Preoperative pulmonary hemodynamics and assessment of operability: is there a pulmonary vascular resistance that precludes cardiac operation?

Deterioration in Renal Function in Patients With a Fontan Circulation and Association With Mortality

Background

Renal dysfunction is a well-established risk factor in cardiovascular disease, but little is known about the prevalence and factors associated with deterioration in renal function in patients with a Fontan circulation.

Objectives

The purpose of the study was to investigate the course and factors associated with deterioration in renal function in patients with a Fontan circulation and its association with mortality.

Methods

This is a longitudinal study of patients with a Fontan circulation (n = 82), in which creatinine-based estimated glomerular filtration rate (eGFRcr) was measured over an 11-year time period. Cystatin C and N-terminal prohormone of brain natriuretic peptide (NT-proBNP) levels were measured at baseline. Renal dysfunction was defined as an eGFR <90 ml/min/1.73 m2. Factors associated with annual change in eGFRcr were investigated with linear mixed-effect models and compared with data from a healthy Dutch cohort. The primary endpoint for the survival analyses was all-cause mortality. Associations between repeated eGFRcr levels and the primary endpoint were assessed using a joint model.

Results

The median age at baseline was 20 years (IQR: 14-27 years). Twelve percent of the cohort had renal dysfunction based on eGFRcr and 24% based on cystatin C-based eGFRcys. During follow-up, eGFRcr deteriorated on average by 1.36 ml/min/1.73 m2/year, which is faster than the healthy cohort. Higher baseline NT-proBNP z-scores were associated with a more rapid decline in eGFRcr. A larger decline in eGFRcr was associated with all-cause mortality.

Conclusions

Declines in eGFRcr in patients with Fontan circulation are more rapid than in healthy individuals. Higher baseline NT-proBNP z-scores are associated with a more rapid deterioration of eGFRcr, and eGFRcr deterioration is associated with mortality.

Utility of Balloon Occlusion Testing in Determining Fontan Suitability Among Patients with Elevated Pulmonary Artery Pressure and Additional Antegrade Pulmonary Blood Flow

In individuals with a single ventricle undergoing evaluation before Fontan surgery, the presence of excessive pulmonary blood flow can contribute to increased pulmonary artery pressure, notably in those who had a Glenn procedure with antegrade pulmonary flow. 28 patients who had previously undergone Glenn anastomosis with antegrade pulmonary blood flow (APBF) and with elevated mean pulmonary artery (mPAP) pressure > 15 mmHg in diagnostic catheter angiography were included in the study. After addressing other anatomical factors that could affect pulmonary artery pressure, APBF was occluded with semi-compliant, Wedge or sizing balloons to measure pulmonary artery pressure accurately. 23 patients (82% of the cohort) advanced to Fontan completion. In this group, median mPAP dropped from 20.5 (IQR 19-22) mmHg to 13 (IQR 12-14) mmHg post-test (p < 0.001). Median PVR post-test was 1.8 (IQR 1.5-2.1) WU m2. SpO2 levels decreased from a median of 88% (IQR 86%-93%) pre-test to 80% (IQR 75%-84%) post-test (p < 0.001). In five patients, elevated mPAP post-test occlusion on diagnostic catheter angiography led to non-completion of Fontan circulation. In this group, median pre- and post-test mPAP were 23 mmHg (IQR 21.5-23.5) and 19 mmHg (IQR 18.5-20), respectively (p = 0.038). Median post-test PVR was 3.8 (IQR 3.6-4.5) WU m2. SpO2 levels decreased from a median of 79% (IQR 76%-81%) pre-test to 77% (IQR 73.5%-80%) post-test (p = 0.039). Our study presents a specialized approach for patients initially deemed unsuitable for Fontan due to elevated pulmonary artery pressures. We were able to successfully complete the Fontan procedure in the majority of these high-risk cases after temporary balloon occlusion test.

Operability of atrial septal defect with borderline pulmonary vascular resistance index: A study in developing country

Background

Pulmonary arterial hypertension secondary to atrial septal defect (ASD) is an important determinant of morbidity and mortality in defect closure. We aimed to compare perioperative outcome between preoperative borderline and low pulmonary vascular resistance index (≥4 WU.m2 and &lt;4 WU.m2, respectively) in surgical closure of secundum atrial septal defect with concomitant pulmonary arterial hypertension.

Methods and results

This was a single-center retrospective cohort study between January 2015 and January 2020. We classified patients with low and borderline PVRI who underwent ASD closure and recorded the perioperative outcomes.

