Hemodynamics of patients developing pulmonary arterial hypertension after shunt closure

The role and mechanism of thrombospondin-4 in pulmonary arterial hypertension associated with congenital heart disease

BACKGROUND

Due to a special hemodynamic feature, pulmonary vascular disease in pulmonary arterial hypertension associated with congenital heart disease (PAH-CHD) has two stages: reversible and irreversible. So far, the mechanism involved in the transition from reversible to irreversible stage is elusive. Moreover, no recognized and reliable assessments to distinguish these two stages are available. Furthermore, we found that compared with control and reversible PAH, thrombospondin-4 (THBS4) was significantly upregulated in irreversible group by bioinformatic analysis. Hence, we further verify and investigate the expression and role of THBS4 in PAH-CHD.

METHODS

We established the monocrotaline plus aorto-cava shunt-induced (MCT-AV) rat model. We measured the expression of THBS4 in lung tissues from MCT-AV rats. Double immunofluorescence staining of lung tissue for THBS4 and α-SMA (biomarker of smooth muscle cells) or vWF (biomarker of endothelial cells) to identify the location of THBS4 in the pulmonary artery. Primary pulmonary artery smooth muscle cells (PASMCs) were cultivated, identified, and used in this study. THBS4 was inhibited and overexpressed by siRNA and plasmid, respectively, to explore the effect of THBS4 on phenotype transformation, proliferation, apoptosis, and migration of PASMCs. The effect of THBS4 on pulmonary vascular remodeling was evaluated in vivo by adeno-associated virus which suppressed THBS4 expression. Circulating level of THBS4 in patients with PAH-CHD was measured by ELISA.

RESULTS

THBS4 was upregulated in the lung tissues of MCT-AV rats, and was further upregulated in severe pulmonary vascular lesions. And THBS4 was expressed mainly in PASMCs. When THBS4 was inhibited, contractile markers α-SMA and MYH11 were upregulated, while the proliferative marker PCNA was decreased, the endothelial-mensenchymal transition marker N-cad was downregulated, proapototic marker BAX was increased. Additionally, proliferation and migration of PASMCs was inhibited and apoptosis was increased. Conversely, THBS4 overexpression resulted in opposite effects. And the impact of THBS4 on PASMCs was probably achieved through the regulation of the PI3K/AKT pathway. THBS4 suppression attenuated pulmonary vascular remodeling. Furthermore, compared with patients with simple congenital heart disease and mild PAH-CHD, the circulating level of THBS4 was higher in patients with severe PAH-CHD.

CONCLUSIONS

THBS4 is a promising biomarker to distinguish reversible from irreversible PAH-CHD before repairing the shunt. THBS4 is a potential treatment target in PAH-CHD, especially in irreversible stage.

Development and Validation of a Nomogram of Persistent Pulmonary Hypertension in Adult Pretricuspid Shunts After Correction

BACKGROUND

Pretricuspid shunts have been associated with poorer survival rates in patients with Eisenmenger syndrome compared with postricuspid shunts and complex lesions. However, the risk stratification for persistent pulmonary hypertension (PH) in this population remains uncertain.

METHODS AND RESULTS

We retrospectively enrolled 103 patients with pretricuspid shunts with high total pulmonary resistance >4.5 Wood units (estimated pulmonary vascular resistance ≥3 Wood units). During a mean±SD follow-up of 20.95±24.84 months, 32 patients developed postoperative persistent PH after shunt correction. We identified 3 significant predictors of postoperative persistent PH, including mean pulmonary artery pressure after inhaled oxygen ≥40.5 mm Hg (odds ratio [OR], 7.78 [95% CI, 2.02-30.03]; P<0.01), total pulmonary resistance after inhaled oxygen ≥6.5 Wood units (estimated pulmonary vascular resistance ≥5 Wood units; OR, 12.23 [95% CI, 2.12-70.46]; P<0.01), and artery oxygen saturation at rest <95% (OR, 3.34 [95% CI, 1.07-10.44]; P=0.04). We established the prediction model with the C-statistics of 0.85 (95% CI, 0.77-0.93; P<0.01), and the C-statistic was 0.83 (95% CI, 0.80-0.86) after bootstrapping 10 000 times with a good performance of the nomogram calibration curve for predicting persistent PH.

CONCLUSIONS

Our study presents a multivariable risk stratification model for persistent PH after shunt correction in adults with pretricuspid shunts. This model, based on 3 hemodynamic predictors after inhaled oxygen, may assist in identifying individuals at higher risk of persistent PH after shunt correction.

Feasibility of Treat and Repair Strategy in Congenital Heart Defects With Pulmonary Arterial Hypertension

Background

A treatment strategy for congenital heart defects with moderate to severe pulmonary arterial hypertension (PAH) has not been established.

Objectives

The purpose of this study was to identify patients in whom a treat and repair strategy was considered and to examine pretreatment variables associated with successful defect repair.

Methods

Patients with atrial or ventricular septal defect and PAH (pulmonary vascular resistance [PVR] ≥ 5 Wood units) eligible for the treat and repair strategy were included. Hemodynamics among pretreatment, pre-repair, and post-defect repair were compared. Clinical outcomes in patients with or without defect repair were also compared. Clinical outcomes included all-cause death, hospitalization for worsening pulmonary hypertension, and lung transplantation.

Results

Among 25 eligible for the treat and repair strategy, 20 underwent successful repair (repaired group) and 5 did not have a repair (unrepaired group). In the repaired group, PVR significantly decreased from 9.6 ± 2.6 WU at pretreatment to 5.0 ± 3.4 pre-repair (ß coefficient -4.6 [95% CI: -5.9 to -3.3]). The pulmonary to systemic blood flow ratio (Qp/Qs) increased from 1.5 ± 0.6 at pretreatment to 2.4 ± 1.3 pre-repair (ß coefficient 0.9 [95% CI: 0.4-1.38]). In the unrepaired group, pretreatment PVR decreased with treatment; however, PVR remained elevated. Qp/Qs did not change between pretreatment and post-treatment. The repaired group had a better prognosis than the unrepaired group (HR 0.092 [95% CI: 0.009-0.905]). Pretreatment mean pulmonary artery pressure, PVR, Qp/Qs, and arterial oxygen saturations were associated with undergoing defect repair.

