The statistics are staggering: heart disease is the country's no. 1 killer. Seventy million Americans have some form of cardiovascular disease. Nearly a million people die of heart disease each year.

Warren Sherman, M.D., director of cardiac cell-based endovascular therapies at Columbia's world-renowned cardiology group — CIVT, or the Center for Interventional Vascular Therapy — has spent his career fighting back against these numbers. From his earliest days as an interventional cardiologist, Dr. Sherman pioneered noninvasive, catheter-based techniques to clear blocked arteries, insert stents, and repair damaged hearts.

Now, Dr. Sherman is investigating the use of stem cell-based therapies to repair the devastating damage of a heart attack. When a heart attack occurs, a section of the heart muscle is deprived of essential oxygen and nutrients, leading to tissue death. The affected part of the heart is rendered profoundly weak. While modern treatment is able to limit consequences of the damage, all too often the process leads to congestive heart failure.

Conventional wisdom holds that the heart, unlike self-regenerative organs like the skin and liver, lacks the capacity to repair damaged tissue. "Most forms of damage that affect the heart are permanent," says Dr. Sherman. "When a person has a heart attack the traditional thinking is that there is no potential for the heart to regenerate. Instead, the story goes, the best it can do is generate scar tissue."

But Dr. Sherman and other researchers have begun to poke holes in that conventional wisdom, identifying cells that may be able to replace damaged heart tissue with new growth. Dr. Sherman has found that certain skeletal muscle cells, skeletal myoblasts, can be applied to damaged areas and repair the tissue. "It's been established that these cells can be harvested, isolated, grown in culture, and then implanted in the heart, where they can replace some of the muscle tissue that has died," he says.

The first surgical implantation of skeletal myoblasts in a human took place in 2000. In 2001, Dr. Sherman participated in another first: using a specially designed catheter to deliver the cells with pinpoint accuracy to the precise site of the damage in human patients who had a history of acute myocardial infarction and congestive heart failure.

By developing a method to implant cells in the heart using a catheter, invasive surgery could be avoided. To date, in published and unpublished studies, Dr. Sherman estimates that nearly 200 patients have undergone skeletal myoblast implantation, by either surgical or catheter procedures, in an attempt to repair damaged heart tissue.

Much of this research has yet to be systematically analyzed, but anecdotal evidence shows that many patients who have undergone the stem cell therapy have improved heart function and generally feel better after the procedure.

There is still much work to be done and Dr. Sherman plans to continue to pursue the promise of stem cell therapy for heart patients at CIVT. Studies are ongoing at Columbia using bone marrow-derived cells in patients with acute heart attacks; others will soon follow in patients with advanced coronary disease and heart failure. In Spring 2006, Dr. Sherman expects to begin a Phase II randomized, controlled multicenter study at Columbia on the therapeutic use of skeletal myoblasts. Much of this work has occurred in collaboration with other Columbia researchers, including Drs. Silviu Itescu, Eric Rose, Martin Leon, Tim Martens, and others. P& S Journal, Winter 2006. To contact Dr. Warren Sherman call 212.305.7060 or email him at ws2157@columbia.edu