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Raising Awareness of Endovascular
Intervention in the Management of



Carotid Artery Stenosis (CAS)
ACTION - Atherosclerosis and Circulation
Training and Information Network

• ACTION is a programme aimed at increasing the
  awareness and detection of peripheral vascular
  disease in clinical practice, as well as increasing the
  awareness of this condition amongst the general
  public
• ACTION is being developed in association with
  vascular specialists and is supported by an
  educational grant from Cordis Endovascular
   Focus on Carotid Artery Disease
Objectives of this presentation

   • Highlight the need for increased detection and
     awareness of carotid artery disease
   • Review the epidemiology and main risk factors
   • Review the diagnosis and opportunity for screening
   • Explain advances in minimally-invasive treatment of
     carotid artery disease
   • Encourage timely and appropriate referral of patients
     for vascular imaging and early treatment
Carotid Artery Disease


• Carotid artery disease is caused by
  atherosclerotic plaque deposition on the
  arterial walls leading to:
   – stenosis
   – ulceration
   – occlusions
• Carotid artery disease can lead to:
   – transient ischaemic attack (TIA, “mini
     stroke”)
   – stroke (thromboembolism from stenosis
     of the carotid arteries is a major cause
     of stroke)
 Carotid Artery Disease is a Progressive
 Condition

  Asymptomatic
  Narrowed carotid                                                          TIA
  arteries and thrombus                    Symptomatic
                                                                           Stroke
  formation impedes blood flow             Detaching plaque from carotid
  to the brain                             arteries may cause occlusions
                                           in the cerebral arteries that
                                           lead to cell death and
                                           neurological consequences1




1. Ross R. N Engl J Med1999; 340:115-26.
 Carotid Artery Disease: A Major Risk Factor for
 TIA and Stroke

 • Carotid artery disease is responsible for 25–35% of all
   ischaemic strokes1 and nearly 50% of all TIAs1-3
 • Transient ischaemic attacks caused by carotid artery
   stenosis are also a strong predictor of stroke3
 • Warning signs often do not occur – first symptom
   associated with carotid artery disease may be a TIA
   or a catastrophic stroke




1. North American Symptomatic Endarterectomy Trial Collaborators. NEJM 1991; 325:445-53.
2. Weinberger J. CNS Spectr 2005;10(7):553-64.
3. Alpert J. Tex Heart Inst J 1991;18:93-7.
 Evaluation of Carotid Artery Stenosis


 • Baseline degree of carotid artery stenosis on initial duplex
   ultrasound is the most significant predictor of future stroke, and
   it retains its predictive power for more than three years1,2

                Degree of stenosis                         Diameter stenosis
                MILD                                       1-39%
                MODERATE                                   40-59%
                SEVERE                                     60-79%
                CRITICAL                                   80-99%

 • Plaque structure, in addition to the degree of carotid stenosis,
   may be a critical factor in determining stroke risk

1. Mintz BL, Hobson RW. JAOA 2000; Nov (suppl): s22-s26.
2. Biller J, Thies W. Am Fam Physician 2000; 61:400-6.
 Vascular Risks of Asymptomatic Carotid
 Stenosis

 • Prospective study in 696 patients evaluated with Carotid Duplex
   Ultrasonography (CDU)1
 • 369 male/327 female
         – Mean age 64 years
 • Mean follow-up 41 months
 • CDU categories
         – Mild                            <50% stenosis
         – Moderate                        50-75% stenosis
         – Severe                          >75% stenosis



1. Norris et al. Stroke 1991;22:1485-90.
 Degree of Stenosis is Related to the Risk of
 Stroke

                                                             Cardiac   Vascular
       Category                            N     TIA   CVA
                                                              Event     Death
       <50%                                303   1     1.3     2.7       1.8
       50-75%                              216   3     1.3     6.6       3.3
       <75                                 177   7.2   3.3     8.3       6.5

