Sunday July 1, 2012
Opening up arteries
We take a look at how one little balloon can mean the difference between life and death for heart patients.
WE have always been told that to take good care of our hearts, we have to eat a healthy diet, exercise regularly, quit smoking, sleep well and avoid stress.
But let’s just say that we aren’t model human beings, and had a bit too much fun at the expense of our health. What happens then?
One of two things could occur.
One, we get very lucky and nothing actually happens.
Or two, that extra curry mee does not do us any favours, and now, we are in a bit of trouble. So off we go to see a cardiologist.
They do an angiogram; and then we wait apprehensively for the results.
There’s good news and bad news.
The bad news is that there is a blockage.
The good news is that we don’t live in the 1970s, and a heart bypass surgery is not the only way to fix the problem any more.
Now, the first-line treatment is usually an angioplasty.
“Angioplasty was started in the early 1980s by a Swiss physician named Andreas Gruentzig.
“He began performing the procedure in the vessels of the leg, and found that it was very effective for improving blood circulation. So, he decided to try it for the heart.
“His first patient had a tight narrowing in one of his vessels, and the procedure opened up the vessels very successfully.
“Since then, angioplasty has become one of the most common procedures done worldwide, with more than 600,000 cases done every year in the US alone,” says Datuk Dr Devan Pillay, a senior consultant interventional cardiologist practising in Kuala Lumpur.
He explains that in the beginning, angioplasties were performed using balloons to open up the blood vessels to allow blood flow.
But after six months, it was discovered that the arteries actually narrowed down again.
Doctors then decided that a metal scaffold might be needed to keep the artery open, signalling the initial usage of stents.
These were known as bare metal stents. They were made out of stainless steel, and were not very flexible.
“Then, along came the factory-mounted stents, which are actually crimped onto the balloon.
“As they are very flexible, stable and easily deliverable, we found that procedures became simpler, and more complex narrowings could now be tackled with the use of these stents.
“However, after some time, these stents also narrowed down with scar tissue. The question then arose, how do we limit the scar formation from forming?” he says.
According to Dr Pillay, this heralded the creation of a drug-coated stent, or the drug-eluting stent (DES), which was able to decrease the occurrence of restenosis within these stents.
The results were almost equivalent to a bypass surgery. However, with a DES, patients need to be on two types of anti-platelet agents to thin the blood.
The dual anti-platelet regiment has to be continued for at least a year. If there is a reduction in the duration of anti-platelet therapy, clots tend to form on the surface of the stent.
Reintroducing the balloon
“A few years later, progress was made with the introduction of the drug-eluting balloon (DEB).
“It was launched worldwide in 2008 by (German medical and pharmaceutical company) B. Braun, and in fact, Malaysia was the first country to have this new technology,” shares Dr Pillay.
He explains that once the drug-coated balloon is inflated, the drug is released slowly onto the vessel wall.
It works to heal the vessel wall and prevents the re-narrowing process without the need for a stent.
Initially, DEBs were only used for a condition called in-stent restenosis; that is, the balloons were used to prevent re-narrowing and scar tissue from forming, as a result of a previous stenting procedure.
While patients would still need to be on anti-platelet agents, the duration is reduced to three months, making DEBs a more cost-effective and acceptable treatment option.
Four years after the DEB was introduced in the market, Dr Pillay shares that there have been new developments in the use of the balloon.
“The whole of Europe is involved in this study, along with countries in Asia, including Malaysia. So now we have our own local data, involving a total of 50 patients from local hospitals.
“This nine-month study involves the use of DEBs in vessels that are 2.5mm and less in diameter.
“We’re looking at clinical outcomes and complication rates.
“I have about 20 patients in this study, and they will give us a good idea on how the vessel actually behaves using DEBs.
“So far, I’ve had the one-month follow-up for my patients, and they’re all doing well with no angina symptoms.
“I believe that the final results of this study will be very positive, and will help patients in deciding that DEBs are the way to go,” he says.
The Malaysian portion of the study started at the beginning of last year.
He adds that the DEB has also been found effective in treating diffuse disease, where there are multiple narrowings of the vessels.
“You can actually use one long balloon to cover the whole area with the drug. So nowadays, DEBs are a good option for these types of vessels, and especially for diabetics as they have very small vessels.
“In fact, some vessels are so small that if you use a stent, you could burst the vessel!”
Looking to the future
“Some doctors are starting to use DEBs for bifurcations, meaning that you have a narrowing within the divisions of arteries.
“For these cases, when you put in the stent, it almost invariably leads to the re-narrowing within the stent. Thus, a DEB is definitely more suitable,” says Dr Pillay.
“However, despite treatments being revolutionised, it’s still very difficult to get our patients to change their mind-sets.
“Many believe that stenting is the answer for everything.
“Often, DEBs could be the better answer. Patients need to be educated that with DEBs, the vessels heal themselves, and may remain open for many months after the procedure, and they don’t actually need a stent to be put in.”
Dr Pillay gives an example of a patient who is scheduled for surgery, but is discovered during the process, to have a blood vessel blockage that needs to be fixed.
If this patient uses a standard drug-eluting stent, he would need to take two anti-platelet drugs for a year.
However, if he still needed the surgery to be done in that time, he would need to stop the anti-platelets for about one to two weeks prior to the surgery. This is because the drugs would cause excessive bleeding during the surgery.
But if he stops taking the anti-platelet drugs, blood clots are liable to form on the stent, and lead to re-narrowing of the blood vessel.
“So in this case, a DEB would be a better choice because the duration of the anti-platelets will be much shorter,” says Dr Pillay.
“Very importantly, patients must know and understand that DEBs are safe, especially with a proper predilatation.
“The preparation of the vessel has to be immaculate. Your doctor should be well-trained in DEBs, and the right size of balloon must be used, so that the vessel looks full and well-expanded.
“Angioplasty has become so predictable that rarely do patients lose their lives.”
He adds: “The DEB works well and is economical. As a cardiologist, that’s what’s important to us.
“So, my advice is that you talk to your doctor, and carefully consider the options before you decide.”
He adds: “The recent results on the largest international registry for treatment with DEBs have also proven the safety and efficacy of DEBs for treatment of patients in real-world conditions for multiple indications.”
According to Dr Pillay, patients should just remember the three positive impacts of using a DEB:
·There is no metal in the body.
·It cuts down the cost of the entire treatment. Not only is the period of taking the antiplatelet medications shortened to three months, but a DEB is also cheaper than a DES.
·It is easy to use.
“Remember, the most popular might not always be the best choice. Give your heart a chance,” he says.
■ This article is courtesy of B. Braun Medical Supplies Sdn Bhd. For more information, e-mail firstname.lastname@example.org. The information provided is for educational purposes only and should not be considered as medical advice. The Star does not give any warranty on accuracy, completeness, functionality, usefulness or other assurances as to the content appearing in this column. The Star disclaims all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.