Pulmonary Artery Denervation for Patients With Residual Pulmonary Hypertension After Pulmonary Endarterectomy

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

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

Pulmonary artery denervation versus conventional therapies for PAH: a systematic review and updated network meta-analysis

AIMS

A recent guideline presented by the ESC Congress in 2022 had indicated a novel therapy targeted at pulmonary artery hypertension, known as pulmonary artery denervation (PADN), which get inspired from a laboratorial trial that could lowering the pulmonary artery pressure through the intervention on the animals. Our aim is to conduct a network meta-analysis to compare the efficacy and safety of PADN from six aspects with the current conventional therapies.

METHODS AND RESULTS

According to the PRISMA guidance, databases including Ovid, ClinicalTrials.gov, Medline, Embase, and PubMed were searched from inception to 22 August 2023, along with a full assessment of the previous five meta-analyses. Data were extracted and curated for Bayesian network meta-analysis. The primary outcome was the change in the 6-min walking distance (6MWD) from baseline with a secondary outcome called change in mean pulmonary artery pressure (mPAP) from baseline. The four safety outcomes included risk of clinical worsening, hospitalization, mortality and severe adverse events (SAEs). The comparison is structured on a contrast model based on 65 randomized controlled trials (RCTs) on PADN and the other conventional mainstream drugs. PADN had a better effect in improving 6MWD than Placebo (-77.76 m, 95% CI: -102.04 to -54.34 m), Macitentan (-65.32 m, 95% CI: -95.34 to -36.1 m), Bosentan (-64.5 m, 95% CI: -94.7 to -35.07 m), Iloprost (-62.66 m, 95% CI: -99.48 to -27.13 m), Oxygen (-62.42 m, 95% CI: -100.01 to -25.78 m), Treprostinil (-62.01 m, 95% CI: -89.04 to -35.61 m), Riociguat (-60.59 m, 95% CI: -86.11 to -35.98 m), Selexipag (-47.2 m, 95% CI: -85.61 to -10.19 m), Sildenafil (-44.92 m, 95% CI: -74.43 to -16.15 m), or Sitaxsentan (-39.53 m, 95% CI: -78.99 to -0.76 m). PADN had a better antihypertensive effect than placebo and showed statistical significant lower risks to induce clinical worsening and re-hospitalization than treprostinil, riociguat, and placebo groups. No statistically significant difference in risk of mortality and severe adverse events was observed between PADN versus the other interventions.

CONCLUSIONS

Compared with 16 types of conventional therapies and Placebo, PADN has advantage over nine single therapies and Placebo in improving 6MWD and appears to be better than two types of dual-drug combined therapies while with no statistical significance. PADN shows a favourable antihypertensive effect on mPAP and has a lower risk to trigger clinical worsening or hospitalization, while its risk on mortality and severe adverse events is still inconclusive.

Carotid Baroreceptor Stimulation Improves Pulmonary Arterial Remodeling and Right Ventricular Dysfunction in Pulmonary Arterial Hypertension

Autonomic nervous system imbalance is intricately associated with the severity and prognosis of pulmonary arterial hypertension (PAH). Carotid baroreceptor stimulation (CBS) is a nonpharmaceutical intervention for autonomic neuromodulation. The effects of CBS on monocrotaline-induced PAH were investigated in this study, and its underlying mechanisms were elucidated. The results indicated that CBS improved pulmonary hemodynamic status and alleviated right ventricular dysfunction, improving pulmonary arterial remodeling and right ventricular remodeling, thus enhancing the survival rate of monocrotaline-induced PAH rats. The beneficial effects of CBS treatment on PAH might be mediated through the inhibition of sympathetic overactivation and inflammatory immune signaling pathways.

Performance-based outcome measures for assessing physical capacity in patients with pulmonary embolism: A scoping review

INTRODUCTION

Up to 50 % of patients surviving a pulmonary embolism (PE) report persisting shortness of breath, reduced physical capacity and psychological distress. As the PE population is heterogeneous compared to other cardiovascular patient groups, outcome measures for assessing physical capacity traditionally used in cardiac populations may not be reliable for the PE population as a whole. This scoping review aims to 1) map performance-based outcome measures (PBOMs) used for assessing physical capacity in PE research, and 2) to report the psychometric properties of the identified PBOMs in a PE population.

METHODS

The review was conducted according to the Joanna Briggs Institute framework for scoping reviews and reported according to the PRISMA-Extension for Scoping Reviews guideline.

RESULTS

The systematic search of five databases identified 4585 studies, of which 243 studies met the inclusion criteria. Of these, 185 studies focused on a subgroup of patients with chronic thromboembolic pulmonary hypertension. Ten different PBOMs were identified in the included studies. The 6-minute walk test (6MWT) and cardiopulmonary exercise test (CPET) were the most commonly used, followed by the (Modified) Bruce protocol and Incremental Shuttle Walk test. No studies reported psychometric properties of any of the identified PBOMs in a PE population.

CONCLUSIONS

Publication of studies measuring physical capacity within PE populations has increased significantly over the past 5-10 years. Still, not one study was identified, reporting the validity, reliability, or responsiveness for any of the identified PBOMs in a PE population. This should be a priority for future research in the field.