Conclusions

In this small cohort, a treat and repair strategy was successfully used in a significant proportion of the patients with congenital heart defects with moderate to severe PAH.

Atrial septal defect-associated pulmonary hypertension with decompensated heart failure: outcomes after fenestrated device closure

BACKGROUND

Up to 90% of adults with untreated atrial septal defect will be symptomatic by 4th decade, and 30-49% will develop heart failure. 8-10% of these patients have pulmonary arterial hypertension with a female predominance regardless of age. We aimed to demonstrate that fenestrated closure can be safely performed in patients with decompensated heart failure and atrial septal defect-associated pulmonary arterial hypertension with improved outcome.

METHODS

Transcatheter fenestrated atrial septal defect closures (Occlutech GmbH, Jena, Germany) were performed on a compassionate-use basis in 5 consecutive adult patients with atrial septal defect-associated pulmonary arterial hypertension and severe heart failure with prohibitive surgical mortality risks. Change in systemic oxygen saturation, 6-minute walk test, NYHA class, echocardiographic and haemodynamic parameters were used as parameters of outcome.

RESULTS

All patients were female, mean age 48.8 ± 13.5 years, followed up for a median of 29 months (max 64 months). Significant improvements observed in the 6-minute walk test, and oxygen saturation comparing day 0 time point to all other follow-up time points data (B = 1.32, SE = 0.28, t (22.7) = -4.77, p = 0.0001); and in the haemodynamic data (including pulmonary vascular resistance and pulmonary pressure) (B = -0.60, SE = 0.22, t (40.2) = 2.74, p = .009). All patients showed improved right ventricular size and function along with NYHA class. There were no procedure-related complications.

CONCLUSION

Fenestrated atrial septal defect closure is feasible in adults with decompensated heart failure and atrial septal defect-associated pulmonary arterial hypertension. It results in sustained haemodynamic and functional improvement.

A Meta-Analysis of Atrial Septal Defect Closure in Patients With Severe Pulmonary Hypertension: Is There a Room for Poking Holes Amid Debate?

Severe pulmonary arterial hypertension (PAH) associated with atrial septal defect (ASD) poses a challenge to a closure of ASD, particularly severe PAH that persists even after pharmacological therapeutic strategy. Our study was aimed to evaluate this matter. A systematic literature search from several databases was conducted up until August 1st, 2023. A meta-analysis was undertaken on studies that reported hemodynamic measurements in ASD patients with severe PAH before and after closure. The primary objectives were the extent of improvement in all hemodynamic parameters following closure, and the secondary outcomes were major adverse cardiac events (MACEs) during follow-up. Our study comprised 10 studies with a total of 207 participants. Patients were divided into treat-and-repair and straight-to-repair groups based on the therapeutic strategy. Meta-analysis of all studies demonstrated significant improvement in mean pulmonary arterial pressure (mPAP), pulmonary vascular resistance (PVR), pulmonary vascular resistance index (PVRI), 6-minutes walking distance (6MWD), and lower prevalence of World Health Organization functional classes (WHO fc), particularly in the treat-and-repair strategy subgroup. Additionally, merely 4 of the 156 individuals died from cardiac causes, and only 1 required rehospitalization, indicating a low likelihood of MACEs arising. Our new findings support the notion that effective shunt closure can improve various hemodynamic parameters in carefully chosen patients with noncorrectable ASD-PAH. Further large and prospective observational studies are still warranted to validate these findings.

Utility of Follow-Up Echocardiograms in Uncomplicated Surgical Secundum Atrial Septal Defect Closures: Preliminary Analysis

INTRODUCTION

Though less common in the current era, surgical closure of secundum atrial septal defects (ASD2) is still performed in certain clinical situations. Guidelines currently recommend lifelong follow-up with transthoracic echocardiograms (TTE) for patients who have undergone a surgical ASD2 closure. The goal of this study was to determine the utility of follow-up TTE in patients who underwent an uncomplicated ASD2 closure.

METHODS

Chart review was performed on patients who had a surgical ASD2 closure between April 1, 1996, and August 30, 2021. Patients were excluded if they had other congenital heart disease, had a diagnosis of a residual ASD2, atrial/ventricular arrhythmias, pulmonary hypertension, heart failure, or did not have a follow-up TTE > 6 months after the procedure. The most recent TTEs and clinic notes were evaluated.

RESULTS

A total of 30 patients met the criteria. The median age at ASD2 surgery was 4.0 years (IQ; 1.9-10.5). ASD2 was closed via patch repair in 16 patients and primarily closed in 14 patients. The most recent TTE was performed a median of 9.5 years (IQ; 4.0, 14.7) after ASD2 closure. Two patients had mild right atrial and ventricular dilation, one patient had mild right atrial dilation, and one patient had mild right ventricular dilation. All other patients had qualitatively normal right-sided chamber sizes. All patients had normal biventricular function (left ventricular fractional shortening (median 36% (IQ; 33, 42)), no evidence of residual atrial shunts, and no evidence of pulmonary hypertension. No patient was on any cardiac medications at last clinic visit. Four patients were discharged from cardiology clinic and 10 patients were lost to follow-up. There were no deaths. Twenty-four patients had 46 repeat echocardiograms > 1 year after ASD2 with no change in clinical management.

CONCLUSION

In patients who underwent an uncomplicated ASD2 closure, there were no significant abnormalities noted on follow-up TTEs. The need for repeat lifetime TTEs and their frequency, in this uncomplicated population, should be reassessed if larger studies with longer follow-up confirm these initial findings.

