Progression of Plaque Burden of Intracranial Atherosclerotic Plaque Predicts Recurrent Stroke/Transient Ischemic Attack: A Pilot Follow-Up Study Using Higher-Resolution MRI

Background: Patients with intracranial atherosclerotic disease (ICAD) have a high frequency of stroke recurrence. However, there has been little investigation into the prognostic value of higher-resolution magnetic resonance imaging (HR-MRI).

Purpose: To investigate the use of intracranial atherosclerotic plaques features in predicting risk of recurrent cerebrovascular ischemic events using HR-MRI.

Study type: Prospective.

Population: Fifty-eight patients with acute/subacute stroke (N = 46) or transient ischemic attack (N = 12).

Field strength/sequence: A 3.0 T, 3D time-of-flight gradient echo sequence and T1- and T2-weighted fast spin echo sequences with 0.31 x 0.39 mm² in-plane resolution, twice (with >3 months between scans) following the initial event.

Assessment: Patients were also followed clinically for recurrent ischemic events for up to 48 months or until a subsequent event occurred. The degree of stenosis, plaque burden (PB), minimal lumen area (MLA), and contrast enhancement ratio were assessed at each scanning session and the percentage change of each over time was calculated.

Statistical tests: Univariable and multivariable Cox regression analyses were used to calculate the hazard ratio (HR) and 95% confidence interval (CI) for predicting recurrent events.

Results: The mean time interval between baseline and follow-up MRI scans was 6.2 ± 4.1 months. After the second MRI scan, 20.7% of patients (N = 12) had experienced ipsilateral recurrent TIA/stroke within 10.9 ± 9.2 months. Univariable analyses showed that baseline triglyceride, percentage change of PB, and progression of PB were significantly associated with recurrent events (all P < 0.05). Multivariable Cox regression indicated that progression of PB (HR, 6.293; 95% CI, 1.620-24.444; P < 0.05) was a significant independent imaging feature for recurrent ischemic events.

Data conclusion: Progression of PB was independently associated with recurrent ischemic cerebrovascular events. HR-MRI may help risk stratification of patients at risk of recurrent stroke.

Level of evidence: 2 TECHNICAL EFFICACY: Stage 4.