Graded balloon dilation atrial septostomy in severe primary pulmonary hypertension. A therapeutic alternative for patients nonresponsive to vasodilator treatment

Embracing the challenges of neonatal and paediatric pulmonary hypertension

Paediatric pulmonary arterial hypertension (PAH) shares common features with adult disease, but is associated with several additional disorders and challenges that require unique approaches. This article discusses recent advances, ongoing challenges and distinct approaches for caring for infants and children with PAH, as presented by the paediatric task force of the 7th World Symposium on Pulmonary Hypertension. We provide updates on diagnosing, classifying, risk-stratifying and treating paediatric pulmonary hypertension (PH) and identify critical knowledge gaps. An updated risk stratification tool and treatment algorithm is provided, now also including strategies for patients with associated cardiopulmonary conditions. Treatment of paediatric PH continues to be hindered by the lack of randomised controlled clinical trials. The challenging management of children failing targeted PAH therapy is discussed, including balloon atrial septostomy, lung transplantation and pulmonary-to-systemic shunt (Potts). A novel strategy using a multimodal approach for the management of PAH associated with congenital heart diseases with borderline pulmonary vascular resistance is included. Advances in diagnosing neonatal PH, especially signs and interpretation of PH by echocardiography, are highlighted. A team approach to the rapidly changing physiology of neonatal PH is emphasised. Challenges in drug approval are discussed, particularly the challenges of designing accurate paediatric clinical trials with age-appropriate end-points and adequate enrolment.

Anesthetic management of children with medically refractory pulmonary hypertension undergoing surgical Potts shunt

INTRODUCTION

Pulmonary hypertension in children is associated with high rates of adverse events under anesthesia. In children who have failed medical therapy, a posttricuspid shunt such as a Potts shunt can offload the right ventricle and possibly delay or replace the need for lung transplantation. Intraoperative management of this procedure, during which an anastomosis between the pulmonary artery and the descending aorta is created, is complex and requires a deep understanding of the pathophysiology of acute and chronic right ventricular failure. This retrospective case review describes the intraoperative management of children undergoing surgical creation of a Potts shunt at a single center.

METHODS

A retrospective case review of all patients under the age of 18 who underwent Potts shunt between April 2013 and June 2022. Medical records were examined, and clinical data of demographics, intraoperative vital signs, anesthetic management, and postoperative outcomes were extracted.

RESULTS

Twenty-nine children with medically refractory pulmonary hypertension underwent surgical Potts shunts with a median age of 12 years (range 4 months to 17.4 years). Nineteen Potts shunts (65%) were placed via thoracotomy and 10 (35%) were placed via median sternotomy with use of cardiopulmonary bypass. Ketamine was the most frequently utilized induction agent (17 out of 29, 59%), and the majority of patients were initiated on vasopressin prior to intubation (20 out of 29, 69%). Additional inotropic support with epinephrine (45%), milrinone (28%), norepinephrine (17%), and dobutamine (14%) was used prior to shunt placement. Following opening of the Potts shunt, hemodynamic support was continued with vasopressin (66%), epinephrine (62%), milrinone (59%), dobutamine (14%), and norepinephrine (10%). Major intraoperative complications included severe hypoxemia (21 out of 29, 72%) and hypotension requiring boluses of epinephrine (10 out of 29, 34.5%) but no patient suffered intraoperative cardiac arrest. There were four in-hospital mortalities.

DISCUSSION

A Potts shunt offers another palliative option for children with medically refractory pulmonary hypertension. General anesthesia in these children carries high risk for pulmonary hypertensive crises. Anesthesiologists must understand underlying physiological mechanisms responsble for acute hemodynaic decompensation during acute pulmonary hypertneisve crises. Severe physiological perturbations imposed by thoracic surgery and use of cardiopulmonay bypass can be mitigated by aggresive heodynamic support of ventricle function and maintainence of systemic vascular resistance. Early use of vasopressin, before or immidiately after anesthesia induction, in combination with other inotropes is a useful agent during the perioperative care of thes. Early use of vasopressin during anesthesia induction, and aggressive inotropic support of right ventricular function can help mitigate effects of induction and intubation, single-lung ventilation, and cardiopulmonary bypass.

CONCLUSIONS

Our single center expereince shows that the Potts shunt surgery, despite high short-term mortaility, may offer another option for palliation in children with medically refractory pulmonary hypertension.

Cardiac arrest and cardiopulmonary resuscitation in pediatric patients with cardiac disease: a narrative review

