New Delhi: Until a few years ago, scientists assumed that it was impossible to repair a damaged heart due to heart attack. But researches have proved that adult and embryonic stem cells may be able to replace damaged heart muscle cells and establish new blood vessels to supply them. This news has brought a big relief to the cardiologists all over the nation as heart attacks and congestive heart failures are among the Nation's most prominent health challenges despite many breakthroughs in cardiovascular medicine.
In India in the past five decades, rates of coronary disease among urban populations have risen from 4 per cent to 11 per cent. 60% patients in India suffer from acute coronary syndrome, as compared to 40% in the developed world. Also 60% of the heart attack victims in India reach hospital well after 60 minutes of the onset of the heart attack. The World Health Organization (WHO) estimates that India is set to be the heart disease capital of the world by 2010 accounting for 60 per cent of the world's cardiac patients. 9% of the victims of a major heart attack die in India, compared to about 6% in the developed world due to lack of attention and facilities.
Dr KK Sethi, Senior Cardiologist, Delhi Heart & Lung Institute shares this good news with us with a positive tone in his voice. “Yes, it works”, he beams enthusiastically. He further adds, “In less than three years, studies are able to explain the magical aspects of these stem cells. They have an ability to regenerate and grow into various types of cells including endothelial (cells lining the blood vessels), heart cells and smooth muscle cells”.
Dr Anil Dhall, Senior Consultant, Cardiology, Max Heart & vascular Institute, New Delhi explains the entire process in details. He says, “Over time, the inside of the arteries develop plaques of different sizes. Platelets come to the area, and blood clots form around the plaque. The coronary arteries constrict or spasm on and off, causing lack of blood supply to the heart muscle (ischemia) due to which few heart cells die causing damage/malfunctioning of that part of the heart. This is called Heart attack. Transplanting bone marrow stem cells into injured hearts within 5 hours of an attack can actually repair some damaged part of the heart.”
Stem cells are unspecialized cells that have two defining properties: the ability to differentiate into other cells and the ability to self-regenerate. The ability to differentiate is the potential to develop into other cell types and self-regeneration is the ability of stem cells to divide and produce more stem cells. Based on their origin, these can be divided into, First Embryonic Stem Cells which are obtained from donated embryos that have developed from eggs fertilized in vitro not from eggs fertilized in a woman's body.
Second Adult Stem Cells which are basically undifferentiated cells found in a tissue or organ. Lastly Cord Blood Stem Cells which are obtained from the placenta and umbilical cord shortly after birth. Stem Cells are derived and preserved from this.
Scientists are still trying to dig deeper insight of these stem cells which include understanding exactly which cells in the bone marrow (or in the blood) are having an effect on the damaged heart. Scientists are also studying whether the bone marrow stem cells become new heart muscle cells and/or blood vessel cells, whether they stop existing heart cells from dying, or whether they release substances that stimulate the existing heart stem cells to divide and replace those that have died. Till now these were just unheard gestures, assumed by a handful of scientists who had a god gift of farsightedness.
Bureau Report