Pulmonary arterial hypertension in congenital heart disease

Short- and Long-term Outcome After Interventional VSD Closure: A Single-Center Experience in Pediatric and Adult Patients

Interventional closure of congenital ventricular septal defects (VSD) is recording a continuous rise in acceptance. Complete atrioventricular block (cAVB) and residual shunting are major concerns during follow-up, but long-term data for both are still limited. We retrospectively evaluated the outcome of patients with interventional VSD closure and focused on long-term results (> 1 year follow-up). Transcatheter VSD closures were performed between 1993 and 2015, in 149 patients requiring 155 procedures (104 perimembranous, 29 muscular, 19 residual post-surgical VSDs, and 3 with multiple defects). The following devices were used: 65 × Amplatzer™ Membranous VSD Occluder, 33 × Duct Occluder II, 27 × Muscular VSD Occluder, 3 × Duct Occluder I, 24 × PFM-Nit-Occlud®, and 3 × Rashkind-Occluder. The median age at time of implantation was 6.2 (0.01-66.1) years, median height 117 (49-188) cm, and median weight 20.9 (3.2-117) kg. Median follow-up time was 6.2 (1.1-21.3) years and closure rate was 86.2% at last follow-up. Complications resulting in device explantation include one case of cAVB with a Membranous VSD occluder 7 days after implantation and four cases due to residual shunt/malposition. Six (4%) deaths occurred during follow-up with only one procedural related death from a hybrid VSD closure. Overall, our reported results of interventional VSD closure show favorable outcomes with only one (0.7%) episode of cAVB. Interventional closure offers a good alternative to surgical closure and shows improved performance by using softer devices. However, prospective long-term data in the current era with different devices are still mandatory to assess the effectiveness and safety of this procedure.

Lumped-Parameter Circuit Platform for Simulating Typical Cases of Pulmonary Hypertensions from Point of Hemodynamics

Pulmonary hypertension (PH) presents unusual hemodynamic states characterized by abnormal high blood pressure in pulmonary artery. The objective of this study is to simulate how the hemodynamics develops in typical PH cases without treatment. A lumped-parameter circuit platform of human circulation system is set up to simulate hemodynamic abnormalities of PH in different etiologies and pathogenesis. Four typical cases are considered, which are distal pulmonary artery stenosis, left ventricular diastolic dysfunction, ventricular septal defect, and mitral stenosis. The authors propose regulation laws for chambers and vessels to adapt the abnormal hemodynamic conditions for each PH case. The occurrence and development of each PH case are simulated over time using the lumped-parameter circuit platform. The blood pressure, blood flow, pressure-volume relations for chambers and vessels are numerically calculated for each case of PH progression. The model results could be a quite helpful to understand the hemodynamic mechanism of typical PHs. Graphical Abstract.

Emergent Decompression of Intracranial Abscess in Eisenmenger Syndrome

BACKGROUND

Eisenmenger syndrome is a rare sequela of uncorrected congenital heart disease complicated by pulmonary hypertension, from which reversal of the pathologic left-to-right cardiovascular shunt and cyanosis follow. Right-to-left shunting can lead to paradoxical cerebral emboli-increasing the risk of spontaneous or iatrogenic stroke and cerebral abscess.

CASE DESCRIPTION

A 38-year-old man presented with new focal seizures due to a brain abscess. Ventricular septal defect and pulmonary hypertension were identified. Despite dexamethasone and broad-spectrum antibiotics, he developed hemiparesis and altered mental status and required emergent stereotactic abscess drainage. Despite the anesthetic hazards of Eisenmenger syndrome, the procedure was successful and the patient recovered completely.

CONCLUSIONS

Noncardiac perioperative mortality in Eisenmenger syndrome is historically reported up to 19%, and risks are further increased with prolonged case duration or hypotension, mandating vigilant attention to volume status. Correspondingly, shorter- or lower-risk procedures such as stereotactic drainage are recommended. Procedures should be performed only at centers with expertise in management of Eisenmenger syndrome and cardiac-specialized anesthesiologists whenever possible. Although a conservative approach with early, aggressive medical management is preferred, operative intervention may be required in the setting of progressive deterioration and excellent postoperative outcomes are achievable.

Living Donor Liver Transplantation in Biliary Atresia Children with Pulmonary Hypertension

OBJECTIVE

Though living donor liver transplantation (LDLT) is commonly performed for pediatric patients with biliary atresia (BA), pulmonary hypertension (PH) is seldom encountered or reported previously. The aim of this study is mainly to identify the prevalence of PH in pediatric patients undergoing liver transplantation and assess whether PH significantly augment the operative risk and evaluate the outcomes in this series of patients.