Machine learning for clustering and postclosure outcome of adult CHD-PAH patients with borderline hemodynamics

BACKGROUND

Patients with uncorrected isolated simple shunts associated pulmonary arterial hypertension (PAH) had increased mortality. Treatment strategies for borderline hemodynamics remain controversial. This study aims to investigate preclosure characteristics and its association with postclosure outcome in this group of patients.

METHODS

Adults with uncorrected isolated simple shunts associated PAH were included. Peak tricuspid regurgitation velocity<2.8 m/sec with normalized cardiac structures was defined as the favorable study outcome. We applied unsupervised and supervised machine learning for clustering analysis and model constructions.

RESULTS

Finally, 246 patients were included. During a median follow-up of 414days, 58.49% (62/106) of patients with pretricuspid shunts achieved favorable outcome while 32.22% (46/127) of patients with post-tricuspid shunts. In unsupervised learning, two clusters were identified in both types of shunts. Generally, the oxygen saturation, pulmonary blood flow, cardiac index, dimensions of the right and left atrium, were the major features that characterized the identified clusters. Specifically, mean right atrial pressure, right ventricular dimension, and right ventricular outflow tract helped differentiate clusters in pretricuspid shunts while age, aorta dimension, and systemic vascular resistance helped differentiate clusters for post-tricuspid shunts. Notably, cluster 1 had better postclosure outcome than cluster 2 (70.83% vs 32.55%, p < .001 for pretricuspid and 48.10% vs 16.67%, p < .001 for post-tricuspid). However, models constructed from supervised learning methods did not achieve good accuracy for predicting the postclosure outcome.

CONCLUSIONS

There were two main clusters in patients with borderline hemodynamics, in which one cluster had better postclosure outcome than the other.

Progressive Memory Decline in a Patient With Atrial Septal Defect: Case Report and Literature Review

Atrial septal defect (ASD) is a common congenital anomaly that increases the risk of heart failure as well as strokes which can lead to cognitive impairment. The risk of stroke is higher when pulmonary hypertension develops and there is reversal of shunt. Stroke in ASD may be due to paradoxical emboli from the right heart or a left ventricular thrombus which develops as a result of atrial fibrillation, a common arrhythmia in ASD. We present a case of a 32-year-old Ghanaian man with history of ASD who presented with progressive memory loss with magnetic resonance imaging scan of the brain showing multiple infarcts, microvascular disease, and cerebral atrophy.

Updates in the management of congenital heart disease in adult patients

INTRODUCTION

Adults with congenital heart disease represent a highly diverse, ever-growing population. Optimal approaches to management of problems such as arrhythmia, sudden cardiac death, heart failure, transplant, application of advanced therapies and unrepaired shunt lesions are incompletely established. Efforts to strengthen our understanding of these complex clinical challenges and inform evidence-based practices are ongoing.

AREAS COVERED

This narrative review summarizes evidence underpinning current approaches to congenital heart disease management while highlighting areas requiring further investigation. A search of literature published in 'Medline,' 'EMBASE,' and 'PubMed' using search terms 'congenital heart disease,' 'arrhythmia,' 'sudden cardiac death,' 'heart failure,' 'heart transplant,' 'advanced heart failure therapy,' 'ventricular assist device (VAD),' 'mechanical circulatory support (MSC),' 'intracardiac shunt' and combinations thereof was undertaken.

EXPERT OPINION

Application of novel technologies in the diagnosis and management of arrhythmia has and will continue to improve outcomes in this population. Sudden death remains a prevalent problem with many persistent unknowns. Heart failure is a leading cause of morbidity and mortality. Improved access to specialist care, advanced therapies and cardiac transplant is needed. The emerging field of cardio-obstetrics will continue to define state-of-the-art care for the reproductive health of women with heart disease.

Canadian Cardiovascular Society 2022 Guidelines for Cardiovascular Interventions in Adults With Congenital Heart Disease

Interventions in adults with congenital heart disease (ACHD) focus on surgical and percutaneous interventions in light of rapidly evolving ACHD clinical practice. To bring rigour to our process and amplify the cumulative nature of evidence ACHD care we used the ADAPTE process; we systematically adjudicated, updated, and adapted existing guidelines by Canadian, American, and European cardiac societies from 2010 to 2020. We applied this to interventions related to right and left ventricular outflow obstruction, tetralogy of Fallot, coarctation, aortopathy associated with bicuspid aortic valve, atrioventricular canal defects, Ebstein anomaly, complete and congenitally corrected transposition, and patients with the Fontan operation. In addition to tables indexed to evidence, clinical flow diagrams are included for each lesion to facilitate a practical approach to clinical decision-making. Excluded are recommendations for pacemakers, defibrillators, and arrhythmia-directed interventions covered in separate designated documents. Similarly, where overlap occurs with other guidelines for valvular interventions, reference is made to parallel publications. There is a paucity of high-level quality of evidence in the form of randomized clinical trials to support guidelines in ACHD. We accounted for this in the wording of the strength of recommendations put forth by our national and international experts. As data grow on long-term follow-up, we expect that the evidence driving clinical practice will become increasingly granular. These recommendations are meant to be used to guide dialogue between clinicians, interventional cardiologists, surgeons, and patients making complex decisions relative to ACHD interventions.