Results

We analyzed a total of 183 patients with atrial septal defect and pulmonary arterial hypertension; 92 patients with borderline PVRI and 91 patients with low PVRI. Borderline pulmonary vascular resistance index was not associated with increased risk of postoperative mortality (p = 0.621; OR0.48, 95% CI 0.04–5.48), but associated with higher risk of overall morbidity in bivariate analysis (p = 0.002; OR3.28, 95% CI 1.5–6.72). Multivariate analysis showed positive association of borderline pulmonary vascular resistance index (p = 0.045; OR2.63, 95% CI 1.02–6.77) and preoperative tricuspid valve gradient ≥64 mmHg (p = 0.034; OR2.77, 95% CI 1.08–7.13) with overall morbidity.

Conclusion

There is no difference in incidence of in-hospital mortality between preoperative borderline and low pulmonary vascular resistance index patients. However, preoperative borderline pulmonary vascular resistance index and tricuspid valve gradient ≥64 mmHg are associated with increased overall morbidity after surgical closure in secundum atrial septal defect patients with pulmonary arterial hypertension.

Long-Term Follow-Up of Pediatric Patients with Severe Postoperative Pulmonary Hypertension After Correction of Congenital Heart Defects

The surgical repair of congenital heart defects in children with preoperative pulmonary hypertension (PH) is to varying degree associated with the occurrence of postoperative PH. The objective of this study was to follow up children with severe postoperative PH (pulmonary arterial/aortic pressure ratio ≥ 1.0) to evaluate if pulmonary arterial pressure spontaneously normalized or needed PH-targeting therapy and to identify potential high-risk diagnoses for bad outcome. Twenty-five children who developed clinically significant severe PH on at least three occasions postoperatively were included in the follow-up (20-24 years). Data from chart reviews, echocardiographic investigations, and questionnaires were obtained. Three children died within the first year after surgery. Three children were lost to follow-up. The remaining 17 children normalized their pulmonary arterial pressure without the use of PH-targeting drugs at any time during the follow-up. Two children had a remaining mild PH with moderate mitral valve insufficiency. All three children with bad outcome had combined cardiac lesions causing post-capillary pulmonary hypertension. Normalization of the pulmonary arterial pressure occurred in almost all children with severe postoperative PH, without any need of supplemental PH-targeting therapies. All children with bad outcome had diagnoses conformable with post-capillary PH making the use of PH-targeting therapies relatively contraindicated. These data emphasize the need to perform randomized, blinded trials on the use of PH-targeting drugs in children with postoperative PH before accepting it as an indication for routine treatment.

Congenital Heart Disease-Associated Pulmonary Hypertension

Presently, with increasing survival of patients with congenital heart disease (CHD), pulmonary arterial hypertension (PAH) associated with CHD is commonly encountered in children and adults. This increased prevalence is seen despite significant advances in early diagnosis and surgical correction of patients with structural CHD. PAH is the cause of significant morbidity and mortality in these patients and comes in many forms. With the increased availability of targeted therapies for PAH, there is hope for improved hemodynamics, exercise capacity, quality of life, and possibly survival for these patients. There may also be opportunities for combined medical and interventional/surgical approaches for some.

Endothelial shear stress enhancements: a potential solution for critically ill Covid-19 patients

Most critically ill Covid-19 patients succumb to multiple organ failure and/or sudden cardiac arrest (SCA) as a result of comorbid endothelial dysfunction disorders which had probably aggravated by conventional mechanical assist devices. Even worse, mechanical ventilators prevent the respiratory pump from performing its crucial function as a potential generator of endothelial shear stress (ESS) which controls microcirculation and hemodynamics since birth. The purpose of this work is to bring our experience with ESS enhancement and pulmonary vascular resistance (PVR) management as a potential therapeutic solution in acute respiratory distress syndrome (ARDS). We propose a non-invasive device composed of thoracic and infradiaphragmatic compartments that will be pulsated in an alternating frequency (20/40 bpm) with low-pressure pneumatic generator (0.1–0.5 bar). Oxygen supply, nasogastric with, or without endotracheal tubes are considered.