Children with cardiac disease are at a higher risk of cardiac arrest as compared to healthy children. Delivering adequate cardiopulmonary resuscitation (CPR) can be challenging due to anatomic characteristics, risk profiles, and physiologies. We aimed to review the physiological aspects of resuscitation in different cardiac physiologies, summarize the current recommendations, provide un update of current literature, and highlight knowledge gaps to guide research efforts. We specifically reviewed current knowledge on resuscitation strategies for high-risk categories of patients including patients with single-ventricle physiology, right-sided lesions, right ventricle restrictive physiology, left-sided lesions, myocarditis, cardiomyopathy, pulmonary arterial hypertension, and arrhythmias. Cardiac arrest occurs in about 1% of hospitalized children with cardiac disease, and in 5% of those admitted to an intensive care unit. Mortality after cardiac arrest in this population remains high, ranging from 30 to 65%. The neurologic outcome varies widely among studies, with a favorable neurologic outcome at discharge observed in 64%-95% of the survivors. Risk factors for cardiac arrest and associated mortality include younger age, lower weight, prematurity, genetic syndrome, single-ventricle physiology, arrhythmias, pulmonary arterial hypertension, comorbidities, mechanical ventilation preceding cardiac arrest, surgical complexity, higher vasoactive-inotropic score, and factors related to resources and institutional characteristics. Recent data suggest that Extracorporeal membrane oxygenation CPR (ECPR) may be a valid strategy in centers with expertise. Overall, knowledge on resuscitation strategies based on physiology remains limited, with a crucial need for further research in this field. Collaborative and interprofessional studies are highly needed to improve care and outcomes for this high-risk population. What is Known: • Children with cardiac disease are at high risk of cardiac arrest, and cardiopulmonary resuscitation may be challenging due to unique characteristics and different physiologies. • Mortality after cardiac arrest remains high and neurologic outcomes suboptimal. What is New: • We reviewed the unique resuscitation challenges, current knowledge, and recommendations for different cardiac physiologies. • We highlighted knowledge gaps to guide research efforts aimed to improve care and outcomes in this high-risk population.

Left Ventricular Filling Pressure in Chronic Thromboembolic Pulmonary Hypertension

BACKGROUND

Chronic thromboembolic pulmonary hypertension (CTEPH) is characterized by obstruction of major pulmonary arteries with organized thrombi. Clinical risk factors for pulmonary hypertension due to left heart disease including metabolic syndrome, left-sided valvular heart disease, and ischemic heart disease are common in CTEPH patients.

OBJECTIVES

The authors sought to investigate prevalence and prognostic implications of elevated left ventricular filling pressures (LVFP) in CTEPH.

METHODS

A total of 593 consecutive CTEPH patients undergoing a first diagnostic right and left heart catheterization were included in this study. Mean pulmonary arterial wedge pressure (mPAWP) and left ventricular end-diastolic pressure (LVEDP) were utilized for assessment of LVFP. Two cutoffs were applied to identify patients with elevated LVFP: 1) for the primary analysis mPAWP and/or LVEDP >15 mm Hg, as recommended by the current pulmonary hypertension guidelines; and 2) for the secondary analysis mPAWP and/or LVEDP >11 mm Hg, representing the upper limit of normal. Clinical and echocardiographic features, and long-term mortality were assessed.

RESULTS

LVFP was >15 mm Hg in 63 (10.6%) and >11 mm Hg in 222 patients (37.4%). Univariable logistic regression analysis identified age, systemic hypertension, diabetes, atrial fibrillation, calcific aortic valve stenosis, mitral regurgitation, and left atrial volume as significant predictors of elevated LVFP. Atrial fibrillation, calcific aortic valve stenosis, mitral regurgitation, and left atrial volume remained independent determinants of LVFP in adjusted analysis. At follow-up, higher LVFPs were measured in patients who had meanwhile undergone pulmonary endarterectomy (P = 0.002). LVFP >15 mm Hg (P = 0.021) and >11 mm Hg (P = 0.006) were both associated with worse long-term survival.

CONCLUSIONS

Elevated LVFP is common, appears to be due to comorbid left heart disease, and predicts prognosis in CTEPH.

Is combined use of radiofrequency ablation and balloon dilation the future of interatrial communications?

INTRODUCTION

Personalized and stable interatrial communication is an important palliative therapy for patients with heart failure. However, this remains a technically challenging task.

AREAS COVERED

In the past decades, substantial advancements in atrial septostomy for the creation of controllable and durable interatrial communication have been made, and numerous novel devices and techniques are in various stages of development. In this review, we discuss the evolving indications for atrial septostomy, current approaches with or without device implantation, and indicators for optimal interatrial communication. The combined use of radiofrequency ablation and balloon dilation (CURB) is an individualized management approach based on underlying hemodynamics, which demonstrates unique advantages in creating a sufficient interatrial communication with satisfactory stability. The advantages and disadvantages of this implant-free procedure are analyzed and its clinical prospects are assessed.

EXPERT OPINION

With ready availability, high safety, and efficacy, CURB is a promising procedure for creating personalized and stable interatrial communication without device implantation. Further research is required to simplify the procedure, screen optimal reference parameters for personalized therapy, and evaluate the long-term outcome in a large population of patients.

Computational models of ventricular mechanics and adaptation in response to right-ventricular pressure overload

Pulmonary arterial hypertension (PAH) is associated with substantial remodeling of the right ventricle (RV), which may at first be compensatory but at a later stage becomes detrimental to RV function and patient survival. Unlike the left ventricle (LV), the RV remains understudied, and with its thin-walled crescent shape, it is often modeled simply as an appendage of the LV. Furthermore, PAH diagnosis is challenging because it often leaves the LV and systemic circulation largely unaffected. Several treatment strategies such as atrial septostomy, right ventricular assist devices (RVADs) or RV resynchronization therapy have been shown to improve RV function and the quality of life in patients with PAH. However, evidence of their long-term efficacy is limited and lung transplantation is still the most effective and curative treatment option. As such, the clinical need for improved diagnosis and treatment of PAH drives a strong need for increased understanding of drivers and mechanisms of RV growth and remodeling (G&R), and more generally for targeted research into RV mechanics pathology. Computational models stand out as a valuable supplement to experimental research, offering detailed analysis of the drivers and consequences of G&R, as well as a virtual test bench for exploring and refining hypotheses of growth mechanisms. In this review we summarize the current efforts towards understanding RV G&R processes using computational approaches such as reduced-order models, three dimensional (3D) finite element (FE) models, and G&R models. In addition to an overview of the relevant literature of RV computational models, we discuss how the models have contributed to increased scientific understanding and to potential clinical treatment of PAH patients.

