Stem cell therapy for heart failure patients holds hope

Chennai, June 23: A revolutionary treatment is in the offing for patients suffering from heart failure using stem cell therapy, according to Dr M P Naresh Kumar, Chairman and Chief Cardiac Thoracic Surgeon of the city-based Harvey Super Speciality Hospital.

Addressing the press here yesterday, he said heart failure was the most common cause of death and disability in the world with more than 60 per cent of people over 60 years suffering from varying degrees of heart failure.

Heart attacks, high blood pressure and valve diseases were the common causes of this global problem.

Despite major advances in the last 50 years in both preventive and therapeutic cardiology, this problem was emerging as a major destroyer of the human race.

Drugs, angioplasty and bypass surgeries while saving the lives of patients do not always prevent heart failure,particularly in those whose heart had already suffered damage.

In recent years, the understanding that regenerative processes exist at the level of the heart muscle (myocardium) had placed stem cell research at the centre stage of cardiology.

Through cellular therapies, the concept of 'growing' heart muscle and vascular tissue and manipulating the myocardial cellular environment had revolutionised the approach to treating heart disease, he claimed.

He said embryonic stem cells could be obtained from the inner cell mass of the embryonal blastocyst.

Though it was recently shown that human embryonic stem cells could differentiate into cardiomyocytes, because of the immunogenicity and rejection as well as ethical considerations, these cells might be restricted to experimental in vitro studies and their therapeutical potential remained to be determined, he added.

Dr Kumar also claimed that adult human stem cells (hematopoietic, mesenchymal) were found in mature tissues, namely the bone marrow and peripheral blood. Plasticity of adult stem cells could probably generate lineages of cells different from their original organ of origin. Thus, these cells could be used for organ regeneration and cellular repair in various species, as well as in humans.

He said ethical problems for adult autologous stem cells did not exist and although much experimental work remains to be done, their clinical relevance and therapeutic benefit in heart disease have recently been shown for the first time.

The primitive bone marrow cells mobilised by stem cell factor and granulocyte-colony stimulating factor and harvested from the peripheral blood by cytopheresis using state of the art cell separators (hemonetics USA) are capable of homing to infarct regions, replicating, differentiating and promoting heart muscle (myocardial) repair.

He said the transplanted stem cells, differentiating to cardiomyocytes, become indistinguishable over time from the surrounding cardiomyocytes and they begin to express the contractile proteins specific for striated hear muscle, including desmin, a-myosin, heavy chain, a-actinin and phospholamban at levels that are the same as in the host cardiomyocytes.

This trans differentiation process is more pronounced in injured tissue than in healthy organs and may be intensified when the heart, as the recipient organ, contributes to its enhanced environment by high chronotropic and inotropic activity. Thus, regionally large concentrations of stem cells and increased mechanical activity of the recipient heart muscle might provide a favourable environment for successful engraftment of stem cells after cardia injury, he added.

Dr kumar said the harvesting of CD34+ stem cell from the peripheral blood was done at their hospital in conjunction with Jeevan Blood Bank and technical staff of hemonetics, US, the manufacturer of the cell separatory machine. To a question, he said patients were connected via the leg blood vessels using central venous cannulae to the blood cells separator machine called hemonetics MCS Plus, which by a sterile, closed, automatically programmed sequence called Cytopheresis, spins into the stem cells.

For each patient, around six to seven litre of his own blood is spun and given back to generate about 80-100 ml of stem cell.

Siting the case of Ms Kasturi, a 53 year-old lady having high BP and diabetes, was diagnosed as having dilated cardiomyopathy with normal coronaries by angiogram. She was diagnosed with severe heart problem with ejection fraction of 35 per cent.

He said as the only real hope for her was the transplantation of the heart, which even today is beyond the means of an average Indian, she underwent stell cell therapy. The cells were injected by coronary route by catheter. She has been discharged and is doing well now, he claimed.

In another case, Mr Kabali (58), an employee of CLRI, was diagnosed with high BP and anginal pains on heart. He was admitted with severe chest pain and underwent a coronary angiogram, which showed that he had suffered a massive heart attack due to cent per cent blockage of his left major artery.

This had caused damage to a substantial portion of the pumping chamber of his heart which was not contracting well, he added.

The patient underwent bypass surgery to reestablish blood supply to the heart and stem cell therapy by injecting them directly into the heart muscle and through the newly established grafts. The patient has recovered now.

The treatment is cost effective and requires less period of hospitalisation, he added.

UNI