Ongoing research with heart valve procedures

Researchers continue to explore new ways to repair or replace heart valves. Currently available replacement valves last between 10 and 30 years. Though they may last a lifetime for older patients, younger patients may need several replacement procedures over time. Therefore, one focus of research is to create longer-lasting replacement valves, particularly for patients with congenital heart disease. Two areas of research have shown potential toward this goal: stem cell research and the use of endothelial cells.

Stem cells are immature cells that can grow to become any one of a variety of different body cells. They are found in bone marrow, lymphatic tissue and in embryos. Studies have demonstrated success in isolating and culturing stem cells toward growing into specific heart valve tissue cells. Catheter-based procedures are also being developed for certain heart-valve replacement surgeries.

Endothelial cells make up the lining of blood vessels and play an important role in communication between body cells. Researchers have successfully grown endothelial cells on a valve “scaffolding” created by stripping a human or pig valve of all its living cells. The patient’s own endothelial cells were then grown over the scaffolding in a laboratory before the valve was used in a replacement procedure. By incorporating a patient’s own cells into the replacement valve, researchers hope to lessen the rate of deterioration and reduce the need for multiple replacement procedures in younger patients.

Researchers are also exploring nonsurgical approaches to the treatment of some heart valve disorders, such as aortic stenosis, which may offer significant benefit. One such approach deals with the problem of calcification on the valve's surface. Calcium deposits that form on the valve leaflets decrease mobility in the valve, thus restricting blood flow through the valve. This calcification is similar to the calcium build-up that can affect arteries during atherosclerosis. Because statin therapy is common in the treatment of high cholesterol, which contributes to atherosclerosis, researchers are exploring the effectiveness of such medications in slowing the progression of aortic stenosis. The therapeutic effect of statins on aortic stenosis is still undergoing evaluation.

Other research has suggested that statin use following any major surgery may decrease the risk of death. Though more investigation is needed, the use of these medications may eventually become more common for people following heart valve procedures.

A number of new technologies are being explored to allow patients who formerly would need an open-heart surgery to have a less-invasive procedure. For instance, the use of a tiny metallic clip is being studied for the treatment of mitral regurgitation to help the valve close properly.