Mesenchymal stromal cells for cardiovascular repair: current status and future challenges

Ischemic heart disease is the most common cause of death in most industrialized countries. Early treatment with stabilizing drugs and mechanical revascularization by percutaneous coronary intervention or coronary bypass surgery has reduced the mortality significantly. In spite of improved offers of treatments in patients with heart failure, the 1-year mortality is still approximately 20% after the diagnosis has been established. Treatment with stem cells with the potential to regenerate the damaged myocardium is a relatively new approach. Mesenchymal stromal cells are a promising source of stem cells for regenerative therapy. Clinical studies on stem cell therapy for cardiac regeneration have shown significant improvements in ventricular pump function, ventricular remodeling, myocardial perfusion, exercise potential and clinical symptoms compared with conventionally treated control groups. The results of most studies are promising, but there are still many unanswered questions. In this review, we explore present preclinical and clinical knowledge regarding the use of stem cells in cardiovascular regenerative medicine, with special focus on mesenchymal stromal cells. We take a closer look at sources of stem cells, delivery method and methods for tracking injected cells.