Revolution in Cardiology - Soon, a stent that will vanish from the heart

After cardiologists clear a blocked artery of the heart, they usually insert a metal tube called stent to prevent recurrence. They may soon replace the metallic device with a mesh, which would be absorbed by the body in two years after restoring the blood flow.


Interventional cardiologists at Apollo Hospitals, Chennai presented before reporters on Tuesday, two patients on whom the drug-coated absorbable stent has been tried a fortnight ago. The patients, two men aged 68 and 70, are medically fit, the doctors said. The treatment is part of the last leg of a clinical trial being conducted at more than 100 centres across the world. Once pronounced a success, the stent would be available in the market.

The stent used in the trial has been made of materials used to make absorbable sutures and implants. The anti-cancer drug coat on the stent prevents the artery from clotting up. By two years, the stent degrades into water and carbon dioxide. By then the artery gains the strength to function independently as any other artery. Patients who get these absorbable stents are likely to be taken off blood thinning medicines which other patients with metal stents will have to take life long.


"This is another revolution in cardiology. If the trial succeeds, this stent is likely to replace all the existing ones," said consultant cardiologist Dr Sai Satish, consultant interventional cardiologist, Apollo Hospitals, who is a part of the trial. During the earlier trials, the device was found to be effective in treating heart diseases. It was absorbed into the walls of the patients' arteries, with no clots reported after three years.


It is estimated that at least six million people in India have cardiovascular diseases. Blocks in the blood vessels reduce supply to heart muscles increasing risks of heart attacks. To avoid surgery, since early 1980s, cardiologists insert a collapsed balloon mounted on a thin wire, balloon catheter, into the blocked artery. The balloon is inflated to crush the blocks. It is then withdrawn.


From the early 1990s doctors started inserting metal stents inside the artery to prevent further blocks. They reduced the recurrence by 20%, but sometimes cells grew over the stents and blocked arteries again. Then came drug-eluting stents in the early 2000s which prevented regrowth.


"Drug-eluting stents have been proven safe, but the presence of a metal in the body makes doctors anxious. It is good to have a device that can be absorbed after it does its job," said Dr Mathew Samuel Kalarickal, director and head of interventional cardiology.


The product has been approved for marketing in Europe, but it is yet to be made commercial. The manufacturers said it would be available in Europe next year and in India in 2013. As a part of the clinical trial over 100 institutes from all the over the world including six centres from India will implant the stent free of cost. Of these two hospitals Apollo Hospitals and Madras Medical Mission are from Chennai. Others include Escorts Heart Research Institute in Delhi, SGPGI in Lucknow, Care Hospital in Hyderabad and SAL Hospital in Ahmedabad.
                                                                                      The Times of India