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.

First in-human modified atrial septostomy combining radiofrequency ablation and balloon dilation

OBJECTIVE

Preclinical research suggests that the combined use of radiofrequency ablation and balloon dilation (CURB) could create stable interatrial communications without device implantation. This study examined the first in-human use of CURB for modified atrial septostomy in patients with severe pulmonary arterial hypertension (PAH).

METHODS

Between July 2018 and October 2021, CURB was performed in 19 patients with severe PAH (age: 31.5±9.1 years; mean pulmonary artery pressure: 73 mm Hg (IQR: 66-92); pulmonary vascular resistance: 18.7 Wood units (IQR: 17.8-23.3)). Under guidance of intracardiac echocardiography and three-dimensional location system, (1) fossae ovalis was reconstructed and ablated point-by-point with radiofrequency; (2) then graded balloon dilation was performed after transseptal puncture and the optimal size was determined according to the level of arterial oxygen saturation (SatO₂); (3) radiofrequency ablation was repeated around the rims of the created fenestration. The interatrial fenestrations were followed-up serially.

RESULTS

After CURB, the immediate fenestration size was 4.4 mm (IQR: 4.1-5.1) with intracardiac echocardiography, systolic aortic pressure increased by 10.2±6.9 mm Hg, cardiac index increased by 0.7±0.3 L/min/m² and room-air resting SatO2 decreased by 6.2±1.9% (p<0.001). One patient experienced increased pericardiac effusion postoperatively; the others had no complications. On follow-up (median: 15.5 months), all interatrial communications were patent with stable size (intraclass correlation coefficient=0.96, 95%CI:0.89 to 0.99). The WHO functional class increased by 1 (IQR: 1-2) (p<0.001) with improvement of exercise capacity (+159.5 m, P<0.001).

CONCLUSION

The interatrial communications created with CURB in patients with severe PAH were stable and the mid-term outcomes were satisfactory.

TRIAL REGISTRATION NUMBER

NCT03554330.

Heart failure therapy based on interventricular mechanics and cardio-vascular communications

The heart should not be divided in right and left, whether in health nor in disease. However, the morphological and functional differences between the right and left ventricle should be known and the impact of the ventricle's position considered. Further, the parameters beyond heart rate, contractility, pre- and afterload guaranteeing a sufficient systemic cardiac output have to be integrated in therapeutic measures; preferentially the influence of interventricular mechanics. Despite of recent developments of specific drug therapies, heart failure is associated with a high rate of morbidity and mortality in children. During the progression of heart failure, pulmonary vascular disease is the consequence or the reason for further failing. Clinical symptoms are associated with congestion and low cardiac output at rest or exercise. Improved understanding of the pathophysiological mechanisms particularly of ventricular failure has resulted in the development of innovative therapies that target atrial/ventricular/arterial interactions. Recent advances in interventional and surgical approaches provide promising new strategies to deal with right and left ventricular deterioration. These techniques may delay listing for heart and (heart-) lung transplantation or even make redundant in individual cases. The beneficial effects of these ventricular interaction strategies are mainly based on the mechanics of the interventricular septum and improvement of systolic and diastolic ventricular performance.

Right Ventricular Epicardial Pacing Postcardiac Surgery Can Cause Dynamic Right Ventricular Outflow Tract Obstruction: A Case Report

Dynamic right ventricular outflow tract obstruction is rare in the cardiac surgical population. Significant obstruction developing in the perioperative period can contribute to systemic hemodynamic instability. We describe 2 cases of dynamic right ventricular outflow tract obstruction that developed immediately after separation from cardiopulmonary bypass, due to temporary right ventricular epicardial pacing. Both patients had systemic hypotension which improved once ventricular pacing was discontinued. We discuss the recognition of right ventricular outflow tract obstruction as a contributing factor to hemodynamic instability, as well as the importance of identifying the underlying cause such as to institute appropriate management in these patients.

Interventional and Surgical Treatments for Pulmonary Arterial Hypertension

Despite significant advancements in pharmacological treatment, interventional and surgical options are still viable treatments for patients with pulmonary arterial hypertension (PAH), particularly idiopathic PAH. Herein, we review the interventional and surgical treatments for PAH. Atrial septostomy and the Potts shunt can be useful bridging tools for lung transplantation (Ltx), which remains the final surgical treatment among patients who are refractory to any other kind of therapy. Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) remains the ultimate bridging therapy for patients with severe PAH. More importantly, VA-ECMO plays a crucial role during Ltx and provides necessary left ventricular conditioning during the initial postoperative period. Pulmonary denervation may potentially be a new way to ensure better transplant-free survival among patients with the aforementioned disease. However, high-quality randomized controlled trials are needed. As established, obtaining the Eisenmenger physiology among patients with severe pulmonary hypertension by creating artificial defects is associated with improved survival. However, right-to-left shunting may be harmful after Ltx. Closure of the artificially created defects may carry some risk associated with cardiac surgery, especially among patients with Potts shunts. In conclusion, PAH requires an interdisciplinary approach using pharmacological, interventional, and surgical modalities.