 • With stenosis greater than 75%, combined transient
   ischaemic attack and stroke rate was 10.5% per year1
 • 75% of events were ipsilateral to the stenosed artery1




1. Norris et al. Stroke 1991;22:1485-90.
 TIA: A Major Predictor for Stroke


 • TIA symptoms are temporary and reversible but often a warning
   sign of an impending stroke:
        – loss of vision in one eye
        – speech disorders
        – numbness and tingling of the skin
        – weakness of an arm or leg
 • 90-day risk of stroke after a TIA estimated to be approximately
   10%1
 • Approx 25% of patients with TIA will develop a stroke within the
   next two years2


1. Johnston et al.. JAMA 2000:284:2901-6
2. Nadalo LA and Walters MC.Carotid artery stenosis. www.emedicine.com/radio/topic133.htm
 Incidence and Prevalence of Stroke


 • Stroke is the third most common cause of death in
   developed countries, exceeded only by coronary heart
   disease and cancer1-3
 • Annually, 15 million people worldwide suffer a stroke1
        – of these, 5 million die
        – another 5 million are left permanently disabled
 • In the EU, there are 1.1 million new stroke events each
   year1-3



1. WHO: http://www.who.int/cardiovascular_diseases/en/cvd_atlas_15_burden_stroke.pdf.
2. WHO: http://www.who.int/cardiovascular_diseases/en/cvd_atlas_16_death_from_stroke.pdf
3. White RA. Endovascular Today. 2005; Sept:137-49.
Risk Factors for Carotid Artery Disease

• In addition to a history of carotid artery disease, the
  principal risk factors for ischaemic stroke are:
   –   increased age
   –   hypertension
   –   hyperlipidaemia
   –   smoking
   –   peripheral vascular disease
   –   coronary artery disease
   –   atrial fibrillation
   –   diabetes
   –   sedentary lifestyle
• Awareness of the diagnosis of carotid artery disease and its
  associated risks may motivate asymptomatic patients to modify
  their risk factors
Coronary Artery Disease is a Marker for Carotid
Artery Stenosis
             Distribution of carotid disease according to extent of CAD1

                                                     40
                 Carotid Artery Disease (% of pts)


                                                     35
                                                     30

                                                     25

                                                     15

                                                     10

                                                     5

                                                     0
                                                          0-VD     1-VD      2-VD        3-VD       LMS-CAD

                                                                 Extent of Carotid Artery Disease


VD: vessel disease; LMS-CAD: left main stem CAD

1. Kallikazaros et al. Stroke 1999;30:1002-7.
Combined Coronary and Carotid Disease is a
Marker of Poor Outcome

         Combined stroke and mortality rates for lone and simultaneous
                             CEA and CABG1
                  Combined Stroke and Mortality (%)

                                                      10
                                                           P<0.001
                                                      8

                                                      6
                                                      4

                                                      2
                                                             176
                                                      0
                                                             CEA     Staged with Staged with   Simultaneous
                                                             only    CABG first   CEA first     CEA/CABG




1. Hertzer and Mascha. J Vasc Surg 2006;43:959-68.
Diagnosis of Carotid Artery Disease
• Physical examination and medical history
   – most commonly identified by clinical auscultation for carotid
     (cervical) bruits
   – symptoms or prior history of TIA
   – risk factors
• Patients with cervical bruits can be evaluated further with
  greater accuracy by imaging techniques
   –   duplex ultrasound (DUS)
   –   computed tomography angiography (CTA)
   –   magnetic resonance angiography (MRA)
   –   diffusion weighted magnetic resonance imaging (DW MRI)
   –   digital subtraction angiography (DSA)
• Screening is the most effective way to detect asymptomatic
  carotid artery disease
Imaging Tests for Evaluating Carotid Artery
Disease




                     Computed           Magnetic
Duplex ultrasound   tomography         resonance
                    angiography       angiography
Imaging Tests for Evaluating Carotid Artery
Disease




