Journal Club Ani Balmanoukian and Peter Benjamin November 9, 2006 by termo


									Journal Club
Ani Balmanoukian and
   Peter Benjamin

 November 9, 2006
   Endarterectomy versus
  Stenting in Patients with
Symptomatic Severe Carotid
             Mas et al.
    NEJM 355;16 October 19, 2006
   Carotid Endarterectomy is the standard
    treatment for symptomatic or asymptomatic
    high-grade(> 60% or 70%) internal carotid
    artery stenosis.

   Carotid artery stenting has become another
Carotid Endarterectomy
    trials have demonstrated
    the efficacy in
    symptomatic patients

   Complications include
    local nerve injury and

Carotid Stenting
   Less invasive than CEA
   Can be done under local
    anesthesia and sedation
   Less costly than CEA
   Risk of stroke and local
   Long term efficacy not
    well known yet

   Hypothesis/Goal: Evaluate whether stenting is
    not inferior to endarterectomy with regard to
    the risks of the procedure and long-term efficacy
    in patients with symptomatic carotid stenosis.

   Design: Randomized, noninferiority trial.

   Setting: 20 academic and 10 non-academic
    centers in France.
   Investigators: Each center had to have a team of
    physicians consisting of
       1 Neurologist
       1 Vascular surgeon: had to have performed at least
               25 CEAs
       1 Interventional physician: had to have performed
               at least 12 carotid stenting procedures or at
               least 35 stenting procedures in the
               supraaortic trunks, of which 5 were in the
               carotid artery.
   Participants: 527 patients >18 y/o, with history of a
        hemispheric or retinal TIA or a nondisabling stroke
        within 120 days before enrollment.
        Stenosis of 60-99% in the symptomatic carotid

        Exclusion: disabling stroke, nonatherosclerotic
    carotid disease, previous revascularization, bleeding
    disorder, uncontrolled HTN or diabetes, unstable
    angina, life expectancy <2 years.
Figure 1.
Mas et al, Endarterectomy vs. stenting in
patients with symptomatic severe carotic
stenosis. NEJM 2006;355:1660-71
   Data Collection: Evaluation by Neurologist at 48 hrs, 30 days,
    6 months after treatment and 6 months thereafter.

   Outcome:
         Primary: Any stroke or death occurring within 30 days after
         Secondary: MI, TIA, cranial nerve injury, major local
    complications, and systemic complications within 30 days.

   Analysis: Kaplan-Meier method, intention to treat principle.
Table 1. Baseline Characteristics of the Patients.

Key Points
• Patients overall very similar
• Only differences:
      • More patients older than 75 yo in CEA group (40.5%
        vs. 32.2%)
      • More patients with h/o stroke in CEA group
        (20.1% vs 12.6%)
      • Higher proportion of contralateral carotid occlusion
        in stenting group (none of these had a stroke after
Table 3: Risk of stroke or death and other outcomes
within 30 days

Key Points:
• Unadjusted RR of stroke/death is 2.5 for stenting vs CEA
  (Number Needed to Harm: 17)

• No significant correlation between RR of stroke/death and
  number of patients treated at each center

• No significant difference in stroke/death outcomes
  between interventionalists who were experienced, tutored
  during training, tutored after training

• Decreased incidence in stroke/death in pts who had
  cerebral protection along with stenting vs stenting alone

• RR stroke/death adjusted for age was 2.4, h/o stroke 2.6

• Cranial nerve injury much more likely with CEA (7.7% vs
   In pts with symptomatic carotid stenosis >60%,
    CEA has lower rates of stroke/death through 6
   These results agree with some (e.g. SPACE), but
    not all (e.g. SAPPHIRE) prior studies
   Taken together, pending further evidence,
    stenting should be limited to symptomatic pts
    with >70% stenosis who are high surgical risk
   Large, Multicenter RCT
   All patients accounted for at conclusion
   Groups were similar at start of trial
   Required minimal experience for
    interventionalists doing procedure
   Didn’t indicate differences in complications
    based on experience
   Anesthesiology or periop differences?
   No standardization of stenting device used (5
    different stents, 7 different cerebral protection
    systems used)
   What are unique aspects of a noninferiority trial
   What is the significance of an intention to treat
   Intricacies in a surgical rct that are unique
     How to minimize differences in
      surgeon/interventionalist experience?
     How to minimize effects of other aspects (e.g.
      anesthesia, postop care, etc)
     Can you standardize experience level differences
      between CEA and carotid stenting?
     Any way to blind such a trial?
   Mas JL et al. Endarterectomy versus stenting in
    patients with symptomatic severe carotid
    stenosis. N Engl J Med. 2006 Oct

   North American Symptomatic Carotid
    Endarterectomy Trial Collaborators. Beneficial
    effect of carotid endarterectomy in symptomatic
    patients with high-grade carotid stenosis. N Engl
    J Med 1991; 325:445-53.

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