Normalization of Four Different Types of Pulmonary Hypertension After Atrial Septal Defect Closure

Pulmonary hypertension (PH) is an established risk factor in patients with atrial septal defect (ASD), and its persistence after ASD closure is associated with increased mortality. Therefore, predictors for PH normalization after defect closure are needed. Multiple hemodynamic types of PH exist, but little is known about their prevalence and prognostic value for PH normalization after ASD closure. We carried out a retrospective study on 97 patients (76% female, median age at ASD closure 58 years) with four types of PH determined predominantly by right heart catheterization: hyperkinetic, pulmonary arterial hypertension, isolated post-capillary, and combined pre- and post-capillary. We investigated the frequency of the PH types and their prognostic significance for PH normalization after ASD closure. Frequency of PH types before ASD closure in our study was: hyperkinetic 55%, pulmonary arterial hypertension 10%, isolated post-capillary PH 24%, and combined PH 11%. Hyperkinetic PH type was positively associated with PH normalization after ASD closure (78% patients normalized), remaining a significant independent predictor when adjusted for age at closure, sex, heart failure, and NYHA. Hyperkinetic PH patients also had significantly better survival prognosis versus patients with other PH types (p = 0.04). Combined PH was negatively associated with PH normalization, with no patients normalizing. Pulmonary arterial hypertension and isolated post-capillary PH had intermediate rates of normalization (60 and 52%, respectively). In summary, all four hemodynamic types of PH are found in adult patients with ASD, and they can be used to stratify patients by their likelihood of PH normalization and survival after ASD closure.

Long-Term Survival of Adult Patients With Atrial Septal Defect With Regards to Defect Closure and Pulmonary Hypertension

Background

Atrial septal defect (ASD) is the most common congenital heart disease (CHD) in adults and pulmonary hypertension (PH) is an established risk factor. A decision whether to perform ASD closure, especially in elderly patients with PH, is a complex dilemma. The aim of our study was to compare long-term survival in patients with closed and open ASD.

Methods

A retrospective cohort study was performed on 427 patients with ASD (median age at diagnosis 38 years, IQR 18-56) out of which 186 patients (44%) manifested PH. ASD closure in patients with PH was only considered in patients without Eisenmenger syndrome with pulmonary vascular resistance < 5 WU. Median follow-up duration was 18 years (IQR 9-31 years). Kaplan-Meier and Cox proportional hazards survival analyses were performed to evaluate 12 potential predictors of survival.

Results

Defect closure was associated with improved long-term survival in ASD patients both with (P < 0.001) and without PH (P = 0.01) and this association was present also in patients over 40 years. The 20-year survival since diagnosis was significantly higher in patients with PH and closed ASD compared to those with PH and open ASD (65% vs. 41%). ASD closure was a significant independent predictor of long-term survival (P = 0.003) after accounting for age at diagnosis, PH, NYHA class, Eisenmenger syndrome, and mitral regurgitation. Significant negative independent predictors of survival were older age at diagnosis (P < 0.001), Eisenmenger syndrome (P < 0.001), and PH (P = 0.03).

Conclusion

ASD closure appears to be associated with improved long-term survival independently of age, PH, and other clinical variables.

Post-operative course of pulmonary artery pressure after complete atrioventricular canal defect repair

Complete atrioventricular canal defect is a CHD associated with intra-cardiac shunting of blood, which can lead to irreversible changes in pulmonary vascular resistance and pulmonary artery hypertension if unrepaired. Patients with Trisomy 21 are at risk for early development of pulmonary artery hypertension if left uncorrected.1,2.

OBJECTIVES

The purpose of this study is to describe the evolution of pulmonary artery hypertension after repair of complete atrioventricular canal defect and to determine the time to normalisation of pulmonary artery pressure in both patients with and without Trisomy 21.

METHODS

This is a single centre, retrospective analysis of patients with complete atrioventricular canal defect admitted for surgical repair at the University of Maryland Medical Center from 2005 to 2015. T-test or Mann-Whitney test and Chi-Square or Fisher's exact tests were used to compare the two groups (patients with Trisomy 21 and those without). Repeated measures of analysis of variance and serial measurement analysis were performed.

RESULTS

Twenty-nine patients meeting the inclusion criteria underwent repair of complete atrioventricular defects during the study period. The right ventricular pressure estimate remained elevated over time and did not show a significant difference between the two groups. Right ventricular to systolic blood pressure ratios for all patients remained > 0.5 over the time periods assessed.

CONCLUSIONS

Our study suggests that in patients with complete atrioventricular canal defects, the right ventricular pressure remains elevated and does not normalise on echocardiograms performed up to one year after surgery, suggesting a sustained elevation in pulmonary vascular resistance.

Patient selection, procedural planning and interventional guidance for non-valvular structural intervention

Percutaneous non-valvular structural interventions, encompassing patent foramen ovale, atrial or ventricular septal defect closure and left atrial appendage closure, are usually performed in young and healthy patients and represent a valid alternative to pharmacological or surgical interventions. In order to minimize procedural and device related complications, a careful pre-procedural planning together with an accurate intra-procedural imaging are crucial to improve patient's outcome. In this article, we review currently available evidence on patient selection, procedural planning and interventional guidance helping physician to determine who will derive the most benefit from the procedure.

Clinical application of pulmonary vascular resistance in patients with pulmonary arterial hypertension

Pulmonary arterial hypertension is a type of malignant pulmonary vascular disease, which is mainly caused by the increase of pulmonary vascular resistance due to the pathological changes of the pulmonary arteriole itself, which eventually leads to right heart failure and death. As one of the diagnostic indicators of hemodynamics, pulmonary vascular resistance plays an irreplaceable role in the pathophysiology, diagnosis and treatment of pulmonary arterial hypertension. It provides more references for the evaluation of pulmonary arterial hypertension patients. This article summarizes the clinical application of pulmonary vascular resistance in patients with pulmonary arterial hypertension.

Atrial septal defect in adulthood: a new paradigm for congenital heart disease

Atrial septal defects (ASDs) represent the most common congenital heart defect diagnosed in adulthood. Although considered a simple defect, challenges in optimal diagnostic and treatment options still exist due to great heterogeneity in terms of anatomy and time-related complications primarily arrhythmias, thromboembolism, right heart failure and, in a subset of patients, pulmonary arterial hypertension (PAH). Atrial septal defects call for tertiary expertise where all options may be considered, namely catheter vs. surgical closure, consideration of pre-closure ablation for patients with atrial tachycardia and suitability for closure or/and targeted therapy for patients with PAH. This review serves to update the clinician on the latest evidence, the nuances of optimal diagnostics, treatment options, and long-term follow-up care for patients with an ASD.

