Derived from the words angio (blood vessels) and genesis (creation), angiogenesis is the creation of new blood vessels. This process occurs naturally under certain circumstances, such as the healing of a cut. Therapeutic angiogenesis is an experimental treatment that medically promotes the creation of new blood vessels.

In oncology (the study of cancer), anti-angiogenesis treatments have shown promise because they prevent the growth of new blood vessels that feed tumors. In cardiology (the study of the heart), angiogenesis has shown promise in growing new blood vessels to increase the flow of blood to the heart. For people whose coronary artery disease is so advanced that bypass surgery would be of only limited benefit, therapeutic angiogenesis may offer an alternative.

The therapy is also being studied for use in patients after surgery or such catheter-based procedures as balloon angioplasty. Many of these patients still experience symptoms of heart disease even after treatment because of incomplete blood flow. Therapeutic angiogenesis offers the promise of restoring these patients to a symptom-free state. 

Whether used in patients before or after surgery, the goal of therapeutic angiogenesis in the heart or peripheral arteries (e.g., peripheral artery disease) is to increase blood supply to the muscle. In most cases, this blood supply is constricted because of plaque that has built up in the arteries, the result of a disease process known as atherosclerosis. This plaque may result in the blockage of blood flow, resulting in cardiac ischemia when the heart demand increases as during exercise. Cardiac ischemia may result in either chest pain (angina) or no symptoms at all (silent ischemia).

Over time, episodes of cardiac ischemia can become longer, more severe and may become dangerous. A worsening of cardiac ischemia generally means that the underlying coronary artery disease is worsening, and the flow of blood to the heart is gradually reducing. In severe cases, this may result in a heart attack or a permanent weakening of the heart muscle that leads to an enlarged or deformed heart (ischemic cardiomyopathy).

Therapeutic angiogenesis is designed to promote the growth of new (collateral) blood vessels that are free of plaque and other blockages. These new blood vessels can deliver much-needed oxygen to the heart and help to avoid future episodes of cardiac ischemia or help improve blood flow after a surgical procedure or minimally invasive intervention such as balloon angioplasty.

Recent clinical studies of therapeutic angiogenesis have failed to decisively conclude that the therapy is effective, however many researchers believe the technique will one day prove useful. The possibility of side affects associated with the treatment remains a concern and the most efficient delivery method for the therapy remains in dispute. More research and testing are required before this therapy is pronounced effective by the wider medical community.