The innate capacity of the human heart for self-regeneration is not enough to compensate the loss of cardiac muscle after an ischemic injury (heart attack).  Interventions and therapies have been developed and are helpful in buying time, but ultimately cannot preserve the life of the patient.  Millions of patients each year could be helped by the ability to regenerate cardiomyocytes.  Ultimately, heart failure usually results from a deficiency of cardiomyocytes. Heart regeneration occurs naturally in lower vertebrates and in developing mammals. However, human heart regeneration becomes quickly limited following birth, and this is the case with most mammals.

Of all the organs in the body, the heart is the one with the least regenerative capacity; however, current research has begun to close the gap by advancing our understanding of how to bioengineer new cardiac cells, tissues, and even who organs. For example:

• Significant advances have been made in understanding how regeneration is activated in animal models (such as zebrafish) where regeneration occurs naturally.
• Recent work has also resulted in stem cells differentiating to beating cardiomyocytes in space.
• Re-working human hearts (perfusion-decellularization of human cadaveric hearts) is showing promise.

Many other significant advances could also be listed, this is a dynamic and active field.  But foundational milestones and challenges have not previously been clearly described in a succinct manner.  The work of the New Organ Cardiovascular Engineering Committee will help identify and clarify significant specific challenges and sub-challenges associated with the heart.