[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).

Pulmonary hypertension associated with lung disease: new insights into pathomechanisms, diagnosis, and management

Patients with chronic lung diseases, particularly interstitial lung disease and chronic obstructive pulmonary disease, frequently develop pulmonary hypertension, which results in clinical deterioration, worsening of oxygen uptake, and an increased mortality risk. Pulmonary hypertension can develop and progress independently from the underlying lung disease. The pulmonary vasculopathy is distinct from that of other forms of pulmonary hypertension, with vascular ablation due to loss of small pulmonary vessels being a key feature. Long-term tobacco exposure might contribute to this type of pulmonary vascular remodelling. The distinct pathomechanisms together with the underlying lung disease might explain why treatment options for this condition remain scarce. Most drugs approved for pulmonary arterial hypertension have shown no or sometimes harmful effects in pulmonary hypertension associated with lung disease. An exception is inhaled treprostinil, which improves exercise capacity in patients with interstitial lung disease and pulmonary hypertension. There is a pressing need for safe, effective treatment options and for reliable, non-invasive diagnostic tools to detect and characterise pulmonary hypertension in patients with chronic lung disease.

Pulmonary Artery Denervation as a New Therapeutic Option for Pulmonary Hypertension: A Systematic Review and Meta-Analysis

Pulmonary hypertension (PH) is a progressive disease with a high morbidity and mortality. The treatment is based on the type of PH. Prognosis still remains poor despite the use of different medications. Pulmonary artery denervation (PADN) has been studied as a novel therapeutic option in these patients. PUBMED, EMBASE and COCHRANE databases were searched by 2 investigators until January 2023. Information was analyzed for the following outcomes: 6-minute walk distance (6MWD), mean pulmonary artery pressure, pulmonary vascular resistance and cardiac output. Subgroup analysis comparing pre and post PADN in different PH groups was done. Statistical analysis was performed with the Review Manager version 5.4. This meta- analysis included 6 controlled trials and 6 single-arm prospective studies with a total of 616 patients. Our pooled analysis showed a significant reduction in mean pulmonary artery pressure [WMD -6.51, 95% CI (-9.87, -3.15), p = 0.0001], pulmonary vascular resistance [WMD -3.69, 95% CI (-6.74, -0.64), p = 0.02] and increased cardiac output [WMD -0.37, 95% CI (0.08, 0.65), p = 0.01]. Subgroup analysis pre and post PADN demonstrated a significant improvement in 6MWD in the WHO group 1 [WMD 99.53, 95% CI (19.60, 179.47), p = 0.01], group 2 [WMD: 69.96, 95% CI (36.40, 103.51), p = < 0.0001] and group 4 [WMD: 99.54, 95% CI (21.80, 177.28), p = 0.01]. This meta-analysis supports PADN as a therapeutic option for patients with PH, regardless of group class. Further randomized trials are still needed to evaluate safety and efficacy.

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.

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.

New trends in pulmonary hypertension

Pulmonary hypertension (PH) is a prevalent disease of the pulmonary vasculature that is characterised by considerable morbidity and mortality. Substantial efforts have been made in recent years to improve disease recognition, diagnosis and management, and this is reflected in current guidelines. The haemodynamic definition of PH has been revised and a definition for exercise PH has been provided. Risk stratification has been refined and the importance of comorbidities and phenotyping have been highlighted. These changes provide an opportunity to potentially identify pulmonary vascular disease at an earlier stage and to enhance patient-centred, goal-orientated treatment decisions. A promising fourth treatment pathway for pulmonary arterial hypertension and potential targeted therapies for group 3 PH are on the horizon, concepts which seemed inconceivable only a few years ago. Beyond medication, there is a greater appreciation for the importance of supervised training in stable PH and the possible role of interventional therapies in select cases. The landscape of PH is changing and it is characterised by progress, innovation and opportunities. In this article, we highlight some of the new trends in PH, with a specific focus on the revised European Society of Cardiology/European Respiratory Society 2022 guidelines for the diagnosis and management of PH.

Surgical and Device Interventions in the Treatment of Chronic Thromboembolic Disease

Chronic thromboembolic pulmonary disease (CTEPD) is characterized by unresolved clot burden in large pulmonary arteries, obstructive disease in smaller arteries, and increased downstream clot burden. This occurs in the setting of abnormal fibrinolysis or hematological disorders. Up to 50% of patients in some studies are unaware of a self-history of a deep venous thrombosis or pulmonary embolism. Ultimately, they present with symptoms of pulmonary hypertension (PH), which can result in right heart failure (RHF). Pulmonary endarterectomy (PEA) is curative, though many patients have prohibitive surgical risk or surgically inaccessible disease, warranting other interventions such as balloon pulmonary angioplasty (BPA) and medical therapy. Rarely, other treatment options may be implemented. We focus this review on PEA and BPA, with an overview of the history of CTEPD and the evolution of these procedures. We will briefly discuss other treatment modalities.

