway. These drugs dramatically improved pulmonary hemodynamics, cardiac function, exercise tolerance, quality of life, and prognosis in PAH patients, but could only reduce pulmonary arterial pressure and right ventricular afterload to a limited extent. Current targeted agents delay the progression of PAH but cannot fundamentally reverse pulmonary vascular remodeling. Through unremitting efforts, new therapeutic drugs such as sotatercept have emerged, injecting new vitality into this field. This review comprehensively summarizes the general treatments for PAH, including inotropes and vasopressors, diuretics, anticoagulants, general vasodilators, and anemia management. Additionally, this review elaborates the pharmacological properties and recent research progress of twelve specific drugs targeting three classical signaling pathways, as well as dual-, sequential triple-, and initial triple-therapy strategies based on the aforementioned targeted agents. More crucially, the search for novel therapeutic targets for PAH has never stopped, with great progress in recent years, and this review outlines the potential PAH therapeutic agents currently in the exploratory stage to provide new directions for the treatment of PAH and improve the long-term prognosis of PAH patients.

Should We Change the Target of Therapy in Pulmonary Hypertension?

Despite the evolution of drug therapy in pulmonary arterial hypertension and the more aggressive treatment approach according to the guidelines, patients continue to have unacceptable mortality rates. Furthermore, specific drug therapy alone in chronic thromboembolic pulmonary hypertension also does not seem to have any beneficial impact on survival. As the function of the right ventricle (RV) determines the prognosis of patients with pulmonary hypertension, the treatment strategy should focus on modifying factors involved in RV dysfunction. Although some previous reports demonstrated that the survival of patients with pulmonary hypertension was associated with mPAP, nevertheless, mPAP is still not considered as a target of therapy. There are many examples of effective mPAP lowering with early and aggressive drug therapy in pulmonary arterial hypertension, or with interventions in chronic thromboembolic pulmonary hypertension. This effective mPAP reduction can lead to reverse RV remodeling, and thus, improvement in survival. In this article, the importance of mPAP lowering is stated, as well as why the change of our current strategy and considering mPAP reduction as the target of therapy could make pulmonary hypertension a chronic but not fatal disease.

The soluble guanylyl cyclase pathway is inhibited to evade androgen deprivation-induced senescence and enable progression to castration resistance

Castration-resistant prostate cancer (CRPC) is fatal and therapeutically under-served. We describe a novel CRPC-restraining role for the vasodilatory soluble guanylyl cyclase (sGC) pathway. We discovered that sGC subunits are dysregulated during CRPC progression and its catalytic product, cyclic GMP (cGMP), is lowered in CRPC patients. Abrogating sGC heterodimer formation in castration-sensitive prostate cancer (CSPC) cells inhibited androgen deprivation (AD)-induced senescence, and promoted castration-resistant tumor growth. We found sGC is oxidatively inactivated in CRPC. Paradoxically, AD restored sGC activity in CRPC cells through redox-protective responses evoked to protect against AD-induced oxidative stress. sGC stimulation via its FDA-approved agonist, riociguat, inhibited castration-resistant growth, and the anti-tumor response correlated with elevated cGMP, indicating on-target sGC activity. Consistent with known sGC function, riociguat improved tumor oxygenation, decreasing the PC stem cell marker, CD44, and enhancing radiation-induced tumor suppression. Our studies thus provide the first evidence for therapeutically targeting sGC via riociguat to treat CRPC.

Statement of significance

Prostate cancer is the second highest cancer-related cause of death for American men. Once patients progress to castration-resistant prostate cancer, the incurable and fatal stage, there are few viable treatment options available. Here we identify and characterize a new and clinically actionable target, the soluble guanylyl cyclase complex, in castration-resistant prostate cancer. Notably we find that repurposing the FDA-approved and safely tolerated sGC agonist, riociguat, decreases castration-resistant tumor growth and re-sensitizes these tumors to radiation therapy. Thus our study provides both new biology regarding the origins of castration resistance as well as a new and viable treatment option.