DESIGN

Retrospectively cohort study.

SETTING

Renji hospital, Shanghai, China.

PARTICIPANTS

This study comprised 161 pediatric patients undergoing LDLT.

INTERVENTIONS

Patient diagnosed of PH in preoperative examination was compared to those without PH in intra- or post- operative complications or outcomes.

MEASUREMENTS AND MAIN RESULTS

We collected clinical records of LDLT surgery for pediatric patients during the year of 2016 in our hospital. Results suggested that pediatric patients undergoing LDLT had a substantial number of PH with a prevalence of 16.1% in this study. No significant difference was identified between two groups of patients regarding intraoperative outcomes and postoperative complications and mortality.

CONCLUSION

LDLT is a safe procedure in a selected group of BA patients with PH, however, further long-term clinical investigations and mechanical researches are needed.

Low dose monocrotaline causes a selective pulmonary vascular lesion in male and female pneumonectomized rats

Purpose/Aim: Low doses (30-80 mg/kg) of monocrotaline are commonly used to create experimental models of pulmonary hypertension in rats. At these doses, monocrotaline causes pulmonary endothelial apoptosis and acute lung injury which ultimately results in pulmonary vascular disease. Higher doses of monocrotaline (300 mg/kg) are known to create severe liver injury, but previous investigations with lower doses have not reported histology in other organs to determine whether the vascular injury with monocrotaline is pulmonary-selective or generalized.

MATERIALS AND METHODS

We therefore sought to determine whether monocrotaline caused extra-pulmonary injury at doses commonly used in pulmonary hypertension studies. We performed left pneumonectomy on young male and female rats before administering 50-60 mg/kg monocrotaline 7 days later. We monitored serum chemistry and urine dipsticks during the first 3 weeks while the animals developed pulmonary hypertension. After 3 weeks, we sacrificed animals and stained the lungs and highly vascular visceral organs (kidney, liver, and spleen) for elastin to evaluate the degree of vascular injury and remodeling.

RESULTS

We did not observe proteinuria or significant transaminitis over the 3 weeks following monocrotaline. As previously published, monocrotaline caused severe pulmonary vascular disease with neointimal lesions and medial hypertrophy. We did not identify significant large or small arterial damage in the kidneys, liver, or spleen. Two external veterinary pathologists did not identify histopathology in the kidneys, liver, or spleen of these rats.

CONCLUSIONS

We conclude that 50-60 mg/kg of monocrotaline causes a selective pulmonary vascular lesion and that male and female rats have little non-pulmonary damage over 3 weeks at these doses of monocrotaline.

Sudden infant deaths from undiagnosed ventricular septal defect - Report of two autopsy cases

Ventricular septal defect (VSD) has a relatively non-aggressive clinical course; either spontaneous closure or causing congestive heart failure treatable with surgical intervention. We present two autopsy cases of sudden infant deaths from clinically undiagnosed VSDs. Case 1 was an 18-day-old boy. As the deceased coughed and became limp after feeding, he was carried to a hospital. Heart murmur was not auscultated there, so he was brought back to home. He presented severe dyspnea and then he was pronounced dead the next day. Case 2 was a 3-week-old boy. Any abnormality was pointed out at physical examination, although his mother felt his wheeze. He developed respiratory arrest at home in the morning and then he was confirmed dead at the hospital. Heart weights of these babies were heavier than mean weights of each normal development. There were perimembranous VSDs in both cases. Histology revealed that the pulmonary arterial walls were thickened. We diagnosed the cause of death in these cases was cardiac collapse with pulmonary hypertension due to VSD. Congenital heart diseases can be diagnosed as early as before birth, because echocardiograph and fetal echography are prevalent in these days. Most VSDs can be noticed by systolic murmur even today. We consider that the failure of initial clinical diagnosis of VSD in primary physical assessment could lead unexpected sudden death. These two cases reminded us to the importance of auscultation which is conventional but as one of the indispensable measure to find a clue for the congenital abnormality.