Pulmonary Vasodilator Therapy in Children with Single Ventricle Physiology: Effects on Saturation and Pulmonary Arterial Pressure

In children with single ventricle physiology, increased pulmonary vascular resistance may impede surgical progression or result in failing single ventricle physiology. The use of pulmonary vasodilators has been suggested as a potential therapy. However, knowledge on indication, dosage, and effect is limited. A retrospective case notes review of all (n = 36) children with single ventricle physiology, treated with pulmonary vasodilators by the UK Pulmonary Hypertension Service for Children 2004-2017. Therapy was initiated in Stage 1 (n = 12), Glenn (n = 8), or TCPC (n = 16). Treatment indications were high mean pulmonary arterial pressure, cyanosis, reduced exercise tolerance, protein-losing enteropathy, ascites, or plastic bronchitis. Average dose of sildenafil was 2.0 mg/kg/day and bosentan was 3.3 mg/kg/day. 56% had combination therapy. Therapy was associated with a reduction of the mean pulmonary arterial pressure from 19 to 14 mmHg (n = 17, p < 0.01). Initial therapy with one or two vasodilators was associated with an increase in the mean saturation from 80 to 85%, (n = 16, p < 0.01). Adding a second vasodilator did not give significant additional effect. 5 of 12 patients progressed from Stage 1 to Glenn, Kawashima, or TCPC, and 2 of 8 from Glenn to TCPC during a mean follow-up time of 4.7 years (0-12.8). Bosentan was discontinued in 57% and sildenafil in 14% of treated patients and saturations remained stable. Pulmonary vasodilator therapy was well tolerated and associated with improvements in saturation and mean pulmonary arterial pressure in children with single ventricle physiology. It appears safe to discontinue when no clear benefit is observed.

Aortopulmonary window in adults: A rare entity leading to Eisenmenger syndrome

An aortopulmonary window (APW) is a rare congenital heart defect involving an abnormal communication between the ascending aorta and the pulmonary trunk with separate aortic and pulmonary valves. This defect accounts for 0.2% of all congenital cardiac anomalies and if left untreated can lead to Eisenmenger syndrome, severe pulmonary hypertension, heart failure, and poor survival. The authors herein present a case of APW type III with Eisenmenger syndrome in an adult patient whose initial complaint was cyanosis, and provide a thorough review of the literature of cases of APW with Eisenmenger syndrome that have survived into adulthood.

EXPRESS: Parameters associated with outcome in pediatric patients with congenital heart disease and pulmonary hypertension subjected to combined vasodilator and surgical treatments

Management of pediatric pulmonary hypertension associated with congenital heart disease (PHT-CHD) is challenging. Some patients have persistently elevated pulmonary artery pressure (PAP) after cardiac surgery, an undesired condition that is difficult to predict. We investigated the value of clinical, hemodynamic, and histopathological data in predicting the outcome in a prospective cohort. Patients with PHT-CHD received sildenafil orally pre- and postoperatively for six months and then were subjected to a catheter study. Thirty-three patients were enrolled (age range = 4.6–37.0 months). Pulmonary vascular resistance (PVR) was 4.9 (range = 3.9–7.2) Wood units × m2 (median with IQR). Twenty-two patients had a ≥ 20% decrease in PVR and pulmonary-to-systemic vascular resistance ratio (PVR/SVR) in response to inhaled nitric oxide (NO). The response was directly related to the degree of medial hypertrophy of pulmonary arterioles (P < 0.05) (morphometric analysis, intraoperative lung biopsy). Subsequently, five of the non-responders had a ≥ 30% increase in pulmonary blood flow in response to sildenafil (3.0 [2.0–4.0] mg/kg/day). Six months after surgery, PAP and PVR were significantly lower (P < 0.001 vs. baseline), even in seven patients with Heath-Edwards grade III/IV pulmonary vascular lesions (P = 0.018), but still abnormal in 12 individuals (>25 mmHg and >3.0 U × m2, respectively). A preoperative PVR/SVR of ≥24% during NO inhalation and a wall thickness of arteries accompanying respiratory bronchioli of ≥4.7 (Z score) were identified, respectively, as risk and protection factors for abnormal postoperative hemodynamics (hazard ratio [95% CI] = 1.09 [1.01–1.18], P = 0.036; and 0.69 [0.49–0.98], P = 0.040, respectively). Thus, in PHT-CHD patients receiving oral sildenafil pre- and post-surgical repair of cardiac lesions, mid-term postoperative outcome is predictable to some extent.

Invasive Hemodynamics of Adult Congenital Heart Disease: From Shunts to Coarctation

Adults with congenital heart disease are a growing population with increasingly more complex disease, in large part due to improvements in delivery of care to the pediatric population. Cardiac catheterization is an integral component of diagnosis and management in these patients. Careful attention to detail and a thorough understanding of intracardiac hemodynamics are critical to performing complete diagnostic evaluations. This article outlines the most commonly encountered lesions with guidelines for invasive assessment to help guide further therapy.

