Pulmonary arterial hypertension associated with congenital heart disease: lessons learnt from the large Turkish Nationwide Registry (THALES)

Pulmonary hypertension is a group of diseases, including pulmonary arterial hypertension associated with congenital heart disease (APAH-CHD), characterized by progressive deterioration in pulmonary hemodynamics associated with substantial morbidity and mortality risk. THALES is a national multicenter, prospective observational registry, providing data on patients with APAH-CHD. The study comprised APAH-CHD patients (>3 months of age) with confirmed diagnosis of right heart catheterization or echocardiographic findings. Initial and follow-up data were collected via regular hospital visits. Descriptive statistics are used for definitive purposes. Overall, 1034 patients aged 3 months–79 years (median 11.2 [Q1–Q3: 2.2–24.3] years) with APAH-CHD were enrolled at 61 centers, 50.3% being retrospectively enrolled. Most had either Eisenmenger's syndrome (49.2%) or systemic-to-pulmonary shunts (42.7%). Patients were mostly in functional class I–II at the time of diagnosis (46.6%). Mean 6-min walk distance (6MWD) was 369 ± 120 m. Mean pulmonary arterial pressure was 54.7 ± 22.2 mmHg for the whole group, and was highest in patients with Eisenmenger's syndrome. Targeted therapies were noted in 398 (38.5%) patients (monotherapy in 80.4%). Follow-up data were available in 506 patients. Survival at 140 months was 79% and was associated with baseline 6MWD >440 m (p = 0.009), brain natriuretic peptide level < 300 ng/L (p < 0.001). Follow-up 6MWD >165 m (p < 0.0001), brain natriuretic peptide level <300 ng/L (p = 0.031), and targeted therapies (p = 0.004) were also predictive of survival. THALES is the largest registry dedicated to APAH-CHD to date and provides important contributions on demographics, clinical characteristics, and gaps in disease management.

How to evaluate patients with congenital heart disease-related pulmonary arterial hypertension

INTRODUCTION

Patients with congenital heart disease (CHD), who develop pulmonary arterial hypertension (PAH), live longer, and have better quality of life compared to the past due to PAH-specific therapy and improved tertiary care. Areas covered: Clinical examination, objective assessment of functional capacity, natriuretic peptide levels, cardiac imaging, and hemodynamics all play a pivotal role in the evaluation, general care, and management of PAH-specific therapy. This review discusses the epidemiology and pathophysiology of PAH-CHD and provides hints for the optimal evaluation of these patients. Expert commentary: Further research should be performed in the field of PAH-CHD, as there are many of areas lacking evidence that should be addressed in the future. Networking, especially among the tertiary expert centers, could play a key role in this direction.

Hospitalisations for heart failure predict mortality in pulmonary hypertension related to congenital heart disease

OBJECTIVE

Despite the progress in the management of patients with adult congenital heart disease (ACHD), a significant proportion of patients still develop pulmonary hypertension (PH). We aimed to highlight the rate of the complications in PH-ACHD and the predicting factors of cumulative mortality risk in this population.

METHODS

Data were obtained from the cohort of the national registry of ACHD in Greece from February 2012 until January 2018.

RESULTS

Overall, 65 patients receiving PH-specific therapy were included (mean age 46.1±14.4 years, 64.6% females). Heavily symptomatic (New York Heart Association (NYHA) class III/IV) were 53.8% of patients. The majority received monotherapy, while combination therapy was administered in 41.5% of patients. Cardiac arrhythmia was reported in 30.8%, endocarditis in 1.5%, stroke in 4.6%, pulmonary arterial thrombosis in 6.2%, haemoptysis in 3.1% and hospitalisation due to heart failure (HF) in 23.1%. Over a median follow-up of 3 years (range 1-6), 12 (18.5%) patients died. On univariate Cox regression analysis history of HF hospitalisation emerged as a strong predictor of mortality (HR 8.91, 95% CI 2.64 to 30.02, p<0.001), which remained significant after adjustment for age and for NYHA functional class.

CONCLUSIONS

Long-term complications are common among patients with PH-ACHD. Hospitalisations for HF predict mortality and should be considered in the risk stratification of this population.

