SVS Clinical Research Priorities: Carotid

Disease

John J Ricotta MD FACS

Background: Public Health Impact

(AHA Heart Disease and Stroke Statistics 2011 Update, Circ 2011;123: e18-e209) 7M strokes, 13M silent infarctions

795k strokes/yr – 610k new, 185k recurrent - 87% (690k) ischemic (140-200k CAD) - 2/3 unheralded

- 150k fatal (16.7% of all CVD) - 15-30% survivors permanent serious disabled, only 1/3 completely recover

250-500 K TIA/yr – 17% stroke w/in 90 days

Early RX of TIA/Stroke reduces death and disability from recurrence

Background: Imaging

CDUS preferred for initial imaging No agreement on best imaging

protocols CDUS, CTA, MRA, DSA Neck imaging not routinely

incorporated into acute stroke protocols

No agreement on role of imaging in asymptomatic patients

No agreement on follow up protocols

Background: Therapy

CEA beneficial for Sx and Asx CS CAS beneficial for Sx pts CEA decreasing CAS increasing

86% /14% CREST: CEA reduced stroke/death

CAS reduced MI Composite endpoints equivalent

90% of Interventions on Asymptomatic pts. NNT 16-19

Role of BMT?

CEA vs CAS Met Analysis(Murad et al JVS 2011;53:792-7)

Background: Economic Impact (AHA Heart Disease and Stroke Statistics 2011

Update, Circ 2011;123: e18-e209)

Annual stroke Cost 40.8 Billion-direct costs 25.2 Billion

Lifetime Cost / stroke $140,048 CEA cost effective even Asx pts

- low stroke rate, longevity and high cost of stroke

CEA more cost effective than CAS d/t procedural costs ($4,000/ case)

Background Economic Impact

Carotid and Neuroimaging costs are a significant portion of health care costs

- CMS reimbursed 3m CDUS/yr- CT/ MRI cost likely much more

Defining appropriate algorithms for case finding and follow up is important

Identifying imaging protocols that identify stroke prone lesions is important

-avoid unnecessary Interventions in Asx pts.

Current Evidence

Review recent Guidelines from ASA/ACC/AHA and SVS to Identify clinical issues that require further study

Review SVS Membership recommendations

Issues divided based on several criterion- Resource Utilization

- Patient Selection for Intervention - Comparison of Alternative Therapies - Conditions with little data to guide treatment

Guidelines: Imaging

No Benefit to population based Screening - bruit alone not an indication

High Risk screening may be indicated- smokers, PVD, CAD (L

main), age >65, multiple factors increase yield

F/U with disease or after intervention indicated but no agreement on intervals or what to do with pts who are “normal” after intervention

Guidelines: Imaging

Plaque character, surface ulceration, “hits” on TCD, asymptomatic lesions on brain imaging all associated with increased stroke risk

Impression but no evidence that severity (60-79 vs. 80-99) of Asymptomatic Stenosis is related to stroke risk

Duplex, CT and MR all utilized to describe plaque character but with inconsistent results

Silent on imaging protocols in acute stroke

Imaging in Acute Stroke Patients

“Brain attack” protocols focus on MRI with intracranial MRA

-neck MRA or carotid duplex is not standard

“Just in time” duplex not mentioned in patients with ANS, EXPRESS data shows expedited evaluation reduces recurrent Sxs

This is inconsistent with recommendation for early CEA in acute stroke patients

Selection of therapy depends on distribution of intracranial and extracranial disease

Imaging Questions

When is screening Asymptomatic Pts for CS indicated?

How do we define “stroke prone” lesions?

Impact of early duplex in TIA pts What imaging is needed in the acute

stroke patient IC vs EC ? What follow up is appropriate for CS

or after carotid intervention?

Potential Studies

Identify “high risk” subgroups to screen with CDUS

Identify/ Compare reproducible, available techniques to identify plaque and surface characteristics to identify “high risk” lesions

Determine natural history of 60-79% vs 80-99% stenosis

Evaluate “just in time” imaging in TIA pts Evaluate yield of routine neck imaging in

acute stroke patients (race, age) Utility of post intervention imaging

Guidelines: Patient Selection

Intervention for Sx > 50%, Asx >60%, >70% provided AHA procedural guidelines met

CEA preferred to CAS in good risk pts.

CAS preferred in High risk SX pts CAS an alternative in Sx and Asx

pts within AHA guidelines In Sx pts intervention preferred

within 2 weeks of Symptoms

Guidelines: Patient Selection Acknowledge the dysjunction of the

“composite” endpoints of stroke, death, MI

Definition of “Medical High Risk” Acknowledge need for Medical arm in

Asymptomatic patients Intervention for High Grade

recurrent stenosis despite poor data

Guidelines Unanswered Questions

Definition of “High Risk” CAS / CEA pts

Ideal stent , EPD Long term sequelae of “silent hits”

on MRI, chemical MI Recommendations on combined

carotid and coronary disease

Patient Selection Questions

Medical Treatment vs intervention in Asx pts. (2 ongoing trials underway)

Long term cognitive impact of MRI lesions

How to reduce MI in CEA and Stroke in CAS

What is contemporary CEA/CAS High Risk

When to intervene in restenosis Carotid interventions in CABG pts

Potential Studies

CAS/CEA/Med Rx in asymptomatic pts- can combine with lesion

characterization Long Term Cognitive Function

CAS/CEA/BMT Intervention vs observation in Asx

restenosis Role of Carotid Screening in CAD pts

-identify “high yield” group Revascularization Strategies in CABG pts

-unilateral Asx >80%, b/l Asx >70%, Sx >50% ( evaluate aortic arch)

Potential Studies

How to improve results of Interventions - Role of CAD screening in Asx CEA pts

- Role of anatomic selection in CAS -“Learning curve” in

CAS- Influence of stent design, EPD

type in CAS

Guidelines: Insufficient Data to Guide Treatment

Intervention in acute stroke Crescendo TIA Stroke in Evolution FMD - symptomatic and

asymptomatic Carotid Dissection

Questions

Define acute stroke pts who will benefit from urgent/emergent intervention -size infarct IC vs EC disease

Treatment of SIE, Crescendo TIA Treatment for FMD – sx and asx

-observation, AP, AC, CAS Carotid dissection – if/when to

intervene, AC vs. AP

Potential Studies

Urgent (<48hrs) vs. Early (<2wks) intervention in acute stroke –role of brain imaging and arterial anatomy in selection

FMD – Asx: Antiplt vs. observation Sx: Antiplt vs. CAS

Dissection – AC vs. AP vs. CAS in symptomatic pts

Early intervention vs. Medical Rx for Crescendo TIA and SIE, selection factors

Priorities

CAS/CEA/BMT in Asymptomatic pts

Optimal imaging protocols Improving results of

Interventions Management of Pts with

combined disease, recurrent stenosis

Management of Acute Neurological Syndromes

Unusual Conditions