Guest: Dr. Christopher D. Nielsen - Director of Cardiac Catheterization Laboratory.
Host: Dr. Pamela B. Morris
Dr. Pamela B. Morris: Hi! I am Dr. Pam Morris and you’re listening to Heart Sounds. I am talking today about stents with Dr. Chris Nielsen, who is director of the Cardiac Catheterization Laboratories. Dr. Nielsen, welcome.
Dr. Christopher D. Nielsen: Thank you.
Dr. Pamela B. Morris: We were talking earlier about there being two different types of stents; the bare metal stents and the drug-eluting stent. How do you decide, which type of stent to place in which patient?
Dr. Christopher D. Nielsen: Well, we know now that the bare metal stents have a slightly increased risk of narrowing down compared to the newer drug-eluting or drug-coated stents and so we often choose, which patients get which stent based on their particular risk of having a stent narrow back down. Patients that are diabetics, patients that have previously had multiple stents that have narrowed down are more likely to have their stent develop scar tissue and have that artery narrow again. So, those are patients that we would often choose a drug-coated stent. Also, arteries or blockages in blood vessels that are very small or very long diffuse blockages tend to be blockages that may narrow down again and so those are ones that we would often choose a drug-coated stent. Blockages that are in very, very large arteries or blockages that are very, very short blockages we often will use the bare metal stents because their risk of narrowing down is very, very low.
Dr. Pamela B. Morris: Are there treatments that you can use to prevent the stents from narrowing down again?
Dr. Christopher D. Nielsen: There really are no medication treatments, so that specifically decreased the chance of a stent forming scar tissue and narrowing down. We base patients on medication called Plavix or the generic name of which is Clopidogrel, which prevents thrombosis or blood clot inside the stent, but it doesn’t really prevent any of the scar tissue from forming in there. The medication coatings on the stent can prevent or decrease the risk of the stent forming scar tissue and narrowing back down.
Dr. Pamela B. Morris: So then, patients will need to be on blood thinners for some period of time after they have a stent placed.
Dr. Christopher D. Nielsen: That's correct. When we put a stent in the artery, as soon as we have placed it in there, there is metal exposed within the vascular system.
Dr. Pamela B. Morris: Like a foreign body.
Dr. Christopher D. Nielsen: That’s right, it’s a foreign body and the body’s first reaction is to cause inflammation around that because the body wants to try to get rid of this foreign body and so it’s a normal reaction for the body to deposit some of its own cells over this metal and cause that metal to be covered. So that covers the metal inside the vascular system and then doesn’t allow any blood clotting to occur on that metal. Now, when we place a bare metal stent inside the artery that reaction occurs over the course of a couple of weeks, maybe out to a month and the entire stent is covered over with - with the body’s own tissue. So the risk of blood clotting is highest in the first few days or the first few weeks. With the drug-coated stents, the medications that are on those stents slows down the body’s healing reaction and so there maybe metal that’s exposed in the artery for a longer than several weeks and it maybe for several months or maybe even out to a year. So those patients will need to be on blood thinners or Plavix a little bit longer.
Dr. Pamela B. Morris: So what are the current recommendations for the length of time that patients with each of the types of stents should stay on Plavix?
Dr. Christopher D. Nielsen: For a patient that gets a bare metal stent, the usual recommendation is that they should be on it for one month. For patients that get a drug-eluting or drug-coated stent, the current recommendation is they stay on Plavix for one year.
Dr. Pamela B. Morris: Now, I know there are some discussion right now and controversy about whether patients with stent should stay on blood thinner indefinitely?
Dr. Christopher D. Nielsen: That’s correct. There were several studies early on when the drug-coated stents were first released; that showed that you really needed Plavix for only three to six months and that was what we used to do. We use to place patients on Plavix for three to six months after a drug-coated stent was placed; however, more recent studies and looking back at some of the older studies found that it was rare, but that a very small percentage of these patients even after six months, even out to a year, and in some studies maybe even beyond a year were having some blood clotting inside those stents; that lead to a blanket recommendation that patient needs to be on Plavix for at least one year and we are looking into whether this is going to need to be extended even further in certain patients.
Dr. Pamela B. Morris: Are there problems when a patient is on a blood thinner such as Plavix?
Dr. Christopher D. Nielsen: Certainly, any blood thinner increases your risk for bleeding. Plavix and aspirin have both been shown that in long-term studies even though they are very beneficial for the heart, they do slightly increase the risk of bleeding over the long-term. Most of the risk of bleeding is what we would consider very minor bleeding and it’s rare that these medications cause major bleeding.
Dr. Pamela B. Morris: What happens if a patient with a stent on blood thinners needs some sort of a surgical procedure in that first year?
Dr. Christopher D. Nielsen: Well certainly, we try to ascertain at the time that we are going to place a stent, whether there are any anticipated surgeries in the near future in these patients. Obviously, we can’t always determine that, but if we determine that a patient is going to need a surgery within the next few months we would often chose a bare metal stent so that we don’t have to worry about them being on Plavix long-term. Now, if we have placed a drug-coated stent and they end up needing surgery that was unanticipated we often have to stop the Plavix for a couple of days or a week or two depending on the type of surgery and again the risk of stopping the Plavix for a few days or a week is low, but certainly we can never say it’s no risk in the first year.
Dr. Pamela B. Morris: So that may give someone an excuse to delay their colonoscopy for another six months to a year.
Dr. Christopher D. Nielsen: Well, certainly elective surgeries or elective procedures probably should be delayed, but certainly if necessary, procedures need to go forward.
Dr. Pamela B. Morris: Are there any drug interactions with the blood thinner, I know we are so cautious these days about multiple drug interactions especially in heart patients who are on so many drugs?
Dr. Christopher D. Nielsen: There is really not any major drug interaction with Plavix and so that’s usually not a concern.
Dr. Pamela B. Morris: Not a problem. What about other types of medications in heart patients once you have had a stent placed, is there a role for some of the other preventive medications in long-term management?
Dr. Christopher D. Nielsen: Most patients that have had any amount of coronary artery disease and that includes the patients that have had balloon angioplasty or stent probably should be on a cholesterol medication. The way that I always put it to my patients is that even though your cholesterol seems not to be terribly high, it’s obviously too high for your body because you have developed plaque or blockages in the arteries. So I would say that the vast majority of patients that have had a stent need to be on cholesterol medication.
Dr. Pamela B. Morris: What about the role of diet in terms of long-term management after stent placement.
Dr. Christopher D. Nielsen: I think diet is very important. We can’t always say that we can just take a pill and still eat what we want to eat. I think that following a low fat and a low cholesterol diet along with your cholesterol medication is very important in patients with coronary artery disease.
Dr. Pamela B. Morris: And one final question after a patient has had an elective stent placement, how quickly do they return to their normal activities?
Dr. Christopher D. Nielsen: Most patients that have had an elective stent placement stay in the hospital overnight and we usually tell them to take it easy for a couple of days and usually they are back to full activities within a week.
Dr. Pamela B. Morris: Great. Well, thank you so much Dr. Nielson for this discussion on stent.
Dr. Chris Nielson: Thank you.
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