     Diffusion weighted
           magnetic           Digital subtraction
          resonance              angiography
           imaging
 Treatment Decisions


 • All patients with symptomatic or suspected asymptomatic
   carotid artery disease should be referred for further
   evaluation1
 • Treatment decision is then based on whether the patient is
   symptomatic or asymptomatic and the degree of stenosis1
 • Treatment choices include:
        – pharmacological treatment
        – carotid endarterectomy (CEA)
        – carotid artery stenting (CAS)
 • The benefit of carotid intervention increases with the
   degree of stenosis2
1. Alving B et al. Hematology 2003;540-58.
2. Karolinska Stroke Update Consensus Statement 2004.
Pharmacological Treatments to Reduce Risk of
Stroke in Patients with Carotid Artery Disease

• Pharmacological treatment for risk
  factor management should be
  considered in all patients with <70%
  occlusion1
       – antiplatelet drugs (ASA, clopidogrel)
       – anticoagulant drugs (warfarin)

• Reduction of risk factors for
  cardiovascular disease:
       – antihypertensives
       – lipid-lowering drugs
       – diabetes management with appropriate
         hypoglycaemic therapy
1. Alving et al. Hematology 2003.
 Treatment by CEA is Guided by Degree of
 Stenosis

 • For symptomatic patients, invasive surgery CEA1 *
        – produces substantial benefit for patients with 70-99% stenosis
        – has a lower benefit for patients with 50-69% stenosis
        – has no benefit for patients with 30-49% stenosis
        – is harmful for patients with <30% stenosis

 • For asymptomatic patients, the absolute benefit of invasive
   surgery is less than for symptomatic stenosis1
        – in patients <75 years of age, CEA halves the 5-year risk of stroke*
        – further follow-up is necessary before exact calculations can be
          made
*Based on Grade A evidence vs best medical therapy

1. Karolinska Stroke Update Consensus Statement 2004.
Invasive Vascular Surgery
Carotid Endarterectomy (CEA)
 Artery is opened at the       Plaque is removed from   The cleaned artery is
 area of stenosis, revealing   the artery               sutured shut with or
 plaque                                                 without a shunt
 Carotid Endarterectomy


 • CEA has been the standard of care for patients with
   significant carotid stenoses for the past four decades
         – clinical trials NASCET1, ECST2, ACAS3, and ACST4 demonstrated
           the advantages of surgery versus best medical therapy (BMT) in
           symptomatic and asymptomatic patients
         – 80% relative reduction in risk of major ipsilateral stroke for patients
           with
           70 to 99% stenoses vs BMT1

 • However, the trials excluded patients with anatomical
   difficulties or co-morbid conditions for whom surgical
   treatment may be risky or even precluded
1. Fisher M et al. Stroke 1993;24(12 Suppl):I24-5.
2. Rothwell PM et al. Stroke 200;34:514-23.
3. Young B et al. Stroke 1996;27:2216-24.
4. Halliday AW. Int Angiol 1995;14:18-20.
 Minimally-invasive Endovascular Procedures
 • Minimally invasive endovascular procedures, are an innovative
   alternative to more invasive surgery
 • Benefits of minimally invasive procedures include1-3
         –    no requirement for general anaesthesia
         –    less trauma than vascular surgery
         –    no incision necessary
         –    typically earlier full recovery times
         –    fewer complications vs surgery including
                 • nerve injury (cranial nerve palsies)
                 • haematoma
                 • wound infection
         – reduced length of hospital stay
         – ability to treat narrowed arteries that are hard to reach or
           difficult to treat with surgery
1.Rabe K, Sievert H. J Interventional Cardiol 2004; 17: 417-26.
2.Yadav JS et al. N Engl J Med 2004; 351:1493-501.
3.Gray WA. Minerva Cardioangiol 2005; 53: 69-77.
 Minimally-invasive Procedures: Patient
 Populations

