Evaluation of Biochemical Markers of Neurohumoral Activity and Correlation With Clinically Significant Parameters in Patients With Right Ventricular Failure and Congenital Heart Defects

Usually, "heart failure" refers to myocardial insufficiency of the left ventricle. In patients with congenital heart defects, predominantly the right ventricle and secondarily the right atrium and the pulmonary vasculature are affected. Due to advancing treatment options and the resulting higher life expectancy of patients with congenital heart defects, the number of these patients is increasing steadily. As, for these patients, right ventricular failure often is the factor limiting quality of life and life-span, evidence based drug treatment is both clinically important and of relevance with respect to health policy and health economics.

Concerning left ventricular failure, large controlled and randomised studies in the past years have provided evidence that treatment with beta-adrenergic blockers improves the systolic left ventricular function and decreases mortality in cases of left ventricular failure. These therapeutic achievements corroborated the hypothesis that stimulation of the neurohumoral, particularly the noradrenergic, system is a pathophysiological mechanism significant for the development of left ventricular failure.

Large studies demonstrated that brain natriuretic peptide (BNP) is a sensitive biomarker for activation of the noradrenergic system. Plasma levels of BNP closely correlate with the severity of left ventricular failure, qualifying BNP also as a marker of success/failure of treatment.

If right ventricular dysfunction also involves stimulation of the neurohumoral axis, it is conceivable that BNP in this condition also is a sensitive biomarker for activation of the noradregergic system. Under this condition BNP levels might also serve as a predictive marker for clinical outcome and success/failure of therapy as well.

The objective of the present investigation is to assess the predictive value of BNP as a biomarker for right ventricular function, clinical symptoms and/or the patients' quality of life. For this purpose, blood levels of neurohumoral markers are measured and tested for statistical correlation with exercise tolerance and right ventricular function, as assessed by imaging methods. A sample of healthy volunteers serves as a control group.