Interventional and surgical therapeutic strategies for pulmonary arterial hypertension: Beyond palliative treatments

Case report: Beneficial long-term effect of the atrial-flow-regulator device in a pediatric patient with idiopathic pulmonary arterial hypertension and recurring syncope

We report the long-term effect after successfully implanting an 8 mm Atrial-flow-regulator (AFR) device in a 7-year-old girl with idiopathic pulmonary hypertension with persistent syncope under triple therapy with significant improvement after implantation and absence of any further syncope. Early Implantation of the AFR device (Occlutech, Germany) can be efficient and safe interventional therapy option for pulmonary arterial hypertension with a history of syncope.

Transcatheter interventions in refractory pulmonary artery hypertension and pulmonary embolism

Pulmonary artery hypertension causes remodeling of distal pulmonary arterial vasculature leading to increased resistance of the pulmonary arterial system, right ventricular dysfunction, and sudden cardiac death. The diagnosis of pulmonary arterial hypertension (PAH) diagnosis is made when mean pulmonary artery pressure during catheterization is ≥25 mmHg at rest, pulmonary vascular resistance (PVR) more than 3 wood units, a pulmonary capillary wedge pressure of <15 mmHg. One year survival rate is 86.3% and 5 year survival rate in PAH is 61.2%, and only 7 years of median survival. Although several breakthrough advances are made in the medical management for PAH, there are some patients who do not respond to medications and continue to detoriate despite optimal medical therapy. The non-responders to medical management are those patients whose right atrial pressure is >20 mmHg or cardiac index is <2.0 L/min/m2, which are pointers of poor prognosis. For medical refractory patients invasive procedures such as atrial septostomy, Potts shunt, and pulmonary artery denervation are a therapeutic or palliative strategy in the treatment of pulmonary artery hypertension and serve as a bridge before surgery and heart lung transplantation.

Long-term outcomes of transcatheter Potts shunt in children with suprasystemic pulmonary arterial hypertension

BACKGROUND

Transcatheter Potts shunt (TPS) is a palliation alternative for children with severe pulmonary arterial hypertension (PAH). Debates on the long-term outcomes remain unsolved.

OBJECTIVES

To evaluate long-term clinical and procedural outcomes of TPS intervention.

METHODS

Single-center retrospective data review of children with severe PAH who had TPS between 2009 and 2018. Patients who died per-operatively and early post-procedure were excluded. Long-term outcomes of survivors were evaluated.

RESULTS

Out of 13 identified patients (53.8% males), 7 had endovascular stenting of probe/patent arterial ducts, while 6 individuals had aorta-to-pulmonary radiofrequency perforation and covered stent placement. Compared to baseline, the overall clinical condition significantly improved at discharge (p < 0.001) and stayed better at the last visit (p < 0.05) despite frequent clinical worsening events across follow-up. Improvement in functional class across follow-up was significant (p < 0.001). There was, however, no significant improvement in other disease markers (TPASE, 6MWD z-scores, and NT-proBNP levels) or reduction in PAH medications. The median follow-up was 77.4 months (IQR, 70.7-113.4). Survival was 100% at 1 year and 92.3% at 6 years. Freedom from reinterventions was 77% at 1 year and 21% at 6 years. Nine (69.2%) patients had stent reinterventions at a median of 25 months (IQR, 9.5-56) postoperative. Balloon dilatation and restenting were performed in 53.8% and 46.2% of patients, respectively. High-pressure post-dilatation of implanted stents was performed in 53.8% of patients during TPS intervention for incomplete stent expansion and/or residual pressure gradient and was associated with higher rates of reinterventions (p = 0.021). Stent malfunctioning was present in 46.2% of patients at last follow-up. Two patients are listed for heart-lung transplantation.

CONCLUSION

Survivors of TPS procedures experience significant improvement in functional class that can be durable. Clinical worsening and stent malfunctioning are frequent morbid events indicating recurrent transcatheter reinterventions throughout follow-up. Six-year survival is, however, satisfactory.