Deleterious effects of indomethacin in the mid-gestation human intestine

The use of the anti-inflammatory drug indomethacin (INDO) in preterm infants has been associated with an increased risk of developing enteropathies. In this study, we have investigated the direct impact of INDO on the human mid-gestation intestinal transcriptome using serum-free organ culture. After determining the optimal dose of 1 μM of INDO (90% inhibition of intestinal prostaglandin E2 production and range of circulating levels in treated preterm babies), global gene expression profiles were determined using Illumina bead chip microarrays in both small and large intestines after 48 h of INDO treatment. Using Ingenuity Pathway Analysis software, we identified critical metabolic pathways that were significantly altered by INDO in both intestinal segments including inflammation and also glycolysis, oxidative phosphorylation and free radical scavenging/oxidoreductase activity, which were confirmed by qPCR at the level of individual genes. Taken together, these data revealed that INDO directly exerts multiple detrimental effects on the immature human intestine.

Complete atrioventricular canal defect in a foal: Clinical and pathological features

Atrioventricular (AV) canal defects comprise a rare category of congenital heart disease associated with abnormal development of the endocardial cushions. These anomalies include a broad spectrum of lesions involving the atrial septum primum, the inlet portion of the ventricular septum, and the atrioventricular valves. In severe cases heart failure may result. The present report describes cardiopulmonary findings in a six-week-old, female Thoroughbred foal with persistent tachypnea and tachycardia since birth. Clinical, echocardiographic, cardiac catheterization, and pathologic findings were compatible with complete AV canal defect with bi-directional shunting, congestive heart failure, and pulmonary hypertension. Gross cardiac pathologic findings included a large atrioventricular septal defect, a common atriovalvular orifice, five atrioventricular leaflets, with two free-floating bridging leaflets. Histopathologic lesions in the lung included hypertrophy of the pulmonary arteriolar walls due to thickening of the tunica media. This represents a well documented case of complete endocardial cushion defect with anomalous development of the atrioventricular valves and resultant pulmonary hypertension and heart failure.

[MRI for therapy planning in patients with atrial septum defects]

PURPOSE

The aim of this study was to determine the value of a combined magnetic resonance imaging (MRI) protocol including steady-state free precession (SSFP) imaging, phase-contrast measurements and contrast-enhanced MR angiography (CE-MRA) for presurgical or preinterventional diagnostic imaging in patients with suspected atrial septum defects.

MATERIAL AND METHODS

Out of 65 MRI studies of patients with suspected atrial septum defects, 56 patients were included in the study. The atrial septum defects were identified on cine images. Velocity encoded flow measurements were used to determine shunt volumes, which were compared with invasive oxymetry in 24 patients. Contrast-enhanced MRI was used to assess the thoracic vessels in order to detect vascular anomalies. The findings were compared with the intraoperative results.

RESULTS

A total of 24 patients with high shunt volumes were treated either surgically (16 patients) or interventionally (8 patients) and 32 patients with low shunt volumes did not require surgical or interventional treatment. The vascular anomaly, which in all cases was anomalous pulmonary venous return, was confirmed by the intraoperative findings. The type and location of atrial septal defects which required treatment, were confirmed intraoperatively or during the intervention. The results of shunt quantification by MRI showed a good correlation with the results of invasive oximetry (r=0.91, p <0.0001).

CONCLUSION

A combined MRI protocol including cine SSFP images, velocity-encoded flow measurements and CE-MRA is an accurate method for preoperative and preinterventional evaluation of atrial septum defects.

Management of patent ductus arteriosus in term or near-term neonates with respiratory distress

BACKGROUND

Respiratory distress and patent ductus arteriosus (PDA) in neonates are mutually perpetuating. Contrary to the situation in premature infants, the recognition, clinical relevance and optimal management of PDA in full-term neonates are unclear. The present study aimed to identify PDA as a possible cause of respiratory distress in term and near-term neonates, and to examine the clinical responsiveness of PDA to different treatment modalities in mature-gestational-age neonates.

METHODS

Patients with gestational ages of over 34 weeks were included in this retrospective chart review; they had PDA as the sole recognizable cause of respiratory distress and were free of all other diseases. Clinical responsiveness to different regimens, including conservative treatment, drug therapy with preload reduction and inotropic agent with or without the addition of indomethacin, and surgical intervention were analyzed.

RESULTS

Forty-four neonates qualified for this study. Six received no treatment and their cardiorespiratory symptoms resolved within 1 week (regimen A). Symptoms in 11 neonates were relieved after use of diuretic and inotropic agents (regimen B). Twelve neonates became asymptomatic without further intervention after indomethacin treatment in addition to preload reduction and inotropes (regimen C). A total of 15 of the 44 infants underwent PDA ligation (regimen D) due to persistent heart failure following regimens B or C, but had speedy resolution of respiratory symptoms following surgery. There were significant differences in birth body weight and hemodynamic variation based on left atrium to aortic root dimensional ratio between the treatment (regimens B, C and D) and non-treatment (regimen A) groups (p < 0.05).

