Stent, then angioplasty, could increase the risk of stroke, suggests CREST analysis

I'm putting this out there for two reasons.
1. Letting you know about risks your doctor should be telling you about.
2. highlighted text about why carotid arteries are cleaned.
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Performing balloon angioplasty following the deployment of a carotid stent reduces the risk of restenosis but also appears to increase the risk of stroke, according to an analysis of the Carotid Revascularization Endarterectomy Versus Stenting Trial (CREST) [1].

The analysis, presented at the Society for Cardiovascular Angiography and Intervention (SCAI) 2013 Scientific Sessions, showed that poststent angioplasty reduced the risk of restenosis by 64% but was associated with a nearly fourfold increased risk of periprocedural stroke (hazard ratio 3.7; 95% CI 0.5-27.9).

Speaking with the media, lead investigator Dr Mahmoud Malas (Johns Hopkins University, Baltimore, MD) noted that the 30-day stroke risk following carotid stenting in CREST, at 4.1%, was the lowest reported in all the clinical trials to date, with a stroke rate approximately half that observed in the European trials. Still, there are aspects of the procedure, including technical aspects, which might help reduce the risk of stroke further.

Do you believe the p value or the clinical outcomes?

"A lot of interventionalists like to balloon after stenting, and I always thought that might increase the risk of showering emboli to the brain and increase the risk of stroke," said Malas. "We went back to the CREST data to see the effects [of balloon angioplasty after stenting] on the risk of stroke and restenosis. We found that there was a difference in the risk of stroke. It was not statistically significant, but there was a lot more stroke in the group that had the stent ballooned after it was deployed compared with the group that only had the balloon prior to stenting."

19 strokes vs one stroke in the two arms

The CREST study compared carotid artery stenting and carotid endartectomy for stroke prevention in patients with both asymptomatic and symptomatic extracranial carotid stenosis. The primary end point was a composite, including any clinical stroke, MI, or death during the periprocedural period, plus ipsilateral stroke on the vessel that was treated, with patients followed up to four years. No significant difference between the two treatment groups was seen on the primary end point, and Kaplan-Meier curves confirmed most events were periprocedural.

Led by Malas, the researchers retrospectively analyzed the data on patients who received a carotid stent in CREST and compared the risk of stroke and two-year restenosis rates in patients who received only balloon angioplasty before the procedure vs those who received poststent-deployment angioplasty. In total, 69 patients underwent predilation angioplasty, 344 underwent poststent-deployment angioplasty, and 687 received both pre- and poststent angioplasty.

There were 20 periprocedural strokes, including 19 among patients who underwent poststent deployment angioplasty and one patient who received balloon angioplasty before the stent (5.5% vs 1.5%, respectively; p=0.26). Two-year rates of restenosis were 10.3% in the group who received prestent balloon angioplasty and 3.7% in the group treated with balloon angioplasty following stenting, a difference that was statistically significant (p=0.02).

Stroke vs restenosis: The tradeoff

Despite the reduction in restenosis, Malas said the improvement is not a clinically meaningful measurement, because most cases are asymptomatic, and physicians do not necessarily need to intervene if it occurs. In contrast to the coronary arteries, where restenosis is a major issue because of blood flow to the heart muscle, the carotid artery is a "very different animal."

"When we're trying to fix the carotid artery, we're not really trying to improve blood flow to the brain," said Malas. "That's a very common misunderstanding. The idea is that when you have this atherosclerotic lesion, it can break off and cause a stroke. The whole idea with carotid endartectomy is to remove the plaque, and the amazing thing is that stents work because even though you're not removing the plaque, you're just pushing the plaque against the wall of the artery, you get this nice intimal hyperplasia."

Currently, there are no guidelines to direct physicians with regard to postdilation following stent deployment. There is a tendency among interventionalists to position the stent as perfectly as possible, and for this reason angioplasty is frequently employed after the procedure. However, this study questions whether that extra risk is needed, said Malas. Although the study was not powered to detected differences between the pre- and poststent angioplasty groups, and despite the lack of statistical significance, Malas said clinicians should be aware of the potential stroke risks if they elect to perform angioplasty after the stent is placed.

"It becomes a judgment call on the part of the interventionalist doing the procedure," said Malas. "Do you believe the p value or the clinical outcomes? To me, I don't want the patient to have a stroke. I'd rather have restenosis."