The Role of Factor Xa Inhibitors in the Management of CAD/PAD - Episode 7
Deepak L. Bhatt, MD, MPH: Well, you’ve introduced us now to the concept of antithrombotics: what to do, at what stage of disease, and duration. Let’s drill down into that a little bit. You talked about ACS [acute coronary syndrome], and I think, as you said, most people would say the anchor right in the guidelines, based on the trials and data, is a year of dual antiplatelet therapy [DAPT] in someone who has come in with ACS, assuming that they’re not bleeding or have other contraindications.
Manesh Patel, MD: That may change over time.
Deepak L. Bhatt, MD, MPH: Yes, it may change, and certainly from a stent perspective, the durations don’t need to be a year necessarily. But from the plaque rupture, thrombosis, and ACS perspective, I think that still remains the anchor. But getting past that year, what would we want to do in the patient with a history of prior ACS? Options are to de-escalate to aspirin monotherapy, or clopidogrel or ticagrelor monotherapy, for example; to continue whatever DAPT regimen they were on; or potentially to even throw an anticoagulant in the mix. What would be the approach?
Vamsi Krishna, MD: That’s a great question. Currently after 1 year, now, they have “stabilized” and we’re treating the continued risk. With PEGASUS-TIMI 54, that was a good study on ticagrelor 60 mg twice a day with aspirin, and up to 3 years out with certain high-risk features, they had benefit in ischemic reduction. There was not necessarily a net clinical benefit and survival, but there was ischemic reduction.
As an interventionist how I look at this is, what are the angiographic factors in there and what are clinical factors? And the DAPT score does something of that nature. What I mean by this is if I’m dealing with small arteries and I’m but putting in lots of stents, that is a higher risk angiographic patient. Now you throw in that a patient is diabetic and has a smoking history, definitely the risk keeps going higher for ischemic events, and now I want to be probably more cautious with what type of antithrombotic regimen we’re going to continuously place them on. Now let’s say we had a patient with ACS with a proximal or coronary artery, it was a large stent I was able to place, and I post dilated appropriately. OCT [optical coherence tomography] shows excellent expansion. Those are patients now in whom I feel more comfortable de-escalating therapy, and their risk factors are angiographically not high. And then clinically, they do not have as many risk factors. They’re patients where I believe that their ischemic burden is lower.
When we’re talking about trials and DAPT duration, I think what’s been lost is it’s not just 1 variable or 3 variables. It’s literally the components of what their anatomy is looking like, and what we’d have to do to treat it, and then what the patient clinical factors are.
Deepak L. Bhatt, MD, MPH: Let me ask you this. Everything you said makes a lot of sense, but there’s some complexity in that you mentioned OCT, with a good result. That’s all appropriate, optical coherence tomography is a way of imaging from the inside that interventional cardiologists use. But that’s a lot of information. If that’s in your report, a primary care physician may not fully follow exactly what you were referring to with post dilation. So who should make that decision at a year then in terms of what to do with that patient? Should that be the primary care physician, should they call you, or should you be seeing that patient? What is the way that you would recommend handling that?
Vamsi Krishna, MD: I typically recommend, if you’re the person to put that stent in or treat that patient, you should continue treating that patient and make that clinical decision. I think for a primary care physician who is not involved in that procedure, it’s hard for them to know what to do afterward. With all these ways of imaging and testing, when I’m at the very end making my impression, I’m having both clinical and procedural aspects to help me conclude why I’m going to utilize a regimen.
Deepak L. Bhatt, MD, MPH: The other thing you have to factor in is what happened in that year in terms of recurrent events, or bleeding, which might alter the strategy. And bleeding, you’ve thought a lot about bleeding, you probably caused some bleeding along the way too. Is bleeding important? Obviously it is, but how does that factor in?
John Eikelboom, MBBS, MSc, FRCPC: I just want to challenge that.
Deepak L. Bhatt, MD, MPH: Oh please challenge him, he needs to be challenged once more.
John Eikelboom, MBBS, MSc, FRCPC: Because I think in theory, you’re absolute right, you’re the operator, you know what the anatomy is, you should have a say. In reality, it’s just not feasible that interventionists look after all these people. And the family physician out there today in reality is forced to be closely involved in this. So I say, get the interventionist to provide guidance. Ideally in their discharge letter they’ll say, “You know, this was lots of metal, this was a bifurcation, this was a left main stent; this is a person with stent thrombosis, I think they need 1 to 3 years, lifelong.” Or, “This patient has a very high burden of atherosclerosis. They’re at high risk for subsequent events, they need long-term intensification of antithrombotic therapy, but you might consider something other than DAPT.” So I think that’s really important that the interventionist provide some guidance there.
Manesh Patel, MD: I think so, and I’ll just say one other thing. Let’s be clear, I think one other thing I’ll, not challenge, but sort of say, I’ll call it competing risk. That the year after the heart attack we would all say the anchor for when you’re likely getting dual antiplatelet therapy with 2 of those drugs.
From 1 to 3 years, I’m going to call it intermediate time point, where there’s some evidence where we’re making a decision about extending 2 versus 1. Within that amalgam there are also other therapies, a low-dose oral anticoagulant, like rivaroxaban or something like that, we could talk about in a second. That 1- to 3-year period, I think there is still some residual risk from that event with that stent. But what we should be thinking about is that big box of the patient risk that’s going to continue on, and that anatomy artery risk that’s getting less with time.
I think you are absolutely right that the primary care physician should be getting information from the interventionalist. But they’re going to see a lot of patients, 3, 5, 8 years out, who are on chronic therapies. It will be hard to find the note that I appropriately wrote the duration on, let’s say 3 years ago. So what you have to do at that point is have this conversation. Because a lot of patients, almost every patient I’ve ever met, they want to de-escalate. They don’t like pills. So if I could stop one of these, Dr Patel, I would love it.
Deepak L. Bhatt, MD, MPH: I think though John, you are right that the primary care physician has to be part of this conversation, and certainly in the longer term therapy decision making. But I also agree with what both of you have said, that the interventionalist should write a good note, and I also try to be specific. But of course circumstances might change. I might say life-long DAPT, but then the person might have a big GI [gastrointestinal] bleed and another GI bleed.
Manesh Patel, MD: Develop a carotid stenosis, have limb threatening issues, other things that happen.
Deepak L. Bhatt, MD, MPH: Absolutely, so things happen for sure.
Vamsi Krishna, MD: They develop AFib [atrial fibrillation], so there’s a hierarchy.
Deepak L. Bhatt, MD, MPH: That’s a good point.
Transcript edited for clarity.