CONCLUSION

PDA plays an important role in prolonging respiratory distress in term or near-term neonates. Although most infants respond to noninvasive medical treatment, surgical ligation during the neonatal period is warranted in certain mature infants. Surgical treatment should be considered in patients with smaller birth body weights and those with increased left atrium to aortic root dimensional ratios.

HLA-B35 upregulates endothelin-1 and downregulates endothelial nitric oxide synthase via endoplasmic reticulum stress response in endothelial cells

The presence of the HLA-B35 allele has emerged as an important risk factor for the development of isolated pulmonary hypertension in patients with scleroderma, however the mechanisms underlying this association have not been fully elucidated. The goal of our study was to determine the molecular mechanisms that mediate the biological effects of HLA-B35 in endothelial cells (ECs). Our data demonstrate that HLA-B35 expression at physiological levels via adenoviral vector resulted in significantly increased endothelin-1 (ET-1) and a significantly decreased endothelial NO synthase (eNOS), mRNA, and protein levels. Furthermore, HLA-B35 greatly upregulated expression of chaperones, including heat shock proteins (HSPs) HSP70 (HSPA1A and HSPA1B) and HSP40 (DNAJB1 and DNAJB9), suggesting that HLA-B35 induces the endoplasmic reticulum (ER) stress and unfolded protein response in ECs. Examination of selected mediators of the unfolded protein response, including H chain binding protein (BiP; GRP78), C/Ebp homologous protein (CHOP; GADD153), endoplasmic reticulum oxidase, and protein disulfide isomerase has revealed a consistent increase of BiP expression levels. Accordingly, thapsigargin, a known ER stress inducer, stimulated ET-1 mRNA and protein levels in ECs. This study suggests that HLA-B35 could contribute to EC dysfunction via ER stress-mediated induction of ET-1 in patients with pulmonary hypertension.

Non-invasive measurement of the response of right ventricular pressure to exercise, and its relation to aerobic capacity

INTRODUCTION

Exercise echocardiography assesses exercise-induced pulmonary hypertension. The upper normal limit of right ventricular systolic pressure during exercise is not well established. Our study aims to investigate the response of right ventricular systolic pressure in relation to aerobic capacity.

METHODS AND RESULTS

Cardiopulmonary exercise testing using a treadmill, and echocardiography during supine cycling, were performed in 113 healthy volunteers aged 13 to 25 years. Maximal right ventricular systolic pressure during evaluable exercise studies obtained in 108 subjects showed a Gaussian distribution only after separating the endurance trained subjects, specifically 12 athletes with Z-score of peak oxygen uptake higher than 2.0, from the normally trained group of 97 subjects. Maximal right ventricular systolic pressure during exercise in the normally trained group showed a mean of 38.0 millimetres of mercury, with standard deviation of 7.2, a median value of 39.0, and a range from 17 to 63, and the 95th percentile was 51 millimetres of mercury. In the athletes, the maximal right ventricular systolic pressure was higher, with a median of 55.5, a range from 28 to 69, this being significant, with p equal to 0.004). Of the 12 athletes, 8 (67%) showed a response of right ventricular systolic pressure to exercise exceeding 50 millimetres of mercury, but only 8 of 97 normally trained subjects (8%) showed a similar response, this also being significant, with p less than 0.001.

CONCLUSIONS

Our study confirms the great variability in the response of right ventricular systolic pressure to exercise in healthy individuals, with 50 millimetres of mercury representing the upper normal limit. Endurance-trained athletes show higher levels, and two-thirds have abnormal responses exceeding 50 millimetres of mercury.

Establishment of rat model of cardiopulmonary bypass in pulmonary hypertension

An experimental model of cardiopulmonary bypass in rats with pulmonary hypertension is necessary to understand underlying mechanisms and develop protective strategies. Male Sprague-Dawley rats were randomly divided into a sham group, cardiopulmonary bypass group, pulmonary hypertension group, and pulmonary hypertension with cardiopulmonary bypass group. Both groups with pulmonary hypertension received a subcutaneous injection of monocrotaline 60 mg x kg(-1) on day 0. Cardiopulmonary bypass was instituted in one of them 21 days later. The sham and pulmonary hypertension control groups underwent cannulation only. Cardiopulmonary bypass was conducted for 60 min at a flow rate of 100 mL x kg(-1) x min(-1). Hemodynamic investigations, blood gas analysis, interleukin-6, tumor necrosis factor-alpha, and survival studies were performed subsequently. Time-dependent increases of serum interleukin-6 and tumor necrosis factor-alpha were found after cardiopulmonary bypass in both groups. This model allows the study of multiple organ pathophysiological processes after cardiopulmonary bypass in rats with pulmonary hypertension, as well as the evaluation of possible protective strategies.