Fluid challenge and balloon occlusion testing in patients with atrial septal defects

INTRODUCTION

Careful, stepwise assessment is required in all patients with atrial septal defect (ASD) to exclude pulmonary vascular or left ventricular (LV) disease. Fluid challenge and balloon occlusion may unmask LV disease and post-capillary pulmonary hypertension, but their role in the evaluation of patients with 'operable' ASDs is not well established.

METHODS

We conducted a prospective study in three Italian specialist centres between 2018 and 2020. Patients selected for percutaneous ASD closure underwent assessment at baseline and after fluid challenge, balloon occlusion and both.

RESULTS

Fifty patients (46 (38.2, 57.8) years, 72% female) were included. All had a shunt fraction >1.5, pulmonary vascular resistance (PVR) <5 Wood Units (WU) and pulmonary arterial wedge pressure (PAWP) <15 mm Hg. Individuals with a PVR ≥2 WU at baseline (higher PVR group) were older, more symptomatic, with a higher baseline systemic vascular resistance (SVR) than the lower PVR group (all p<0.0001). Individuals with a higher PVR experienced smaller increases in pulmonary blood flow following fluid challenge (0.3 (0.1, 0.5) vs 2.0 (1.5, 2.8) L/min, p<0.0001). Balloon occlusion led to a more marked fall in SVR (p<0.0001) and a larger increase in systemic blood flow (p=0.024) in the higher PVR group. No difference was observed in PAWP following fluid challenge and/or balloon occlusion between groups; four (8%) patients reached a PAWP ≥18 mm Hg following the addition of fluid challenge to balloon occlusion testing.

CONCLUSIONS

In adults with ASD without overt LV disease, even small rises in PVR may have significant implications on cardiovascular haemodynamics. Fluid challenge may provide additional information to balloon occlusion in this setting.

Elevated Left and Right Atrial Pressures Long-Term After Atrial Septal Defect Correction: An Invasive Exercise Hemodynamic Study

Background

Despite correction of the atrial septal defect (ASD), patients experience atrial fibrillation frequently and have increased morbidity and mortality. We examined physical capacity, cardiac performance, and invasive hemodynamics in patients with corrected ASD.

Methods and Results

Thirty‐eight corrected patients with isolated secundum ASD and 19 age‐matched healthy controls underwent right heart catheterization at rest and during exercise with simultaneous expired gas assessment and echocardiography. Maximum oxygen uptake was comparable between groups (ASD 32.7±7.7 mL O₂/kg per minute, controls 35.2±7.5 mL O₂/kg per minute, P=0.3), as was cardiac index at both rest and peak exercise. In contrast, pulmonary artery wedge v wave pressures were increased at rest and peak exercise (rest: ASD 14±4 mm Hg, controls 10±5 mm Hg, P=0.01; peak: ASD 25±9 mm Hg, controls 14±9 mm Hg, P=0.0001). The right atrial v wave pressures were increased at rest but not at peak exercise. The transmural filling pressure gradient (TMFP) was higher at peak exercise among patients with ASD (10±6 mm Hg, controls 7±3 mm Hg, P=0.03). One third of patients with ASD demonstrated an abnormal hemodynamic exercise response defined as mean pulmonary artery wedge pressure ≥25 mm Hg and/or mean pulmonary artery pressure ≥35 mm Hg at peak exercise. These patients had significantly elevated peak right and left atrial a wave pressures, right atrial v wave pressures, pulmonary artery wedge v wave pressures, and transmural filling pressure compared with both controls and patients with ASD with a normal exercise response.

Conclusions

Patients with corrected ASD present with elevated right and in particular left atrial pressures at rest and during exercise despite preserved peak exercise capacity. Abnormal atrial compliance and systolic atrial function could predispose to the increased long‐term risk of atrial fibrillation.

Registration Information

clinicaltrials.gov. Identifier: NCT03565471.

Efficacy of treat-and-repair strategy for atrial septal defect with pulmonary arterial hypertension

OBJECTIVE

Therapeutic strategies for atrial septal defect (ASD) with severe pulmonary arterial hypertension (PAH) are controversial. This study aimed to evaluate the efficacy of PAH-specific medications and subsequent transcatheter closure (ie, treat-and-repair strategy) on clinical outcomes.

METHODS

We enrolled 42 patients who were referred to 13 institutions for consideration of ASD closure with concomitant PAH and underwent the treat-and-repair strategy. The endpoint was cardiovascular death or hospitalisation due to heart failure or exacerbated PAH.

RESULTS

At baseline prior to PAH-specific medications, pulmonary to systemic blood flow ratio (Qp:Qs), pulmonary vascular resistance (PVR), and mean pulmonary artery pressure (PAP) were 1.9±0.8, 6.9±3.2 Wood units and 45±15 mm Hg. Qp:Qs was increased to 2.4±1.2, and PVR and mean PAP were decreased to 4.0±1.5 Wood units and 35±9 mm Hg at the time of transcatheter ASD closure after PAH-specific medications. Transcatheter ASD closure was performed without any complications. During a median follow-up period of 33 months (1-126 months) after transcatheter ASD closure, one older patient died and one patient was hospitalised due to heart failure, but the other patients survived with an improvement in WHO functional class. PAP was further decreased after transcatheter ASD closure.

CONCLUSIONS

The treat-and-repair strategy results in low complication and mortality rates with a reduction in PAP in selected patients with ASD complicated with PAH who have a favourable response of medical therapy.