Protection against monocrotaline-induced pulmonary arterial hypertension and caveolin-1 downregulation by fluvastatin in rats

Statins are Hydroxymethylglutaryl-coenzyme A reductase inhibitors, which are typically used to lower blood cholesterol. Additional beneficial effects, including improvement to pulmonary arterial hypertension (PAH), have also been confirmed. However, the mechanisms underlying this improvement have not yet been clarified. The present study was conducted to determine if fluvastatin was protective against experimental PAH development and to investigate the potential effects of fluvastatin on caveolin‑1 (cav‑1) expression. Rats were randomized to either receive a single subcutaneous injection of monocrotaline (MCT; 60 mg/kg; MCT group) or a single subcutaneous injection of MCT (60 mg/kg) followed by an oral gavage of fluvastatin (10 mg/kg) once daily until day 42 (M + F group). Rats in the MCT group received an equivalent volume of saline following the MCT injection. Six additional rats were given an equivalent volume of saline throughout as a control measure. PAH associated variables and cav‑1 protein expression were measured in each group at various times during the experimental period. Hemodynamic and morphometric analysis revealed that M + F rats developed moderate, delayed PAH. Cav‑1 western blot analysis demonstrated that cav‑1 expression was not significantly different in fluvastatin treated rats; however, MCT injured rats given saline had markedly reduced cav‑1 expression. It was concluded that fluvastatin may protect against PAH development and ameliorate MCT induced inhibition of cav‑1 expression in rats.

Simulation of Eisenmenger syndrome with ventricular septal defect using equivalent electronic system

BACKGROUND

In this study, we aim to investigate the simulation of the cardiovascular system using an electronic circuit model under normal and pathological conditions, especially the Eisenmenger syndrome.

METHODS AND RESULTS

The Eisenmenger syndrome includes a congenital communication between the systemic and pulmonary circulation, with resultant pulmonary arterial hypertension and right-to-left reversal of flow through the defect. When pulmonary vascular resistance exceeds systemic vascular resistance, it results in hypoxaemia and cyanosis. The Westkessel model including Resistor-Inductance-Capacitance pi-segments was chosen in order to simulate both systemic and pulmonary circulation. The left and right heart are represented by trapezoidal shape stiffness for better simulation results. The Eisenmenger syndrome is simulated using a resistance (septal resistance) connected between the left ventricle and right ventricle points of the model. Matlab® is used for the model implementation. In this model, although there is a remarkable increase in the pulmonary artery pressure and right ventricle pressure, left ventricle pressure, aortic pressure, aortic flow, and pulmonary compliance decrease in the Eisenmenger syndrome. In addition, left-to-right septal flow reversed in these diseases.

CONCLUSION

Our model is effective and available for simulating normal cardiac conditions and cardiovascular diseases, especially the Eisenmenger syndrome.

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.

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.

[Pregnancy and heart disease]

Pregnancy and delivery are associated with substantial physiological changes that require adaptations in the cardiovascular system. These changes, well-tolerated in pregnant women without heart disease, expose woman with cardiovascular disease to serious risk. In fact, heart disease is the most frequent cause of maternal death, after psychiatric disorders, and the number of pregnant women with heart disease is expected to grow in the coming years. Preventing cardiovascular complications should be the main aim of every cardiologist involved in managing pregnant woman with congenital or acquired heart disease. Unfortunately, there is a lack of data which would help in the management of these patients during pregnancy and the clinical practice guidelines are often based on assumptions regarding how a specific substrate is going to respond to the physiological changes occurring due to pregnancy.

[Progress in pediatric cardiology and congenital heart defects]

We present a review of progress reported in the fields of pediatric cardiology and congenital heart disease between July 2004 and July 2005. The review covers diagnosis, medical treatment, interventional cardiology, and surgery. Among advances in diagnosis, we highlight new diagnostic imaging methods such as three-dimensional echocardiography, magnetic resonance imaging, CT angiography, and tissue Doppler imaging. In the area of fetal cardiology, we focus on advances in fetal interventions, such as percutaneous aortic valvuloplasty, percutaneous pulmonary valvuloplasty, and intact or restrictive atrial balloon septostomy. In interventional cardiology, we highlight advances in the application of percutaneous techniques to adult congenital heart disease to help solve problems resulting from previous surgery, and we review new devices for enabling the percutaneous closure of muscular and membranous ventricular septal defects. In cardiac surgery, a number of developments in valved conduits and in aortic translocation in patients with complex transposition of the great arteries are of particular interest.