Evolution in Interventional Cardiology

With timely detection, treatment for heart disorders is now possible without surgical opening of the heart

Dr Mathew Samuel Kalarickal

It is not a myth, but a fact that heart attack is the world's prime killer disease. For ages together, it has been crippling and claiming lives, especially so, plundering and ravaging people in their 30s-50s, an age group which is vitally contributory to the family and the nation's productivity and development. As it has affected mankind since ages, there has been many developments in cardiac care.

Stent Revolution

In the initial years of evolution of this science, when only balloons were available and used, it was seen that re-blocks occurred in as many as 50 per cent of the patients who underwent just plain balloon angioplasty. Pondering into how to allay this handicap led to the invention of stents, which are springs of stainless steel or alloys, which provide a radial strength or outward force when deployed across blocks, thus scaffolding the blocks and preventing recurrence of blocks. But again, in spite of the use of these bare-stents (non-medicated) the re-blocks occurred in as many as 25-35 per cent, though recurrence was reduced by almost 50 per cent. Thus, evolved the medicated stents.

Medicated stents are stents coated with medicines, which act locally on the blocks and further reduce the recurrence rates significantly to as low as five-seven per cent. These stents have off late, taken the mainstream news and limelight in the media and in medical debates, on their propensity to cause heart attacks due to their susceptibility to develop clots within the stents.

It goes without saying that every invention or discovery, like the catheter of Forssmann, has to take the test of time and critical and constructive scrutiny. The medicated stents certainly have a chance of clot formation within them. But, it occurs only in a small subset of 0.5-1.2 per cent of the patients who are successfully treated by angioplasty and that too, only after offsetting the incidence of re-blockage and heart attacks from a high 35 per cent down to as low as five per cent. This propensity for clot formation can be further decreased by stringent adherence by the patient to anti-clot forming tablets like aspirin and clopidogrel. So clearly, in the backdrop of all the discussions and intellectual turmoil, medicated stents, without any second thoughts, is clearly superior to all other available stents.

Current research is being potentiated into bio-degradable stents, where, after a period of time, the stent gets dissolved or removed from the blood vessel and thus mitigates the risk of clot formation within the stents. Thus, angioplasty and stents in their current forms have revolutionised cardiac care and saved many lives from the clutches of impending doom and is still evolving to reach strata of perfection.

Percutaneous Treatment Of Valves

Another area in interventional cardiology which has made a striking impact on the outlook of cardiac morbidity and care is the development of trans-catheter valve replacements. In contrast to the conventional forms of treatment for diseases of the valve, which require open heart procedures, requiring general anaesthesia, valve replacement is now being achieved non-surgically through the aforementioned catheters. Currently, this involves aortic valves in a select subgroup of patients, like the terminally ill or those who are otherwise at high risk of death from open heart procedures. Pioneering work in this field is being done by Dr Alain Cribier of France. Research work is also going on in the non-surgical trans-catheter repair of leaking valves. This form of treatment will revolutionise cardiac care into a bafflingly simple dimension altogether.

Treatment of Birth Defects

Yet another milestone in interventional cardiology, though in a smaller but significant subset, is the treatment of birth disorders or congenital heart diseases, like holes in the heart or septal defects and abnormal blood vessel connections as the patent ductus arteriosus, to mention a few. With timely detection, treatment for these disorders is now possible without surgical opening of the heart, by deploying devices through special catheters across these holes and sealing them in entirety allowing for an absolutely normal life as early as third day from the procedure. Of notable mention is the special impact on the life of the female child, who can avoid the scars and traumas of a surgery and from being isolated from the society as a heart patient and from being denied a married life and the joys of motherhood.

Thus, if from the fictitious and imaginative world of Jules Verne, science could flourish and man could ascend and hold the reins of air, water and space travel, it is in all probability only a patient wait before stem cell therapy, gene-therapy and science with all its spectral probabilities deliver the panacea for all ill health.

With inputs from Dr Binoy John, Consultant Cardiologist, Apollo Hospitals, Chennai
The writer is Consultant and Director Interventional Cardiologist Apollo Hospitals Chennai
E-mail: skmathew@eth.net