Sympathetic Denervation and Pharmacological Stimulation of Parasympathetic Nervous System Prevent Pulmonary Vascular Bed Remodeling in Rat Model of Chronic Thromboembolic Pulmonary Hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) develops in 1.5-2.0% of patients experiencing pulmonary embolism (PE) and is characterized by stable pulmonary artery obstruction, heart failure, and poor prognosis. Little is known about involvement of autonomic nervous system (ANS) in the mechanisms of CTEPH. This study was aimed at evaluation of the effect of vagal and sympathetic denervation, as well as stimulation of the parasympathetic nervous system, on the outcomes of CTEPH in rats. CTEPH was induced by multiple intravenous injections of alginate microspheres. Sympathetic and vagal denervation was performed using unilateral surgical ablation of the stellate ganglion and vagotomy, respectively. Stimulation of the parasympathetic nervous system was carried out by administering pyridostigmine. The effect of neuromodulatory effects was assessed in terms of hemodynamics, histology, and gene expression. The results demonstrated the key role of ANS in the development of CTEPH. Sympathetic denervation as well as parasympathetic stimulation resulted in attenuated pulmonary vascular remodeling. These salutary changes were associated with altered MMP2 and TIMP1 expression in the lung and decreased FGFb level in the blood. Unilateral vagotomy had no effect on physiological and morphological outcomes of the study. The data obtained contribute to the identification of new therapeutic targets for CTEPH treatment.

Pulmonary Artery Denervation for Pulmonary Arterial Hypertension: A Sham-Controlled Randomized PADN-CFDA Trial

BACKGROUND

World Health Organization (WHO) group 1 pulmonary arterial hypertension (PAH) is a progressive, debilitating disease. Previous observational studies have demonstrated that pulmonary artery denervation (PADN) reduces pulmonary artery pressures in PAH. However, the safety and effectiveness of PADN have not been established in a randomized trial.

OBJECTIVES

The aim of this study was to determine the treatment effects of PADN in patients with group 1 PAH.

METHODS

Patients with WHO group 1 PAH not taking PAH-specific drugs for at least 30 days were enrolled in a multicenter, sham-controlled, single-blind, randomized trial. Patients were assigned to receive PADN plus a phosphodiesterase-5 inhibitor or a sham procedure plus a phosphodiesterase-5 inhibitor. The primary endpoint was the between-group difference in the change in 6-minute walk distance from baseline to 6 months.

RESULTS

Among 128 randomized patients, those treated with PADN compared with sham had a greater improvement in 6-minute walk distance from baseline to 6 months (mean adjusted between-group difference 33.8 m; 95% CI: 16.7-50.9 m; P < 0.001). From baseline to 6 months, pulmonary vascular resistance was reduced by -3.0 ± 0.3 WU after PADN and -1.9 ± 0.3 WU after sham (adjusted difference -1.4; 95% CI: -2.6 to -0.2). PADN also improved right ventricular function, reduced tricuspid regurgitation, and decreased N-terminal pro-brain natriuretic peptide. Clinical worsening was less (1.6% vs 13.8%; OR: 0.11; 95% CI: 0.01-0.87), and a satisfactory clinical response was greater (57.1% vs 32.3%; OR: 2.79; 95% CI: 1.37-5.82) with PADN treatment during 6-month follow-up.

CONCLUSIONS

In patients with WHO group 1 PAH, PADN improved exercise capacity, hemodynamic status, and clinical outcomes during 6-month follow-up. (Safety and Efficacy of Pulmonary Artery Denervation in Patients With Pulmonary Arterial Hypertension [PADN-CFDA]; NCT03282266).

Pulmonary Endarterectomy for Chronic Thromboembolic Pulmonary Hypertension: A Systematic Review of the Most Updated Literature

Pulmonary endarterectomy (PEA) is the treatment of choice in case of chronic thromboembolic pulmonary hypertension (CTEPH). PEA is performed by an increasing number of surgeons; however, the reported outcomes are limited to a few registries or to individual centers' experiences. This systematic review focuses on pre-operative evaluation, intra-operative procedure and post-operative results in patients submitted to PEA for CTEPH. The literature included was searched using a formal strategy, combining the terms "pulmonary endarterectomy" AND "chronic pulmonary hypertension" and focusing on studies published in the last 5 years (2017-2022) to give a comprehensive overview on the most updated literature. The selection of the adequate surgical candidate is a crucial point, and the decision should always be performed by expert multidisciplinary teams composed of surgeons, pulmonologists and radiologists. In all the included studies, the surgical procedure was performed through a median sternotomy with intermittent deep hypothermic circulatory arrest under cardiopulmonary bypass. In case of residual pulmonary hypertension, alternative combined treatments should be considered (balloon angioplasty and/or medical therapy until lung transplantation in highly selected cases). Short- and long-term outcomes, although not homogenous across the different studies, are acceptable in highly experienced CTEPH centers.