Interventionelle Behandlungsverfahren der pulmonalen Hypertension im Kindesalter

Die pulmonale Hypertension (PH) ist eine progressive Gefäßerkrankung und führt über eine Widerstands- und/oder Druckerhöhung im kleinen Kreislauf zu einem fortschreitenden Rechtsherzversagen. Auch wenn mithilfe aktueller medikamentöser Therapien eine deutliche Verbesserung der Lebensqualität und des Überlebens der Betroffenen erreicht werden konnte, bleibt die PH eine zumeist nichtheilbare Erkrankung, die im fortgeschrittenen Stadium eine Lungentransplantation notwendig macht. Interventionelle Verfahren, wie die Anlage eines interatrialen Shunts (z. B. durch atriale Septostomie oder den Atrial Flow Regulator) oder eines Reversed Potts Shunt, verbessern die RV-Funktion und die ventrikuläre Interaktion durch Schaffung einer prä- oder posttrikuspidalen „Eisenmenger-Physiologie“ und stellen eine Überbrückung oder sogar Alternative zur Lungentransplantation dar. Bei Patienten mit segmentaler PH oder chronisch thrombembolischer pulmonaler Hypertension (CTEPH) stellt die Ballonangioplastie eine bereits etablierte Intervention zur Verbesserung der pulmonalen Perfusion und damit rechtsventrikulären (RV-)Funktion dar. Dagegen ist die pulmonalarterielle Denervation ein neuartiges Verfahren, mit dem Ziel, die neurohumorale Dysregulation bei PH positiv zu beeinflussen. Der individuelle Einsatz solcher Interventionen, additiv zu den bereits etablierten medikamentösen Therapien, erweitert die Behandlungsmöglichkeiten und kann die Prognose betroffener Patienten noch weiter verbessern.

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.

Beyond transplant: Roles of atrial septostomy and Potts shunt in pediatric pulmonary hypertension

Despite significant successes in treating children with pulmonary hypertension, many still die from their disease. Death most often results from right ventricular failure. Bilateral lung transplantation has historically been the ultimate palliation for children who develop heart failure despite maximal medical therapy. Creating an atrial level shunt has been advocated as a pre-transplant intervention to help reduce symptoms and perhaps serve as a bridge to transplant. More recently, the utilization of a pulmonary-to-systemic anastomosis, that is, Potts shunt, has demonstrated efficacy in ameliorating symptoms in children with severe, progressive disease. This improvement is often coincident with a reduction in expensive and onerous pulmonary hypertension specific medications. Improvement has been sustained over the years in some children, delaying the need for transplant consideration. Research is ongoing to determine more specific risks/benefits of using the Potts shunt in children with pulmonary hypertension both in the short term and long.

Management of Pulmonary Arterial Hypertension

Purpose of Review

This review focuses on the therapeutic management and individualized approach to Group 1 pulmonary arterial hypertension (PAH), utilizing Food and Drug Administration-approved PAH-specific therapies and various interventional and surgical options for PAH.

Recent Findings

The paradigm for the optimal management of PAH has shifted in recent years. Upfront combination therapy with an endothelin receptor antagonist and a phosphodiesterase 5 inhibitor is now widely accepted as standard of care. In addition, there is increasing emphasis on starting prostanoids early in order to delay time to clinical worsening. However, less is known regarding which prostanoid agent to initiate and the optimum time to do so. In order to facilitate shared decision-making, there is an increasing need for decision tools based on guidelines and collective clinical experiences to navigate between pharmacologic and interventional treatments, as well as explore innovative, therapeutic pathways for PAH.

Summary

The management of PAH has become increasingly complex. With a growing number of PAH-specific therapies, intimate knowledge of the therapeutics and the potential barriers to adherence are integral to providing optimal care for this high-risk patient population. While current PAH-specific therapies largely mediate their effects through pulmonary vasodilation, ongoing research efforts are focused on ways to disrupt the mechanisms leading to pulmonary vascular remodeling. By targeting aberrations identified in the metabolism and proliferative state of pulmonary vascular cells, novel PAH treatment pathways may be just on the horizon.

Graded balloon atrial septostomy for palliation of congenital pulmonary hypertension in a dog: A case report

CASE DESCRIPTION

A 6-month-old intact female Maltese dog was presented for acute onset of syncope.

CLINICAL FINDINGS

The dog was presented for collapse upon excitement and exercise. It collapsed at discharge and suffered cardiopulmonary arrest. Echocardiography after resuscitation indicated severe pulmonary hypertension without evidence of intracardiac or extracardiac shunting. A presumptive diagnosis of congenital pulmonary hypertension was made.

