Treating Peripheral Arterial Disease After Revascularization - Episode 8

Antithrombotic Therapy in the PAD Post-Vascularization Setting

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Drs Patel and Bonaca explain limited data results from some key trials, such as CASPAR and Dutch BOA, and apply them to antithrombotic therapy for patients with PAD in the post-vascularization setting.

Manesh Patel, MD: Putting the VOYAGER findings into some context for ourselves, we got through these lessons, and now we can think about COMPASS and VOYAGER and how that helps our patients. Before we delve deeply into those for at least a few minutes, I wanted to make sure we think about the level of evidence for antiplatelet therapy postrevascularization. I say that humbly because I’m a guy who, even though I’ve done the trials and I’m in our lab, and sometimes it’s hard to change what you’ve done in the past. People postrevascularization, extrapolated from the coronary world, would get aspirin and clopidogrel in our lab and most places—right or wrong—after a stenting procedure of the SFA [superficial femoral artery] or below the knee.

That has started to change, but before we think about the VOYAGER findings, Marc, I’ll come back to you to say it’s not too many sentences or trials we have to quote when we think about postrevascularization evidence—a few, maybe Dutch BOA [Bypass Oral Anticoagulant or Aspirin] or others. What’s your sort of summary statement on the level of evidence before we had VOYAGER in this space?

Marc P. Bonaca, MD, MPH: These were antithrombotic therapies. It’s fair to say there were no clear wins. There was CASPAR, which was the familiar combination of DAPT vs aspirin after bypass. It was a solidly neutral trial. The hazard ratio was 0.98. There was heterogeneity for vein vs prosthetic, which raised a lot of questions. It didn’t address the endothelium question, but mortality went the wrong way. There’s no benefit from limb outcomes, so that largely prevented surgeons from broadly adapting DAPT in the postrevascularization setting, although there’s some question of whether you might use it for certain graft types.

Then there was Dutch BOA, which recapitulated what WAVE showed. It was focused on graft occlusion, but there’s no benefit. There’s no benefit for MACEs [major adverse cardiovascular events] and the same bleeding signal that WAVE showed. Those were the 2 that left people with a lot of questions. There were some subgroup findings that raised questions but no clear win.

Then there was CAMPER, which tried to address the question of endothelium. But because everybody does it, no one would recruit, and we don’t have an answer. Although if you look at elective revascularization for coronary disease, the momentum is to shorter durations of DAPT because the devices are so safe. It’s broadly utilized, between what we know from CASPAR and from what we know from the coronary field, but I’m not sure that a long duration of DAPT would be warranted. So you’re right: it was a desert of evidence for practice.

Manesh Patel, MD: I certainly have sunbathed on the evidence-free beach before, and I’m sure I’ll do it again. A lot of my colleagues do it.

This transcript has been edited for clarity.