Atherosclerosis not Embolism main cause of deep embolic stroke of undetermined source

The study provided the first high-resolution magnetic resonance imaging (MRI) evidence that deep embolic stroke of an undetermined source and cortical with/without deep ESUS should be two distinct entities.

For this purpose, the researchers retrospectively screened successive patients with unilateral anterior circulation ESUS. The patients with probable embolism from an extracranial artery, such as carotid plaque, aortic arch plaque, and so on, were excluded. Following the exclusion, patients with ESUS were divided into two groups: deep ESUS and cortical with/without deep ESUS.

Patients underwent high‐resolution intracranial MRI to assess the characteristics of nonstenotic intracranial atherosclerotic plaque. The researchers collected biomarkers of atrial cardiopathy (i.e., P‐wave terminal force in lead V1 on ECG, N‐terminal pro-brain natriuretic peptide (NT‐proBNP), and left atrial diameter).

The study led to the following findings:

• The authors found 155 patients with ipsilateral nonstenotic intracranial atherosclerotic plaque, with 49.0% deep ESUS and 51.0% cortical with/without deep ESUS.
• The researchers found a more prevalent plaque in the ostia of the perforator and M1 segment of the middle cerebral artery, with a smaller remodeling index plaque burden and less common occurrence of complicated plaque in deep ESUS compared with cortical with/without deep ESUS.
• Higher level of brain natriuretic peptide (BNP) and a higher prevalence of atrial cardiopathy in cortical with/without deep ESUS than deep ESUS.
• There was a significant enhancement in the discrimination of vulnerable plaque for predicting ESUS after adjusting for or excluding patients with deep ESUS.

"The study provided the first high-resolution MRI evidence supporting the distinct mechanism of deep vs. cortical with/without deep ESUS," the authors wrote in their study. "The main cause of deep ESUS might be atherosclerosis, not embolism."

They conclude, "the results indicate that because of the nonembolic mechanism, deep ESUS should be ruled out from the family of ESUS."

The study found distinct characteristics of intracranial plaque, such as remodeling index and plaque burden, plaque distribution, and atrial cardiopathy in deep vs. cortical with/without deep ESUS.

Reference:

Luo N, Shang ZY, Tao L, Yang BQ, Chen HS. Atherosclerosis as a Potential Cause of Deep Embolic Stroke of Undetermined Source: A 3T High-Resolution Magnetic Resonance Imaging Study. J Am Heart Assoc. 2022 Oct 27:e026737. doi: 10.1161/JAHA.122.026737. Epub ahead of print. PMID: 36300665.