Effects of endogenous sulfur dioxide on monocrotaline-induced pulmonary hypertension in rats

AIM

The present study aimed to explore the protective effect of endogenous sulfur dioxide (SO2) in the development of monocrotaline (MCT)-induced pulmonary hypertension (PH) in rats.

METHODS

Forty Wistar rats were randomly divided into the MCT group receiving MCT treatment, the MCT+L-aspartate-beta- hydroxamate (HDX) group receiving MCT plus HDX treatment, the MCT+SO2 group receiving MCT plus SO2 donor treatment, and the control group. Mean pulmonary artery pressure (mPAP) and structural changes in pulmonary arteries were evaluated. SO2 content, aspartate aminotransferase activity, and gene expression were measured. Superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), reduced glutathione (GSH), oxidized glutathione, and malondialdehyde (MDA) levels were assayed.

RESULTS

In the MCT-treated rats, mPAP and right ventricle/(left ventricle+septum) increased significantly (P<0.01), pulmonary vascular structural remodeling developed, and SOD, GSHPx, CAT, GSH, and MDA levels of lung homogenates significantly increased (P<0.01) in association with the elevated SO2 content, aspartate aminotransferase activity, and gene expression, compared with the control rats. In the MCT+HDXtreated rats, lung tissues and plasma SO2 content and aspartate aminotransferase activities decreased significantly, whereas the mPAP and pulmonary vascular structural remodeling were markedly aggravated with the decreased SOD, CAT, and GSH levels of lung tissue homogenates compared with the MCT-treated rats (P<0.01). In contrast, with the use of a SO2 donor, the pulmonary vascular structural remodeling was obviously lessened with elevated lung tissue SOD, GSH-Px, and MDA content, and plasma SOD, GSH-Px, and CAT levels.

CONCLUSION

Endogenous SO2 might play a protective role in the pathogenesis of MCT-induced PH and promote endogenous antioxidative capacities.

Longer-term bosentan therapy improves functional capacity in Eisenmenger syndrome: Results of the BREATHE-5 open-label extension study

BACKGROUND

Bosentan, an oral endothelin ET(A)/ET(B) receptor antagonist, improves hemodynamics and exercise capacity in patients with Eisenmenger syndrome but longer-term effects are unknown. This study investigated the efficacy and safety of bosentan up to 40 weeks in these patients.

METHODS

Following the 16-week, double blind, placebo-controlled BREATHE-5 study of bosentan in patients with Eisenmenger syndrome, an open-label extension (OLE) was performed. Patients who completed BREATHE-5 received bosentan for an additional 24 weeks (62.5 mg b.i.d. for 4 weeks, then 125 mg b.i.d.) and were analyzed in two groups; ex-placebo and ex-bosentan, according to BREATHE-5 treatment.

RESULTS

Thirty-seven patients with Eisenmenger syndrome who participated in BREATHE-5 were included in the OLE. At week 24, the 6-minute walk distance (mean+/-SE) increased from OLE baseline for the ex-placebo (+33.2+/-23.9 m) and ex-bosentan group (+6.7+/-10.0 m). The overall improvement from baseline of BREATHE-5 was +61.3+/-8.1 m (95% confidence interval: [44.7, 78.0]) for the ex-bosentan group. WHO functional class was improved in both groups. Bosentan did not reduce systemic arterial blood oxygen saturation; safety profile was comparable to previous trials.

CONCLUSIONS

In conclusion, these longer follow-up data support the efficacy and safety profile reported in the preceding BREATHE-5 study of bosentan treatment of Eisenmenger syndrome, challenging the notion that pulmonary vascular disease and severe functional impairment in these patients are not amenable to therapy.

Pulmonary arterial hypertension in congenital heart disease: An epidemiologic perspective from a Dutch registry

BACKGROUND

Pulmonary arterial hypertension (PAH) associated with congenital heart disease is usually the result of a large systemic-to-pulmonary shunt, and often leads to right ventricular failure and early death. The purpose of this study was to determine the prevalence of PAH among adult patients included in a national registry of congenital heart disease and to assess the relation between patient characteristics and PAH.

