PDF: ICSS
(2015)Objective
Carotid artery stenting (CAS) versus carotid endarterectomy (CEA) in symptomatic carotid artery stenosis.
Study Summary
• Risk of stroke was similar for CAS and CEA in symptomatic carotid stenosis. • The initial publication (first 4 months post-intervention) showed that CAS failed to demonstrate non-inferiority to CEA due to a higher risk of stroke and death. However, long-term follow-up showed similar stroke incidence in both groups.
Intervention
Carotid artery stenting (CAS) vs. carotid endarterectomy (CEA).
Inclusion Criteria
Patients >40 years old with symptomatic carotid stenosis >50% within the preceding 12 months. Degree of stenosis was >70% in 90% of patients.
Study Design
Arms: CAS vs. CEA
Patients per Arm: 1710 total patients (split between CAS and CEA)
Outcome
• 5-year incidence of: Disabling stroke risk: 6.4% in CAS vs. 6.5% in CEA (P=0.77). <br>• Any stroke risk: 15.2% in CAS vs. 9.4% in CEA (P=0.001). <br>• mRS at 1 and 5 years showed no significant difference..
Bottom Line
Stenting and endarterectomy have similar long-term functional outcomes and risk of fatal or disabling stroke in patients with symptomatic carotid stenosis up to 10 years after treatment.
Major Points
- Primary endpoint of fatal or disabling stroke showed no significant difference between stenting and endarterectomy (6.4% vs 6.5% at 5 years, HR 1.06, p=0.77)
- Stenting associated with higher risk of any stroke (15.2% vs 9.4% at 5 years, HR 1.71, p<0.001), mainly non-disabling strokes
- Functional outcomes measured by modified Rankin scale were similar between treatment groups at 1 year, 5 years, and final follow-up
- No significant difference in all-cause mortality between groups
- Severe carotid restenosis rates were similar between groups (10.8% vs 8.6% at 5 years)
Study Design
- Study Type
- Randomized controlled trial
- Randomization
- Yes
- Blinding
- Independent endpoint committee unaware of treatment assignment; patients and investigators not masked
- Sample Size
- 1713
- Follow-up
- Median 4.2 years (maximum 10 years)
- Centers
- 50
- Countries
- Europe, Australia, New Zealand, Canada
Primary Outcome
Definition: Fatal or disabling stroke in any territory after randomisation
| Control | Intervention | HR/OR | P-value |
|---|---|---|---|
| 49 events, 6.5% cumulative 5-year risk | 52 events, 6.4% cumulative 5-year risk | 1.06 (0.72-1.57) | 0.77 |
Limitations & Criticisms
- Carotid stenting was relatively new procedure when ICSS started, limiting experience
- Unable to account for causes of functional decline over time other than endpoint events
- Modified Rankin scale not precise measure of independence level
- Trial not powered to detect variations in treatment effects between subgroups
- Cannot rule out subtle differences in functional outcome not captured by modified Rankin scale
Citation
Lancet 2015; 385: 529-38