Skip to main content

Advancing percutaneous heart valve repair in children through the development of new cardiac imaging strategies

Final Report Summary - HEART DEVICE IMAGING (Advancing percutaneous heart valve repair in children through the development of new cardiac imaging strategies)

Project context and objectives

In cardiac diagnostics, recent advances in magnetic resonance imaging (MRI) now enable us to investigate 3-D cardiac morphology and function, and faster sequences allow the widespread use of cardiac MRI in routine clinical practice. The new developments in cardiac MRI also enable us to investigate questions in paediatric cardiology that could not be tackled before.

This project had the scientific objective of using the new capabilities of cardiac MRI to investigate current questions in clinical paediatric cardiology, thus providing the researcher with the opportunity to acquire a broad array of research methodologies. These include protocol writing, grant submissions, the ethics process, the patient consent process, patient recruitment, research magnetic resonance (MR) and computed tomography (CT) imaging, research cardiac catheterisation, statistical data analysis, abstract writing, poster preparation, oral presentation skills, manuscript writing and submission, and the manuscript reviewing process.

Work performed

We have applied cardiac MRI to investigate children with congenital heart disease, in particular patients with single ventricle physiology. These patients only have one functioning heart chamber to pump the blood through the lungs and around the body. Their treatment involves a series of three palliative surgical operations that are carried out during the first years of life. The first secures pulmonary and body perfusion for the first months. The second operation, called bidirectional cavopulmonary connection (BCPC), directs blood from the upper half of the body directly into the lungs. After the third operation, called the total cavopulmonary connection (TCPC), all venous blood returning from the body streams directly into the lungs and then gets pumped actively into the body by the single ventricle, thus avoiding any mixing of oxygenated and non-oxygenated blood and abolishing cyanosis.

It has been observed that many of these patients develop collateral vessels arising from the aorta and going to the lungs between stages II (BCPC) and III (TCPC) of their surgical palliation. It is not yet known which factors are responsible for this collateralisation.

Although it has been postulated that the presence of collateral vessels might be important for the patient's further clinical course, particularly during their TCPC operation, this has not been scientifically demonstrated yet either.

Main results

We have investigated 65 patients using cardiac MRI to evaluate if, and to what extent, aorto-pulmonary collaterals were present. We also collected their clinical data before and after the MRI. Of those patients who proceeded to the TCPC operation, all the relevant data of the operation and hospital stay was also collected and evaluated. The statistical analysis of the database and the creation of statistical models are currently running. However, preliminary results indicate that the age at BCPC, the oxygen saturations at the time of cardiac MRI and the size of the pulmonary arteries play a role in the development of aorto-pulmonary collaterals. Preliminary results also indicate that the amount of collateralisation might play a role in the future clinical course of these patients, causing a greater need for post-operative chest drainage and higher chest drain volumes. If these are confirmed, this might help in the decision as to whether there is an indication to treat, i.e. close aorto-pulmonary collaterals in these patients to reduce the risk of a complicated post-operative course and the socio-economic burden. Publication of the final results is projected for the end of the year.