Administering stem cells to patients with myocardial infarction leads to a reduction of the size of the infarct

This week, doctors at the Catholic University of Leuven, connected with the University Hospital – Gasthuisberg, the Stem Cell Institute Leuven (SCIL), and the Flanders Interuniversity Institute for Biotechnology (VIB), are publishing a major breakthrough in the treatment of patients with acute myocardial infarction. Their research shows that the administration of a patient’s own stem cells has a significant positive effect on the heart’s recovery: in the patients studied, the size of the infarct was clearly reduced. The use of stem cells appears to be safe, and to date no side effects have occurred that can be attributed to the stem cells. This study is a world-first – its exciting results are being published in the prominent medical journal The Lancet.

In an acute myocardial infarction, the flow of blood from a blood vessel in the heart is blocked, whereby the cardiac muscle receives insufficient oxygen and heart tissue dies. In many cases, the supply of blood in the deadened portion of the heart can be restored via the so-called balloon technique. But the heart suffers permanent damage, primarily to the left ventricle.

The researchers in Leuven have tested the administration of bone marrow stem cells on patients stricken with acute myocardial infarction. In the 67 patients of the study, the supply of blood in the heart was restored optimally via the balloon technique. Then, within 24 hours, some patients received an injection of stem cells from their own bone marrow and some received an aqueous (placebo) solution (the patients in each group were selected by drawing lots). Such a double-blind, placebo-controlled study has never before been conducted.

Collaboration among the cardiology, hematology, radiology and nuclear medicine services yielded an unparalleled study in which state-of-the-art technology was used to investigate changes in the left ventricle, blood supply and heart metabolism.

Improvement in the global functioning of the left ventricle was comparable in both the control group (injected with the placebo) and the group that received the stem cells. But a clear global improvement in function was found in the sub-group of patients who had been afflicted with the most serious infarctions. Moreover, the reduction of the size of infarct was significantly greater in all patients in the ’stem cell group’ and correlates with a better preserved regional left ventricle function. It is still much too early to conclude that every patient with a myocardial infarction should be treated with stem cells. Indeed, there is still a long road to travel in the development of a medication, and no risks must be taken along the way.

One of the major scientific merits of this study is that it has investigated – in a rigorously controlled manner – the possible role as well as the limitations of the administration of stem cells. The findings are thus an important driving force for further targeted clinical and pre-clinical research. This study is the initial impetus for VIB and the Catholic University of Leuven and the newly established SCIL to quickly combine fundamental research on stem cells with clinical applications for the benefit of patients.