CREST Subanalysis: Post Carotid Stent Balloon Dilatation May Reduce Restenosis
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Post-stent balloon dilatation in carotid stenting patients decreases the restenosis risk by almost two-thirds. The effect on periprocedural stroke, though, is not as clear-cut, according to a CREST subanalysis presented Thursday, May 9, 2013, at the annual meeting of the Society for Cardiovascular Angiography and Interventions in Orlando, FL.
Researchers led by Mahmoud B. Malas, MD, MHS, of Johns Hopkins Bayview Medical Center (Baltimore, MD), looked at 1,109 patients from CREST (Carotid Revascularization Endarterectomy versus Stenting Trial) who received carotid stents. Dr. Malas and colleagues stratified patients according to those who received pre-stent balloon dilatation alone (n = 69; 6%) post dilatation alone (n = 344; 31%) or both (n = 696; 63%), comparing all 3 groups in terms of periprocedural events (table 1).
Restenosis and reintervention at 2 years were lowest in the post-dilatation group, while periprocedural stroke was highest, though the differences among the 3 groups were not significant. Other periprocedural outcomes were low and equivalent (table 1).
Table 1. Periprocedural and 2-Year Outcomes
|
Pre- Dilatation |
Post-Dilatation |
Pre- and Post-Dilatation |
P Value |
Periprocedural MI |
1.4% |
1.4% |
0.9% |
0.67 |
Periprocedural Stroke |
1.4% |
5.5% |
4.0% |
0.26 |
Periprocedural Death |
0 |
0 |
0.9% |
0.16 |
2-Year Restenosis |
10.3% |
3.95% |
5.7% |
0.10 |
2-Year Reintervention |
4.3% |
0.6% |
1.7% |
0.64 |
On multivariable analysis, combined pre- and post-stent balloon dilatation was not associated with reductions in any periprocedural endpoint compared with pre-dilatation, and neither was post-dilatation. However, post-stent balloon dilatation was associated with a 61% reduction in the 2-year risk of restenosis (HR 0.39; 95% CI 0.16-0.98), while the numerical increase in periprocedural stroke did not reach significance (HR 3.8; 95% CI 0.50-28.8).
When comparing patients who received post-stent balloon deployment only vs. those who received only pre-stent dilatation, 2 endpoints favored post dilatation (table 2).
Table 2. Pre- vs. Post Dilatation
|
Pre-stent Dilatation |
Post-stent Dilatation |
P Value |
Periprocedural Stroke |
1.5% |
5.5% |
0.26 |
2-Year Restenosis |
10.3% |
3.7% |
0.02 |
On multivariable analysis, post-stent balloon dilatation was again associated with a reduction in restenosis risk (HR 0.36; 95% CI 0.14-0.91) while the results for stroke were not significant (HR 3.7; 95% CI 0.50-27.9).
The authors note that the “decision to perform post-stent deployment angioplasty is operator-dependent and often influenced by the interpretation of the degree of residual stenosis based on post-stent deployment angiography.”
Based on the results, post-stent deployment angioplasty “reduced the risk of restenosis in CREST,” they concluded. “Whether [post-stent deployment angioplasty] increases the risk of periprocedural stroke is possible though uncertain, possibly because of the small numbers of periprocedural strokes in the [pre-stent deployment angioplasty] only and the [post-stent deployment angioplasty] only groups.”
There was 1 periprocedural stroke in the pre-stent deployment angioplasty group and 19 in the post-stent angioplasty group.
The main CREST study randomized 2,502 patients with symptomatic or asymptomatic carotid stenosis to carotid endarterectomy or stenting. Overall, there was no difference between the 2 groups in the estimated 4-year rates of the primary endpoint (composite of periprocedural stroke, MI, or death, or the incidence of ipsilateral stroke ≤ 4 years). However, stenting carried a higher risk of stroke and surgery a higher risk of MI.
‘Jury Still Out’ On Restenosis
In a telephone interview with TCTMD, Christopher J. White, MD, of the Ochsner Heart and Vascular Institute (New Orleans, LA), noted that the standard of care in carotid stenting is generally to use both pre- and post-stent balloon deployment, which is what happened in CREST.
A drawback, though, is that restenosis was not clearly defined in terms of whether it was based on angiographic or ultrasound criteria. “It’s nice to know that there isn’t a big safety signal here, [but] I think the jury’s out on restenosis,” Dr. White said. “We’ll need to know what the clinical implication is. Does it mean people needed another procedure, or does it just mean their ultrasound result was higher? Because if [it was only the latter], I don’t really care. That doesn’t seem to impact anybody’s outcome.”
He added that while the results would most likely not affect the decision to pre- or post-dilate in carotid stenting patients, there is a school of thought that post-stent balloon deployment may hold disadvantages.
“There is a group that thinks if you get a pretty good result with a stent, why would you post dilate? [The idea is that] there’s a risk of bad things happening,” he said, citing the “cheese grater” effect.
“These stents are mesh, so if you post dilate them into the wall of the plaque, the plaque is seen to sort of [extrude] into the interstices of the stent, and perhaps bits and pieces can break off,” Dr. White explained. “There’ve been some papers that have suggested that aggressive post dilation is when bad things happen.”
Source:
Malas M. Angioplasty following carotid stent deployment reduces the risk of restenosis and may or may not increase the risk of procedure related stroke. Presented at: Society for Cardiovascular Angiography and Interventions Scientific Sessions; May 9, 2013; Orlando, FL.
Disclosures:
- Dr. Malas reports no relevant conflicts of interest.
- Dr. White reports serving as the steering committee chair for the NCDR Carotid Registry.
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