It has come to light that there’s a sizeable group of patients in whom “coronary angioplasty” is unnecessary and may even be hazardous. These are patients who have suffered a heart attack and whose heart muscle has become scarred and irretrievably damaged. But now, with a breakthrough technique, hope looms on the horizon for those who had nothing forward to look to.
The human heart is truly a technological marvel. Made up of three layers, the inner (endocardium), the middle (myocardium), and the outer (epicardium) the heart is surrounded by a double-layered protective membrane (pericardium). Among these three, the myocardium or the muscular layer of the heart is by far the most important.
The human myocardium is very strong (even in the faint-hearted). Each day it beats 100,000 times and pumps 7 liters of blood. Further, the heart muscle works both when it contracts (systole) as well as when it relaxes (diastole). It never gets tired. Scientists keep unraveling its secrets and it is now known that the “helical” architecture of its magical muscle helps it function better.
Heart attacks (death of heart muscle due to curtailed blood-supply) have become the bane of the century. That’s why so much emphasis is laid on prevention and living a healthy lifestyle to keep heart attacks at bay. However, once a heart attack occurs the damage to the heart muscle is in most cases slight and reversible after an angioplasty. In few instances, however, the damage may be irreversible, because of non-viable scarred muscle. Despite the fact that clot-busting injections and angioplasties may succeed in restoring blocked artery patency, it is impossible to regenerate irretrievably damaged heart muscle. What is more hazardous is the fact that non-viable heart muscle “remodels” setting a downward spiral which leads to progressive decline in cardiac pumping capability and heart failure.
Considering the above gloomy picture we were badly in need of something to overcome the vicious cycle. Embryonic stem-cell research has ushered a new enthusiasm among doctors and a new ray of hope has entered in the hearts of the people. Dr. Kenneth Chien, from the Harvard Stem Cell Institute in the USA successfully produced pure cardiac muscle in the lab – a near miracle. Such a kind of feat fills us with joy and makes the heart skip a beat!
Working with rodents in his lab, much like a mechanic or a mason, Chien prepared scaffolding. Therein he “seeded” painstakingly harvested master stem cells. Then the miracle of miracles took place: a thin strip of mouse heart muscle began to sprout right in the laboratory. This strip not only started beating on its own, it even began to do the kind of work the heart muscle is supposed to do.
Heartwarming isn’t it? Yet “there’s many a slip ‘twist between the cup and the lip”. Granted that we now have the knowledge that both embryonic and adult stem cells can repair scarred heart tissue, many questions remain unanswered till date. First of all, “How long will the replacement cells continue to function? Do the rodent research models accurately reflect human heart conditions? Do these new cardiac muscle cells derived from stem cells have the electrical-signal-conducting capabilities of native cardiac muscle cells?” Moreover, stem cell research on the whole is the subject of a heated controversy with serious ethical, legal and practical issues.
It is, however, painful to place on record that hundreds of our patients here in Goa, India and elsewhere undergo needless angioplasties and stent procedures to revascularize “dead” heart muscle”. This is deplorable. So how can patients protect themselves? Should there be the slightest suspicion of irretrievably damaged heart muscle after a heart attack patients must obligatorily be put through certain tests that will tell you exactly where you stand. The result of the tests will obviate a needless and costly angioplasty.
Nevertheless, let’s rejoice for the stem cell miracle which is undeniably a step in the right direction. But, it may be long, before such stunning discoveries find clinical application in day-to-day medicine. Meanwhile, all we can do is to pray that God strengthens the hands and the minds of scientists who endeavour to give the sick and the suffering a new lease of life.
(Dr. Francisco Colaço is a senior consulting physician, pioneer of Echocardiography in Goa)
