Carotid stenting with embolic protection: evolutionary advances

What can be done for cerebral embolic protection in TAVI? Analysis in the light of 10 years' experience with protected carotid artery stenting

In the last 30 years, development of minimally invasive percutaneous procedures to treat cardiovascular defects has been thriving. Although these techniques present obvious advantages, like avoiding cardiopulmonary bypass, the passage of catheter systems and the deployment of devices in the blood circulation can cause particle embolization that may result in stroke. In carotid artery stenting, cerebral embolic protection devices (CEPD) such as filtering membranes have been available for already 10 years. In transcatheter aortic valve implantation (TAVI), the development of CEPD is starting and three membrane-based devices are in clinical trials. There are controversial discussions about the efficacy of CEPD in TAVI. The experience with CEPD in carotid artery stenting can help to understand some of the technical issues and shortcomings of current devices and thereby ultimately reduce cerebral complication risks during TAVI procedures.

Carotid revascularization using endarterectomy or stenting systems (CaRESS): 4-year outcomes

PURPOSE

To examine the 4-year outcomes from Carotid Revascularization using Endarterectomy or Stenting Systems (CaRESS) in light of the current reimbursement guidelines for carotid artery stenting (CAS) from the Centers for Medicare and Medicaid Services (CMS).

METHODS

CaRESS was designed as a prospective, nonrandomized comparative cohort study of a broad-risk population of symptomatic and asymptomatic patients with carotid stenosis. In all, 397 patients (247 men; mean age 71 years, range 43-89) were enrolled and underwent carotid endarterectomy (CEA; n = 254) or protected CAS (n = 143). More than 90% of patients had >75% stenosis; two thirds were asymptomatic. The primary endpoints included (1) all-cause mortality, (2) any stroke, and (3) myocardial infarction (MI), as well as the composite endpoints of (4) death and any nonfatal stroke and (5) death, nonfatal stroke, and MI. The secondary endpoints were restenosis, repeat angiography, and carotid revascularization. All patients were classified with respect to surgical risk, symptom status, and stenosis grade based on criteria published by the CMS. In addition, separate analyses were performed comparing genders and octogenarians to those <80 years old.

RESULTS

No significant differences in the primary outcome measures were found between the CEA and CAS groups in the 4-year analysis. The incidences of any stroke at 4 years were 9.6% for CEA and 8.6% for CAS (p = 0.444); when combined with death, the composite death/nonfatal stroke rates were 26.5% for CEA versus 21.8% for CAS (p = 0.361). The composite endpoint of death, nonfatal stroke, and MI at 4 years was 27.0% in CEA versus 21.7% in CAS (p = 0.273) patients. The secondary endpoints of restenosis (p = 0.014) and repeat angiography (p = 0.052) were higher in the CAS arm. There were no differences in any of the subgroups stratified according the CMS guidelines or in the gender comparison. Four-year incidences of death/nonfatal stroke and death/nonfatal stroke/MI were higher in the CEA arm among patients <80 years of age (p = 0.049 and p = 0.030, respectively). There were no significant differences between these incidences in the octogenarian subgroup.

CONCLUSION

The risk of death or nonfatal stroke 4 years following CAS with distal protection is equivalent to CEA in a broad category of patients with carotid stenosis. There were no significant differences in stroke or mortality rates between high-risk and non-high-risk patients and no differences in outcomes between symptomatic and asymptomatic patients. After 4 years, CAS had a 2-fold higher restenosis rate compared to CEA. The risk of death/stroke or death/stroke/MI appears to be higher following CEA than CAS among patients <80 years of age, yet there is no statistically significant relationship between death, stroke, or MI among octogenarians.