Epidemiology in HK

Stroke is major cause of morbidity and mortality around the world

4th cause of mortality in HK resulting in >3000 deaths every year

Department of Health 2011

Stroke

80 % of strokes : ischaemic in orgin 20 – 25 % of ischaemic stroke : carotid stenosis Risk of stroke correlates with severity

of carotid stenosis

Treatment options

Medical therapyMedical therapy

Carotid Carotid endarterectomyendarterectomy

Carotid artery Carotid artery stentingstenting

Carotid Endarterectomy (CEA)

First described in 1953 Widely used invasive treatment for significant

carotid stenosis Efficacy was established by 4 RCTs in late 1980s

and early 1990s

CEA superior to medical therapy

Symptomatic carotid stenosis North American Symptomatic Carotid Endarterectomy Trial (NASCET)

Carotid stenosis 70 – 99% : 2 yrs stroke reduced from 26% to 9% (p<0.001) Carotid stenosis 50 – 69% : 2 yrs stroke reduced from 22.2% to 15.7%

(p<0.045)Carotid stenosis <50% : no benefit

European Carotid Surgery Trial (ECST)

JM Henry N Eng Jounral of Medicine 1998

PM Rothwell Lancet 1998

CEA superior to medical therapy

Asymptomatic carotid stenosis Asymptomatic Carotid Surgery Trial (ACST)

Carotid stenosis >60% : 5 yrs stroke rate reduced from 11.8% to 6.4%

10-year stroke prevention after successful carotid endarterectomy for asymptomatic stenosis (ACST-1)

10 yrs stroke rate reduced from 17.9% to 13.4%

Asmptomatic Carotid Atherosclerosis Study (ACAS)

A. Halliday Lancet 2004

JAMA 1995

A. Halliday Lancet 2010

Carotid Endarterectomy (CEA)

Emerge of Carotid artery stenting (CAS)

1. Excluded elderly patients (>80 yrs) with significant comorbidites

2. Excluded high risk lesions such as restenosis after prior CEA, radiation induced stenosis ...

3. CEA associated complications such as cardiovascular events, wound complications, cranial nerve injury, carotid artery dissection...

Carotid artery stenting (CAS)

First case report of carotid angioplasty appeared in early 1980

Embolic-protection device in distal artery

Balloon angioplasty across stenotic area

Deployment of stent

Withdrawl of embolic –protection device

1st RCT (CEA Vs CAS)

Carotid and Vertebral Artery Transluminal Angioplasty Study (CAVATAS) Performed only angioplasty without EPD NO significant difference in 30-day incidence of

death or disabling stroke (6.4% in CAS vs 5.9% in CEA)

8 yrs follow up : Higher restenosis and stroke rate (21.1% in CAS vs 15.4% in CEA)

CAVATAS Investigators Lancet 2001

CAVATAS Investigators Lancet 2009

RCTssssssss (CEA Vs CAS)

TrialTrial No of No of patientspatients

FindingFinding ConclusionConclusion

SPACE 1200 30 days stroke and death rateCAS : 6.84%CEA : 6.34% (p = 0.09)

Failed to prove non-inferiorty of CAS

EVA – 3S 527 30 days stroke and death rateCAS : 9.6%CEA : 3.9% (p = 0.01)

Terminated early due to high stroke rate in CAS group

ICSS 1700 120 days stroke, MI and death rateCAS : 8.5%CEA : 5.2% (p = 0.006)

CEA should remain the treatment of choice

RCTssssssss (CEA Vs CAS)

SPACE, EVA-3S and ICSS were widely criticizedwidely criticized NO roll in phase e.g. SPACE trial : eligible operators for CAS arm do

not need prior carotid stenting experience

Use of EPD was not mandatory e.g. SPACE trial : used in 27% of patients

CREST Trial

Stenting versus Endartrectomy for Treatment of Carotid – Artery Stenosis (CREST)

National Institutes of Health-sponsored study based in United States from 2000 to 2008

2522 patients including both symptomatic and asymptomatic carotid stenosis Lead in phase Single carotid stent with EPD systems

Thomas G. Brott N Eng Journal of Med 2010

CREST – Periprocedural findingOutcomeOutcome CEA %CEA % CAS %CAS % p valuep value