 • Certain patient populations are unsuitable for CEA
         – CEA should not be considered for symptomatic patients with less
           than 50% stenosis1
         – women with 50% - 69% symptomatic stenosis show no clear
           benefit from CEA in clinical trials1
 • Other contraindications for CEA include1,2
         –    tracheostomies
         –    previous endarterectomy
         –    radiation therapy to the neck
         –    stenoses too high or too low in the neck
         –    completely occluded coronary vessels
         –    multiple ipsilateral stenosis (tandem lesions)

1. Chaturvedi S et al. Neurology 2005;65:794-801.
2. Gray WA. Minerva Cardioangiol 2005; 53: 69-77.
Minimally-invasive Endovascular Procedures
Percutaneous Transluminal Angioplasty (PTA)


• Balloon angioplasty is increasingly used
  for treating localised atherosclerotic
  obstructive lesions in the peripheral
  vasculature
• Simple balloon angioplasty, however,
  increases risk of neurological
  complications from emboli and is not used
  for treating carotid artery disease without
  use of a stent

                                                Balloon angioplasty
Minimally-invasive Endovascular Procedures
Stenting
• PTA is not performed without the use of a stent in order to prevent the
  plaque from dislodging and subsequent embolic complications occurring

 Implantation of a stent
 Stenting of Carotid Arteries and Embolic
 Protection

 •     Carotid EPDs are used to capture debris
       following angioplasty and stenting of carotid
       arteries for cerebral protection
 •     3 main strategies:
        – distal filtration
        – proximal occlusion
        – distal balloon occlusion
 •     The risk of distal embolisation may be higher
       if embolic protection devices are not used
       during carotid stenting procedures1-3



1. Kulik et al. Curr Control Trials Cardiovasc Med. 2005;6:15.
2. Nolan et al. Am Heart J. 1997;134:939-44.
3. Cordis Angioguard XP Emboli Capture Guidewire System, Product Catalogue.
Embolic Protection
                                      30-day stroke rate of carotid artery stenting with and
                                                  without embolic protection1*
                                                Without carotid EPD          With carotid EPD
                                       15
                Percent of patients




                                                                10.0
                                       10                                             8.6
                                                8.0


                                        5
                                                                        3,2
                                                      2.4                                   2.6

                                                176    85        90     31            266   116
                                        0
                                               FEASIBILITY      CASCADE                POOLED
                                                                                 FEASIBILITY/CASCADE
Results from 2 non-randomised studies using PRECISE® and SMART® stents in Europe (CASCADE2)
and the US (Feasibility study3)
*Angioguard XP Emboli Capture Guidewire
1.Cordis Angioguard XP Emboli Capture Guidewire System, Product Catalogue.
2.Kulik et al. Curr Control Trials Cardiovasc Med 2005;6:15.
3.Nolan et al. Am Heart J 1997;134:939-44.
 Carotid Artery Stenting




                  Pre-procedure1   Post-procedure1

1. Courtesy of Dr Fanelli
Studies on CEA and CAS


     Study                               Date                Stent used          No. of pts   %EPD
     CAVATAS1                            2001                   In 22%              504       None
     SAPPHIRE2                           2004                     Yes               334       100
     EVA-3S3                             2004                      Yes              527        73
     SPACE4                              2006                      Yes             1200        26
     EXACT5                              2007                      Yes             1500       100
     CAPTURE6                            2007                      Yes              600       100
   EPD: carotid embolic protection device




1. CAVATAS Investigators. Lancet 2001;357:1729-37.
2. Yadav et al. NEJM Volume 351:1493-501.
3. Mas JL et al. N Engl J Med 2006;355:1660-71.
4. The SPACE Collaborative Group. Lancet 2006;368:1239-47.
5-6. Interim results, available at http://www.medscape.com/viewarticle/554613.
 SAPPHIRE Outcomes
Cumulative MAE at 3 year follow-up1
                                      Similar incidence of major adverse events
                                                between CEA and CAS
                                           CEA         PCAS
                                 40
                                                                                                                 p=0.231
           Cumulative % of MAE




