Stenting Versus Best Medical Treatment of Asymptomatic High Grade Carotid Artery Stenosis
Stenting Versus Best Medical Treatment of Asymptomatic High Grade Carotid Artery Stenosis
Background. Carotid artery stenting (CAS) recently has become an accepted method for
 treatment of patients with high-grade carotid artery stenosis, who are at an increased risk
 for surgical carotid endarterectomy (CEA). The reported rates of neurological complications
 of CAS substantially decreased during the past years, and the routine use of cerebral
 protection devices and low profile catheter systems have further increased the procedure´s
 safety. In the early 90's large surgical trials in North America and Europe (NASCET, ECST and
 ACAS) demonstrated superiority of CEA compared to best medical treatment for symptomatic and
 asymptomatic patients. Provided that the ongoing randomized controlled trials comparing CAS
 and CEA confirm equivalence between the these methods, CAS similar to CEA is applicable to
 symptomatic and asymptomatic patients with high grade carotid stenosis. However, particularly
 in asymptomatic patients, the indication for revascularisation remains debatable. Protected
 CAS is associated with a very low rate of neurological complications, which are below the AHA
 recommendation for treating asymptomatic patients (3%). However, the introduction of new
 vascular protective medications like statins and clopidogrel during the recent years
 substantially improved the spectrum of best medical treatment, and the findings of NASCET,
 ECST and ACAS with respect to best medical treatment may therefore not be applicable any
 more.

 Study hypothesis and aims. Given the low frequency of spontaneous neurological complications,
 the preferable therapeutic approach to patients with asymptomatic high grade ( > 80%) carotid
 artery stenoses is currently unknown. Modern best medical treatment may manage to stabilize
 the atherosclerotic plaque, while CAS has the potential of resolving the carotid stenosis.
 Comparative data, however, are not available as yet. We hypothesized that protected CAS has a
 beneficial effect on occurrence of ipsilateral neurological complications and major adverse
 cardiac events in high-risk patients with asymptomatic > 80% internal carotid artery
 stenosis. Therefore, the aim of the present randomized controlled trial was to analyze
 neurological and cardiovascular outcome of patients treated with elective CAS plus best
 medical treatment compared to best medical treatment only.
Carotid artery stenting (CAS) recently has become an accepted method for treatment of
 patients with high-grade carotid artery stenosis, who are at an increased risk for surgical
 carotid endarterectomy (CEA). The reported rates of neurological complications of CAS
 substantially decreased during the past years, and the routine use of cerebral protection
 devices and low profile catheter systems have further increased the procedure´s safety. In
 the early 90ies large surgical trials in North America and Europe (NASCET, ECST and ACAS)
 demonstrated superiority of CEA compared to best medical treatment for symptomatic and
 asymptomatic patients. Provided that the ongoing randomized controlled trials comparing CAS
 and CEA confirm equivalence between the these methods, CAS similar to CEA is applicable to
 symptomatic and asymptomatic patients with high grade carotid stenosis. However, particularly
 in asymptomatic patients, the indication for revascularisation remains debatable. Protected
 CAS is associated with a very low rate of neurological complications, which are below the AHA
 recommendation for treating asymptomatic patients (3%). However, the introduction of new
 vascular protective medications like statins and clopidogrel during the recent years
 substantially improved the spectrum of best medical treatment, and the findings of NASCET,
 ECST and ACAS with respect to best medical treatment may therefore not be applicable any
 more.

 Given the low frequency of spontaneous neurological complications, the preferable therapeutic
 approach to patients with asymptomatic high grade ( > 80%) carotid artery stenoses is
 currently unknown. Modern best medical treatment may manage to stabilize the atherosclerotic
 plaque, while CAS has the potential of resolving the carotid stenosis. Comparative data,
 however, are not available as yet. We hypothesized that protected CAS has a beneficial effect
 on occurrence of ipsilateral neurological complications and major adverse cardiac events in
 high-risk patients with asymptomatic > 80% internal carotid artery stenosis. Therefore, the
 aim of the present randomized controlled trial was to analyze neurological and cardiovascular
 outcome of patients treated with elective CAS plus best medical treatment compared to best
 medical treatment only.

 SYNOPSIS

 BACKGROUND:

 The preferable treatment - whether revascularization or conservative - of asymptomatic
 high-risk patients with > 80% internal carotid artery stenosis (NASCET criteria) is currently
 unknown.

 STUDY HYPOTHESIS:

 We hypothesized that protected carotid artery stenting (CAS) plus best medical treatment is
 associated with reduced rates of ipsilateral neurological complications and major adverse
 cardiac events in high-risk patients with asymptomatic > 80% internal carotid artery stenosis
 compared to best medical treatment only.

 STUDY DESIGN:

 The study is designed as a randomized controlled trial with 1:1 random assignment between two
 treatment modalities including 300 patients within an scheduled inclusion period of 18
 months. The primary and secondary study endpoints are evaluated for an initial two year
 follow-up period after randomization. Secondary follow-up will be performed for 1, 1.5, 3, 5
 and 10 years post randomization.
Inclusion Criteria:

 -  Atherosclerosis is the underlying disease

 -  Patients with an asymptomatic stenosis >80% (NASCET) with a documented progression of
 the degree of stenosis to >80% within 6 months with a very tight stenosis ≥90% at
 initial presentation with a >80% stenosis plus silent ipsilateral ischemia documented
 by CCT or MRI with ipsilateral >80% stenosis plus contralateral >80% stenosis or
 occlusion with >80% stenosis plus planned major surgery

 -  Neurologist´s explicit consent to potentially perform CAS

 Exclusion Criteria:

 -  Inability to provide informed consent

 -  Underlying disease other than atherosclerosis (inflammatory or autoimmune disease)

 -  Traumatic or spontaneous carotid dissections

 -  Life expectancy <6 months

 -  Advanced dementia

 -  Advanced renal failure (serum creatinine >2.5 mg/dL)

 -  Unstable severe cardiovascular comorbidities (e.g. unstable angina, heart failure)

 -  Restenosis after prior CAS or CEA

 -  Allergy or contraindications to study medications (clopidogrel, statins, ASA)