Current status of pulmonary artery denervation

Pulmonary hypertension is a progressive disease with a poor long-term prognosis and high mortality. Pulmonary artery denervation (PADN) is emerging as a potential novel therapy for this condition. The basis of pursuing a sympathetic denervation strategy has its origins in a body of experimental translation work that has demonstrated that denervation can reduce sympathetic nerve activity in various animal models. This reduction in pulmonary sympathetic nerve activity is associated with a reduction in pathological pulmonary hemodynamics in response to mechanical, pharmacological, and toxicologically induced pulmonary hypertension. The most common method of PADN is catheter-directed thermal ablation. Since 2014, there have been 12 reports on the role of PADN in 490 humans with pulmonary hypertension (311:179; treated: control). Of these, six are case series, three are randomized trials, and three are case reports. Ten studies used percutaneous PADN techniques, and two combined PADN with mitral and/or left atrial surgery. PADN treatment has low mortality and morbidity and is associated with an improved 6-minute walking distance, a reduction in both mean pulmonary artery pressure and pulmonary vascular resistance, and an improvement in cardiac output. These improved outcomes were seen over a median follow-up of 12 months (range 2–46 months). A recent meta-analysis of human trials also supports the effectiveness of PADN in carefully selected patients. Based on the current literature, PADN can be effective in select patients with pulmonary hypertension. Additional randomized clinical trials against best medical therapy are required.

High-circulating gut microbiota-dependent metabolite trimethylamine N-oxide is associated with poor prognosis in pulmonary arterial hypertension

Aims

We aimed to examine the hypothesis that circulating trimethylamine-N-oxide (TMAO) levels serve as a biomarker in pulmonary arterial hypertension (PAH), and to determine whether 3,3-dimethyl-1-butanol (DMB), a TMAO inhibitor, exerted a protective effect in monocrotaline (MCT)-induced PAH rats.

Methods and results

In-patients with PAH were prospectively recruited from the Fuwai Hospital. Fasting blood samples were obtained to assess the TMAO levels and other laboratory values during the initial and second hospitalization. In a MCT-induced PAH rat, a normal diet and water supplemented with or without 1% DMB were administered for 4 weeks. The TMAO levels, haemodynamic examinations, changes in organ-tissue, and molecular levels were evaluated. In total, 124 patients with PAH were enrolled in this study. High TMAO levels were correlated with increased disease severity and poor prognosis even after adjusting for confounders. The TMAO levels in the rats decreased in the MCT + DMB group, accompanied by improved haemodynamic parameters, decreased right ventricular hypertrophy, and amelioration of pulmonary vascular remodelling. The decrease in abnormal apoptosis, excessive cell proliferation, transforming growth factor-β expression, and restoration of endothelial nitric oxide synthase after DMB treatment further explained the amelioration of PAH.

Conclusion

Increased TMAO levels were associated with poor prognosis in patients with PAH, and DMB played a protective effect in MCT-induced PAH rat.

Update in approaches to pulmonary hypertension because of left heart disease

PURPOSE OF REVIEW

Left heart disease is the most common cause of pulmonary hypertension. This review summarizes the current care of patients with pulmonary hypertension caused by left heart disease (PH-LHD) and discusses recent and active clinical trials in this patient population.

RECENT FINDINGS

The primary focus of interventions aimed at treating PH-LHD address the treatment of left heart disease. Significant advancements in the treatment of heart failure with preserved ejection fraction (HFpEF), a frequent cause of PH-LHD, are supported in the current literature. Patients with residual pulmonary hypertension despite optimal treatment of left heart disease have poor outcomes. Yet, interventions targeting the pulmonary vasculature in PH-LHD patients have not demonstrated significant benefits in studies to date. Current work focuses on differentiating isolated postcapillary pulmonary hypertension (IpcPH) from combined precapillary and postcapillary pulmonary hypertension (CpcPH) in a clinically consistent manner. It is hopeful that thorough phenotyping of PH-LHD patients will translate into effective treatment strategies addressing pulmonary vascular disease.

SUMMARY

Referral to centers of excellence, considerations for enrollment in clinical trials, and evaluation for transplant is recommended for patients with residual pulmonary hypertension despite optimal treatment of left heart disease, particularly those with CpcPH.

New progress in diagnosis and treatment of pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a progressive disease. Although great progress has been made in its diagnosis and treatment in recent years, its mortality rate is still very significant. The pathophysiology and pathogenesis of PAH are complex and involve endothelial dysfunction, chronic inflammation, smooth muscle cell proliferation, pulmonary arteriole occlusion, antiapoptosis and pulmonary vascular remodeling. These factors will accelerate the progression of the disease, leading to poor prognosis. Therefore, accurate etiological diagnosis, treatment and prognosis judgment are particularly important. Here, we systematically review the pathophysiology, diagnosis, genetics, prognosis and treatment of PAH.

Percutaneous Treatments for Pulmonary Hypertension: Reviewing the Growing Procedural Role for Interventional Cardiology

Pulmonary arterial hypertension is a common and highly morbid medical problem resulting in elevated pulmonary arterial pressures and pulmonary vascular resistance. Medical therapies are costly, and not always well-tolerated. Surgical therapies such as pulmonary endarterectomy and lung transplantation are limited to a small subset of patients due to various patient, disease, or institutional factors. Over the past decade, there has been growing investigation into endovascular interventional therapies for patients with pulmonary hypertension such as balloon pulmonary angioplasty and pulmonary denervation. In this review, we describe the current status, future directions, and our recommendations on technical considerations with these therapies.