                                 30
                                                                                                                   30.3%
                                                                                                                    25.5%
                                 20


                                 10


                                  0
                                       0    90     180    270   360   450    540    630   720     810   900     990 1080
                                                                      Time (days)
                                  Days            0                 360                  720                    1080
                                  CEA            167             150 (90%)            139 (83%)               117 (70%)
                                  PCAS           167             161 (96%)            154 (92%)               139 (83%)



1.Yadav JS et al. N Engl J Med 2004; 351:1493-501.
 SAPPHIRE Outcomes
Cumulative percentage of stroke to 30 days and
ipsilateral stroke from 31 days to 3 years1
                                                   Equivalent prevention of stroke
                                                  CEA     PCAS
                                         40
                                                                                               p=0.945
                Cumulative % of Stroke




                                         30


                                         20


                                         10                                         6.3%         7.1%
                                                                 5.8%
                                                   3.0%
                                                                 4.9%               6.7%         6.7%
                                          0        3.6%
                                              0    90     180 270 360 450 540 630 720 810 900 990 1080
                                                                     Time (days)
                             Days                    0               360              720        1080
                             CEA                    167           150 (90%)        134 (80%)   112 (67%)
                             PCAS                   167           161 (96%)        154 (92%)   139 (83%)



1.Yadav JS et al. N Engl J Med 2004; 351:1493-501.
SAPPHIRE summary of results


• First study to show that PCAS is non-inferior to CEA
• First study to show that PCAS can yield durable outcomes
• Compared with CEA, PCAS resulted in
   – significantly shorter mean hospital length of stay
   – equivalent 1 year outcomes of death, MI, stroke, and MAE
   – significantly less cranial nerve palsy
   – lower incidence of TLR at 3 years (NS)
   – equivalent 30 day incidence of stroke and 3 year incidence
     of ipsilateral stroke
   – similar incidence of major adverse events at 3 years
Conclusions


• Minimally invasive endovascular procedures are an innovative
  alternative to more invasive surgery with several benefits
  including
   – less trauma to the patient
   – fewer complications
   – reduced length of hospital stays
• The use of carotid EPD improves outcomes in CAS
• Efficacy results from clinical studies to date are inconclusive
   – insufficient data are available for long-term comparison
• Long-term results and a combined analysis with other large
  randomised controlled trials are needed before definitive
  conclusions can be drawn
 Improving Success Rates
 • Advances in techniques and experience may further improve
   CAS success rates, for example through patient selection and
   stratification
         – the ICAROS (Imaging in Carotid Angioplasty and Risk of Stroke)
           study showed that higher echolucency of the carotid plaque,
           reflecting plaque histology, increases risk of stroke with CAS1
         – inclusion of echolucency in the planning of any endovascular
           procedure of carotid lesions allows stratification of patients at
           different risks of complications in carotid artery stenting
 • Future development in this field will include
         – device and technique refinement
         – the ability to stratify patients best suited to either stenting or
           surgery
                 • including normal-risk asymptomatic patients with significant stenosis



1.Biasi GM et al, Circulation 2004;110:756-62.
Carotid Artery Disease - A Call to Action

• Carotid artery disease is a major risk factor for TIA and stroke,
  but is often asymptomatic and therefore untreated
• Early detection and treatment (including modification of risk
  factors) can reduce morbidity associated with stroke
• Prevention of disabling neurological events associated with
  carotid artery disease can be addressed through:
   – increased awareness of carotid artery disease and its
     consequences
   – screening and early diagnosis to reduce risk of TIA and stroke
   – referral to specialist for extent and location of stenosis
   – improved preventive treatment in patients with asymptomatic
     carotid artery stenosis or previous TIA and timely intervention in
     appropriate patients

				
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