Advanced Surgical and Percutaneous Approaches to Pulmonary Vascular Disease

Despite progress in modern medical therapy, pulmonary hypertension remains an unremitting disease. Once severe or refractory to medical therapy, advanced percutaneous and surgical interventions can palliate right ventricular overload, bridge to transplantation, and overall extend a patient's course. These approaches include atrial septostomy, Potts shunt, and extracorporeal life support. Bilateral lung transplantation is the ultimate treatment for eligible patients, although the need for suitable lungs continues to outpace availability. Measures such as ex vivo lung perfusion are ongoing to expand donor lung availability, increase rates of transplant, and decrease waitlist mortality.

Update on pediatric pulmonary arterial hypertension

PURPOSE OF REVIEW

Pulmonary arterial hypertension (PAH) causes high morbidity and mortality in children. In this review, we discuss advances in diagnosis and treatment of this disorder.

RECENT FINDINGS

Proceedings published from the 2018 World Symposium updated the definition of pulmonary hypertension to include all adults and children with mean pulmonary artery pressure more than 20 mmHg. Targeted PAH therapy is increasingly used off-label, but in 2017, bosentan became the first Food and Drug Administration-targeted PAH therapy approved for use in children.

SUMMARY

In recent years, advanced imaging and clinical monitoring have allowed improved risk stratification of pulmonary hypertension patients. New therapies, approved in adults and used off-label in pediatric patients, have led to improved outcomes for affected children.

Study of the effect of Occlutech Atrial Flow Regulator on symptoms, hemodynamics, and echocardiographic parameters in advanced pulmonary arterial hypertension

Optimal sized balloon atrial septostomy improves hemodynamics in advanced pulmonary arterial hypertension. Occlutech Atrial Flow Regulator is designed to provide an atrial septal fenestration diameter titrated according to the age and right atrial pressures. This observational study analyzed symptoms, exercise distance, oxygen saturations, hemodynamics and echocardiographic parameters after Atrial Flow Regulator implantation in patients with syncope or right-heart failure. Patients with high-risk predictors of mortality during septostomy were scrutinized. Thirty-nine patients (9 children) with syncope (34/39) or right-heart failure (27/39) underwent Atrial Flow Regulator implantation without procedural complications. Six-minute walk distance increased from 310 ± 158.2 to 376.4 ± 182.6 m, none developed syncope. Oxygen saturations reduced from 96.4 ± 6.4% to 92 ± 4.9% at rest and further to 80.3 ± 5.9% on exercise. Right atrial pressures reduced from 9.4 ± 5 (2-27) mmHg to 6.9 ± 2.6 (1-12) mmHg, while cardiac index increased from 2.4 ± 0.8 (0.98-4.3) to 3 ± 1 (1.1-5.3) L/min/m² and systemic oxygen transport increased from 546.1 ± 157.9 (256.2-910.5) to 637.2 ± 191.1 (301.3-1020.2) ml/min. Echocardiographic improvement included significant reduction of pericardial effusion and inferior caval congestion at a median follow-up of 37 months. Overall survival improved except two early and one late deaths in high-risk patients. Five of seven patients with advanced disease and key hemodynamic predictors of mortality survived. Acute hemodynamic benefits in pulmonary arterial hypertension after Atrial Flow Regulator were improved cardiac output, systemic oxygen transport, and reduced right atrial pressures. Improvement of symptoms especially syncope, exercise duration, and right ventricular systolic function as well as device patency were sustained on mid-term follow-up. Implantation was safe in all including young children without procedural complications. Mortality was noted only in patients who had high-risk predictors and patients at advanced stage of the disease.

Influence of advanced pulmonary vascular remodeling on accuracy of echocardiographic parameters of left ventricular filling pressure

Evaluation of left ventricular filling pressure plays an important role in the clinical management of pulmonary hypertension. However, the accuracy of echocardiographic parameters for the determination of left ventricular filling pressure in the presence of pulmonary vascular lesions has not been fully addressed. We retrospectively investigated 124 patients with pulmonary hypertension due to pulmonary vascular lesions (noncardiac pulmonary hypertension group) and 113 patients with ischemic heart disease (control group) who underwent right heart catheterization and echocardiography. The noncardiac pulmonary hypertension group was subdivided into less-advanced and advanced groups according to median pulmonary vascular resistance. Pulmonary artery wedge pressure was determined as left ventricular filling pressure. As echocardiographic parameters of left ventricular filling pressure, the ratio of early- (E) to late-diastolic transmitral flow velocity (E/A), ratio of E to early-diastolic mitral annular velocity (E/e′), and left atrial volume index were measured. In the less-advanced noncardiac pulmonary hypertension and control groups, positive correlations were observed between pulmonary artery wedge pressure and late-diastolic transmitral flow velocity (R = 0.41, P = 0.002 and R = 0.71, P < 0.001, respectively) and left atrial volume index (R = 0.53, P < 0.001 and R = 0.41, P < 0.001), whereas in the advanced noncardiac pulmonary hypertension group, pulmonary artery wedge pressure was only correlated with left atrial volume index (R = 0.27, P = 0.032). In the controls, only pulmonary artery wedge pressure determined E (β = 0.48, P < 0.001), whereas both pulmonary artery wedge pressure and pulmonary vascular resistance were independent determinants of E (β = 0.29, P < 0.001 and β = –0.28, P = 0.001, respectively) in the noncardiac pulmonary hypertension group. In conclusion, in the presence of advanced pulmonary vascular lesions, conventional echocardiographic parameters may not accurately reflect left ventricular filling pressure. Elevated pulmonary vascular resistance would lower the E, even when pulmonary artery wedge pressure is elevated, resulting in blunting of echocardiographic parameters for the detection of elevated left ventricular filling pressure.

