Evaluating the correlations of treatment regimens and prognosis with shear stress test and biological markers that are used to diagnose and treat pediatric pulmonary hypertension

Introduction and Aim: The present thesis aims to identify the diagnostic tests which can be used to determine the etiology and prognosis in children with pulmonary hypertension (PH), and thus, to specify whether these tests can be utilized to predict the response to specific treatment regimens.Materials and Methods: The first arm of the present thesis reviews a total of 40 patients who were diagnosed with pediatric PH between January 2001 and March 2012 at the department of pediatric cardiology in Gazi University Medical School. The second arm of the present thesis compares 40 patients with pediatric PH (recruited for the first arm), 31 healthy children and 18 children who had congenital heart disease with left-to-right cardiac shunt in aspect of shear stress test results.Results: Congenital heart diseases, particularly ventricular septal defects, make up the most common underlying factor for PH in children. Cyanosis and fatigue were the most frequently encountered clinical symptoms at the time of initial clinical evaluation. The second arm of the thesis study shows that hemodynamic parameters recorded at the initial and last catheterization procedures were statistically similar just as were pulmonary vasoreactivity test results. When compared with the initial clinical evaluation, mid-expiratory flow 25-75% was significantly lower and six minute walk distance was significantly longer at the last clinical evaluation. Serum concentrations of brain natriuretic peptide (BNP), troponine and CA-125 increased significantly while six minute walk distance shortened significantly with respect to advancing functional class. There were significantly negative correlations between six minute walk distance and biological markers including BNP, CA-125 and vWF values. Six minute walk distance was significantly shorter, functional class was more advanced and serum concentrations of serum BNP, troponine and CA-125 were significantly lower in 20 children who were on combination treatment for PH. The third arm of the thesis study point out that serum concentrations of BNP were significantly higher and platelet counts were significantly lower in pediatric PH patients who were on anticoagulation treatment. When compared with healthy children and children with congenital heart diseases, patients with pediatric PH had significantly higher shear stress test results. There were significantly positive correlations among hemoglobin, hematocrit and shear stress test results.Discussion: The results of this thesis study indicate that the clinical course of pediatric PH is rather progressive even if there was improvement in clinical symptoms and affirmative results were obtained by diagnostic tests. Biological markers such as BNP, CA-125, vWF and uric acid reflect the clinical course of pediatric PH and they emerge as a simple, cheap and non-invasive method which can be used in the clinical follow up of patients with pediatric PH. Shear stress test is a simple and non-invasive method that can be used to support and confirm the diagnosis of pediatric PH. Moreover, this test can be utilized to predict the clinical course of this disease and to determine the effects of specific drugs for PH diagnosed in children and adults.