METHODS

Patients with PAH associated with a septal defect were identified from the registry. Gender, age, underlying diagnosis, previous closure, age at repair and NYHA classification were recorded. PAH was defined as a systolic pulmonary arterial pressure (sPAP) greater than 40 mm Hg, estimated by means of echocardiographical evaluation.

RESULTS

The prevalence of PAH among all 5970 registered adult patients with congenital heart disease was 4.2%. Of 1824 patients with a septal defect in the registry, 112 patients (6.1%) had PAH. Median age of these patients was 38 years (range 18-81 years) and 40% were male. Of these patients, 58% had the Eisenmenger syndrome. Among the patients with a previously closed septal defect, 30 had PAH (3%). Ventricular septal defect (VSD) was the most frequent underlying defect (42%) among patients with PAH and a septal defect. Female sex (Odds ratio=1.5, p=0.001) and sPAP (Odds ratio=0.04, p<0.001) were independently associated with a decreased functional class.

CONCLUSION

PAH is common in adult patients with congenital heart disease. In our registry the prevalence of PAH in septal defects is around 6%. More than half of these patients have the Eisenmenger syndrome, which accounts for 1% of the total population in the CONCOR registry. Whether the prevalence of PAH will decrease in the future as a result of early detection and intervention remains to be awaited.

Bosentan for increased pulmonary vascular resistance in a patient with single ventricle physiology and a bidirectional Glenn shunt

We present a case of the successful use of bosentan for increased pulmonary vascular resistance (PVR) in a 10-year-old male who underwent late single ventricle surgical palliation for double-inlet left ventricle with pulmonary artery banding and a bidirectional Glenn shunt. The patient was treated with bosentan for 16 weeks, with decreases in mean pulmonary artery pressure from 23 to 16 mmHg on the right and from 31 to 21 mmHg on the left, and a decrease of the transpulmonary gradient by 7-8 mmHg. Cardiopulmonary exercise testing demonstrated an increase in peak oxygen consumption (VO2) by 8% and peak work rate by 10%. Bosentan is a relatively new oral therapy option for increased PVR in patients with single ventricle physiology and bidirectional Glenn shunts.

An open-label, multicentre pilot study of bosentan in pulmonary arterial hypertension related to congenital heart disease

BACKGROUND

Bosentan has been shown to be a safe and efficacious treatment for idiopathic pulmonary arterial hypertension (PAH) and PAH associated with connective tissue disease. However, there are limited studies examining the benefits of bosentan in PAH associated with congenital heart disease (CHD).

OBJECTIVE

The aim of the present pilot study was to explore the safety and efficacy of bosentan in patients with PAH associated with CHD.

PATIENTS AND METHODS

In the present study, 11 patients with PAH associated with CHD were enrolled to receive bosentan for a minimum of 16 weeks (62.5 mg twice a day for four weeks; thereafter 125 mg twice a day). Safety was assessed by monitoring adverse events, oxygen saturation, systemic blood pressure, pulse, complete blood count and liver function tests. Efficacy was assessed by the World Health Organization functional class, 6 min walk test (6-MWT), modified Borg dyspnea index, echocardiography and the 36-item short form health survey.

RESULTS

Ten patients completed the 16-week treatment period (one patient withdrew). Bosentan was not associated with a deterioration in resting oxygen saturation (83.0+/-4.6% at week 16 versus 81.9+/-6.1% at baseline; P = 0.402), or a deterioration in post-6-MWT oxygen saturation (70.1+/-10.9% at week 16 versus 68.7+/-15.1% at baseline; P = 0.747). Two patients experienced three serious adverse events. The distance walked in 6 min improved significantly by 28 m (P = 0.005) at week 16 compared with baseline, and the modified Borg dyspnea index also improved at week 16 compared with baseline (P = 0.050). The World Health Organization functional class improved from class III to class II for five of 10 patients (50%). Patients' self-rated quality of life (36-item short form health survey) demonstrated a nonsignificant improvement in each of the eight domains. Obtaining reliable echocardiographic measurements was difficult. Most echocardiographic parameters were only measurable on few patients, and none were measured on all patients, questioning the usefulness of echocardiography as a measuring tool for patients with complex CHD.