Transcatheter Closure of Atrial Septal Defect Associated With Pulmonary Artery Hypertension using Fenestrated Devices

In patients with pulmonary artery hypertension (PAH) associated with atrial septal defect (ASD), closure of ASD may carry significant risks. We aimed to evaluate the safety and efficacy of transcatheter closure of ASD in selected patients with PAH using a fenestrated device followed by pulmonary vasodilator therapy. During the 14.8-year period, 51 ASD patients (10 males, age 46 ± 18 years) with a mean pulmonary artery pressure (PAP) ≥ 35 mm Hg and/or systolic PAP ≥ 60 mm Hg, underwent closure with a fenestrated device. Of them, mean Qp/Qs ratio, systolic PAP and mean PAP were 2.6 ± 1.2, 73 ± 14 mm Hg, and 44 ± 8 mm Hg, respectively. A total of 35 patients received pulmonary vasodilator therapy. The New York Heart Association (NYHA) functional class improved at 3 to 6 months follow-up. (p < 0.001) Nineteen patients underwent repeated catheterization. A comparison of the hemodynamic parameters between baseline and repeated catheterization revealed significant decreases in both systolic and mean PAP (77 ± 11 vs 55 ± 14 mm Hg, p < 0.0001 & 48 ± 7 vs 37 ± 8 mm Hg, p = 0.001, respectively), pulmonary vascular resistance (PVR) (5.1 ± 2.3 vs 4.0 ± 1.7 WU, p = 0.011) and PVRi (7.7 ± 3.3 vs 6.2 ± 2.4 WU*m2, p = 0.024). After a follow-up period of 84 ± 45 months, 6 mortalities were noted in which 2 were due to cardiac causes. In conclusion, catheter closure of ASD in patients with PAH using a fenestrated device followed by vasodilator therapy is safe and effective.

Echocardiography for the Assessment of Pulmonary Hypertension and Congenital Heart Disease in the Young

While invasive assessment of hemodynamics and testing of acute vasoreactivity in the catheterization laboratory is the gold standard for diagnosing pulmonary hypertension (PH) and pulmonary vascular disease (PVD) in children, transthoracic echocardiography (TTE) serves as the initial diagnostic tool. International guidelines suggest several key echocardiographic variables and indices for the screening studies when PH is suspected. However, due to the complex anatomy and special physiological considerations, these may not apply to patients with congenital heart disease (CHD). Misinterpretation of TTE variables can lead to delayed diagnosis and therapy, with fatal consequences, or–on the other hand-unnecessary invasive diagnostic procedures that have relevant risks, especially in the pediatric age group. We herein provide an overview of the echocardiographic workup of children and adolescents with PH with a special focus on children with CHD, such as ventricular/atrial septal defects, tetralogy of Fallot or univentricular physiology. In addition, we address the use of echocardiography as a tool to assess eligibility for exercise and sports, a major determinant of quality of life and outcome in patients with PH associated with CHD.

Pulmonary arterial hypertension associated with congenital heart disease after defect repair: the effect of pregnancy

Background

An increasing number of patients with previously repaired congenital heart disease (CHD) present with pulmonary arterial hypertension (PAH). This can occur immediately after repair (residual PAH) or years later.

Case presentation

We present the case of a young woman who underwent repair of a ventricular septal defect in later childhood. Three years after repair, she was found to have significant residual PAH. She remained stable on PAH therapies, but a decade later decided to become pregnant against medical advice. She deteriorated during pregnancy and required escalation of PAH therapies and eventual admission to the intensive care unit, with an uneventful delivery at 32 weeks. Despite successful delivery, she remained symptomatic post-partum, with evidence of disease progression at right heart catheterisation.

Conclusions

All patients with repaired CHD should undergo routine screening for PAH. Early diagnosis and expert management, including the use of PAH therapies, is recommended to optimise outcome. Pregnancy is contraindicated in PAH patients, including patients with CHD, and requires an expert multidisciplinary approach to reduce morbidity and mortality when patients opt to proceed.

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.

Nestin represents a potential marker of pulmonary vascular remodeling in pulmonary arterial hypertension associated with congenital heart disease

OBJECTIVE

Reportedly, nestin was re-expressed in proliferative synthetic-type pulmonary artery smooth muscle cells (PASMCs) and obligatory for PASMC proliferation in pulmonary arterial hypertension (PAH). Accordingly, nestin is increased in pulmonary vascular lesions of congenital heart disease (CHD)-associated PAH patients. We tested the hypothesis whether nestin was re-expressed in proliferative synthetic-type PASMCs and associated with pulmonary vascular remodeling in CHD-PAH.

MATERIALS AND METHODS

Nestin expression was tested using lung tissues from CHD-PAH patients and monocrotaline (MCT) plus aortocaval (AV) shunt-induced PAH rats, human PASMCs (HPASMCs), and pulmonary artery endothelial cells (PAECs) and PASMCs from MCT-AV-induced PAH rats. The role and possible mechanism of nestin on HPASMC proliferation, apoptosis, cell cycle and migration were investigated by assays of CCK-8, EdU, TUNEL, flow cytometry, transwell chamber and immunoblotting assays.

RESULTS

Nestin was solely expressed in proliferative synthetic-type PASMCs, but rarely detected in PAECs. Nestin was barely detected in normal pulmonary arterioles and occlusive pulmonary vascular lesions. Its expression was robustly increased in developing pulmonary vasculature, but returned to normal levels at the late stage of pulmonary vascular remodeling in lung tissues from CHD-PAH patients and MCT-AV-induced PAH rats. Besides, nestin peaks were consistent with the histological features in lung tissues of MCT-AV-induced PAH rats. Moreover, nestin overexpression effectively promoted HPASMC phenotypic transformation, proliferation, apoptosis resistance and migration via enhancing Wnt/β-catenin activation.

CONCLUSIONS

These data indicated that nestin was re-expressed in proliferative synthetic-type PASMCs and might represent a potential marker of pulmonary vascular remodeling in CHD-PAH.

