The rapidly escalating prevalence of metabolic disease such as diabetes, and the associated increase in cardiovascular complications, has created intense interest in the use of stem cell therapies to treat heart disease. This page will summarize the results achieved in trials as reported in leading medical journals.  The three conditions most frequently treated with cellular therapy are:

Acute Myocardial Infarction(AMI)

The heart is like any other tissue in the body in that it requires a steady supply of blood to transport oxygen and nutrients to the cells.  Myocardial infarction occurs when a coronary artery, one of the arteries supplying the heart itself, becomes blocked and the portion of the heart beyond the blockage dies from lack of oxygen. The term “heart attack” is often used to describe an acute myocardial infarction.

The goal of therapy immediately following a cardiac event is to restore blood flow as quickly as possible.  This is accomplished by a combination of "clot busting" drugs that help dissolve the blockage, and by physically opening the vessels by use of a balloon catheter in a technique known as angioplasty.  In some angioplasty procedures, the catheter is used to place a stent, a wire mesh device that is left behind in the vessel to hold it open by mechanical means.

Cellular therapy has been used with various degrees of success in the treatment of AMI.  There remains a considerable debate in the medical community whether the improvements seen are due to angiogenesis (new blood vessel formation), differentiation of cardiac progenitors into cardiomyocytes (creation of new cardiac muscle), induction of paracrine signaling in the infarcted tissue, an increase in inflammation, recruitment of growth factors from the tissue factor coagulation cascade following angioplasty, or some combination of these factors.

Delivery of cells via a catheter-based approach has not been successful except in isolated cases because once delivered the cells remain mobile and will return to the blood flow as the heart beats.  The studies that have been the most useful delivered the cells directly into the heart means of a mini-thoracotomy, a small incision into the chest that allows the physician to directly visualize the heart.  Direct injection is only feasible when the affected area of the heart is in front, near the chest wall, but injections are not possible when the affected area of the heart is toward the patient's spine.

Those interventions that delivered a large cell dose immediately following a heart attack had the best, and most sustained, results.  Cultured cell products deliver large doses, but cells take days to weeks to complete the culture process while the optimal time to administer cells is in the first twenty-four hours following the event.  Cascia believes that its rapid preparation process allows delivery of a therapeutically effective dose with a few hours of the patient being admitted to the hospital, but patients who have had severe heart attacks may not be good candidates for an immediate surgery.

Angina Pectoris

Angina pectoris is caused by coronary artery disease that reduces blood flow to the heart. It is common for patients to report chest pain, often radiating down the left arm. In the early stages angina is treated by drug therapy, such as nitroglycerin tablets, but recurring bouts of chest pain can become debilitating in more advanced cases.  There have been a number of studies that reported symptomatic relief that was sustained for more than twelve months.  While these reports are promising, the patient groups were small so the results may not generalize to larger patient populations.  Considerable clinical work remains to be done in this area.

Heart Failure

Congestive heart failure results from various degenerative diseases that impair pumping function of the heart. The most common cause is a series of small heart attacks that cause death of previously functional heart tissue, replacing the cells responsible for pumping blood with non-functional scar tissue.  The left ventricle, the main pumping chamber, enlarges and the pumping efficiency declines.

Heart failure is a chronic and extremely debilitating condition that severely impairs the quality of the patient’s life and which places a severe economic burden on the healthcare delivery system. As such, there has been considerable interest in use of cellular therapies for treatment of heart failure but these have been less successful than treatments for acute myocardial infarction, most likely due to a large amount of unresolved fibrosis and/or on-going metabolic disease such as Type II diabetes.

Cells are typically administered directly to the ischemic portions of the tissue during open heart surgery. Most frequently the cells are administered during a surgery for a coronary artery bypass graft (CABG), an invasive procedure where the heart is fully exposed and the surgeon has maximum access to the heart.  Administering cells by direct injection to the ischemic and peri-ischemic regions of the heart during the CABG procedure only prolongs the surgery by a few minutes, and the results from surgeries where the patient received cells are generally superior to those where the patients received the CABG alone.  The improvement is most noticeable in patients with more pronounced declines in function.

A consistent observation is that patients receiving cells see a marked increase in function parameters in the first three months post-surgery. A gradual improvement continues until around six months with minimal further improvement thereafter, an observation consistent with the ability of cell therapy to influence tissue remodeling for one to two cycles. These improvements may not be maintained, and the prognosis for treatment group and control group patients tends to converge around eighteen months following treatment.  The reasons for the convergence are not fully understood but a likely explanation is that the underlying disease state that initially contributed to heart failure, such as diabetes, continues unabated since the cell treatment addresses the immediate tissue damage, but not the underlying pathology.