Advances in targeted therapy for pulmonary arterial hypertension in children

Pulmonary arterial hypertension (PAH) is a rare and devastating disease of the pulmonary vasculature with a high morbidity and mortality rate in infants and children. Currently, treatment approaches are mostly based on adult guidelines and pediatrician clinical experience, focusing on specific pulmonary antihypertensive therapy and conventional supportive care. The advent of targeted drugs has led to significant advances in the treatment of PAH in children, including endothelin receptor antagonists, phosphodiesterase type 5 inhibitors, and prostacyclins, which have been studied and proven to improve hemodynamics and functional class in children PAH. A new targeted drug, riociguat, is assessing its safety and efficacy in clinical trials. However, more randomized controlled studies are needed to evaluate the combination of drugs, treatment strategies, and clinical endpoints of targeted therapy in children PAH. In this review, we summarize the research advances of PAH-targeted therapy in children over the last decade in order to provide a theoretical basis for future studies.

CONCLUSION

Pulmonary arterial hypertension (PAH) is a rare and devastating pulmonary vascular disease that is associated with a variety of diseases of any age in childhood onset.

WHAT IS KNOWN

• Therapeutic strategies for targeted drugs for PAH in children are based almost exclusively on data from adult studies and clinical experience of pediatric specialists. • Due to the complex etiology of PAH in children and the relative lack of clinical trial data, the selection of appropriate targeted drug therapy remains difficult.

WHAT IS NEW

• We redefine the definition of pulmonary arterial hypertension in children and summarize the progress of targeted therapy of pulmonary arterial hypertension in children in the past ten years. • The dosage and adverse reactions were summarized, and the mechanism of action was drawn according to the available targeted drugs. It can provide theoretical support for the development of guidelines and treatment strategies for the diagnosis and treatment of pulmonary arterial hypertension in children.

Novel Drugs for the Treatment of Pulmonary Arterial Hypertension: Where Are We Going?

Pulmonary arterial hypertension (PAH) is a progressive disease that despite advances in therapy is associated with a 7-year survival of approximately 50%. Several risk factors are associated with developing PAH, include methamphetamine use, scleroderma, human immunodeficiency virus, portal hypertension, and genetic predisposition. PAH can also be idiopathic. There are traditional pathways underlying the pathophysiology of PAH involving nitric oxide, prostacyclin, thromboxane A2, and endothelin-1, resulting in impaired vasodilation, enhanced vasoconstriction and proliferation in the pulmonary vasculature. Established PAH medications targets these pathways; however, this paper aims to discuss novel drugs for treating PAH by targeting new and alternative pathways.

Quality of life and functional status after pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension: A Swedish single-center study

Little is known about long-term quality of life (QOL) and functional status after pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension (CTEPH). We investigated QOL and functional status late after PEA. All patients who underwent PEA for CTEPH 1993-2020 at one Swedish center were included. Baseline characteristics and data from right heart catheterization, 6-min walk test, and Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR) were obtained from patient charts and national registers. The RAND 36-Item Health Survey was sent by post, and Karnofsky Performance Status (KPS) was evaluated by telephone. A total of 110 patients were included. The survey was completed by 49/66 (74%) patients who were alive in 2020. In all domains except for bodily pain, QOL was slightly lower than that of an age-matched reference population. The KPS score was obtained from 42/49 (86%) patients; of these, 31 patients (74%) had a KPS score of ≥80% (able to carry on normal activity). All 42 patients were able to live at home and care for personal needs. The median postoperative CAMPHOR scores were: 4 for symptoms, 4 for activity, and 2.5 for QOL. We observed that QOL after PEA approached the expected QOL in a reference population and that CAMPHOR scores were comparable to those of a large UK cohort after PEA. Functional status improved when assessed late after PEA. Three-quarters of the study population were able to conduct normal activities at late follow-up. Our findings suggest that many patients enjoy satisfactory QOL and high functional status late after PEA.