Pushing the envelope: a treat and repair strategy for patients with advanced pulmonary hypertension associated with congenital heart disease

Pulmonary arterial hypertension (PAH) is a frequent complication of congenital heart disease as a consequence of altered pulmonary hemodynamics with increased pulmonary blood flow and pressure. The development of pulmonary vascular disease (PVD) in this patient population is an important concern in determining operative strategy. Early, definitive surgical repair, when possible, is the best therapy to prevent and treat PVD. However, this is not possible in some patients because they either presented late, after the development of PVD, or they have complex lesions not amenable to one-step surgical correction, including patients with single ventricle physiology, who have a continuing risk of developing PVD. These patients represent an important, high-risk subgroup and many have been considered inoperable. We present a case series of two patients with complex congenital heart disease and advanced PVD who successfully underwent a treat and repair strategy with aggressive PAH therapies before surgical correction. Both patients had normalization of pulmonary vascular resistance prior to surgical correction. Caution is warranted in applying this strategy broadly and long-term follow-up for these patients is crucial. However, this treat and repair strategy may allow for favorable outcomes among some patients who previously had no therapeutic options.

Inaccuracy of a continuous arterial pressure waveform monitor when used for congenital cardiac catheterization

OBJECTIVE

To determine the accuracy of a continuous cardiac output monitor (FloTrac sensor) for measuring cardiac index in children with congenital heart disease undergoing cardiac catheterization. Cardiac index is a critical hemodynamic parameter measured during catheterizations in children with congenital heart disease. This has been challenging to measure accurately and many clinicians rely on predictive equations for calculating cardiac index.

DESIGN

Prospective, nonrandomized trial.

SETTING

Tertiary care congenital heart center.

PATIENTS

Consecutive participants ≤18 years old undergoing clinically indicated cardiac catheterizations from September 2014 through August 2015.

INTERVENTIONS

Oxygen consumption was measured using the Vmax Encore 229 monitor attached to the ventilator circuit. The FloTrac transducer with third generation software was connected to a pigtail catheter in the descending aorta and cardiac index was obtained.

OUTCOME MEASURES

Cardiac index by the Fick equation using measured oxygen consumption was compared to cardiac index from the FloTrac sensor using paired t-test and Bland-Altman analysis.

RESULTS

39 participants (median age 5.1 years, 1.5-18.3, 64% female) were studied. Cardiac index by FloTrac was higher than cardiac index by Fick (6.4 ± 3.4 vs 3.7 ± 1.2 L/min/m² , P < .001). Bland-Altman analysis showed a consistent overestimation of cardiac index by FloTrac which worsened as cardiac index increased (mean bias 2.7 L/min/m² , 95% limits of agreement -4.2, 9.5).

CONCLUSIONS

The results of this study show that the FloTrac sensor provides cardiac index measures which are not accurate enough to justify use in children with congenital heart disease undergoing catheterization. Further studies may allow for modifications of the algorithms to obtain more accurate cardiac index in this population.

Relation of Cytokine Profile to Clinical and Hemodynamic Features in Young Patients With Congenital Heart Disease and Pulmonary Hypertension

In congenital heart disease, severity of pulmonary hypertension and operability is defined by noninvasive parameters (clinical history, physical examination, and echocardiography) and sometimes, cardiac catheterization. We investigated how circulating levels of inflammatory mediators correlate with such parameters in a young pediatric population (age, 2.0 months to 3.1 years) and the effects of preoperative pulmonary vasodilator therapy with sildenafil. Cytokines were analyzed in serum using chemiluminescence signals. In the whole patient group (n = 47), interleukin 17E, a Th2 immune response mediator increased with increasing age, considered as a parameter of disease severity (R² = 0.24, p <0.001), whereas the angiogenic chemokine growth-regulated oncogene alpha decreased (R² = 0.21, p = 0.001). Macrophage migration inhibitory factor chemokine was greater in subjects with elevated pulmonary vascular resistance (n = 16, p = 0.022), whereas regulated on activation, normal T cell expressed and secreted chemokine was greater in subjects with pulmonary congestion due to increased pulmonary blood flow (n = 31, p = 0.037). The observations were the same for the specific subpopulation of patients with Down syndrome (p = 0.009 and p = 0.012 for migration inhibitory factor and regulated on activation, normal T cell expressed and secreted in the respective subgroups). Sildenafil administration to patients with elevated pulmonary vascular resistance resulted in improvement of pulmonary blood flow (p = 0.012) and systemic oxygen saturation (p = 0.010), with a decrease in serum interleukin 6 (p = 0.027) and soluble ICAM-1 (p = 0.011). In conclusion, levels of circulating inflammatory molecules seem to correlate with disease severity in this population, with potential pathophysiological and therapeutic implications.

