Dr Patrick Serruys is one of the greatest authorities on angioplasty and coronary stenting in the world today. Currently, he is the Director of the Clinical Research Program of the Catheterization Laboratory, Erasmus University and a recipient of ‘James Herrick Award’- the highest award of Clinical Council of American Heart Association. Dr Serruys is also the Head of the Interventional Department, Heart Center, Rotterdam for the past 20 years. He talks about his experiences from the earliest days of angioplasty to the present time in an interview with FM. Edited excerpts:
What are the most important milestones in cardiac stenting and later internal carotid artery stenting over the past 35-40 years?
Before stenting, there was, of course, balloon angioplasty, in which Andreas Gruentzig was a pioneer. I first met Andreas Gruentzig in 1974 at a cardiology conference in Frankfurt where he was making a poster presentation in the hall outside the main auditorium. His poster depicted a technique for ligating the coronary artery in dogs. Initially, his success rate was just about 70 percent and by 1982 there were debates on topics like ‘Balloon angioplasty is going to disappear!’ Fortunately, John Simpson developed a steerable guidewire for angioplasty, and a few years later, Charlie Dotter came up with a nitinol (nickel-titanium alloy) spiral that could be used as a stent.
Parallel to this, you had Dr Palmaz, an Argentine radiologist and Schatz, an American who were working together. Their first series of 100 had a 25 percent occlusion, until we figured out that we had to use aspirin and diclopidine as anti-platelet to avoid thrombosis. In 1994, I did the first randomised trial with the Benestent, which was approved by the US FDA the same year.
Between 2000 and 2002, I had special access to the Cipher, and we organised the Havell trial, which was the first blind trial. There was zero restenosis in the Cipher and 26 per cent in the bare metal stent. So that was really a critical moment in the introduction of the drug-eluting stent. Apparently, the coating was somewhat allergic, but it was quickly improved, and the results got better.
One question which concerns a lot of physicians is: In the 1980s, angioplasty was put forth as an alternative for open cardiac surgery, particularly for high-risk patients. Today, with minimally invasive cardiac surgery, has the importance of angioplasty and stenting gone down a little, say in the past five years?
No, I think two things have happened. First, there was probably an excess of stenting and an excess of balloon angioplasty – an excess of stenting because it is easy treatment. But in the last 15 years, we realised that we should treat the lesions that really need to be treated. So, you have to do pressure wire studies and prove that this is the lesion which is ischemic. That has slowed down the use and misuse of the stent. That’s one thing.
In countries like India and China, naturally, the people propose the PCI (percutaneous coronary intervention) and stenting and the patient often agrees because it is less invasive. In Europe, we have a dialogue with the patient, and we say, surgery may be more invasive but in the long term, it will be better. That debate is still very, very active and will take a few more years, or a decade, because in the meantime, pharma is coming back. What you have in pharma is PCSK-9, monoclonal antibodies against PCSK-9. And for the first time, not only can you block the progression of the disease, but you can also cause regression. So, I think that is something which is going to become important.
When a plaque happens, it is not one plaque in one artery. There will be multiple plaques in one artery or there will be multiple vessels affected. How do you make the choice between one long stent and two short ones, particularly if the plaque is in a bifurcation of arteries?
Initially, we had to depend on simple angiography. You got black and white shadows on a background; it’s what we call a luminogram and you judge visually and say it looks to be about 20 mm, you don’t measure. So, let’s put a 20 mm device. Today, it is much more precise and critical, so you have techniques like IVUS and OCT, and then you see the inside of the vessel, and you see where the vessel is more or less healthy. And that’s your landing zone, and defines the length of the stent very precisely in mm. So, there is a lot of precision introduced by the imaging techniques.
Now for the patient, who has to pay for the procedure, the charges often depend on the number of stents that are put. So, the government will say you cannot charge more than Rs 8,000 or 10,000 per stent. But if the patient needs three stents, then that’s three times the number. How much does that play on a cardiologist’s mind when he takes the decision?
It’s a very important question. Obviously, surgery is expensive, certainly in western countries where a surgeon can easily charge $10,000 to 20,000 for surgery. Then, there is the heart-lung machine, the perfusionist, the anaesthetist, three, four, five days in the hospital and so on. With angioplasty, there is no need for anaesthesia, no perfusionist, no heart-lung machine. We may need to sedate the patient a little bit. And you could put many stents in one session. So, in terms of cost-effectiveness, we are already more cost-effective than the surgeon. Also, in Europe, mass production and purchase by large healthcare organisations have brought the stent prices down to about 250 Euros. Now the Indian government has also decided to put a price cap, which is a good thing.
If I could take you in another direction, internal carotid artery stenting must have begun in the mid-1990s or so?
Yeah, initially it was more or less the same story; first, there was surgery — that is endarterectomy — then came the stent, then good anti-platelet treatment, and then the protective filter so that there were fewer strokes during the implantation. It is a very well-established technique now.
You know there was a stage in treatment protocols where you would inject streptokinase and urokinase within six hours of an impending stroke.
It’s still there, very much there. Now there is Professor Erwich from Boston, as a combination of 5 mg of TPA with the mutant of urokinase, and in Rotterdam we are doing a study now with people who are being given these medications already in the ambulance. And then, we look at the patency when they arrive in the hospital. So, there is some kind of revival of thrombolytic therapy.
How do you see the next five years in terms of technology and the physicians’ expertise?
That is a question which I get frequently. Maybe not in five years but in 10-15 years, I think what is going to come into our lives is genomics. You might remember when the Human Genome Project was a one-billion-dollar project. But now in Rotterdam, a private lab offers the human genome in just 1200 Euros, and you may get it in India at some point. They will not tell you what the gene means, you have to go to a doctor for that. And the doctor will tell you that this and this and this gene will be responsible for Alzheimer and this will be responsible for diabetes. It is much more complicated because you have epigenetic factors, so that you have [a situation that] some gene is upregulated or down-regulated.