Mechanosensitive channel Piezo1 is required for pulmonary artery smooth muscle cell proliferation

Concentric pulmonary vascular wall thickening due partially to increased pulmonary artery (PA) smooth muscle cell (PASMC) proliferation contributes to elevating pulmonary vascular resistance (PVR) in patients with pulmonary hypertension (PH). Although pulmonary vasoconstriction may be an early contributor to increasing PVR, the transition of contractile PASMCs to proliferative PASMCs may play an important role in the development and progression of pulmonary vascular remodeling in PH. A rise in cytosolic Ca2+ concentration ([Ca2+]cyt) is a trigger for PASMC contraction and proliferation. Here, we report that upregulation of Piezo1, a mechanosensitive cation channel, is involved in the contractile-to-proliferative phenotypic transition of PASMCs and potential development of pulmonary vascular remodeling. By comparing freshly isolated PA (contractile PASMCs) and primary cultured PASMCs (from the same rat) in a growth medium (proliferative PASMCs), we found that Piezo1, Notch2/3, and CaSR protein levels were significantly higher in proliferative PASMCs than in contractile PASMCs. Upregulated Piezo1 was associated with an increase in expression of PCNA, a marker for cell proliferation, whereas downregulation (with siRNA) or inhibition (with GsMTx4) of Piezo1 attenuated PASMC proliferation. Furthermore, Piezo1 in the remodeled PA from rats with experimental PH was upregulated compared with PA from control rats. These data indicate that PASMC contractile-to-proliferative phenotypic transition is associated with the transition or adaptation of membrane channels and receptors. Upregulated Piezo1 may play a critical role in PASMC phenotypic transition and PASMC proliferation. Upregulation of Piezo1 in proliferative PASMCs may likely be required to provide sufficient Ca2+ to assure nuclear/cell division and PASMC proliferation, contributing to the development and progression of pulmonary vascular remodeling in PH.

Long-term mortality after pulmonary artery denervation stratified by baseline functional class in patients with pulmonary arterial hypertension: Long-term mortality after PADN stratified by functional class

AIMS

This study aimed to assess the long-term effects of pulmonary artery denervation (PADN) on mortality in patients with pulmonary arterial hypertension (PAH).

METHODS AND RESULTS

Between March 2012 and March 2018, a total of 120 patients with PAH, who underwent PADN treatment and were prospectively followed up, were analysed. Patients were classified into World Health Organization (WHO) Functional Class I and II (FC 1-2; n=46) and Functional Class III and IV (FC 3-4; n=74) according to their FC prior to PADN. The primary endpoint was lung transplantation-free mortality until March 2021. The secondary endpoint was a change in the six-minute walk distance (6MWD). During the median of 4.8 years of follow-up, 23 (19.2%) patients died, predominantly from the FC 3-4 group (25.7%), compared to 8.7% in the FC 1-2 group (p=0.034). The mortality rate at one year (2.2% vs 12.2%, p=0.087) and three years (6.5% vs 17.6%, p=0.102) was numerically low in the FC 1-2 group versus the FC 3-4 group, respectively. The median net increase of 6MWD was +29 m in the FC 1-2 group, compared to +60.5 m in the FC 3-4 group (p=0.037).

CONCLUSIONS

PADN results in significant improvements in survival at long-term follow-up, especially in patients with PAH in FC 3-4. This study was the continuation of the PADN-1 study which was registered at URL: http://www.chictr.trc.com.cn. Unique identifier: chiCTR-ONC-12002085.

Heart-Rate Recovery at 1 Min After Exercise Predicts Response to Balloon Pulmonary Angioplasty in Patients With Inoperable Chronic Thromboembolic Pulmonary Hypertension

Background

Dysfunction of autonomic nervous system plays an important role in the development of pulmonary hypertension. The present study aimed to investigate the interaction between balloon pulmonary angioplasty (BPA) and cardiac autonomic function by using heart-rate recovery at 1 min (HRR1) after exercise as a surrogate marker.

Methods and Results

We retrospectively enrolled 89 consecutive patients with inoperable chronic thromboembolic pulmonary hypertension who underwent BPA from May, 2018 to Jan, 2021. According to hemodynamics at follow-up, patients were categorized as BPA responders if they met one or both of the following criteria: (1) mean pulmonary arterial pressure ≤ 30 mmHg and (2) a reduction of pulmonary vascular resistance ≥ 30%. Compared with baseline, HRR1 tended to increase within 7 days after the first BPA session, and this improvement persisted at follow-up. HRR1 at baseline and at follow-up were associated with well-validated markers of CTEPH severity, including N-terminal pro-brain natriuretic peptide, mean pulmonary arterial pressure and pulmonary vascular resistance. Furthermore, the change of HRR1 from baseline to follow-up was also associated with the change of those variables. After adjustment for confounders, baseline HRR1 was still a strong independent predictor of BPA outcome. Receiver operator characteristic curve analysis showed that the cutoff value for HRR1 in predicting BPA outcome was 19 beats.

Conclusions

BPA could significantly improve HRR1, suggesting the alleviation of sympathovagal imbalance. Easily available and non-invasive HRR1 seems to be a useful tool in predicting outcome of BPA and dynamically monitoring the efficacy of BPA.

