Image: Research shows clearing blood clots in stroke patients is effective even those with blocked carotid arteries (Photo courtesy of FotoSearch).
Intra-arterial treatment (IAT) for acute ischemic stroke caused by intracranial proximal occlusion is effective even in patients with extracranial carotid disease (ECD), according to a new study.
Researchers at Academic Medical Center (AMC; Amsterdam, The Netherlands), Leiden University Medical Center (LUMC, The Netherlands), and other institutions conducted a subgroup analysis of the Multicenter Randomized Clinical Trial of Endovascular Treatment (MR CLEAN) study to examine if the presence of ECD--defined as cervical internal carotid artery stenosis higher than 50%, or occlusion--modified the effect of IAT for intracranial proximal anterior circulation occlusion. The MR CLEAN IAT protocol included intra-arterial thrombolysis, mechanical treatment, or both as treatment for acute ischemic stroke.
The primary measure was functional outcome, as measured by modified Rankin Scale at 90 days and reported as adjusted common odds ratio (acOR) for a shift in direction of a better outcome. The results showed that functional outcome was associated with an acOR of 1.67 in favor of the IAT intervention. In the analysis of the pre-specified subgroup of patients with ECD, acOR was 3.1, compared to an acOR of 1.3 in patients presenting without ECD. The study was published on May 23, 2017, in Annals of Internal Medicine.
“The presence of ECD is associated with less favorable clinical outcomes in patients with acute ischemic stroke caused by intracranial proximal occlusion, and acute IAT in the setting of extracranial and intracranial lesions is considered challenging,” concluded lead author Olvert Berkhemer, MD, PhD, of AMC, and colleagues. “IAT may be at least as effective in patients with ECD as in those without ECD, and it should not be withheld in these complex patients with acute ischemic stroke.”
Based on the Framingham Heart Study and Cardiovascular Health Study populations, the prevalence of ECD is approximately 9% in men and 6–7% in women, and it accounts for up to 15–20% of all ischemic strokes. Several possible mechanisms are involved, including atheroembolism of cholesterol crystals or other debris, artery-to-artery embolism of thrombus, dissection, acute thrombotic occlusion, and reduced cerebral perfusion with plaque growth.
Academic Medical Center
Leiden University Medical Center