Noninvasive Cardiac Output Estimation by Inert Gas Rebreathing in Mechanically Ventilated Pediatric Patients

OBJECTIVE

To assess the feasibility and accuracy of inert gas rebreathing (IGR) pulmonary blood flow (Qp) estimation in mechanically ventilated pediatric patients, potentially providing real-time noninvasive estimates of cardiac output.

STUDY DESIGN

In mechanically ventilated patients in the pediatric catheterization laboratory, we compared IGR Qp with Qp estimates based upon the Fick equation using measured oxygen consumption (VO2) (FickTrue); for context, we compared FickTrue with a standard clinical short-cut, replacing measured with assumed VO2 in the Fick equation (FickLaFarge, FickLundell, FickSeckeler). IGR Qp and breath-by-breath VO2 were measured using the Innocor device. Sampled pulmonary arterial and venous saturations and hemoglobin concentration were used for Fick calculations. Qp estimates were compared using Bland-Altman agreement and Spearman correlation.

RESULTS

The final analysis included 18 patients aged 4-23 years with weight >15 kg. Compared with the reference FickTrue, IGR Qp estimates correlated best and had the least systematic bias and narrowest 95% limits of agreement (results presented as mean bias ±95% limits of agreement): IGR -0.2 ± 1.1 L/min, r = 0.90; FickLaFarge +0.7 ± 2.2 L/min, r = 0.80; FickLundell +1.6 ± 2.9 L/min, r = 0.83; FickSeckeler +0.8 ± 2.5 L/min, r = 0.83.

CONCLUSIONS

IGR estimation of Qp is feasible in mechanically ventilated patients weighing >15 kg, and agreement with FickTrue Qp estimates is better for IGR than for other Fick Qp estimates commonly used in pediatric catheterization. IGR is an attractive option for bedside monitoring of Qp in mechanically ventilated children.

Pediatric Pulmonary Hypertension: Guidelines From the American Heart Association and American Thoracic Society

Pulmonary hypertension is associated with diverse cardiac, pulmonary, and systemic diseases in neonates, infants, and older children and contributes to significant morbidity and mortality. However, current approaches to caring for pediatric patients with pulmonary hypertension have been limited by the lack of consensus guidelines from experts in the field. In a joint effort from the American Heart Association and American Thoracic Society, a panel of experienced clinicians and clinician-scientists was assembled to review the current literature and to make recommendations on the diagnosis, evaluation, and treatment of pediatric pulmonary hypertension. This publication presents the results of extensive literature reviews, discussions, and formal scoring of recommendations for the care of children with pulmonary hypertension.

Surgical strategies for patients with congenital heart disease and severe pulmonary hypertension in low/middle-income countries

In this review, we discuss specific surgical strategies that are used in patients with congenital heart disease and severe pulmonary arterial hypertension. Our own experience, with the use of unidirectional valved patches in managing these patients, is also discussed in detail.

[Pulmonary hypertension associated with congenital heart disease and Eisenmenger syndrome]

Pulmonary arterial hypertension is a common complication of congenital heart disease (CHD). Congenital cardiopathies are the most frequent congenital malformations. The prevalence in our country remains unknown, based on birthrate, it is calculated that 12,000 to 16,000 infants in our country have some cardiac malformation. In patients with an uncorrected left-to-right shunt, increased pulmonary pressure leads to vascular remodeling and endothelial dysfunction secondary to an imbalance in vasoactive mediators which promotes vasoconstriction, inflammation, thrombosis, cell proliferation, impaired apotosis and fibrosis. The progressive rise in pulmonary vascular resistance and increased pressures in the right heart provocated reversal of the shunt may arise with the development of Eisenmenger' syndrome the most advanced form de Pulmonary arterial hypertension associated with congenital heart disease. The prevalence of Pulmonary arterial hypertension associated with CHD has fallen in developed countries in recent years that is not yet achieved in developing countries therefore diagnosed late as lack of hospital infrastructure and human resources for the care of patients with CHD. With the development of targeted medical treatments for pulmonary arterial hypertension, the concept of a combined medical and interventional/surgical approach for patients with Pulmonary arterial hypertension associated with CHD is a reality. We need to know the pathophysiological factors involved as well as a careful evaluation to determine the best therapeutic strategy.