A Meta-analysis of the efficacy of pulmonary artery denervation in the treatment of pulmonary hypertension

BACKGROUND

Pulmonary hypertension (pH) is a progressive and fatal disease with poor long-term prognosis and high mortality. Although great progress has been made in current treatment methods, the survival rate is still poor. Therefore, we need to find an effective treatment for pH.

OBJECTIVE

pH is a type of refractory, progressive, and fatal pulmonary vascular disease which involves a variety of clinical conditions and may complicate most cardiovascular and respiratory diseases. Pulmonary artery denervation (PADN) therapy for pH has become the current trend, but its clinical application still faces a series of problems, and its efficacy remains controversial. The purpose of the study is to evaluate the literature on the effects of PADN for pH.

METHOD

The PubMed, Embase, and Web of Science databases were searched by two researchers until April 9th, 2021. The literature was read and screened, and effective data(6-minute walking distance, cardiac output, mPAP, PVR,Left ventricular end-systolic diameter,Cardiac output,Readmission rate,Mortality,Cardiac function,and so on) was extracted, collated, and analyzed. The literature was managed by Endnote 9.3 software and evaluated by RevMan 5.3 software.

RESULTS

The meta-analysis included five controlled experiments with a total of 339 patients. The literature quality evaluations were all Level B. The meta-analysis results showed that compared with the control group, PADN treatment could improve the 6-minute walking distance of pH patients [WMD = 103.72, 95%CI (49.63, 157.82), P < 0.05], reduce mean pulmonary artery pressure (mPAP) [WMD = -7.26, 95%CI (-10.86, -3.66), P < 0.05], reduce pulmonary vascular resistance (PVR) [WMD = -4.53, 95%CI (-8.23, -0.83), P < 0.05], and improve cardiac output [WMD = 0.48, 95%CI (0.23, 0.73), P < 0.05]. There was no significant effect on the left ventricular end-systolic diameter [WMD = -0.13, 95%CI (-0.49, 0.24), P > 0.05], readmission rate [OR = 0.14, 95%CI (0.01, 1.87), P > 0.05], mortality rate [OR = 0.77, 95%CI (0.22, 2.69), P > 0.05], or cardiac function [OR = 0.32, 95%CI (0.05, 2.10), P > 0.05].

CONCLUSION

PADN is an effective method for the treatment of pH which is worthy of clinical promotion.

Transcatheter radiofrequency pulmonary artery denervation in swine: the evaluation of lesion degree, hemodynamics and pulmonary hypertension inducibility

Background

Mechanisms of positive effects of pulmonary artery (PA) denervation (PADN) remain poorly understood. The study aimed to evaluate pulmonary hemodynamic changes after PADN and their association with the extent of PA wall damage in an acute thromboxane A2 (TXA2)-induced pulmonary hypertension (PH) model in swine.

Methods

In this experimental sham-controlled study, 17 normotensive male white Landrace pigs (the mean weight 36.2 ± 4.5 kg) were included and randomly assigned to group I (n = 9)—PH modeling before and after PADN, group II (n = 4)—PADN only, or group III (n = 4)—PH modeling before and after a sham procedure. Radiofrequency (RF) PADN was performed in the PA trunk and at the proximal parts of the right and left PAs. PA wall lesions were characterized at the autopsy study using histological and the immunohistochemical examination.

Results

In groups I and II, no statistically significant changes in the mean pulmonary arterial pressure nor systemic blood pressure were found after PADN (−0.8 ± 3.4 vs 4.3 ± 8.6 mmHg, P = 0.47; and 6.0 ± 15.9 vs -8.3 ± 7.5 mmHg, P = 0.1; correspondingly). There was a trend towards a lower diastolic pulmonary arterial pressure after PADN in group I when compared with group III during repeat PH induction (34.4 ± 2.9 vs 38.0 ± 0.8; P = 0.06). Despite the presence of severe PA wall damage at the RF application sites, S100 expression was preserved in the majority of PA specimens. The presence of high-grade PA lesions was associated with HR acceleration after PADN (ρ = 0.68, p = 0.03). No significant correlation was found between the grade of PA lesion severity and PA pressure after PADN with or without PH induction.

Conclusions

Extended PADN does not affect PH induction using TXA2. Significant PA adventitia damage is associated with HR acceleration after PADN. Possible delayed effects of PADN on perivascular nerves and pulmonary hemodynamics require further research in chronic experiments.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01786-y.

Device-Based Sympathetic Nerve Regulation for Cardiovascular Diseases

Sympathetic overactivation plays an important role in promoting a variety of pathophysiological processes in cardiovascular diseases (CVDs), including ventricular remodeling, vascular endothelial injury and atherosclerotic plaque progression. Device-based sympathetic nerve (SN) regulation offers a new therapeutic option for some CVDs. Renal denervation (RDN) is the most well-documented method of device-based SN regulation in clinical studies, and several large-scale randomized controlled trials have confirmed its value in patients with resistant hypertension, and some studies have also found RDN to be effective in the control of heart failure and arrhythmias. Pulmonary artery denervation (PADN) has been clinically shown to be effective in controlling pulmonary hypertension. Hepatic artery denervation (HADN) and splenic artery denervation (SADN) are relatively novel approaches that hold promise for a role in cardiovascular metabolic and inflammatory-immune related diseases, and their first-in-man studies are ongoing. In addition, baroreflex activation, spinal cord stimulation and other device-based therapies also show favorable outcomes. This review summarizes the pathophysiological rationale and the latest clinical evidence for device-based therapies for some CVDs.

