SCMR 23rd Annual Scientific Sessions
Black blood CMR of intracranial vessel walls is a reliable, noninvasive, and reproducible technique which can provide visualization of high-risk plaque features including intraplaque hemorrhage, contrast enhancement, outward remodeling and so on. However, most of the previous studies were cross-sectional and there has been little investigation of its prognostic value. This study aims to investigate the prognostic value of intracranial atherosclerotic plaques features in predicting risk for recurrent cerebrovascular ischemic events using black blood MRI.
Methods: 41 acute (< 1 month) stroke or Transient Ischemic Attack (TIA) patients (age, 58±12 years; 33 males) were images with black blood MRI of their intracranial vessels two times following the initial event with imaging sessions at >3 months intervals. 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, minimal lumen area, contrast enhancement ratio, remodeling index and changes over time of those metrics were recorded. Progression of these parameters was defined as the increase in value over time was more than the measurement error (5-10% as shown in a separate reproducibility study). Univariate and multivariate Cox regression analyses were used to calculate the hazard ratio for predicting recurrent events.
Results: The average interval between baseline and initial follow-up MRI scans was 6.2±4.1 months with no event observed during this period. After the second MRI, 17.1% of patients (n = 7) experienced ipsilateral recurrent TIA/stroke within 10.9±9.2 months. The baseline triglyceride and progression of plaque burden were significantly associated with recurrent events (Table 1). Multivariate Cox regression indicated that only progression of plaque burden was a significant independent risk factor (HR, 7.839; 95% CI, 1.445–42.518; P = 0.017) for recurrent ischemic events (Figure 1). The enhancement ratio decreased 52.77% in the non-recurrent group, but only decreased 2.73% in the recurrent group (Table 1). A sample case who had recurrent stroke is shown in Figure 2.
Conclusion: Progression of plaque burden was independently associated with recurrent ischemic cerebrovascular events. The enhancement ratio keeps high in patients with recurrent events, but drops significantly in stable patients. Vessel wall MRI may help risk stratification of patients at risk of recurrent stroke.