Regrowing blood vessels to mend broken hearts

Preclinical trial with human pericyte progenitors in a large animal model of myocardial infarction

Over recent decades scientists have carried out clinical trials to try to repair damaged or failing hearts using injections of stem cells, in particular from bone marrow. Although some trials have shown a very slight improvement in heart function, the results have been disappointing for patients. This research team, led by Professor Paolo Madeddu, aims to find a better type of stem cell to stimulate heart repair, and they believe they have an answer: cells taken from the pieces of vein ‘left over’ after heart bypass surgery. Over several years, Professor Madeddu and his colleagues at the University of Bristol –including BHF Professor of Cardiac Surgery Gianni Angelini – have perfected a technique to extract a type of cell called a pericyte from human vein grafts. In mice, they have shown that these cells can stimulate the growth of new blood vessels in a damaged heart – a crucial part of any future regenerative therapy. The cells also seem to increase the number of cardiac progenitor cells, a different type of cell which can turn into functioning heart tissue. Before testing their therapy in humans, the team needs to do one final study to prove the safety and effectiveness of their potential therapy in a larger animal, with a heart and circulation of similar size and function to a human. For this reason the project will test the cells from heart patients in pigs, before hoping to move on to a human clinical trial. This project is at the cutting edge of regenerative heart science and could help make a new treatment for heart failure a reality for thousands of patients in the future.