Endovascular denervation (EDN): From Hypertension to Non-Hypertension Diseases

Recently, the use of endovascular denervation (EDN) to treat resistant hypertension has gained significant attention. In addition to reducing sympathetic activity, EDN might also have beneficial effects on pulmonary arterial hypertension, insulin resistance, chronic kidney disease, atrial fibrillation, heart failure, obstructive sleep apnea syndrome, loin pain hematuria syndrome, cancer pain and so on. In this article we will summarize the progress of EDN in clinical research.

Global trends in chronic thromboembolic pulmonary hypertension clinical trials and dissemination of results

Treatment options for chronic thromboembolic pulmonary hypertension (CTEPH) are rapidly expanding. The purpose of this study is to identify trends in CTEPH clinical trials and the publication of results. We performed a worldwide review of completed and ongoing clinical trials through searching the ClinicalTrials.gov database and the World Health Organization International Clinical Trials Registry Platform for "CTEPH" and related terms. Entries were classified as pharmaceutical/procedural interventions (Group 1), all other clinical trials (Group 2) and patient registries (Group 3). Trial characteristics and national affiliation were recorded. PubMed was searched for related publications. There were 117 clinical trials registry entries after removing duplicates and non-target records. Group 1 comprised 29 pharmaceutical, 15 procedural, and four combined interventions starting in 2005, 2010, and 2016, respectively. Riociguat and balloon pulmonary angioplasty were the most frequent pharmaceutical and procedural interventions, respectively. The proportion of procedural trials increased over time from 0% of those in 2005-2009 to 29% in 2010-2014 and 54% in 2015-2020. There were 56 entries in Group 2 and 13 in Group 3. Japan was the most frequent national affiliation and the most frequent participating country, present in 28% of all trials. The proportion of entries with published results was highest with Group 3 (62%) and lowest with Group 1 (27%). Thirty percent of all publications occurred in 2020. In conclusion, CTEPH clinical trials are increasingly procedural based, with growth largely attributable to Japan and balloon pulmonary angioplasty. Most trials have not published, but results from balloon pulmonary angioplasty clinical trials are anticipated soon.

Evaluation and management of patients with chronic thromboembolic pulmonary hypertension - consensus statement from the ISHLT

ISHLT members have recognized the importance of a consensus statement on the evaluation and management of patients with chronic thromboembolic pulmonary hypertension. The creation of this document required multiple steps, including the engagement of the ISHLT councils, approval by the Standards and Guidelines Committee, identification and selection of experts in the field, and the development of 6 working groups. Each working group provided a separate section based on an extensive literature search. These sections were then coalesced into a single document that was circulated to all members of the working groups. Key points were summarized at the end of each section. Due to the limited number of comparative trials in this field, the document was written as a literature review with expert opinion rather than based on level of evidence.

An Ovine Model for Percutaneous Pulmonary Artery Laser Denervation: Perivascular Innervation and Ablation Lesion Characteristics

Background: Pulmonary artery denervation (PADN) is an evolving interventional procedure capable to reduce pulmonary artery (PA) pressure. We aimed to compare PA nerve distribution in different specimens and assess the feasibility of an ovine model for a denervation procedure and evaluate the acute changes induced by laser energy. Methods: The experiment was divided into two phases: (1) the analysis of PA nerve distribution in sheep, pigs, and humans using histological and immunochemical methods; (2) fiberoptic PADN in sheep and postmortem laser lesion characteristics. Results: PA nerve density and distribution in sheep differ from humans, although pigs and sheep share similar characteristics, nerve fibers are observed in the media layer, adventitia, and perivascular tissue in sheep. Necrosis of the intima and focal hemorrhages within the media, adventitia, and perivascular adipose tissue were evidenced post laser PADN. Among the identified lesions, 40% reached adventitia and could be classified as effective for PADN. The use of 20 W ablation energy was safer and 30 W-ablation led to collateral organ damage. Conclusions: An ovine model is suitable for PADN procedures; however, nerve distribution in the PA bifurcation and main branches differ from human PA innervation. Laser ablation can be safely used for PADN procedures.

Editor-in-Chief's Top Picks From 2020

Each week, I record audio summaries for every paper in JACC, as well as an issue summary. Although this process is quite time-consuming, I have become familiar with every paper that we publish. Thus, I have personally selected the top 100 papers (both Original Investigations and Review Articles) from the distinct specialties each year. In addition to my personal choices, I have included papers that have been the most accessed or downloaded on our websites, as well as those selected by the JACC Editorial Board members. In order to present the full breadth of this important research in a consumable fashion, we will present these abstracts in this issue of JACC, as well as their Central Illustrations. The highlights comprise the following sections: Basic & Translational Research, Cardiac Failure & Myocarditis, Cardiomyopathies & Genetics, Cardio-Oncology, Congenital Heart Disease, Coronary Disease & Interventions, Coronavirus (as a NEW section), Hypertension, Imaging, Metabolic & Lipid Disorders, Neurovascular Disease & Dementia, Promoting Health & Prevention, Rhythm Disorders & Thromboembolism, Valvular Heart Disease, and Vascular Medicine (1-100).

