Asymmetric dimethylarginine is increased in chronic thromboembolic pulmonary hypertension.
ABSTRACT Asymmetric dimethylarginine (ADMA), a potent endogenous nitric oxide synthase (NOS) inhibitor, is increased in idiopathic pulmonary arterial hypertension and associated with unfavorable outcome.
Chronic thromboembolic pulmonary hypertension (CTEPH), although principally amenable to surgical removal of major pulmonary arterial obstructions by pulmonary endarterectomy, may show a small-vessel pulmonary arteriopathy similar to idiopathic pulmonary arterial hypertension. We hypothesized that ADMA plasma levels are increased in patients with CTEPH.
We measured ADMA by high-performance liquid chromatography at the time of diagnosis in 135 patients with CTEPH. Inoperability in 66 patients was based on an imbalance between severity of pulmonary hypertension and morphologic lesions.
ADMA plasma levels were significantly elevated in patients, compared with 40 matched control subjects (0.62 [0.51-0.73] vs. 0.51 [0.45-0.6] micromol/L, P = 0.0002). At baseline, ADMA plasma concentrations correlated with mixed venous saturation (r = -0.25, P = 0.005), right atrial pressure (r = 0.35, P < 0.0001), and cardiac index (r = -0.21, P = 0.01). Patients who underwent surgery demonstrated lower ADMA levels at baseline than inoperable patients (0.60 [0.5-0.68] vs. 0.63 [0.53-0.85] micromol/L, P = 0.02), with a further decrease 12 +/- 1 months after pulmonary endarterectomy (P = 0.02). Endothelial NOS expression in endothelial cells was low in patients with elevated ADMA plasma levels. Survival of patients with ADMA plasma levels >/= 0.64 micromol/L was worse than in patients with ADMA plasma levels < 0.64 micromol/L.
ADMA plasma levels correlate with the severity of pulmonary vascular disease and predict outcome in patients with CTEPH. Measurement of ADMA plasma levels may be useful for estimating the degree of small-vessel arteriopathy in CTEPH.
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ABSTRACT: Therapeutic approaches in pediatric pulmonary arterial hypertension (PAH) are based primarily on clinician experience, in contrast to the evidence-based approach in adults with pulmonary hypertension. There is a clear and present need for non-invasive and objective biomarkers to guide the accurate diagnosis, treatment, and prognosis of this disease in children. The multifaceted spectrum of disease, clinical presentation, and association with other diseases makes this a formidable challenge. However, as more progress is being made in the understanding and management of adult PAH, the potential to apply this knowledge to children has never been greater. This review explores the state of the art with regard to non-invasive biomarkers in PAH, with an eye toward those adult PAH biomarkers potentially suitable for application in pediatric PAH.Frontiers in Pediatrics 01/2014; 2:7.
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ABSTRACT: Nitric oxide (NO) is a diffusible gas with diverse roles in human physiology and disease. Significant progress in the understanding of its biological effects has taken place in recent years. This has led to a better understanding of the pathobiology of pulmonary hypertension (PH) and the development of new therapies. This article provides an overview of the NO physiology and its role in the pathobiology of lung diseases, particularly PH. We also discuss current and emerging specific treatments that target NO signaling pathways in PH.Pulmonary circulation. 01/2013; 3(1):20-30.
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ABSTRACT: Pulmonary arterial hypertension (PAH) is a major cause of morbidity and mortality among patients with congenital heart disease (CHD). This study was designed to determine biomarker levels in patients with PAH associated with CHD (PAH-CHD) and CHD patients without PAH and to investigate the relationship of these potential biomarkers with hemodynamic findings. In this prospective single-center study, patients with CHD were analyzed according to the presence or absence of PAH and compared with healthy control subjects. Cardiac catheterization and echocardiographs were performed. Plasma homocysteine, asymmetric dimethyl arginine (ADMA), and nitric oxide (NO) levels were determined by enzyme-linked immunosorbent assay. Homocysteine and ADMA levels were higher in the PAH-CHD group (n = 30) than among CHD patients with left-to-right shunting but no PAH (n = 20; P < 0.001) and healthy control subjects (n = 20; P < 0.001). There was no difference in NO levels. Cyanotic PAH-CHD patients had significantly higher homocysteine than acyanotic patients in the same group. No correlation was shown between echocardiographic/hemodynamic parameters and homocysteine, ADMA, and NO levels. Homocysteine and ADMA levels are increased in patients with PAH-CHD. These parameters have the potential to be used as biomarkers in the diagnosis and follow-up evaluation of patients with PAH-CHD. However, large, multicentered prospective studies are required to facilitate routine use of these biologic markers in the clinical setting.Pediatric Cardiology 04/2012; · 1.20 Impact Factor