Residual Pulmonary Hypertension more than 20 Years after Repair of Shunt Lesions

Background and Objectives: After successful surgical repair of a congenital shunt lesion, pulmonary hypertension (PH) often disappears. However, PH can persist long-term after the closure. This study aimed to assess the prevalence of PH long-term after surgical repair of congenital heart disease (CHD), and to evaluate the outcomes and preoperative factors related to residual PH. Materials and Methods: In this retrospective cohort study, we reviewed patients who underwent right heart catheterisation in Vilnius University Hospital Santaros Klinikos during the period of 1985–2007. Among 4118 right heart catheterisations performed, 160 patients underwent congenital systemic-to-pulmonary shunt repair at a young age (<18 years) and had pre-operative PH. Half of the patients were foreigners whose follow-up data were unavailable. Eventually, 88 patients with available follow-up data were included in this study. Results: The median age at diagnosis of CHD with PH was 0.8 (0.6–3.0) and 1.1 (0.6–3.9) years at surgery (50% females). Residual PH was assessed 9.5 years after surgery and observed in 30.7% (n = 27) of the patients. It was associated with having more than one shunt (44.4% (n = 12), p = 0.016) and higher median pulmonary vascular resistance (3.4 (2.5–6.5) vs. 2.2 (1.0–3.7), p = 0.035) at baseline. After a median follow-up of 21 (15–24) years, 9.1% of the patients were deceased. Kaplan–Meier survival analysis revealed significantly higher mortality in the residual PH group (p = 0.035). Conclusions: Residual PH affects a significant proportion of patients after surgical repair of a shunt lesion and is associated with worse long-term outcome.

Normalization of the right heart and the preoperative factors that influence the emergence PAH after surgical closure of atrial septal defect

BACKGROUND

Surgical closure of atrial septal defect (ASD) is contraindicated in the condition with severe pulmonary arterial hypertension (PAH), whereas ASD closure in an effective intervention to normalize the structure and function of the right heart after previously experiencing volume overload due to shunting from the defect. This study aimed to evaluate normalization of the right heart and emergence of PAH after surgical closure of ASD.

METHODS

This retrospective study was carried out in 45 patients over 18 years who had undergone surgical closure of ASD. The study has the aim to evaluate the morphological and functional parameters before and after the surgical approach and the preoperative factors that influenced the development of pulmonary arterial hypertension (PAP) after the ASD closure.

RESULTS

The majority of subjects were female (73.3%) although there were no significant differences between males and females from the various parameters. The average of mPAP in the group that experienced PAH was higher than non-PAH group after ASD closure (p = 0.019, 31.23 ± 12.70 mmHg vs 24.07 ± 13.08 mmHg). Significant differences were found in the Right Atrium (RA) dimension, Right Ventricle (RV) dimension, Tricuspid Regurgitation Velocity (TRV) and Tricuspid Annular Plane Systolic Excursion (TAPSE) between before and at 6 months after ASD closure (p = 0.000, p = 0.000, p = 0.000, p = 000, respectively). The sensitivity of the predictive model to estimate PAH at 6 months after surgical closure of ASD was 58%, with a specificity of 62.5%.

CONCLUSION

Structural and functional normalization of the right heart occurs at 6 months after surgical closure of ASD with the decrease of RA and RV dimensions and improvement from tricuspid regurgitation. Emergence of PAH after ASD closure was influenced by higher mPAP before surgical approach.

"Treat and repair" strategy for shunt lesions: a critical review

The issue of operability in patients with shunt lesions and raised pulmonary vascular resistance is contentious. Several reports suggest that patients traditionally considered inoperable may be operated after treatment with targeted drug therapy for pulmonary arterial hypertension. We reviewed all the published literature of "treat and repair" approach to gain more insights into the utility of this approach. A critical appraisal of the published literature suggests that this approach is less established for patients with post tricuspid shunts, and for patients with pre-tricuspid shunts with modestly elevated indexed pulmonary vascular resistance (possibly greater than 11 WU.m²). Targeted drug therapy may be able to extend the therapeutic window in carefully selected patients, but its use as a routine in this setting seems unwarranted.

Challenges in the Patient With Pulmonary Hypertension and Atrial Septal Defect: Understanding When and How to Close the Defect

Atrial septal defects (ASDs) are common congenital heart defects in children and adults. Pulmonary arterial hypertension (PAH) is found in subsets of both pediatric and adult patients with atrial defects under varied clinical contexts. The pulmonary hypertension specialist is often faced with questions surrounding timing and method of defect closure, which may have significant impact on procedural and long-term morbidity and survival. This review highlights important differences in management between children and adults with ASDs associated with PAH, highlighting indications for closure, operability, types of closure, and long-term outcomes.

The prevalence of pulmonary arterial hypertension before and after atrial septal defect closure at adult age: A systematic review

BACKGROUND

The development or persistence of pulmonary arterial hypertension (PAH) after atrial septal defect (ASD) closure at adult age is associated with a poor prognosis. The objective of this review was to investigate the prevalence of PAH before and after ASD closure and to identify factors that are associated with PAH.

METHODS

EMBASE and MEDLINE databases were searched for publications until March 2017. All studies reporting the prevalence of PAH or data on pulmonary artery pressures both before and after surgical or percutaneous ASD closure in an adult population (≥16 years of age) were included. Papers were methodologically checked and data was visualized in tables, bar charts and plots.

RESULTS

A total of 30 papers were included. The prevalence of PAH ranged from 29% to 73% before ASD closure and from 5% to 50% after closure; being highest in older studies, small study cohorts, and studies with high rates of loss to follow-up. The pooled systolic pulmonary artery pressure (PAP) was 43±13 before ASD closure and 32±10 after closure. The overall mean PAP was 34±10 before closure and 28±8 after closure. Studies with a higher mean PAP before closure and a higher mean age of the study cohort reported greater PAP reductions.

CONCLUSIONS

The prevalence of PAH and mean pulmonary pressures decreased in all studies, regardless of the mean age or pulmonary pressures of the cohort. The reported prevalence of PAH after ASD closure is substantial, although widely varying (5%-50%), which is likely affected by selection of the study cohort.

