CMOSS
Trial question
What is the role of extracranial-intracranial bypass surgery in patients with symptomatic atherosclerotic occlusion of the internal carotid artery or middle cerebral artery and hemodynamic insufficiency?
Study design
Multi-center
Open label
RCT
Population
Characteristics of study participants
21.0% female
79.0% male
N = 324
324 patients (67 female, 257 male).
Inclusion criteria: patients with internal carotid artery or middle cerebral artery occlusion with TIA or nondisabling ischemic stroke attributed to hemodynamic insufficiency.
Key exclusion criteria: > 50% stenosis of any other vessel; massive cerebral infarction; other neurovascular diseases likely to cause focal cerebral ischemia.
Interventions
N=161 bypass surgery (extracranial-intracranial bypass surgery plus medical therapy).
N=163 medical therapy alone (antiplatelet therapy and stroke risk factor control).
Primary outcome
Rate of stroke or death within 30 days or ipsilateral ischemic stroke beyond 30 days through 2 years
8.6%
12.3%
12.3 %
9.2 %
6.2 %
3.1 %
0.0 %
Bypass
surgery
Medical therapy
alone
No significant
difference ↔
No significant difference in the rate of stroke or death within 30 days or ipsilateral ischemic stroke beyond 30 days through 2 years (8.6% vs. 12.3%; HR 0.71, 95% CI 0.33 to 1.54).
Secondary outcomes
No significant difference in the rate of any stroke or death within 2 years (9.9% vs. 15.3%; HR 0.69, 95% CI 0.34 to 1.39).
No significant difference in the rate of any stroke within 2 years (9.3% vs. 14.2%; HR 0.67, 95% CI 0.33 to 1.39).
No significant difference in the rate of death within 2 years (2.7% vs. 1.3%; HR 3.72, 95% CI 0.68 to 20.38).
Conclusion
In patients with internal carotid artery or middle cerebral artery occlusion with TIA or nondisabling ischemic stroke attributed to hemodynamic insufficiency, bypass surgery was not superior to medical therapy alone with respect to the rate of stroke or death within 30 days or ipsilateral ischemic stroke beyond 30 days through 2 years.
Reference
Yan Ma, Tao Wang, Haibo Wang et al. Extracranial-Intracranial Bypass and Risk of Stroke and Death in Patients With Symptomatic Artery Occlusion: The CMOSS Randomized Clinical Trial. JAMA. 2023 Aug 22;330(8):704-714.
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