Impact of residual pulmonary hypertension on long-term outcomes after pulmonary endarterectomy in the modern era

Residual pulmonary hypertension (PH) negatively impacts long-term results following pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension (CTEPH). We sought to reveal whether modern PH therapy with PH-targeted medicine and balloon pulmonary angioplasty (BPA) improved long-term results of residual PH after PEA. Long-term findings of 80 patients who survived PEA between 2011 and 2019 were retrospectively investigated. One month after PEA, 30 patients developed residual PH defined as mean pulmonary artery pressure (mPAP) ≥25 mmHg, of whom 23 were treated by PH-targeted medicine and 9 by BPA. Patients with residual PH acquired considerably better functional status and exercise capacity after PEA, however, exhibited significantly worse survival rates than those without. Eleven patients died during follow-up: 8 patients with residual PH and 3 controls. Among patients with residual PH, the deceased had a significantly lower %decrease in mPAP from 1 month to 1 year following PEA (7.4 [-32.6 to 8.0] % vs. 10.4 [3.7-27.8] %, p = 0.03) and higher mPAP at 1 year following PEA (39.5 [33.25-42.5] vs. 27 [26-34] mmHg, p < 0.01) despite PH-targeted medicine than the survived. No patients passed away from right heart failure, and there was no difference between the groups in CTEPH-related mortality. Modern PH therapy was used to address the majority of residual PH. Long-term survival after PEA was negatively impacted by residual PH, but it appeared that long-term mortality was also correlated with unrelieved residual PH despite PH-targeted medicine. Modern PH therapy may have enhanced functional status and excercise capacity, and averted fatal right heart failure.

Vericiguat for the treatment of heart failure with reduced ejection fraction

INTRODUCTION

Despite significant therapeutic advancements in heart failure with reduced ejection fraction (HFrEF), the residual risk of all-cause mortality and hospitalizations remains high among patients with HFrEF. Vericiguat is a novel oral soluble guanylate cyclase (sGC) stimulator which was approved by the US Food and Drug administration (FDA) in January 2021 for use in patients with symptomatic chronic HF and an ejection fraction less than 45% following a hospitalization for HF or the need for outpatient intravenous diuretics.

AREAS COVERED

We provide a concise review of the pharmacology, clinical efficacy, and tolerability of vericiguat in HFrEF. We also discuss the role of vericiguat in current clinical practice.

EXPERT OPINION

Vericiguat reduces the risk of cardiovascular mortality or HF hospitalizations by an absolute event-rate reduction of 4.2 events per 100 patient-years with a number needed to treat of 24 patients, on a background of guideline-directed medical therapy. Almost 90% of the patients with HFrEF were adherent to the 10 mg dose of vericiguat in the VICTORIA trial with a favorable tolerability and safety profile. Considering the high residual risk that persists in HFrEF, vericiguat has a role to improve outcomes among patients with worsening HFrEF.

Pharmacology and Emerging Therapies for Group 3 Pulmonary Hypertension Due to Chronic Lung Disease

Pulmonary hypertension (PH) frequently complicates chronic lung disease and is associated with high morbidity and poor outcomes. Individuals with interstitial lung disease and chronic obstructive pulmonary disease develop PH due to structural changes associated with the destruction of lung parenchyma and vasculature with concurrent vasoconstriction and pulmonary vascular remodeling similar to what is observed in idiopathic pulmonary arterial hypertension (PAH). Treatment for PH due to chronic lung disease is largely supportive and therapies specific to PAH have had minimal success in this population with exception of the recently FDA-approved inhaled prostacyclin analogue treprostinil. Given the significant disease burden of PH due to chronic lung diseases and its associated mortality, a great need exists for improved understanding of molecular mechanisms leading to vascular remodeling in this population. This review will discuss the current understanding of pathophysiology and emerging therapeutic targets and potential pharmaceuticals.