Pulmonary arterial hypertension in congenital heart disease: translational opportunities to study the reversibility of pulmonary vascular disease

Pulmonary arterial hypertension (PAH) is a progressive and lethal pulmonary vascular disease (PVD). Although in recent years outcome has improved by new treatments that delay disease progression, a cure has not yet been achieved. In PAH associated with congenital heart disease (CHD), remodeling of the pulmonary vasculature reaches an irreversible phenotype similar to all forms of end-stage PAH. In PAH-CHD, however, also an early stage is recognised, which can be completely reversible. This reversible phase has never been recognised in other forms of PAH, most likely because these patients are only diagnosed once advanced disease has developed. We propose that the clinical model of PAH-CHD, with an early reversible and advanced irreversible stage, offers unique opportunities to study pathophysiological and molecular mechanisms that orchestrate the transition from reversible medial hypertrophy into irreversible plexiform lesions. Comprehension of these mechanisms is not only pivotal in clinical assessment of disease progression and operability of patients with PAH-CHD; specific targeting of these mechanisms may also lead to pharmacological interventions that transform 'irreversible' plexiform lesions into a reversible PVD: one that is amenable for a cure. In recent years, significant steps have been made in the strive to 'reverse the irreversible'. This review provides an overview of current clinical and experimental knowledge on the reversibility of PAH, focussing on flow-associated mechanisms, and the near-future potential to advance this field.

Pulmonary Hypertension and Atrial Septal Defect: Management Dilemma

The decision making in patients with an atrial septal defect (ASD) in setting of pulmonary hypertension is complex. In the era of pulmonary arterial vasodilator therapy, every patient should undergo evaluation by pulmonary hypertension experts especially if defect closure is being considered. Defect closure in the inappropriate group can lead to poor outcomes.

Pulmonary arterial hypertension in adult congenital heart disease

Pulmonary arterial hypertension (PAH) is commonly associated with congenital heart disease (CHD) and relates to type of the underlying cardiac defects and repair history. Large systemic to pulmonary shunts may develop PAH if untreated or repaired late. PAH, when present, markedly increases morbidity and mortality in patients with CHD. Significant progress has been made for patients with Eisenmenger syndrome in pathophysiology, prognostication and disease-targeting therapy (DTT), which needs to be applied to routine patient care. Patients with PAH–CHD and systemic to pulmonary shunting may benefit from late defect closure if pulmonary vascular resistance (PVR) is still normal or near normal. Patients with PAH and coincidental defects, or previous repair of CHD should be managed as those with idiopathic PAH. Patients with a Fontan circulation, despite not strictly fulfilling criteria for PAH, may have elevated PVR; recent evidence suggests that they may also benefit from DTT, but more data are required before general recommendations can be made. CHD–PAH is a lifelong, progressive disease; patients should receive tertiary care and benefit from a proactive DTT approach. Novel biomarkers and genetic advances may identify patients with CHD who should be referred for late defect closure and/or patients at high risk of developing PAH despite early closure in childhood. Ongoing vigilance for PAH and further controlled studies are clearly warranted in CHD.

The Changing Landscape of Pulmonary Arterial Hypertension in the Adult with Congenital Heart Disease

Pulmonary arterial hypertension associated with congenital heart disease (PAH-CHD) is a common type of pulmonary arterial hypertension (PAH) and a frequent complication of congenital heart disease (CHD). PAH-CHD represents a heterogeneous patient population and it is important to distinguish between the underlying cardiac defects considering the prognostic and therapeutic implications. Improved interventional techniques have enabled repair or palliation of most cardiac defects, though a substantial number of patients remain at high risk for PAH after closure. Traditionally, the treatment and management of PAH-CHD patients has been limited to palliative and supportive care, and based on expert opinion rather than clinical trials. Recently, however, the availability of advanced PAH-specific treatment has opened up a new field for the clinical management of this condition. Nevertheless, there is limited evidence on the optimal therapeutic approach for PAH-CHD. Herein, we discuss the current and novel therapeutic options for PAH-CHD as well as highlight several challenges in the clinical management at present.

Vasopressors induce passive pulmonary hypertension by blood redistribution from systemic to pulmonary circulation

Vasopressors are widely used in resuscitation, ventricular failure, and sepsis, and often induce pulmonary hypertension with undefined mechanisms. We hypothesize that vasopressor-induced pulmonary hypertension is caused by increased pulmonary blood volume and tested this hypothesis in dogs under general anesthesia. In normal hearts (model 1), phenylephrine (2.5 μg/kg/min) transiently increased right but decreased left cardiac output, associated with increased pulmonary blood volume (63% ± 11.8, P = 0.007) and pressures in the left atrium, pulmonary capillary, and pulmonary artery. However, the trans-pulmonary gradient and pulmonary vascular resistance remained stable. These changes were absent after decreasing blood volume or during right cardiac dysfunction to reduce pulmonary blood volume (model 2). During double-ventricle bypass (model 3), phenylephrine (1, 2.5 and 10 μg/kg/min) only slightly induced pulmonary vasoconstriction. Vasopressin (1U and 2U) dose-dependently increased pulmonary artery pressure (52 ± 8.4 and 71 ± 10.3%), but did not cause pulmonary vasoconstriction in normally beating hearts (model 1). Pulmonary artery and left atrial pressures increased during left ventricle dysfunction (model 4), and further increased after phenylephrine injection by 31 ± 5.6 and 43 ± 7.5%, respectively. In conclusion, vasopressors increased blood volume in the lung with minimal pulmonary vasoconstriction. Thus, this pulmonary hypertension is similar to the hemodynamic pattern observed in left heart diseases and is passive, due to redistribution of blood from systemic to pulmonary circulation. Understanding the underlying mechanisms may improve clinical management of patients who are taking vasopressors, especially those with coexisting heart disease.