Periprocedural stroke+MI+death 4.5 5.2 0.38

Periprocedural stroke- Major ipslateral stroke- Minor ipsilateral stroke

2.30.31.4

4.10.92.9

0.010.09

0.009Periprocedural MI 2.3 1.1 0.03

Periprocedural death 0.3 0.7 0.18

Periprocedural cranial nerve injury 4.8 0.3 0.0001Thomas G. Brott N Eng Journal of Med 2010

CREST – 4 years finding

OutcomeOutcome CEA %CEA % CAS %CAS % p valuep value

4 years stroke+MI+death 6.8 7.2 0.51

4 years stroke 2.3 2 0.085

Thomas G. Brott N Eng Journal of Med 2010

CREST Finding – Age

Thomas G. Brott N Eng Journal of Med 2010

Younger patients have better outcome with CAS while older patients have better outcome with CEA

120 days stroke and death risk Age <70 yrs : CAS – 5.8% CEA – 5.7% Age >70 yrs : CAS – 12% CEA – 5.9%

Arterial tortuosity and calcification in elderly prones to catheter provoked cerebral emboli

CEA = CAS ??

Are these conclusion justified?

1. Primary purpose of CEA and CAS is to prevent death and stroke

OutcomeOutcome CEA %CEA % CAS %CAS % p valuep value

Perioperative stroke+MI+death 4.5 5.2 0.38

Perioperative stroke- Major ipslateral stroke- Minor ipsilateral stroke

2.30.31.4

4.10.92.9

0.010.09

0.009Perioperative MI 2.3 1.1 0.03Perioperative death 0.3 0.7 0.18Perioperative cranial nerve injury 4.8 0.3 0.0001

Are these conclusion justified?

2. Stroke ≠ Myocardial Infarction Quality-of-life analyses indicates that stroke had a greater adverse effect on heath-status than MI Even minor stroke had full motor and sensory recovery, patient often have other brain damage

Are these conclusion justified?

3. CAS operators in CREST have a high level of experience and skill, CREST results may not be representative in real world

Carotid Endarterectomy Carotid Endarterectomy (CEA)(CEA)

Carotid Artery Stenting Carotid Artery Stenting (CAS)(CAS)

Pros Cons Pros Cons

Periprocedural stroke

MI Periprocedural MI

Periprocedural stroke

Cranial nerve injury No cranial nerve injury

Wound infection Wound infection

Required GA No GA required

Longer recovery Minimally invasive

Matching patient to intervention Treatment decisions depends on patient-

specific factors1. Risk factors for CEA 2. Risk factors for CAS

Medical

Surgical / Anatomical

Risk factors for CEA Medical risk factorsMedical risk factors CHF and left ventricular

dysfunction Unstable angina or recent MI (<30

days) Coronary artery disease (CAD) Open heart surgery needed within

6 weeks Severe pulmonary dysfunction

Mozes J Vasc Surg 2004

risk of worse outcome remains controversial Similar stroke and death rate between low

and high risk patient Too high risk Medical treatment

Risk factors for CEA Surgical / Anatomical risk factorsSurgical / Anatomical risk factors

Surgical FactorsSurgical FactorsRestenosis after prior CEAPrevious ablative neck surgery (e.g. radical neck dissection, laryngectomy)Previous neck irradiationContralateral vocal cord paralysisTracheostomy

Risk factors for CEA Surgical / Anatomical risk factorsSurgical / Anatomical risk factors

Anatomical FactorsAnatomical FactorsHigh carotid bifurcation (above C2)Extension of athersclerotic lesion into intracranial ICA or proximal CCA below clavicle

Risk factors for CAS

Individualized management Optimal treatment selection specific for each

patient Lowest morbidty rateLowest morbidty rate Most favorable outcomesMost favorable outcomes

Management Algorithm

HIGH risk HIGH risk for surgeryfor surgery

Favourable

anatomy for CAS

CACASS

Unfavourable anatomy

for CAS

CEACEA

Symptomatic >= Symptomatic >= 50% CS50% CS

LOW risk for LOW risk for surgerysurgery

Asymptomatic >= Asymptomatic >= 70% CS70% CS

BMTBMT

Conclusion

CEA continues to be the gold standard for treatment for carotid stenosis

CAS will evolve as a safe and efficacious therapy for carotid stenosis

Individualized treatment plan