Potts anastomosis in children with severe pulmonary arterial hypertension and atrial septal defect

Aims

Potts shunt has been proposed as a bridge or alternative to lung transplantation for children with severe and drug‐refractory suprasystemic pulmonary arterial hypertension (PAH). We describe the management of the atrial shunt when a Potts shunt is planned in refractory PAH.

Methods and results

We report a case series of children in whom a Potts shunt was done for severe PAH associated with an atrial septal defect to illustrate the different clinical and haemodynamic scenarios. Five children (2 to 13 years) underwent a Potts shunt: three surgical, one percutaneous Potts shunt, and one percutaneous stenting of a restrictive arterial duct. All had associated atrial septal defect. Those who had generalized cyanosis before the procedure had a complicated postoperative course and required longer ventilatory and inotropic support, except the one who had atrial septal defect closure before the Potts shunt. One of the three cyanotic patients died. Two patients with left‐to‐right shunt before the Potts shunt had an uncomplicated postoperative course.

Conclusions

Shunt physiology is only partially predictable after the Potts shunt in children with PAH and atrial septal defect. Abrupt drop in left ventricle preload while the right ventricle is decompressed can potentially be prevented by atrial septal defect closure prior to the Potts shunt.

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.

Pediatric Pulmonary Arterial Hypertension

Pulmonary hypertension (PH), the syndrome of increased pressure in the pulmonary arteries, is associated with significant morbidity and mortality for affected children and is associated with a variety of potential underlying causes. Several pulmonary arterial hypertension-targeted therapies have become available to reduce pulmonary artery pressure and improve outcome, but there is still no cure for most patients. This review provides a description of select causes of PH encountered in pediatrics and an update on the most recent data pertaining to evaluation and management of children with PH. Available evidence for specific classes of PH-targeted therapies in pediatrics is discussed.

Evolving Paradigms in the Treatment of Atrial Septal Defects With Pulmonary Arterial Hypertension

Atrial septal defects are one of the most frequently diagnosed congenital heart defects in adulthood. The presence of concurrent moderate or severe pulmonary arterial hypertension without Eisenmenger syndrome at the time of diagnosis can make for a challenging clinical scenario. There is continually evolving literature to determine the ideal approach to this subset of patients. Here we aim to review the clinical presentation, history, medical therapy, and closure options for atrial septal defects-pulmonary arterial hypertension with predominant left-to-right shunting, in the absence of Eisenmenger syndrome.

Outcomes of Atrioseptostomy with Stenting in Patients with Pulmonary Arterial Hypertension from a Large Single-Institution Cohort

The aim of this study was to analyze results of stenting atrioseptostomy in patients with pulmonary arterial hypertension and a different level of risk for one-year mortality that is not well described. Patients that underwent atrioseptostomy with stenting were retrospectively divided in two groups: "intermediate" (n = 55) or "high" risk (n = 13), according to the 2015 ESC/ESR guideline. Results of atrioseptostomy were assessed during hospital period and at follow-up. Patients from "intermediate" risk group demonstrated lower mortality rate (10/55, vs. 6/13) during the course of the study period, as well as higher freedom from lung transplantation or Potts shunt. At discharge, patients of both groups presented improvement in functional class and mobility. Patients from "intermediate" risk group showed longer 6-min walking distance, and lower levels of brain natriuretic peptide. At the latest follow-up, stable position and full patency of stents with right-to-left or bidirectional shunt at atrial level and absence of syncope was confirmed in patients of both groups. Patients from the "intermediate" risk group demonstrated higher functional class, better performance of walking test, and lower levels of brain natriuretic peptide. Stenting atrioseptostomy reliably secured interatrial communication and improved clinical condition in patients with idiopathic pulmonary arterial hypertension. Mid-term results were better in "intermediate" risk group.

The evolving role of interventional cardiology in the treatment of pulmonary hypertension

Pulmonary hypertension (PH) is a heterogeneous group of diseases defined by a mean pulmonary arterial pressure greater than 20 mmHg. Clinically, PH is classified into five groups and the group of PH generally defines the cause of PH and the therapeutic options. Currently, medical therapies that target the prostacyclin, endothelin, and nitric oxide pathways are used in pulmonary arterial hypertension and chronic thromboembolic PH (CTEPH) patients. Moreover, surgery can improve outcomes in PH as pulmonary thromboendarterectomy can be curative for CTEPH and lung transplantation is used for end-stage PH. Despite these diverse treatment options, PH patients continue to have high symptom burden and poor long-term outcomes. However, advances in percutaneous technology are opening new avenues for the management of PH. In this review, we discuss the available data supporting the use of four interventional procedures: balloon atrial septostomy, transcatheter Potts shunt, balloon pulmonary angioplasty, and pulmonary artery denervation for the treatment of PH. These procedures provide hemodynamic and functional improvements in PH patients, but they come with their own unique risk profiles. Hopefully, these procedures will continue to be refined and thereby provide a venue for interventional cardiology to safely and effectively improve outcomes for PH moving forward.

Postpartum Pulmonary Hypertension Masquerading as Submassive Pulmonary Embolism: A Case Report and a Literature Review

Postpartum pulmonary hypertension (PPPHT) is an extremely rare disorder, with few reported cases. Late diagnosis and treatment are associated with significant morbidity and mortality. We present an 18-year-old female patient who presented four-week postpartum with a typical submissive pulmonary embolism picture subsequently diagnosed as postpartum pulmonary hypertension. The patient had an excellent response to treatment, with a dramatic improvement in her functional status. The authors aim to urge physicians to keep this rare disorder in mind as timely and accurate diagnosis is crucial for management—additionally, the importance of counseling patients about the imminent risks associated with planned future pregnancies.

