Advanced cell-based cardiac repair: How to mend a broken heart

Abstract

Cardiovascular disease is still the leading cause of death worldwide, accounting for approximately 13 million deaths a year.1 It is estimated that this number will double in the upcoming 15 years due to aging of the population in combination with an increase of risk factors as hypertension, diabetes mellitus, hypercholesterolemia and obesity. Approximately half of the cardiovascular deaths are related to coronary artery diseases.1 Ischemic heart failure (HF) is usually caused by an acute myocardial infarction (AMI). An AMI develops when a coronary artery is occluded, whereupon the myocardium is deprived of nutrients and oxygen, which results in apoptosis of the cardiomyocytes. In the initial phase following an AMI, an inflammatory process occurs to clear the wound from death cell debris and activate reparative pathways.2 This process is followed by the formation of scar tissue. The remaining viable myocardium has to take over the function of the damaged area and compensate for the loss to maintain cardiac output. Eventually the viable myocardium will be unable to do so, whereupon the ventricle dilates, pump function is reduced and the heart starts to fail (figure 1).3,4 The current treatment strategy for an AMI, which consists of immediate revascularization in combination with optimal pharmacological treatment, has resulted in improved survival, even of severe cases. This increased survival comes at the cost of an increased prevalence of heart failure. Therefore the search for new therapies to limit the damage of an AMI or reverse HF is ongoing. New therapeutic strategies are continuously developed and investigated in preclinical and clinical settings. Stem cell therapy is one the therapeutic strategies that has emerged in the field of clinical cardiology in the past decade.