Extracranial Carotid Disease and Intra-Arterial Treatment

Study Questions:

Do acute stroke patients with extracranial (cervical) carotid disease (ECD) benefit as much from intra-arterial treatment (IAT) as patients without?

Methods:

The investigators performed a prespecified subgroup analysis of the MR CLEAN randomized controlled trial, which enrolled patients with acute ischemic stroke caused by an intracranial occlusion in the distal intracranial internal carotid artery, middle cerebral artery (M1 or M2 branch), or anterior cerebral artery (A1 or A2 branch). Patients in the MR CLEAN trial were randomized to IAT plus usual care versus usual care alone. Inclusion of patients with ECD was left to the discretion of the treating physician. ECD was defined as stenosis >50% or occlusion of the carotid on the same side as the intracranial occlusion. In this analysis, results were reported as the odds ratio (OR) for a shift in the direction of a better outcome on the 3-month modified Rankin scale (mRS), a 7-point scale of disability and dependence ranging from no symptoms (0) to death (6). Results were adjusted for age, baseline stroke severity, time from onset to randomization, previous stroke, atrial fibrillation, diabetes mellitus, and intracranial ICA terminus occlusion.

Results:

Of the 500 patients in the original MR CLEAN trial, 476 met criteria for this subgroup analysis. ECD was identified in 160 of 476 (33.6%) patients. Patients with ECD showed a greater benefit of IAT than patients without (adjusted OR, 3.1 ;95% confidence interval, 1.7-5.8 for a positive mRS shift at 3 months compared with OR, 1.3; 95% CI, 0.9-1.9). There was no difference in the occurrence of serious adverse events between the patients with ECD and the patients without.

Conclusions:

The benefit of IAT in acute stroke patients with ECD is at least as great as in those without ECD. These data support treating eligible patients with ECD with IAT.

Perspective:

This is a prespecified subgroup analysis of a well-designed randomized clinical trial. The biggest limitation of the study is the lack of a screening log, making it possible that patients with less favorable extracranial carotid imaging were not offered enrollment (selection bias). Overall, however, these results support the use of IAT in acute stroke patients with anterior circulation intracranial occlusion, regardless of the presence of ipsilateral extracranial carotid stenosis or occlusion.

Clinical Topics: Arrhythmias and Clinical EP, Prevention, Atrial Fibrillation/Supraventricular Arrhythmias

Keywords: Anterior Cerebral Artery, Atrial Fibrillation, Carotid Artery, Internal, Carotid Stenosis, Constriction, Pathologic, Coronary Occlusion, Diabetes Mellitus, Infusions, Intra-Arterial, Middle Cerebral Artery, Primary Prevention, Stroke, Treatment Outcome, Vascular Diseases


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