Researchers at Harvard Medical School and Massachusetts General Hospital announced they've successfully generated functional heart tissue in a lab for the first time.  It's hoped that this will lead to growing entire human hearts for patients suffering from cardiovascular diseases.

According to the report published in the journal Circulation Research, the new method known as recellularization used cells stripped from 73 hearts obtained from organ donors to generate myocardial tissue - muscles that allow the heart to function.  The breakthrough will hopefully allow doctors to grow tissue from a patient's own cells that can be used to patch a heart damaged from a heart attack or other issues.  This wwould almost ensure an organ is accepted by the patient's body.

"Regenerating a whole heart is most certainly a long-term goal that is several years away, so we are currently working on engineering a functional myocardial patch that could replace cardiac tissue damaged due a heart attack or heart failure," said lead author Dr. Jacques Guyette of Harvard's OTT Lab for Organ Engineering and Regeneration. "Among the next steps that we are pursuing are improving methods to generate even more cardiac cells - recellularizing a whole heart would take tens of billions - optimizing bioreactor-based culture techniques to improve the maturation and function of engineered cardiac tissue, and electronically integrating regenerated tissue to function within the recipient's heart."

Cardiovascular disease kills 17.5 million people around the world, annually - making it mankind's leading cause of death .