Pulmonary Arteriopathy; Evaluation of Invasive Treatments of Peripheral Pulmonary Stenosis in Terms of Right Ventricular Function and Patient Exercise Tolerance

For patients with untreated peripheral pulmonary stenoses, the course of disease is characterised by a chronic pressure load of the right ventricle. In the medium to long term this can lead to right heart failure and cardiac arrhythmia unresponsive to therapy. The probability of these events as well as the time of their occurrence depends on the severity of the stenoses, the duration of stress and a possible additional volume load. Within the scope of the prospective study introduced here, we intend to characterise the stenoses with respect to degree and type and to document the treatment success in terms of decrease of afterload of the right ventricle. In this context, imaging and catheter-based methods as well as respective functional analyses are to be used to provide evidence of a reduction or neutralisation of the pulmonary artery stenoses.

Accordingly, the following questions, or corresponding objectives, can be identified as the base for the conduct of this clinical trial:

• Morphological and functional categorisation of the angiostenoses and standardisation of the diagnostic procedures. For this purpose, the quantitative criteria for both the morphological degree of stenosis (lumen constriction) and the functional degree of stenosis (pressure gradient) are established by means of cardiac catheterisation and angiography. Non-invasive imaging methods, which have as yet been restricted primarily to echocardiography, are complemented by the method of spin angiography. Compared to conventional angiography, this has the advantage of being less invasive and not involving radiation exposure.
• On the strength of past experience, the implantation of stents can be viewed as a very promising approach to a treatment with lasting effectiveness of pulmonary artery stenoses. The stents have the advantage of high radial forces that can be offset against the elastic recoil of the vessels occurring after sole dilatation. Furthermore, constrictions that are caused by either kinking of vessels or their compression by neighbouring structures can be dilated sufficiently by the use of stents.
• With respect to the interconnectedness of all the projects of the Competence Network for Congenital Heart Defects, one essential aspect is the standardisation of diagnostic methods of evaluating right ventricular function. The data obtained during the study are to provide the basis for the development of diagnostic guidelines.
• Concerning evaluation, particular attention is paid to the patients' self-assessment with respect to their exercise tolerance. In this context, it is a matter of interest to what degree the patients' subjective maximum stress and therefore their quality of life correlate with the objective measurement parameters. The anticipated results are of direct clinical significance for the patients, as they aim at medium to long-term relief of the right ventricle, which may effect a decrease in morbidity and therefore an improvement of the quality of life. This is of particular importance with regard to the fact that there will be a continuously increasing number of patients with congenital heart defects reaching adulthood.