Even when a person survives a heart attack, the consequences of such an attack can have life-threatening consequences on a patient. That’s why scientists at the Imperial College London have created a “pumping” patch containing millions of living beating stem cells that can repair the damage caused by a heart attack.

Sewn on to the heart, the 3cm (1in) by 2cm patch, grown in a lab from a sample of the patient’s own cells, then turns itself into the healthy working muscle. It also releases chemicals that repair and regenerate existing heart cells. Tests on rabbit hearts have been successful and safe thus far, leading the British Cardiovascular Society to believe that patient trials will start in the next two years. Looking towards the future, the scientists hope to “add heart patches to the treatments that doctors can routinely offer people after a heart attack.”