NKX2-5 variants screening in patients with atrial septal defect in Indonesia.

BACKGROUND: NKX2-5 variant in atrial septal defect patients has been reported. However, it is not yet been described in the Southeast Asian population. Here, we screened the NKX2-5 variants in patients with atrial septal defect (ASD) in the Indonesian population. METHOD: We recruited 97 patients with ASD for genetic screening of the NKX2-5 variant using Sanger sequencing. RESULTS: We identified three variants of NKX2-5: NM_004387.4:c.63A>G at exon 1, NM_004387.4:c.413G>A, and NM_004387.4:c.561G>C at exon 2. The first variant is commonly found (85.6%) and benign. The last two variants are heterozygous at the same locus. These variants are rare (3.1%) and novel. Interestingly, these variants were discovered in familial atrial septal defects with a spectrum of arrhythmia and severe pulmonary hypertension. CONCLUSION: Our study is the first report of the NKX2-5 variant in ASD patients in the Southeast Asian population, including a novel heterozygous variant: NM_004387.4:c.413G>A and NM_004387.4:c.561G>C. These variants might contribute to familial ASD risk with arrhythmia and severe pulmonary hypertension. Functional studies are necessary to prove our findings.

Usefulness of Combining NT-proBNP Level and Right Atrial Diameter for Simple and Early Noninvasive Detection of Pulmonary Hypertension Among Adult Patients with Atrial Septal Defect.

BACKGROUND: Atrial septal defect developed pulmonary hypertension (ASD-PH) at first diagnosis due to late presentation are common in Indonesia. Transthoracic echocardiogram (TTE) is a common tool to detect ASD-PH, before proceeding to invasive procedure. The NT-proBNP measurement to screen ASD-PH is not yet considered the standard approach, especially in limited resource conditions. The objective of this study is to assess the value of NT-proBNP, along with simple TTE parameter, to screen PH among adults with ASD. METHODS: This was a cross-sectional study. The subjects were adult ASD-PH patients from the COHARD-PH  registry (n=357). Right heart catheterization (RHC) was performed to diagnose PH. Blood sample was withdrawn during RHC for NT-proBNP measurement. The TTE was performed as standard procedure and its regular parameters were assessed, along with NT-proBNP, to detect PH. RESULTS: Two parameters significantly predicted PH, namely NT-proBNP and right atrial (RA) diameter. The cut-off of NT-proBNP to detect PH was ≥140 pg/mL. The cut-off of RA diameter to detect PH was ≥46.0 mm. The combined values of NT-proBNP level ≥140 pg/mL and RA diameter ≥46.0 mm yielded 46.6% sensitivity, 91.8% specificity, 54.3% accuracy, 96.5% positive predictive value and 26.2% negative predictive value to detect PH, which were better than single value. CONCLUSION: NT-proBNP level ≥140 pg/mL represented PH in adult ASD patients. The NT-proBNP level ≥140 pg/mL and RA diameter ≥46.0 mm had a pre-test probability measures to triage patients needing more invasive procedure and also to determine when and if to start the PH-specific treatment.

The COngenital HeARt Disease in adult and Pulmonary Hypertension (COHARD-PH) registry: a descriptive study from single-center hospital registry of adult congenital heart disease and pulmonary hypertension in Indonesia.

BACKGROUNDS: The COngenital HeARt Disease in adult and Pulmonary Hypertension (COHARD-PH) registry is the first registry for congenital heart disease (CHD) and CHD-related pulmonary hypertension (PH) in adults in Indonesia. The study aims to describe the demographics, clinical presentation, and hemodynamics data of adult CHD and CHD-related PH in Indonesia. METHODS: The COHARD-PH registry is a hospital-based, single-center, and prospective registry which includes adult patients with CHD and CHD-related PH. The patients were enrolled consecutively. For this study, we evaluated the registry patients from July 2012 until July 2019. The enrolled patients underwent clinical examination, electrocardiography, chest x-ray, 6-min walking test, laboratory measurement, and transthoracic and transesophageal echocardiography. Right heart catheterization was performed to measure hemodynamics and confirm the diagnosis of pulmonary artery hypertension (PAH). RESULTS: We registered 1012 patients during the study. The majority were young, adult females. The majority of CHD was secundum ASD (73.4%). The main symptom was dyspnea on effort. The majority of patients (77.1%) had already developed signs of PH assessed by echocardiography. The Eisenmenger syndrome was encountered in 18.7% of the patients. Based on the right heart catheterization, 66.9% of patients had developed PAH. Patients with PAH were significantly older, had lower peripheral oxygen saturation, had lower 6-min walking distance, and higher NTproBNP. The NTproBNP level independently predicted the development of PAH among CHD. CONCLUSIONS: The COHARD-PH registry is the first Indonesian adult-CHD and CHD-related PH registry. The demographics, clinical presentation, and hemodynamics dataof this registry reflect the situation in developing countries which needs to be compared with similar registries from developed countries.

Targeted activation of endothelin-1 exacerbates hypoxia-induced pulmonary hypertension.

Pulmonary arterial hypertension (PAH) is a fatal disease that eventually results in right heart failure and death. Current pharmacologic therapies for PAH are limited, and there are no drugs that could completely cure PAH. Enhanced activity of endothelin system has been implicated in PAH severity and endothelin receptor antagonists have been used clinically to treat PAH. However, there is limited experimental evidence on the direct role of enhanced endothelin system activity in PAH. Here, we investigated the correlation between endothelin-1 (ET-1) and PAH using ET-1 transgenic (ETTG) mice. Exposure to chronic hypoxia increased right ventricular pressure and pulmonary arterial wall thickness in ETTG mice compared to those in wild type mice. Of note, ETTG mice exhibited modest but significant increase in right ventricular pressure and vessel wall thickness relative to wild type mice even under normoxic conditions. To induce severe PAH, we administered SU5416, a vascular endothelial growth factor receptor inhibitor, combined with exposure to chronic hypoxia. Treatment with SU5416 modestly aggravated hypoxia-induced pulmonary hypertension, right ventricular hypertrophy, and pulmonary arterial vessel wall thickening in ETTG mice in association with increased interleukin-6 expression in blood vessels. However, there was no sign of obliterative endothelial cell proliferation and plexiform lesion formation in the lungs. These results demonstrated that enhanced endothelin system activity could be a causative factor in the development of PAH and provided rationale for the inhibition of endothelin system to treat PAH.