TREATMENT AND OUTCOME

Initial treatment with sildenafil was effective at relieving syncope, but the extent of pulmonary hypertension as determined by serial echocardiography was unchanged. Graded balloon atrial septostomy was performed as a palliative procedure. Follow-up echocardiography identified a patent interatrial communication with bidirectional shunting. The dog remained asymptomatic 18 months after treatment.

CLINICAL RELEVANCE

To the best of our knowledge, this study is the first report in the veterinary literature of graded balloon atrial septostomy performed for therapeutic purposes. Further studies are required to determine if this palliative procedure is a beneficial treatment option for dogs with congenital or severe refractory pulmonary hypertension.

Diagnosis and treatment of pediatric pulmonary arterial hypertension

INTRODUCTION

Pediatric pulmonary arterial hypertension (PAH) remains a rare and severe disease with a poor prognosis. PAH may be idiopathic, heritable or associated with systemic conditions in particular associated with congenital heart disease. Areas covered: A thorough and extensive diagnostic approach is required for a correct diagnosis. The outcome has improved over the last decade with a better diagnostic approach and with the initiation of new targeted therapies. However, there is still significant progress to achieve as there is still no cure for this devastating disease. Expert opinion: Adapted clinical studies to define the best therapeutic approach are needed. Even if the treatment approach is still mainly derived from adult data and expert consensus, several studies and registries are currently underway and should deliver important information in the next future. This review aims to give an overview of the current diagnosis and treatment strategies of PAH.

Effect of Patent Foramen Ovale in Patients With Pulmonary Hypertension

Septostomy reduces right ventricular (RV) workload at the expense of hypoxemia in patients with advanced pulmonary hypertension (PH). A patent foramen ovale (PFO) may serve as a "natural" septostomy, but the incidence and impact of a PFO in PH remains uncertain. We prospectively examined echocardiograms in 404 PH patients referred for initial hemodynamic assessment. Patients included had saline bubble injection and if negative repeatinjection after Valsalva maneuver. Echocardiographic and hemodynamic data were examined. Survival was modeled using Kaplan-Meier method. Eisenmenger syndrome or known atrial shunts other than PFO were excluded: 292 patients met entry criteria. A PFO was identified in 16.8% of the entire cohort, 22.9% of pulmonary arterial hypertension (PAH) patients, and 8.6% of Dana Point group 2 PH patients. Right atrial to pulmonary capillary wedge pressure difference was lowest in the latter group (-7.9 ± 7.1 vs -1.7 ± 5.5 mm Hg for all others, p <0.01). Patients with a PFO were younger (53.9 vs 58.6 years, p = 0.02). A PFO was more often present with moderately or severely dilated (p = 0.01) or dysfunctional (p = 0.03) RVs. Six year survival was unchanged by PFO presence for all patients, including those with PAH. Proportional hazards analysis found only age and functional class independently predicted survival (p <0.01). A PFO is identified less often in Dana Point group 2 PH, likely due to inability of Valsalva maneuver to overcome right atrial to pulmonary capillary wedge pressure difference. In conclusion, the incidence of a PFO in the PH population increases with more dilated and dysfunctional RVs, suggesting that the PFO may be stretched open rather than congenital. The presence of a PFO does not impact survival in PH or PAH.

Interventional Therapies in Pulmonary Hypertension

Despite advances in drug therapy, pulmonary hypertension-particularly arterial hypertension (PAH)-remains a fatal disease. Untreatable right heart failure (RHF) from PAH eventually ensues and remains a significant cause of death in these patients. Lowering pulmonary input impedance with different PAH-specific drugs is the obvious therapeutic target in RHF due to chronically increased afterload. However, potential clinical gain can also be expected from attempts to unload the right heart and increase systemic output. Atrial septostomy, Potts anastomosis, and pulmonary artery denervation are interventional procedures serving this purpose. Percutaneous balloon pulmonary angioplasty, another interventional therapy, has re-emerged in the last few years as a clear alternative for the management of patients with distal, inoperable, chronic thromboembolic pulmonary hypertension. The current review discusses the physiological background, experimental evidence, and potential clinical and hemodynamic benefits of all these interventional therapies regarding their use in the setting of RHF due to severe pulmonary hypertension.