Spanish researchers have led a clinical trial called CAREMI, the first in the world to evaluate the safety and potential efficacy of donated stem cells in the first days after a heart attack. Cardiac stem cells are produced in Spain in a massive way; they can be frozen and stored for long periods and can be available at any time.

Cardiologists at the Biomedical Research Center in Network for Cardiovascular Diseases (CIBERCV) have shown that the administration of allogenic cardiac stem cells (from donors) after an acute myocardial infarction is feasible and safe.

The CAREMI clinical trial, promoted by the Belgian-Spanish company TiGenix and led by Francisco Fernández Avilés at the Gregorio Marañón Hospital, has been published in Circulation Research.

The injection through the coronary artery, previously repaired through a cardiac catheterization, did not showed any problem nor did it lead to any adverse events or signs of rejection,” said Javier Bermejo, scientific deputy director of CIBERCV and one of the authors.

Patients who survive an acute myocardial infarction, which affects a greater area than 20% of their left ventricle, have a much higher risk of developing heart failure years later, when the ability of healthy tissue to compensate for the lost tissue fails.

Currently, the only measure to avoid this risk is to recover the flow in the coronary artery responsible for the infarction as quick as possible.

Long conservation of stem cells

As Fernández Avilés explains, “allogenic cardiac stem cells are obtained from donor samples and have the great advantage of being able to be produced in massive quantities and stored safely for long periods. That makes them available for use at any time, for example, when a patient enters into the emergency room with a heart attack. ”

Cell therapies with donor cells that had been tested so far required a production of several weeks before they could be implanted, which delayed their potential use and increased the risks for patients. In this study, the cells produced from three Spanish donors allowed to treat the 55 patients. Another huge advantage of this type of cells is their high quality: they come from donors with healthy heart tissue and their ‘vitality’ can be checked before and after they are produced and implanted.

With the aim of bringing these therapies closer to clinical practice, the CAREMI study evaluated two fundamental innovations. First, the cells were administered at a very early stage during the days following the infarction (between 5 and 7 days later) thanks to the fact that these cells were of allogeneic origin, that is, of 3 donors supposedly not compatible with the receptors that determine immunity. Second, this research included a comprehensive MRI study to evaluate the effectiveness of this treatment on infarct size and other functional or structural parameters of the heart.

The results were very satisfactory since the administration of the cells developed and manufactured by the company TiGenix showed no problems to the patients.

The cells did not lead to complications of coronary flow or adverse cardiac or extra-cardiac events of any type, in addition to ruling out the risk of rejection.

Qualitative jump in tissue regeneration

The 55 patients included in both groups are still alive after one year of follow-up. However, new studies with more patients and longer follow-up will be needed to analyze the efficacy of the treatment.

It is very relevant the demonstration that the cells, which are not from the patient, but from donors, can be transplanted without causing rejection, because it opens the door to simpler regenerative treatments and immediate application.

All this supposes a step of enormous transcendence in the long way to travel until achieving the regeneration of the infarcted cardiac tissue, for what it is still necessary to continue the basic and clinical investigation.


Source: Agencia ID