A new predictive equation for oxygen consumption in children and adults with congenital and acquired heart disease

OBJECTIVE

To develop a new predictive equation for oxygen consumption (VO2) in children and adults with congenital and acquired heart disease.

METHODS

We retrospectively reviewed data from 502 consecutive patients (age 0-59 years) undergoing cardiac catheterisation with measured VO2 (M-VO2) and compared M-VO2 with VO2 from the LaFarge equations (LF-VO2) in patients <3 years (Group 1) and ≥3 years (Group 2). Factors associated with inaccurate LF-VO2 were used to develop a new predictive equation, which was prospectively validated in 100 consecutive patients (age 0-59 years).

RESULTS

LF-VO2 was inaccurate in 42% of Group 1 (n=201) and 13% of Group 2 (n=301). Multivariable predictors of inaccurate LF-VO2 included age (OR 0.41, p=0.01) and single ventricle anatomy (OR 2.98, p=0.03) in Group 1 and anaemia (OR 0.84, p<0.001) in Group 2. Critical illness was borderline significant in both groups. The new predictive equation for VO2:[Formula: see text] Intraclass correlation between M-VO2 and the new predictive equation was good (r=0.53), whereas LF-VO2 was not (r=0.17). Bland-Altman analysis comparing M-VO2 with the new equation and with LF-VO2 demonstrated superiority of the new equation (mean bias 2.5 mL/min/m(2) vs -5.0 mL/min/m(2); limits of agreement -51.6, 56.5 vs -82.1, 72).

CONCLUSIONS

VO2 derived from the LaFarge equations is frequently inaccurate, particularly in younger patients, and will lead to erroneous haemodynamic calculations. We developed and prospectively validated a new VO2 predictive equation for use in patients of all ages with congenital and acquired heart disease.

[Update on pediatric cardiology and congenital heart disease: imaging techniques, pulmonary arterial hypertension, hybrid treatment, and surgical treatment]

This article contains a review of the most significant contributions to pediatric cardiology and congenital heart disease reported in publications between September 2009 and August 2010. The review focuses on imaging techniques, new treatment for pulmonary arterial hypertension in pediatric patients, and therapy in general (e.g. hybrid treatment and surgical treatment). With regard to imaging techniques, the review highlights the increasing application of congenital heart disease diagnosis during fetal life, the introduction of new echocardiographic techniques (e.g. tissue Doppler imaging, two-dimensional speckle-tracking imaging and three-dimensional echocardiography) into routine clinical practice, and the growing use of cardiac CT and magnetic resonance imaging in diagnosis and the assessment of cardiac function, respectively. The role played by cardiac interventions continues to increase and cardiac surgery is becoming more advanced and has, in some cases, been combined with hybrid techniques. However, there are still a number of controversial issues in cardiac surgery that have not yet been resolved, such as whether or not fenestration should be used with Fontan surgery, the optimum type of correction for hypoplastic left heart syndrome, and the best conduit for pulmonary artery replacement.

Saudi Guidelines on the Diagnosis and Treatment of Pulmonary Hypertension: Pulmonary arterial hypertension associated with congenital heart disease

Congenital heart disease (CHD) with intracardiac/extracardiac shunts is an important etiology of pulmonary arterial hypertension (PAH). The majority of children with congenital cardiac shunts do not develop advanced pulmonary vasculopathy, as surgical repair of the anomalies is now performed early in life. However, if not repaired early, some defects will inevitably lead to pulmonary vascular disease (truncus arteriosus, transposition of the great arteries associated with a ventricular septal defect (VSD), atrioventricular septal defects remarkably in Down syndrome, large, nonrestrictive VSDs, patent ductus arteriosus and related anomalies). The majority of patients are now assigned to surgery based on noninvasive evaluation only. PAH becomes a concern (requiring advanced diagnostic procedures) in about 2-10% of them. In adults with CHD, the prevalence of advanced pulmonary vasculopathy (Eisenmenger syndrome) is around 4-12%.[1]

This article will discuss the diagnostic and management approach for PAH associated with CHD (PAH-CHD).

Pulmonary hypertension in adult congenital heart disease

OPINION STATEMENT

There is a growing patient population with adult congenital heart disease that needs specialized medical attention and careful long-term evaluation. Pulmonary arterial hypertension (PAH) associated with congenital heart disease (PAH-CHD) is a common late complication, and is associated with increased morbidity and mortality. There are no clear current guidelines for the treatment of PAH-CHD. There are few trials to date investigating PAH treatment specifically in this group of patients. However, the available data seems to demonstrate that with the advent of PAH-targeted therapies, the quality of life, exercise capacity, and outcomes in these patients is improving. In addition, PAH-targeted therapies may be useful in select patients for a combined medical-surgical approach to treatment. Here we discuss the epidemiology and pathophysiology of PAH-CHD, current therapies, and the data supporting their use, and how to evaluate feasibility of late surgical repair.

