Carotid Stenosis: Asymptomatic Patients are not all Created Equal: Indications for Intervention Rabih A. Chaer MD Assistant Professor of Surgery Division of Vascular Surgery University of Pittsburgh Medical Center

Rabih A. Chaer, MD DISCLOSURES I have no real or apparent conflicts of interest to report.

ACAS CEA Reduces Stroke Risk Asymptomatic Carotid Stenosis Risk Reduction at 5 Years >60%stenosis from 11% to 5% (< 3 % without angiography) Men benefit significantly more than women CEA appropriate if Death/Stroke Risk < 3% and Patient has a reasonable life expectancy

USA CEA VOLUME (NCHS) YEARS ACAS NASCET ASYMPTOMATIC UK: 16% USA: 80% D ACAS NASCET ASYMPTOMATIC UK: 16% USA: 80% YEARS

Choices….Choices

CURRENT EVIDENCE VA study: men>50% stenosis, ASA vs. ASA+CEA ACAS: BMT ± CEA ACST: immediate vs. deferred CEA Hobson et al. NEJM 1993; 328:221-7. ACAS. JAMA 1995;273:1421-28. Halliday A et al. Lancet 2004; 363:1491-1502

Risk of Stroke 2% per year in asymptomatic patients with >60% stenosis (ACAS/ACST) May be higher? REACH registry: TIA 3.5 vs. 1.6% (p<.0001) Non fatal stroke 2.65 vs. 1.75% (p<.0009) Aichner FT et al. European Jl of Neurology. 2009; 16:902-8

Level I Pooled data from ACAS and ACST: 4,779 patients: Net procedural hazard (stroke and death): 2.9% RR reduction 31% (p=0.001) Absolute risk reduction 3% over 2-3 years Number needed to treat: 33 to prevent 1 stroke. Benefit at about 3 yrs post intervention.

Patient Selection Modifiers: Age, gender, previous stroke, silent infarcts ACAS RRR 50% vs. 9% for age<68 vs. >68 ACST ARR 7.8% vs. 3.3% for age <75 vs. >75 Contralateral symptoms ACST: higher 5yr gain Severity of stenosis Medical therapy Plaque characteristics

High Risk for CAS Anatomic Physiologic Hostile Arch Severe Tortuosity Lesion Anatomy Tandem Lesions Calcified Lesions Plaque Characteristics Physiologic Symptomatic Patients Octogenarians Renal Failure Patients

High Risk for CAS: Arch Characteristics Type III arch Excessive Tortuosity

High Risk for CAS: Lesion Characteristics Globular Lesions Severe Tortuosity Free Floating Thrombus

More Lesion Characteristics J Vasc Surg 2008; 47:81-87

Lesion Location 7.1 7.8 9.1 1.8 2.5 2.9 Location (n) Proc. CVA (%) 30 day CVA (%) 30 day AE (%) Non Ostial (275) 1.8 2.5 2.9 Ostial (154) 7.1 7.8 9.1 P 0.007 0.015 0.01

Lesion Length Lesion Length in mm (n) Proc. CVA (%) 30 day CVA (%) 30 day AE (%) 5-9.9 (182) 2.2 2.7 3.3 10-14.9 (105) 1.9 2.9 3.8 > 15 (47) 17.0 19.1 P <0.001 0.002 0.001

Echolucent Lesions N Neuro Complications GSM < 25 155 7.1% Biasi GM et al: The Imaging in Carotid Angioplasty and Risk of Stroke (ICAROS) Study. Circulation 2004;110:756-762

The Vulnerable Plaque Well established in the coronary literature Plaques are not identical and have various biologic behavior in propensity for symptoms or in response to therapy Most patients receive more than one device (1.5/patient). Long tapering anatomy Define high-risk = non-surgical (TAA, Dissection, & Trauma)

The Vulnerable Plaque The vulnerable plaque is not only characterized by Anatomic characteristics such as large lipid core, Intraplaque hemorrhage, or a thin fibrous cap but also Pathophysiologic active markers of inflammation Most patients receive more than one device (1.5/patient). Long tapering anatomy Define high-risk = non-surgical (TAA, Dissection, & Trauma)

The Vulnerable Plaque A multimodal approach to studying the carotid plaque appears to be a promising tool in identifying vulnerable carotid plaques. The current literature suggests that in addition to the degree of stenosis other imaging and biochemical findings have important clinical significance. Most patients receive more than one device (1.5/patient). Long tapering anatomy Define high-risk = non-surgical (TAA, Dissection, & Trauma) Cerebrovasc Dis 2009;27:19–24

The Vulnerable Plaque: IVUS VH Most patients receive more than one device (1.5/patient). Long tapering anatomy Define high-risk = non-surgical (TAA, Dissection, & Trauma)

Vulnerable Plaque: Duplex + Microbubbles Most patients receive more than one device (1.5/patient). Long tapering anatomy Define high-risk = non-surgical (TAA, Dissection, & Trauma) Symptomatic Patient Before Microbubbles After Microbubbles Vascularized Plaque with channel through plaque

Vulnerable Plaque: Duplex + Microbubbles Most patients receive more than one device (1.5/patient). Long tapering anatomy Define high-risk = non-surgical (TAA, Dissection, & Trauma) Asymptomatic Patient Before Microbubbles After Microbubbles No change in the plaque

The Vulnerable Plaque a self-expanding stent tailored to shield vulnerable plaques (vProtect® Luminal shield) Most patients receive more than one device (1.5/patient). Long tapering anatomy Define high-risk = non-surgical (TAA, Dissection, & Trauma) Nat. Rev. Cardiol. 2009;6:374–378

CEA vs CAS Gray CAS Always Neville Only CEA

Asymptomatic CEA vs. CAS RCT Asymptomatic Cohort in SAPPHIRE STENT (117) CEA (120) DEATH 1.7 % 0.8 % CVA 5.1 % 3.3 % DEATH / CVA 6.0 % 4.2 % M.I. 2.6 % 6.7 % DEATH / CVA / M.I. 6.0 % 9.2 % ACAS (CVA) 1.3% AHA Guidelines (CVA/Death) < 3.0%

30 day AE CAPTURE Study CVA 11.1% 16.7% MI 2.8 All Death 1.9 10.4 2.4% Non-Octogenarians Octogenarians (n = 108) (n = 48) Symptomatic Patients CVA 11.1% 16.7% MI 2.8 All Death 1.9 10.4 2.4% 5.5% 0.8 0.6 1.0 2.1 (n = 1116) (n = 330) Asymptomatic Patients

REGISTRY CAS DATA EX and C2 data: 2145 Emboshield/Xact, 4175 Acculink/Accunet 30 day stroke and death rate: <80yo: 5.3% for symptomatic patients, 2.9% in asymptomatic >80yo: 10.5% for symptomatic patients, 4.4% in asymptomatic Gray et al. CCI 2009; 2: 159-166

Carotid Revascularization: Asymptomatic No Clear data to answer Both CEA and CAS may be used effectively Plaque characteristics matter We should start clinical evaluation of plaque composition that make them more or less suitable for a particular treatment Most patients receive more than one device (1.5/patient). Long tapering anatomy Define high-risk = non-surgical (TAA, Dissection, & Trauma)

Asymptomatic Carotid: NOT all the same Procedural hazards Life expectancy Age Plaque and lesion characteristics Intracranial circulation: ACA Medical therapy

Insufficient Contemporary level I CAS data CREST ACT1 SPACE2 TACIT ACST-2