CONCLUSION

Bosentan was not associated with worsening of resting oxygen saturation or exercise systemic oxygen saturation, suggesting its potential as a safe treatment option for patients with PAH associated with CHD. Improved 6-MWT and the modified Borg dyspnea index also suggested the possibility of bosentan as an efficacious treatment option for these patients. The results of the present study provide evidence for the need and feasibility of a large randomized, placebo-controlled clinical trial.

Impact of l-arginine on hydrogen sulfide/cystathionine-γ-lyase pathway in rats with high blood flow-induced pulmonary hypertension

The present study was designed to explore the possible effect of L-arginine on endogenous hydrogen sulfide/cystathionine-gamma-lyase (H(2)S/CSE) pathway in the pathogenesis of pulmonary hypertension and pulmonary vascular structural remodeling induced by high pulmonary blood flow. Thirty-two male Sprague-Dawley rats were randomly divided into control group (n=11), shunt group (n=11) and shunt with L-arginine group (n=10). Rats in the shunt and shunt with L-arginine group underwent an abdominal aorta-inferior cava vein shunt operation. After 11 weeks of shunting, the plasma level of H2S and lung tissue H2S production rate in the shunt with L-arginine group were much higher than those in the shunt group (P<0.01). Meanwhile, the expression of CSE mRNA in the lung tissues of rats in the shunt with L-arginine group was increased significantly (P<0.01), and in situ hybridization showed that CSE mRNA expression was obviously up-regulated in the smooth muscle cells (SMCs) of the pulmonary arteries of shunted rats treated with L-arginine when compared with shunted rats without the treatment of L-arginine (P<0.01). In conclusion, H2S/CSE pathway was up-regulated by L-arginine in pulmonary hypertension induced by high blood flow with the attenuation of pulmonary hypertension and pulmonary vascular structural remodeling.

Advanced therapy may delay the need for transplantation in patients with the Eisenmenger syndrome

AIMS

Advanced therapies (prostacyclin analogues, endothelin receptor antagonists) are successfully used in the treatment of idiopathic pulmonary arterial hypertension. In addition, patients with the Eisenmenger syndrome (ES) seem to benefit from these news drugs regarding symptoms, but there is still no evidence for changes in outcome.

METHODS AND RESULTS

The clinical course of 43 patients (M/F 13/30, age 34.0 +/- 12.7 years), registered with unstable ES in our database, was retrospectively analysed. These patients were divided into two groups: those treated with and those treated without advanced therapy. The primary endpoint was defined as death from any cause. Death or inscription on the active waiting list of heart-lung transplantation was considered as secondary endpoint. Kaplan-Meier survival and log rank testing were performed to determine differences in outcome between the two groups. The total cohort was followed for a median period of 4.9 (range 0.2-14.9) years. Mean survival time for patients treated with (n = 26) and without (n = 17) advanced therapy therapies were 8.5 +/- 1.5 and 8.5 +/- 0.9 years, respectively (log rank testing, P = 0.31). However, the mean time to death or inscription on the active waiting list was significantly longer for patients treated with advanced therapy when compared with those without (7.8 +/- 1.0 vs. 3.4 +/- 0.9 years, P = 0.006).

CONCLUSION

For the given follow-up period, no improvement in survival time could be documented in adult patients with unstable ES treated with advanced therapy. However, we might suggest with these data that the need for heart-lung transplantation can be substantially delayed with new drugs.

Down-regulation of endogenous hydrogen sulfide pathway in pulmonary hypertension and pulmonary vascular structural remodeling induced by high pulmonary blood flow in rats

BACKGROUND

The mechanisms responsible for the development of pulmonary hypertension (PH) and pulmonary vascular structural remodeling induced by high pulmonary blood flow are not fully understood. The present study was designed to explore the possible changes in endogenous hydrogen sulfide (H2S), a novel gasotransmitter, on the pathogenesis of PH and pulmonary vascular structural remodeling induced by high pulmonary blood flow.

METHODS AND RESULTS

Twenty-two male Sprague-Dawley rats were randomly divided into a shunting group (n=11) and control group (n=11). Rats in the shunting group underwent an abdominal aorta-inferior cava vein shunting operation. After 11 weeks of shunting, the plasma level of H2S and lung tissue H2S producing rate were much lower than those of the control group (p<0.01). In situ hybridization analysis showed that the expression of cystathionine gamma-lyase (CSE) mRNA was down-regulated in the pulmonary arteries of the shunting rats compared with the control group (p<0.01), and competitive quantitative reverse transcription-polymerase chain reaction showed that the relative amount of CSEmRNA in lung tissue was decreased significantly (p<0.01).