Repair of congenital heart disease with associated pulmonary hypertension in children: what are the minimal investigative procedures? Consensus statement from the Congenital Heart Disease and Pediatric Task Forces, Pulmonary Vascular Research Institute (PVRI)

Standardization of the diagnostic routine for children with congenital heart disease associated with pulmonary arterial hypertension (PAH-CHD) is crucial, in particular since inappropriate assignment to repair of the cardiac lesions (e.g., surgical repair in patients with elevated pulmonary vascular resistance) may be detrimental and associated with poor outcomes. Thus, members of the Congenital Heart Disease and Pediatric Task Forces of the Pulmonary Vascular Research Institute decided to conduct a survey aimed at collecting expert opinion from different institutions in several countries, covering many aspects of the management of PAH-CHD, from clinical recognition to noninvasive and invasive diagnostic procedures and immediate postoperative support. In privileged communities, the vast majority of children with congenital cardiac shunts are now treated early in life, on the basis of noninvasive diagnostic evaluation, and have an uneventful postoperative course, with no residual PAH. However, a small percentage of patients (older at presentation, with extracardiac syndromes or absence of clinical features of increased pulmonary blood flow, thus suggesting elevated pulmonary vascular resistance) remain at a higher risk of complications and unfavorable outcomes. These patients need a more sophisticated diagnostic approach, including invasive procedures. The authors emphasize that decision making regarding operability is based not only on cardiac catheterization data but also on the complete diagnostic picture, which includes the clinical history, physical examination, and all aspects of noninvasive evaluation.

Patients with congenital systemic-to-pulmonary shunts and increased pulmonary vascular resistance: what predicts postoperative survival?

Background

We carried out a retrospective data review of patients with systemic to pulmonary shunts that underwent surgical repair between February 1990 and February 2012 in order to assess preoperative pulmonary vascular dynamic risk factors for predicting early and late deaths due presumably to pulmonary vascular disease.

Methods and Results

A total of 1024 cases of congenital systemic-to-pulmonary shunt and advanced pulmonary vascular disease beyond infancy and early childhood were closed surgically. The mean follow up duration was 8.5±5.5 (range 0.7 to 20) years. Sixty-one in-hospital deaths (5.96%, 61/1024) occurred after the shunt closure procedure and there were 46 late deaths, yielding 107 total deaths. We analyzed preoperative pulmonary vascular resistance index (PVRI), pulmonary vascular resistance index on pure oxygen challenge (PVRIO), difference between PVRI and PVRIO (PVRID), Qp∶Qs, and Rp∶Rs as individual risk predictors. The results showed that these individual factors all predicted in-hospital death and total death with PVRIO showing better performance than other risk factors. A multivariable Cox regression model was built,and suggested that PVRID and Qp∶Qs were informative factors for predicting survival time from late death and closure of congenital septal defects was safe with a PVRIO<10.3 WU.m² and PVRID>7.3 WU.m² on 100% oxygen.

Conclusions

All 4 variables, PVRI, PVRIO, PVRID and Qp∶Qs, should be considered in deciding surgical closure of congenital septal defects and a PVRIO<10.3 WU.m² and PVRID>7.3 WU.m² on 100% oxygen are associated with a favorable risk benefit profile for the procedure.

Assessment of operability of patients with pulmonary arterial hypertension associated with congenital heart disease

Pulmonary arterial hypertension (PAH) is a common complication of congenital heart disease, and is now predominantly among patients with uncorrected left-to-right shunts. A growing population is characterized by persistent or recurrent PAH after surgical or interventional correction of left-to-right shunts; the latter having a worse prognosis than other forms of PAH associated with congenital heart disease. New treatments for PAH have been shown to be effective in improving PAH exercise capacity and hemodynamics, raising the hope for making previously inoperable congenital heart defects operable and shifting the framework for the assessment of operability. This review focuses on current methods for assessing operability in PAH associated with congenital heart disease, and the possibility of "treat-and-repair" vs. "repair-and-treat" strategies for patients with inoperable or borderline PAH.

