How to mend a broken heart

A tiny tube has revolutionised heart surgery and is saving thousands of lives. By Glenda Cooper

Karen Williams avoided a heart and lung transplant by means of a tiny mesh tube no more than a few centimetres long, which is embedded into the main artery of her heart. Five years after surgeons inserted it, Mrs Williams, who has suffered from a serious heart condition since birth, says she feels "liberated": she is able to swim, play badminton and cycle.

Mrs Williams would be unable to do any of these things but for a quiet revolution in cardiology which took place 10 years ago this summer. It happened when a Swiss doctor, Professor Ulrich Sigwart inserted a stent - a tube made of fine metal - into a coronary artery.

Until 1986, those suffering from heart disease caused by narrowing or blockage of the arteries had to rely on open heart surgery to correct the defect, or on conventional angioplasty, where a small balloon is pushed through an incision into the large groin artery and guided up to the diseased coronary artery. When the balloon is inflated, it flattens the blockage against the walls of the vessel, restoring a strong flow of blood to the heart. Unfortunately, in about 30 per cent of cases, the blockage recurs within six months.

The use of the stent transformed this, with trials confirming that it halves the chances of an artery becoming blocked again. Professor Sigwart, now director of the Department of Invasive Cardiology of the Royal Brompton Hospital, London, believes the success rates may be even higher in the future.

The stent is inserted into a blood vessel after it has been unblocked by an angioplasty balloon. Once in place, it keeps the artery walls propped walls apart, which allows the flow of blood to increase.

Dr Sigwart experimented with the stent on dogs and sheep, but the first demonstration on a human took place on 12 June 1986 at the University Hospital in Lausanne, when a woman developed severe chest pain 15 minutes after an angioplasty operation. Prof. Sigwart inserted the stent as an emergency procedure. "It was the first time it had been used on anyone whose life was in danger," he said. The woman, Gladys Demeuls, is still alive and well today.

"There have been 1 million stents since then," said Prof. Sigwart. "It is like an explosion. I would estimate that that three quarters of a million have been done in the past year. I always knew the potential that stents had but until the last couple of years it was unproven. But randomised trials in the US and Europe showing how successful it is means everyone agrees."

Heart failure costs the UK at least pounds 360m a year, accounting for 1.2 per cent of the total health-care expenditure. Prof. Sigwart's hope is that by increased use of the stent, costs can be kept down because there will be less recurrence. Stents themselves cost pounds 1,000.

When stents were first used, they were only given to people who had had one unsuccessful angioplasty already. Mrs Williams, 41, had a stent implanted in one of her pulmonary arteries in 1990. She had suffered from multiple pulmonary stenosis - a congenital heart condition which meant the main artery from the heart to the lungs was very narrow - since birth but her health grew worse after the birth of her son, Alisdair, in 1984.

"By 1990 my health had really deteriorated," she said. "Having Alisdair in 1984 and looking after him really took it out of me. By 1990, I couldn't do very much. I could hardly walk any distance without becoming exhausted.'' Mrs Williams initially had an angioplasty which was not very successful, so a full heart and lung transplant seemed the only option.

While at the Royal Brompton she met Prof. Sigwart who suggested that she have a stent implanted: "I'd never heard of it before, but I thought it sounded amazing if it worked. He filled me with confidence." By the end of the week she was in the operating theatre.

The surgery, she says, has changed her life. "It took me two weeks to get back into a reasonable state of health. I've come on in leaps and bounds. I can cycle and I can walk fairly long distances.It's more fun for my son, as well. I feel he's got a proper mother now."

Prof. Sigwart hopes the reblockage rate can be brought down from the present 10-20 per cent to zero by the use of stents coated with clot-inhibiting drugs. The most successful of these has been a stent coated with heparin, which is slowly released to inhibit the formation of a clot during the dangerous first few weeks before the stent becomes buried within the artery walls.