Stem Cell Therapy For Heart Diseases – An Insight

 

Heart disease and heart failure is a burgeoning problem worldwide and is one of the leading causes for mortality and morbidity.

The heart as a pump becomes vulnerable when its muscle progressively weakens or when a significant portion of the left ventricle is damaged. With ever increasing numbers of diabetes and hypertension coupled with poor lifestyle habits there is now a rapidly increasing incidence of heart attacks and heart failure. Treating and managing heart ailments poses tremendous challenges not just to patients, but to physicians as well as healthcare systems.  In a setting of acute and chronic myocardial ischemia involving large areas of myocardium many heart cells lose their functionality irreversibly and this can adversely affect cardiac function. Various drugs and devices are now available to stem the progression of these heart ailments. Rapid changes in technology and wide availability of improved devices have enabled heart disease patients now being aggressively treated with more devices. But, despite all this, none can reverse the disease and a significant percentage of patients progressively deteriorate. Heart transplant is the final stop for treating these patients when there is extensive damage to the heart muscle and beyond salvage by other means of treatment.  But heart transplant is limited only to a small segment of the population, is expensive and requires medications post surgery which may result in major side effects.

With the advent of stem cell therapy some years back, the question asked was – can this be used to treat heart patients?  Since then stem cell therapy as a treatment option in heart patients has been seriously pursued. Physicians and researchers have long looked at stem cell therapy as an exciting and attractive mode of treatment. But, regenerating heart tissue from stem cells is a complex process and so far it has been a slow process. The past decade has seen advances with various types of stem cells being studied. The path to this has been rocky and there have been many difficult issues to grapple with.

A study last year showed the positive side of stem cell therapy, wherein, patients followed up for two years showed sustained improvement in left ventricular function following a heart attack. No side effects were noted. If positive data from this is obtained after some more years, then one can truly say that stem cell therapy can be seriously considered a mainstream option.  But, another study last year showed a different side of stem cell therapy, wherein, patients after a heart attack who were injected with stem cells showed no improvement in cardiac function after six months, thus showing no benefit.

Apart from heart failure and coronary artery disease, certain types of cardiac disorders are being investigated. Recently researchers from Columbia University used genetically reprogrammed cells to behave like stem cells and were able to demonstrate the basis of arrhythmias in an unusual form of cardiac arrhythmia. This can open a lot of avenues to treat this disorder. Attempts have also been made to regenerate cells for heart valves, but it is still early days and a lot of ground needs to be covered for this to happen.

Many a times stem cells injected never reach their target, so studies have focused on how many cells to be injected, what type of stem cells are to be injected, what is the ideal route and what are the long term effects ? Intracoronary injection has fared better comparatively in most studies. Another challenge reported is how to get these endogenous or exogenous cells reach their target within the body. Ethical and moral issues are also other aspects faced when stem cells are harvested exogenously for infusion into another person.

The benefits of stem cell therapy in heart disease are tremendous, but, it is still not a developed package and it is a therapy in evolution. There is a lot of promising data which shows the feasibility, efficacy and safety, but judgment on it being a standard tool of treatment in clinical practice is still awaited.