CONCLUSIONS

The endogenous H2S pathway is down-regulated in PH and pulmonary vascular structural remodeling is induced by high pulmonary blood flow.

Gene transfer of a TIE2 receptor antagonist prevents pulmonary hypertension in rodents

OBJECTIVES

Overexpression of angiopoietin 1 in the lung has been associated with human pulmonary hypertension. We hypothesized that inhibiting angiopoietin 1 signaling in the lung by administration of a receptor antagonist would block the development of pulmonary hypertensive vasculopathy in rodent models.

METHODS

We injected 2 and 4 x 10(10) genomic particles of adeno-associated virus containing an extracellular fragment of the TIE2 receptor (AAV-sTIE2) into the pulmonary artery of 60 rats by using adeno-associated virus-lacZ and carrier-injected rats as control animals. Pulmonary hypertension was then induced by each of the following methods: (1) monocrotaline (group 1); (2) angiopoietin 1 expression in pulmonary vascular smooth muscle by adeno-associated virus gene transfer (group 2); or (3) oxygen deprivation (group 3). Animals were sacrificed at serial time points. At each time point, pulmonary artery pressures were measured, and pulmonary angiography was performed. Lungs were harvested for pathologic-molecular analysis.

RESULTS

Each rodent pulmonary hypertension model demonstrated a significant increase in pulmonary artery pressures compared with that seen in control animals (P < .01). Administration of AAV-sTIE2 prevented pulmonary hypertension in the monocrotaline and angiopoietin 1 groups (from 44.6 +/- 2.1 to 18.8 +/- 1.9 mm Hg in the monocrotaline group and from 31.2 +/- 3.7 to 18.2 +/- 1.8 mm Hg in the angiopoietin 1 group, P < .001) but did not affect pulmonary hypertension in the hypoxia group. Pathologic analysis of group 1 and 2 lungs treated with AAV-sTIE2 demonstrated absence of smooth muscle cell proliferation within arterioles. Pulmonary angiography confirmed a lack of small pulmonary vessel occlusion in group 1 and 2 animals treated with AAV-sTIE2.

CONCLUSIONS

Molecular blocking of the interaction between angiopoietin 1 and its endothelial receptor, TIE2, in the lung prevents pulmonary hypertension in 2 animal models of the disease. These experiments suggest a new strategy for understanding pulmonary hypertension based on the molecular biology of the pulmonary vascular wall.

Assessment of intracardiac anomalies in two adults with Ivemark's syndrome

Ivemark's syndrome consists of intracardiac anomalies, abnormal lobation of the lungs, and abdominal heterotaxy. A frequent intracardiac anomaly seen in Ivemark's syndrome is a common atrium, which is associated with left-to-right shunting. The increased blood flow and resistance within the pulmonary vasculature creates pulmonary hypertension and eventual reversal of the shunt physiology. In the absence of additional cyanotic malformations, survival into adulthood without prior surgical septation of the common atrium depends on the extent of pulmonary hypertension and intracardiac right-to-left shunting. We present two patients with a common atrium in the setting of Ivemark's syndrome who survived into adulthood without prior operation. Two-dimensional echocardiography assessed their intracardiac structures. One patient had right atrial isomerism manifested by asplenia and a common atrium, into which the hepatic veins drained directly, and the other patient had left atrial isomerism manifested by polysplenia, a common atrium, and a ventricular septal defect with a single atrioventricular valve. Neither patient had additional cyanotic malformations, including obstruction to pulmonary venous return, transposition of the great vessels, or pulmonic valve stenosis. The 2-dimensional echocardiogram guides the clinician to refer patients for surgical septation of the common atrium before the right-to-left shunt physiology predominates. The medical and surgical treatment of these patients is discussed.

Congenital heart disease in the adult: 2004

The number of newborn infants with congenital heart disease is relatively stable.However, because of marked advances in correction and palliation of these conditions,the great majority will survive into adult life, significantly increasing the number of such patients in our population. Most patients with congenital heart disease, treated or not,will require routine, continued medical observation and, therefore, many radiologists will become involved in their care. Not uncommonly, pertinent clinical information is not provided to the radiologist, particularly when the patient presents to an Emergency Room because of intercurrent disease. In order to interpret the chest film or CT examination and provide a pertinent report, the radiologist must be conversant with the patterns of the more common congenital cardiac anomalies as well as their post-operative appearances and potential complications.