Abstract
Introduction: Stroke secondary to intracranial atherosclerosis (ICAD) results in three distinct infarct patterns: (a) border zone infarcts (BZI) due to impaired distal perfusion (b) territorial infarcts due to distal plaque/thrombus embolization, and (c) perforator infarcts due to plaque progression. Previous studies indicate higher stroke recurrence in ICAD patients with BZI.
Methods: This registered systematic review (CRD42021265230) comprised Medline and Web of Science search from inception to March 2022 for keywords (Intracranial Atherosclerosis OR Intracranial Stenosis) AND (Border zone OR Infarct Pattern) to identify papers and conference abstracts reporting initial infarct patterns and recurrence rates in patients with symptomatic ICAD. Sensitivity analyses were performed for studies including any BZI vs isolated BZI and those excluding posterior circulation strokes. The study outcome included neurological deterioration and/or stroke recurrence. For all outcome events, corresponding risk ratios (RR) and 95% confidence intervals (CI) were calculated. Risk of bias assessments will be presented.
Results: Literature search yielded 4478 studies,11 met inclusion criteria (n=1315 patients, 354 with BZI, weighted proportions summarized in figure). The meta-analysis of these studies with moderate heterogeneity (I2=38.7%) demonstrated that RR of outcomes in BZI group compared to non-BZI group was 2.10 (95% CI 1.52-2.90). Limiting analysis to studies including any BZI, RR (and 95% CI) was 2.32 (1.58-3.40), and 3.25 (2.09-5.07) for studies only including anterior circulation strokes with low heterogeneity for both (I2=0%). A non-significantly high outcome rate was seen with isolated BZI (RR 2.29, 95% CI 0.94-5.62) but with moderate heterogeneity across studies (I2=70.25%).
Conclusion: We demonstrate the presence of BZI secondary to symptomatic ICAD can be imaging biomarker to predict neurological deterioration and/or stroke recurrence.