Timely Intervention Improves Prognosis

The majority of cases of complex congenital heart disease requires corrective surgery. Today we know: if it takes place in time, many people are able to live a long life with their heart defect. Here, “in time” means: as early as possible. This is due to the fact that the life-saving intervention, which requires using a heart-lung machine, inevitably interferes with the myocardial tissue. This implies the risk of post-surgical myocardial failure. Accordingly, the myocardial tissue’s capacity to recover has a crucial effect on the post-operative course.

Identifying and Assessing Risks

However, existing risks always have to be balanced against each other. Particularly during the transition from the unborn stage to the newborn stage, the maturing cardiac muscle has to master a complex adjustment. For an exact and optimal timing of corrective surgery, we therefore need to know if, in addition to newborns’ myocardial capacity to recover, there is an equally increased myocardial vulnerability. Furthermore, we need to know how the level of recovery and the level of tissue damage behave in relation to each other.

Pilot Study Yields New Starting Points

In contrast to adults with acquired cardiovascular disease, the causes of myocardial failure in newborns and infants with congenital heart disease are largely uninvestigated. However, clinical practice has shown already today that especially newborns with congenital heart disease are able to recover well from corrective open heart surgery. The myocardial capacity to recover can, therefore, be assumed to be even stronger during the neonatal stage than it is in older infants. Our pilot study yielded important scientific starting points for a more thorough investigation.

Barely Pea-sized Tissue from the Cardiac Auricles

For this purpose, we examined the myocardial tissue of newborns and infants with congenital heart disease before and after the life-saving surgery. In doing so, we investigated what happens in the myocardial cells before and after patients are put on the heart-lung machine. The required samples were taken from the tissue of the right auricle of the heart. This does not imply an additional risk to the little patients. The barely pea-sized material gives way to the tube when a patient is put on the heart-lung machine and is usually disposed of in the surgical trash. The procedure is similar with respect to the comparison sample that is taken when the tube is removed. These samples greatly serve basic research. They allow for observing cell damage, cell division and the settlement of stem cells. The patients’ blood samples yield additional information regarding the mechanisms within a cell that lead to cell damage, as well as to the settlement of stem cells, and thus to the myocardial tissue’s recovery.

Reducing Residual Risks, Enabling Therapy Approaches

During the analysis of DNA extracted from the blood, the microRNA comes in. These signal molecules within the DNA are responsible for turning on and off, that is, for starting and stopping important processes within the cell. Analyzing their activity before and after putting a patient on the heart-lung machine reveals the effect that this process has on the myocardial cells and shows how the myocardial cells of newborns and infants with different complex congenital heart disease each recover from that. It can be assumed that, on the one hand, the residual risk of such an intervention is able to be reduced on this basis. At the same time, the findings obtained might even enable us to find out how repair mechanisms can be stimulated by using, for instance, the body’s own stem cells. The initial results of our research in this area point in that direction.

The Next Step

Accordingly, the evidence found in our pilot study has to be investigated on the basis of a larger data and sample collection in the next step. The intended multicenter study involves the collaboration of several pediatric heart centers in Germany. Should such a multicenter study confirm the findings of the pilot study, then this would be an important step forward for the future of many heart patients.

Thank You

Our patients might be little, but they make a great contribution to all those affected. We would particularly like to thank all patients and their parents who have been supporting the pediatric heart centers’ research by willingly participating in the National Register and by voluntarily donating bio samples and medical data. Only a large number of participants ensures a suitable data basis. It is the essential prerequisite for being able to investigate the causes of myocardial failure and to thus find potential counter-measures.