Pulmonary Hypertension in an Oncologic Intensive Care Unit

Pulmonary hypertension (PH) is the condition of elevated pressures in the pulmonary circulation. PH can develop acutely in patients with critical illness such as acute respiratory distress syndrome, sepsis, massive pulmonary embolism, left ventricular dysfunction, or after surgery. In a cancer patient, unique etiologies such as myeloproliferative disorders, tyrosine kinase inhibitors, or tumor emboli may result in PH. Early recognition and treatment of the causative condition may reverse acute PH or return chronic PH to its baseline status. Progression of the disease or its decompensation due to infection, a thromboembolic event, or other triggers can lead to admission to an intensive care unit. Regardless of etiology, the development or worsening of PH may precipitate hypoxemia, hemodynamic instability, or right ventricular failure, which can be challenging to manage or even fatal. In select cases, rapid institution of advanced treatment modalities may be warranted. This chapter reviews the etiology, epidemiology, pathophysiology, clinical features, diagnosis, and prognosis of PH and presents a comprehensive analysis of PH and right heart failure management strategies in the critical care setting. In particular, a unique perspective on oncologically relevant PH is provided.

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.

The right treatment for the right ventricle

PURPOSE OF REVIEW

Right ventricular (RV) function is an important determinant of morbidity and mortality in patients with pulmonary arterial hypertension (PAH). Although substantial progress has been made in understanding the development of RV failure in the last decennia, this has not yet resulted in the development of RV selective therapies. In this review, we will discuss the current status on the treatment of RV failure and potential novel therapeutic strategies that are currently being investigated in clinical trials.

RECENT FINDINGS

Increased afterload results in elevated wall tension. Consequences of increased wall tension include autonomic disbalance, metabolic shift and inflammation, negatively affecting RV contractility. Compromised RV systolic function and low cardiac output activate renin-angiotensin aldosterone system, which leads to fluid retention and further increase in RV wall tension. This vicious circle can be interrupted by directly targeting the determinants of RV wall tension; preload and afterload by PAH-medications and diuretics, but is also possibly by restoring neurohormonal and metabolic disbalance, and inhibiting maladaptive inflammation. A variety of RV selective drugs are currently being studied in clinical trials.

SUMMARY

Nowadays, afterload reduction is still the cornerstone in treatment of PAH. New treatments targeting important pathobiological determinants of RV failure directly are emerging.

Use of Balloon Atrial Septostomy in Patients With Advanced Pulmonary Arterial Hypertension: A Systematic Review and Meta-Analysis

BACKGROUND

Despite the use and purported benefits of balloon atrial septostomy (BAS), its safety, efficacy, and therapeutic role in the setting of advanced pulmonary arterial hypertension (PAH) are not well defined.

OBJECTIVE

The goal of this study was to conduct a systematic review and meta-analysis to better determine the evidence supporting the use of BAS in PAH.

METHODS

MEDLINE, Scopus, Cochrane Library, and Clinicaltrials.gov were searched from inception through May 2018 for original studies reporting outcomes with PAH prior to and following BAS. Studies comparing BAS vs other septostomy procedures were excluded. Weighted mean differences and 95% CIs were pooled by using a random effects model.

RESULTS

Sixteen studies comprising 204 patients (mean age, 35.8 years; 73.1% women) were included. Meta-analysis revealed significant reductions in right atrial pressure (-2.77 mm Hg [95% CI, -3.50, -2.04]; P < .001) and increases in cardiac index (0.62 L/min/m² [95% CI, 0.48, 0.75]; P < .001) and left atrial pressure (1.86 mm Hg [95% CI, 1.24, 2.49]; P < .001) following BAS, along with a significant reduction in arterial oxygen saturation (-8.45% [95% CI, -9.93, -6.97]; P < .001). The pooled incidence of procedure-related (48 h), short-term (≤ 30 day), and long-term (> 30 days up to a mean follow-up of 46.5 months) mortality was 4.8% (95% CI, 1.7%, 9.0%), 14.6% (95% CI, 8.6%, 21.5%), and 37.7% (95% CI, 27.9%, 47.9%), respectively.

CONCLUSIONS

The present analysis suggests that BAS is relatively safe in advanced PAH, with beneficial hemodynamic effects. The relatively high postprocedural and short-term survival with less impressive long-term survival suggest a bridging role for BAS; its contribution to this change needs to be verified by using a comparator group.

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.

Paediatric pulmonary arterial hypertension: updates on definition, classification, diagnostics and management

Paediatric pulmonary arterial hypertension (PAH) shares common features of adult disease, but is associated with several additional disorders and challenges that require unique approaches. This article discusses recent advances, ongoing challenges and distinct approaches for the care of children with PAH, as presented by the Paediatric Task Force of the 6th World Symposium on Pulmonary Hypertension. We provide updates of the current definition, epidemiology, classification, diagnostics and treatment of paediatric PAH, and identify critical knowledge gaps. Several features of paediatric PAH including the prominence of neonatal PAH, especially in pre-term infants with developmental lung diseases, and novel genetic causes of paediatric PAH are highlighted. The use of cardiac catheterisation as a diagnostic modality and haemodynamic definitions of PAH, including acute vasoreactivity, are addressed. Updates are provided on issues related to utility of the previous classification system to reflect paediatric-specific aetiologies and approaches to medical and interventional management of PAH, including the Potts shunt. Although a lack of clinical trial data for the use of PAH-targeted therapy persists, emerging data are improving the identification of appropriate targets for goal-oriented therapy in children. Such data will likely improve future clinical trial design to enhance outcomes in paediatric PAH.

