Stents in Treatment of CAD and PAD

Deepak Bhatt, MD, MPH: Eric, how has stenting changed? We’re not as dependent for the stent on DAPT [dual antiplatelet therapy] as we used to be. A lot of folks in the audience, maybe in primary care, might be wondering what’s changed about the stent that you can get away with a shorter duration. It’s probably pretty confusing. Initially it started with even 2 weeks, then a month, then a year, then, several years, and then back to maybe 6 months. It must be very confusing if you’re on the receiving end as referring physicians sending these patients. Years ago, we were telling them, “Keep them on DAPT forever.” Now we’re saying, “You can stop.” How do you synthesize that? Why is it OK to not go lifelong from the stent perspective? I don’t mean from the highway perspective. This is the pothole perspective.

Eric Secemsky, MD: We’ll focus on the pothole. Speaking to the identity crisis in the catheterization lab that we’ve had, Manesh highlighted the depth of the DAPT study. It was the focus on long-term therapy, but what’s changed in the catheterization lab? Our modern techniques are much different. For a typical coronary patient coming to catheterization lab, the first thing is the selection of the patient. We treat patients selectively who have either refractory chest pain symptoms or a heart attack. Thus, we’re taking the right patients to lab, which is a first important part of this.

The second thing is the technology. The stents are made a little differently. The size of the struts, the metal cages, are thinner. They have special types of polymers, or they lack polymers that can cause some inflammation that have been thought to be predictive of risk of thrombosis later. The drugs coated on them are pretty similar, but they’ve changed. We used to use something called paclitaxel. Now we use limus-based drugs, which are very effective in the coronary arteries. As the operator, where we’ve done things differently. We have little microcameras, as I call them, that comb the artery. They help us size our devices and make sure those stents are pressed up against the wall. That’s been a strong predictor of a long, safe outcome for the stent.

By adopting all this technology and these practice changes, we’ve seen that we can reduce the risk of the stent clotting in the long term and also other concerns, including renarrowing the stent and needing another procedure. We would have this safety concern of stent thrombosis happening 1, 2, 3 years later, but we don’t see that often anymore. Let’s start to pull back our antiplatelet therapy and tailor it to the shortest time possible so we can focus on other medications that have lifelong benefits.

Deepak Bhatt, MD, MPH: Those are valuable comments. We’ve talking about stents in the heart arteries, but it’s important for the audience to know that you’ve done a lot of great work with the legs too. There might be different things people in the audience have heard. Are there any risks to using stents in the legs? Can the drugs that are on them escape from the stent and kill people?

Eric Secemsky, MD: That’s a great question. It’s something I’ve spent a few years working on. Deepak, you’re highlighting that paclitaxel, which I mentioned earlier, is a very important drug in the peripheral vascular space. When we do endovascular procedures—Sahil leads the way here—we try to open up the arteries in the legs in the most durable way possible. We found that if you use a plain balloon with nothing on it, those tend to have recurrent disease within 3 to 6 months. If you put in a stent with no drug on it—those earlier stents that Manesh talked about—people could do pretty well. But in 1 or 2 years, those stents start to narrow.

We go back to this idea that we need a drug on these devices to keep these devices from renarrowing, and that drug has been paclitaxel. There’s a concern that paclitaxel, based on a meta-analysis published in December 2018, can cause harm to the patient in the form of long-term mortality. There were many problems with those studies. There have been many studies that Marc Bonaca and others have led that showed that there were probably some flaws in those original analyses, because these devices are pretty safe. The important part of it is that the drug and these devices have changed our outcomes for our leg procedures. Just as we’ve evolved in the coronary space, when we’re doing leg procedures with a device that has paclitaxel on it—we have balloons with paclitaxel, we have stents with paclitaxel—patients aren’t coming back at that 6-month or 1-year mark. If we’re lucky, they never come back. If they do come back, it’s 3, 4, or 5 years later.

We’ve talked a little about this risk-benefit trade-off. We’re going to highlight it more in the further conversation, but everything has a little risk. Hopefully we’re always picking something with more benefit. We found that these drug code devices are really improving long-term limb outcomes, so we can focus on the bigger picture.

Deepak Bhatt, MD, MPH:I want to underscore that for the audience. Through the years, there’s been a lot of confusion and noise about stents within the heart arteries or the leg arteries. Dr Manesh Patel reviewed some of that. The bottom line is that, as of now, the stents we’re using in the heart arteries are quite safe. The ones we’re using in the legs are quite safe. Those older concerns and all that noise that you heard? For the most part, you can disregard that. Obviously, only patients who need procedures should get them. But assuming that there’s a good indication, you can be confident that for the patients you’re referring for coronary and peripheral stent procedures, these are safe procedures. Would you agree with that, Sahil?

Sahil Parikh, MD: Yes, 100%. That’s increasingly clear from the coronary analogy and the peripheral artery space, separated by about 15 years. There was similar experience that we had early, perhaps with overexuberant enthusiasm. Then there was a reconciliation with the fact that there are trade-offs. When you put a metallic object in a circulating bloodstream, thrombotic risks will need to be mitigated by at least a short-term treatment that’s more potent than what we do for chronic maintenance therapy. That same analogy applies equally for the heart and legs. There’s also some risk from the therapy, but the fact that they need an intervention is what’s marking their risk. Those patients are the highest risk for events. That’s been recapitulated. There’s no free lunch. If you need more antiplatelet therapy or anticoagulant therapy, there will be potentially a bleeding trade-off. It’s how we balance those risks that has become the forefront of where our next treatment paradigms are going.

Transcript Edited for Clarity