[Cardiac cell therapy-Lost in translation?]

Cardiac cell therapy covers more than two decades of tumultuous history. In this period of time, the perception of the heart as an organ consisting of a fixed number of terminally differentiated cardiomyocytes fundamentally changed. Suddenly, the myocardium was (or is) considered to be regenerative by intrinsic progenitor cells, inducible proliferation, and in particular by exogenic transplanted cells. While the clinical translation of real cardiomyocytes obtained by cellular reprogramming has progressed only slowly, a multitude of clinical studies were carried out with cell products of somatic origin. This was mostly based on assumptions and experimentally acquired data with respect to the plasticity of adult precursor cells that, in retrospect, lacked validity. Accordingly, on closer inspection the results of the clinical studies were not convincing but they were nevertheless often presented and viewed in a very optimistic light. Today, cardiac cell therapy with cells of a somatic origin is considered to have failed. Recapitulating the stages of this era can help recognize and avoid such undesirable developments in the future.