Potts Shunt to Be Preferred Above Atrial Septostomy in Pediatric Pulmonary Arterial Hypertension Patients: A Modeling Study

Aims: To quantitatively evaluate the basic pathophysiological process involved in the creation of Eisenmenger syndrome in pediatric pulmonary arterial hypertension (PAH) patients by either atrial septostomy (AS) or Potts shunt (PS) as well as to predict the effects of AS or PS in future PAH patients.

Methods: The multi-scale lumped parameter CircAdapt model of the cardiovascular system was used to investigate the effects of AS and PS on cardiovascular hemodynamics and mechanics, as well as on oxygen saturation in moderate to severe PAH. The reference simulation, with cardiac output set to 2.1 l/min and mean systemic pressure to 61 mmHg, was used to create a compensated moderate PAH simulation with mPAP 50 mmHg. Thereupon we created a range of decompensated PAH simulations in which mPAP was stepwise increased from 50 to 80 mmHg. Then we simulated for each level of mPAP the acute effects of either PS or AS with connection diameters ranging between 0–16 mm.

Results: For any mPAP level, the effect on shunt flow size is much larger for the PS than for AS. Whereas right ventricular pump work in PS is mainly dependent on mPAP, in AS it depends on both mPAP and the size of the defect. The effects on total cardiac pump work were similar for PS and AS. As expected, PS resulted in a drastic decrease of lower body oxygen saturation, whereas in AS both the upper and lower body oxygen saturation decreased, though not as drastically as in PS.

Conclusion: Our simulations support the opinion that a PS can transfer suprasystemic PAH to an Eisenmenger physiology associated with a right-to-left shunt at the arterial level. Contrary to the current opinion that PS in PAH will decompress and unload the right ventricle, we show that while a PS does lead to a decrease in mPAP toward mean systemic arterial pressure, it does not unload the right ventricle because it mainly diverts flow from the pulmonary arterial system toward the lower body systemic arteries.

Evaluation and Management of Right-Sided Heart Failure: A Scientific Statement From the American Heart Association

Background and Purpose:

The diverse causes of right-sided heart failure (RHF) include, among others, primary cardiomyopathies with right ventricular (RV) involvement, RV ischemia and infarction, volume loading caused by cardiac lesions associated with congenital heart disease and valvular pathologies, and pressure loading resulting from pulmonic stenosis or pulmonary hypertension from a variety of causes, including left-sided heart disease. Progressive RV dysfunction in these disease states is associated with increased morbidity and mortality. The purpose of this scientific statement is to provide guidance on the assessment and management of RHF.

Methods:

The writing group used systematic literature reviews, published translational and clinical studies, clinical practice guidelines, and expert opinion/statements to summarize existing evidence and to identify areas of inadequacy requiring future research. The panel reviewed the most relevant adult medical literature excluding routine laboratory tests using MEDLINE, EMBASE, and Web of Science through September 2017. The document is organized and classified according to the American Heart Association to provide specific suggestions, considerations, or reference to contemporary clinical practice recommendations.

Results:

Chronic RHF is associated with decreased exercise tolerance, poor functional capacity, decreased cardiac output and progressive end-organ damage (caused by a combination of end-organ venous congestion and underperfusion), and cachexia resulting from poor absorption of nutrients, as well as a systemic proinflammatory state. It is the principal cause of death in patients with pulmonary arterial hypertension. Similarly, acute RHF is associated with hemodynamic instability and is the primary cause of death in patients presenting with massive pulmonary embolism, RV myocardial infarction, and postcardiotomy shock associated with cardiac surgery. Functional assessment of the right side of the heart can be hindered by its complex geometry. Multiple hemodynamic and biochemical markers are associated with worsening RHF and can serve to guide clinical assessment and therapeutic decision making. Pharmacological and mechanical interventions targeting isolated acute and chronic RHF have not been well investigated. Specific therapies promoting stabilization and recovery of RV function are lacking.

Conclusions:

RHF is a complex syndrome including diverse causes, pathways, and pathological processes. In this scientific statement, we review the causes and epidemiology of RV dysfunction and the pathophysiology of acute and chronic RHF and provide guidance for the management of the associated conditions leading to and caused by RHF.

Cardiopulmonary Resuscitation in Infants and Children With Cardiac Disease: A Scientific Statement From the American Heart Association

Cardiac arrest occurs at a higher rate in children with heart disease than in healthy children. Pediatric basic life support and advanced life support guidelines focus on delivering high-quality resuscitation in children with normal hearts. The complexity and variability in pediatric heart disease pose unique challenges during resuscitation. A writing group appointed by the American Heart Association reviewed the literature addressing resuscitation in children with heart disease. MEDLINE and Google Scholar databases were searched from 1966 to 2015, cross-referencing pediatric heart disease with pertinent resuscitation search terms. The American College of Cardiology/American Heart Association classification of recommendations and levels of evidence for practice guidelines were used. The recommendations in this statement concur with the critical components of the 2015 American Heart Association pediatric basic life support and pediatric advanced life support guidelines and are meant to serve as a resuscitation supplement. This statement is meant for caregivers of children with heart disease in the prehospital and in-hospital settings. Understanding the anatomy and physiology of the high-risk pediatric cardiac population will promote early recognition and treatment of decompensation to prevent cardiac arrest, increase survival from cardiac arrest by providing high-quality resuscitations, and improve outcomes with postresuscitation care.