Preoperative B-type natriuretic peptide levels are associated with outcome after total cavopulmonary connection (Fontan)

OBJECTIVE

The study objective was to determine the association between preoperative B-type natriuretic peptide levels and outcome after total cavopulmonary connection. Surgical palliation of univentricular cardiac defects requires a series of staged operations, ending in a total cavopulmonary connection. Although outcomes have improved, there remains an unpredictable risk of early total cavopulmonary connection takedown. The prediction of adverse postoperative outcomes is imprecise, despite an extensive preoperative evaluation.

METHODS

We prospectively enrolled 50 patients undergoing total cavopulmonary connection. We collected preoperative clinical data, preoperative plasma B-type natriuretic peptide levels, and postoperative outcomes, including the incidence of an adverse outcome within 1 year of surgery (defined as death, total cavopulmonary connection takedown, or the need for cardiac transplantation).

RESULTS

The mean age of patients was 4.7 years (standard deviation, 2.1 years). The median (interquartile range) preoperative B-type natriuretic peptide levels were higher in patients who required total cavopulmonary connection takedown and early postoperative mechanical cardiac support (n = 3; median, 55; interquartile range, 42-121) compared with those with a good outcome (n = 47; median, 11; interquartile range, 5-17) (P < .05). A preoperative B-type natriuretic peptide level of 40 pg/mL or greater was highly associated with the need for total cavopulmonary connection takedown (sensitivity, 100%; specificity, 93%; P < .05), yielding a positive predictive value of 50% and a negative predictive value of 100%. Higher preoperative B-type natriuretic peptide levels also were associated with longer intensive care unit length of stay, longer hospital length of stay, and increased incidence of low cardiac output syndrome (P < .05).

CONCLUSIONS

Preoperative B-type natriuretic peptide blood levels are uniquely associated with the need for mechanical support early after total cavopulmonary connection and total cavopulmonary connection takedown, and thus may provide important information in addition to the standard preoperative assessment.

Congenital heart disease and pulmonary hypertension: pharmacology and feasibility of late surgery

Pulmonary arterial hypertension (PAH) with increased pulmonary vascular resistance (PVR), previously termed pulmonary vascular obstructive disease or pulmonary vascular disease is a frequent complication of congenital heart disease (CHD).While there have been advances in the medical treatments available for classic Eisenmenger syndrome patients who are not suitable for repair, the sub-group of patients with moderate sized congenital systemic to pulmonary shunts and mild to moderately elevated PVR remains challenging. With the development of targeted medical treatments for pulmonary arterial hypertension (PAH), the concept of a combined medical and interventional/surgical approach for patients with PAH associated with CHD (APAH-CHD) has emerged. Careful evaluation and an understanding of the predominant physiologic features will help guide the management of these complex patients and whether late surgical repair is feasible.

Review of inhaled nitric oxide in the pediatric cardiac surgery setting

Surgical intervention for congenital heart disease (CHD) can be complicated by pulmonary hypertension (PH), which increases morbidity, mortality, and medical burden. Consequently, postoperative management of PH is an important clinical consideration to improve outcomes. Inhaled nitric oxide (iNO) is a widely accepted standard of care for PH and has been studied in the context of cardiac surgery for CHD. However, large randomized, double-blind, placebo-controlled, multicenter clinical trials in pediatric patients are limited. This review will provide an overview of the clinical studies in this setting and will discuss general treatment considerations to facilitate a better understanding of the clinical use of iNO for PH after pediatric cardiac surgery.

Pulmonary hypertension in congenital shunts

Pulmonary arterial hypertension frequently arises in patients with congenital heart disease. The vast majority present with congenital cardiac shunts. Initially these may manifest as left-to-right (i.e. systemic-to-pulmonary) shunts. The natural history of disease progression involves vascular remodeling and dysfunction that lead to increased pulmonary vascular resistance and, finally, to the development of Eisenmenger's syndrome, which is the most advanced form. The anatomical, pathological and structural abnormalities occurring in the pulmonary circulation of these patients are, to some extent, similar to those observed in other forms of pulmonary arterial hypertension. This understanding has recently led to significant changes in the management of Eisenmenger's syndrome, with the introduction of treatment specifically targeting pulmonary vascular disease. Early closure of the cardiac shunt remains the best way of preventing pulmonary vascular lesions. However, it is still not clear which preoperative parameters predict safe and successful repair, though hemodynamic evaluation is still routinely used for assessment. Postoperative pulmonary hypertension, both in the immediate period after surgical repair and during long-term follow-up, remains a real therapeutic challenge. The clinical situation of a single ventricle with Fontan circulation also presents difficulties when pulmonary vascular lesions are present. This article reviews pulmonary hypertension associated with congenital shunts and discusses a number of the specific problems encountered.