Computed tomography angiographic parameters of pulmonary artery as prognostic factors of residual pulmonary hypertension after pulmonary endarterectomy

OBJECTIVES

This study aimed to retrospectively assess using computed tomography pulmonary angiography (CTPA) for predicting residual pulmonary hypertension (RPH) in patients with chronic thromboembolic pulmonary hypertension (CTEPH) after pulmonary endarterectomy (PEA).

METHODS

We retrospectively analyzed data of 131 patients with CTEPH who underwent PEA in our center (2008-2015). We measured several diameters of the pulmonary artery and thoracic aorta preoperatively. We evaluated the relationship between these measurements (and their indices) and signs of RPH represented by pulmonary artery systolic pressure (PASP) estimated by echocardiography.

RESULTS

Significant correlations were observed between the aortopulmonary index and prediction of any residual hypertension and moderate/severe hypertension 1 year after PEA, and any residual hypertension and severe hypertension 2 years after PEA. The aortopulmonary index was significantly related to a reduction in PASP 1 year after the operation. A lower aortopulmonary index (≤0.88 for the ascending aorta and ≤0.64 for the descending aorta) predicted lower RPH.

CONCLUSIONS

Preoperative CTPA parameters can be used to assess the risk of RPH after PEA. The aortopulmonary index has significant predictive value for RPH and a reduction in PASP after PEA. Lower values of the aortopulmonary index suggest a better outcome after PEA.

Interventional and pharmacological management of chronic thromboembolic pulmonary hypertension

Chronic thromboembolic pulmonary hypertension (CTEPH) is caused by obstruction of the pulmonary vasculature, leading to increased pulmonary vascular resistance and ultimately right ventricular failure, the leading cause of death in non-operated patients. This article reviews the current management of CTEPH. The standard of care in CTEPH is pulmonary endarterectomy (PEA). However, up to 40% of patients with CTEPH are ineligible for PEA, and up to 51% develop persistent/recurrent PH after PEA. Riociguat is currently the only medical therapy licensed for treatment of inoperable or persistent/recurrent CTEPH after PEA based on the results of the Phase III CHEST-1 study. Studies of balloon pulmonary angioplasty (BPA) have shown benefits in patients with inoperable or persistent/recurrent CTEPH after PEA; however, data are lacking from large, prospective, controlled studies. Studies of macitentan in patients with inoperable CTEPH and treprostinil in patients with inoperable or persistent/recurrent CTEPH showed positive results. Combination therapy is under evaluation in CTEPH, and long-term data are not available. In the future, CTEPH may be managed by PEA, medical therapy or BPA - alone or in combination, according to individual patient needs. Patients should be referred to experienced centers capable of assessing and delivering all options.

[Pulmonary artery denervation in pulmonary hypertension: physiological and clinical aspects]

This article is a review of the findings of experimental and clinical studies of a new method of treatment of pulmonary hypertension - pulmonary artery denervation with the help of radiofrequency ablation, cryodenervation and ultrasonic impact. Pulmonary artery denervation results in decreased neurogenic tonic sympathetic and, probably, increased parasympathetic effects on pulmonary vessels. On models of experimental monocrotaline-induced pulmonary hypertension in various-species animals, it was determined that pulmonary artery denervation is followed by decreased activity of local pulmonary renin-angiotensin system, slowed processes of remodeling of pulmonary vessels, hypertrophy and fibrosis of the right ventricle, with inhibition of progression of pulmonary hypertension by means of suppression of extracellular signal-regulated kinase 1/2 (ERK 1/2) which regulates differentiation, proliferation and migration of smooth muscle cells. However, the problem of the pattern of pulmonary microcirculation changes (pre- and postcapillary resistance, capillary filtration coefficient) after pulmonary artery denervation warrants further study. The findings of clinical studies in patients with pulmonary hypertension suggest that pulmonary artery denervation inducing a decrease of pressure therein, as well as pulmonary vessel resistance did not lead to normalization of pulmonary haemodynamics.The mentioned impact partially removes the neurogenic component of multicircuit and multifactorial regulation of pulmonary circulation. Therefore, along with pulmonary artery denervation, further search for pharmacological agents selectively influencing pulmonary vessels remains a problem of current importance.

Neurohormonal Modulation as a Therapeutic Target in Pulmonary Hypertension

The autonomic nervous system (ANS) and renin-angiotensin-aldosterone system (RAAS) are involved in many cardiovascular disorders, including pulmonary hypertension (PH). The current review focuses on the role of the ANS and RAAS activation in PH and updated evidence of potential therapies targeting both systems in this condition, particularly in Groups 1 and 2. State of the art knowledge in preclinical and clinical use of pharmacologic drugs (beta-blockers, beta-three adrenoceptor agonists, or renin-angiotensin-aldosterone signaling drugs) and invasive procedures, such as pulmonary artery denervation, is provided.