Diagnosis, Evaluation and Treatment of Pulmonary Arterial Hypertension in Children

Pulmonary Hypertension (PH), the syndrome of elevated pressure in the pulmonary arteries, is associated with significant morbidity and mortality for affected children. PH is associated with a wide variety of potential underlying causes, including cardiac, pulmonary, hematologic and rheumatologic abnormalities. Regardless of the cause, for many patients the natural history of PH involves progressive elevation in pulmonary arterial resistance and pressure, right ventricular dysfunction, and eventually heart failure. In recent years, a number of pulmonary arterial hypertension (PAH)-targeted therapies have become available to reduce pulmonary artery pressure and improve outcome. A growing body of evidence in both the adult and pediatric literature demonstrates enhanced quality of life, functional status, and survival among treated patients. This review provides a description of select etiologies of PH seen in pediatrics and an update on the most recent data pertaining to evaluation and management of children with PH/PAH. The available evidence for specific classes of PAH-targeted therapies in pediatrics is additionally discussed.

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.

The 2017 Seventh World Congress of Pediatric Cardiology & Cardiac Surgery: week in review - interventional cardiology

The interventional cardiology track at the 7th World Congress of Pediatric Cardiology and Cardiac Surgery reflects the pivotal position of transcatheter interventions in the future of our speciality. The highlights of the week are outlined in this review.

Pulmonary hypertension: diagnosis, imaging techniques, and novel therapies

Pulmonary hypertension (PH), defined as the elevation of mean pulmonary arterial pressure (mPAP) above 25 mmHg, has numerous causes, which the World Health Organization (WHO) has divided into five distinct categories based upon the underlying mechanism of action. This review will explore the pathophysiology, diagnostic testing, and treatment of PH. Identification of PH depends on a strong clinical suspicion, a detailed history, and a thorough physical exam. We review the evidence supporting experimental and clinical laboratory parameters for diagnosis and monitoring of PH. Transthoracic echocardiogram (TTE) is the initial screening test of choice. This review will detail specific echocardiographic techniques for the assessment and classification of PH. Furthermore, the importance of advanced imaging, including computed tomography (CT) and magnetic resonance imagining (MRI) is explored. New developments in pharmacology, percutaneous intervention, and surgical approaches are summarized. Finally, we will address the tools available to predict morbidity and mortality.

Pulmonary Hypertension in Children

The prevalence of PH is increasing in the pediatric population, because of improved recognition and increased survival of patients, and remains a significant cause of morbidity and mortality. Recent studies have improved the understanding of pediatric PH, but management remains challenging because of a lack of evidence-based clinical trials. The growing contribution of developmental lung disease requires dedicated research to explore the use of existing therapies as well as the creation of novel therapies. Adequate study of pediatric PH will require multicenter collaboration due to the small numbers of patients, multifactorial disease causes, and practice variability.

Management of obese patients with respiratory failure - A practical approach to a health care issue of increasing significance

In the general population, prevalence of obesity is increasing continuously. Concomitantly, a growing number of obese patients with severe illnesses presents at intensive care units (ICU). Particularly respiratory management of this patient group poses a challenge to intensive care physicians because of differences in respiratory anatomy and physiology in obese compared to non-obese individuals. Aim of this review is to present treatment options for critically ill obese patients requiring mechanical ventilation based on current studies concerning patient positioning, ventilatory regimen as well as extended therapy with veno-venous extracorporeal membrane oxygenation (ECMO). The ideal concept for respiratory management depends on multiple aspects and has to be determined individually. Knowledge of altered respiratory anatomy and physiology in obese patients and possible treatment options may facilitate respiratory management in this patient group.

Pulmonary Arteriovenous Fistula with Pulmonary Hypertension - To Close or Not to Close?

A 37-year-old female presented to our facility suffering from exertional dyspnea for 2-3 months. Her chest x-ray showed a nodular shadow in the right lower lung, and chest CT revealed a pulmonary arteriovenous fistula (PAVF). Subsequent echocardiographic examination detected no intra-cardiac shunt but did indicate pulmonary hypertension as evidenced by a tricuspid regurgitation flow velocity of 4.17 M/sec. Contrast echocardiography with antecubital vein injection of agitated normal saline demonstrated visualization of the left heart chambers compatible with PAVF. At cardiac catheterization, pulmonary arterial pressure was 59/26 mmHg, mean 34 mmHg. Because there was no intra-cardiac communication detected, primary pulmonary hypertension was tentatively diagnosed. Pulmonary angiography demonstrated a PAVF arising from the lower right pulmonary artery, forming a secular structure on its course in draining into the left atrium through a long pulmonary vein. In this particular anomaly, a concurrence of PAVF with pulmonary hypertension, we judged that the PAVF might serve as a safety valve for pulmonary hypertension and should not be closed. We therefore left the PAVF untreated and thereafter provided medical management for this patient. The concomitant presence of PAVF and pulmonary hypertension is a rare clinical condition. The ultimate treatment strategy for this uncommon condition should be carefully considered.

KEY WORDS

Computed tomography; Contrast echocardiography; Pulmonary angiography; Pulmonary arteriovenous fistula; Pulmonary hypertension.