CREST 2 and the Asymptomatic Carotid Dilemma
This episode breaks down the CREST 2 trials and the tough decision facing patients with severe asymptomatic carotid stenosis: accept the upfront risk of stenting or surgery, or rely on intensive medical therapy alone. The hosts examine short-term procedural harms, four-year outcomes, and why modern medication has changed the standard of care.
Show Notes
- Medical Management and Revascularization for ...: https://www.nejm.org/doi/abs/10.1056/NEJMoa2508800
Chapter 1
The Asymptomatic Carotid Dilemma and the CREST 2 Design
Dr. James Whitfield
Imagine you are sitting in clinic, feeling completely healthy, and your doctor runs a screening ultrasound that shows a 70% to 99% blockage in your internal carotid artery. You have zero symptoms. No weakness, no vision changes, nothing.
Dr. Elena Rodriguez
Seventy to ninety nine percent blocked, but feeling totally fine... That is the ultimate bedside dilemma, James, because now you have to decide whether to leave it alone with meds or send them for a procedure.
Dr. James Whitfield
And that is precisely what the CREST 2 trials were designed to answer. We are talking about two parallel, observer blinded trials across 155 international centers, enrolling 2,485 total patients with high grade asymptomatic carotid stenosis. Every single patient got intensive medical management, but 1,245 were in the stenting trial, and 1,240 were in the endarterectomy trial.
Dr. Elena Rodriguez
Two distinct trials running side by side, comparing each invasive approach to medical therapy alone. But before we get to the long term numbers, the perioperative window from day 0 to day 44 showed a stark trade off right out of the gate.
Dr. James Whitfield
It really did. In that initial 44 day window, medical therapy alone was remarkably safe. There were zero strokes or deaths in the stenting control arm, and just three strokes, or 0.5%, in the surgical control arm. But when you look at the procedural groups, revascularization brought immediate upfront risk.
Dr. Elena Rodriguez
Right, because inserting a stent or opening the artery surgically carries its own acute danger. In the stenting group, there were seven strokes and one death, which is 1.3%. And with endarterectomy, nine strokes, or 1.5%.
Dr. James Whitfield
Exactly. As a clinician, explaining that upfront risk to an asymptomatic patient is one of the hardest conversations in medicine. You are asking someone who feels completely healthy to accept an immediate procedural risk of stroke or death today, just to potentially buy protection against a hypothetical stroke years down the road.
Chapter 2
Four Year Outcomes and the Revascularization Paradox
Dr. Elena Rodriguez
So let us talk about what that procedural risk actually bought over the long haul. When the researchers looked at the four year primary outcome, which was a composite of perioperative stroke or death or subsequent ipsilateral stroke, the results between the two trials diverged in a really surprising way.
Dr. James Whitfield
In the stenting trial, the addition of stenting led to a lower risk of a composite of perioperative stroke or death or ipsilateral stroke over four years. Transfemoral stenting plus medical therapy dropped the event rate to 2.8%, compared to 6.0% with medical therapy alone. That is an absolute difference of 3.2%, with a p value of 0.02.
Dr. Elena Rodriguez
That is a statistically significant benefit for stenting. But then you look at open surgery, carotid endarterectomy, which has been our traditional gold standard for decades, and the picture shifts entirely.
Dr. James Whitfield
It does. Endarterectomy plus medical therapy resulted in a 3.7% primary outcome rate versus 5.3% for medical therapy alone. That difference was not statistically significant, with a p value of 0.24. Open surgery failed to show a clear benefit over modern oral medications.
Dr. Elena Rodriguez
That is fascinating. Why did open surgery fail to beat medical management when older trials from the 1990s, like ACAS, showed such a clear surgical benefit?
Dr. James Whitfield
Because medical therapy in the 1990s bears no resemblance to what we do today. In CREST 2, intensive medical therapy meant high potency statins, dual antiplatelet agents, and aggressive blood pressure control. With modern meds alone, the annual post 44 day stroke rate was kept down to just 1.3% to 1.7% per year.
Dr. Elena Rodriguez
The baseline risk of stroke on medical therapy has plummeted so dramatically that the margin for any invasive procedure to show a benefit is razor thin. So how do you translate all of this for a patient sitting in front of you today?
Dr. James Whitfield
The takeaway is nuanced. Transfemoral stenting does offer a statistically significant stroke reduction, but it is modest, with a number needed to treat around 31 over four years. Meanwhile, routine open endarterectomy for asymptomatic high grade stenosis is simply no longer supported by trial evidence over modern medical therapy.
Dr. Elena Rodriguez
It really reframes how we think about carotid disease. Medical management has become so effective that surgery is no longer the default option for someone who feels fine.
Dr. James Whitfield
Precisely. Good chatting with you, Elena.