In patients who had a stroke or TIA, enlarged perivascular spaces in basal ganglia may cause future haemorrhagic strokes.

Introduction: It remains unclear whether enlarged perivascular spaces (EPVS) predict poor clinical outcomes in patients with acute ischaemic stroke (AIS) or transient ischaemic attack (TIA).

Method: Data were obtained from the Third China National Stroke Registry study. We estimated EPVS in basal ganglia (BG) and centrum semiovale (CSO) using a semiquantified scale (Grade from 0 to 4). Using Cox and logistic regression analyses, the associations of EPVS with 3-month and 1-year adverse outcomes (including recurrent stroke, ischaemic stroke, haemorrhagic stroke, combined vascular event, disability and mortality) were explored. Sensitivity analyses of any association of cerebral small vessel disease at baseline and development of a small arterial occlusion (SAO) were conducted.

Result: Among 12 603 patients with AIS/TIA, median age was 61.7±11.6 years, and 68.2% were men. After adjusting for all potential confounders, frequent-to-severe BG-EPVS was associated with a decreased risk of recurrent ischaemic stroke (HR 0.71, 95% CI 0.55 to 0.92, p=0.01) but an increased risk of haemorrhagic stroke (HR 1.99, 95% CI 1.11 to 3.58, p=0.02) at 1 year after AIS/TIA, compared with none-to-mild BG-EPVS. Patients with frequent-to-severe CSO-EPVS had a decreased risk of disability (OR 0.76, 95% CI 0.62 to 0.92, p=0.004) and all-cause death (HR 0.55, 95% CI 0.31 to 0.98, p=0.04) within 3-month but not 1-year follow-ups, compared with those with none-to-mild BG-EPVS. Sensitivity analyses showed that both BG-EPVS (HR 0.43, 95% CI 0.21 to 0.87, p=0.02) and CSO-EPVS (HR 0.58, 95% CI 0.35 to 0.95, p=0.03) were associated with a decreased risk of subsequent ischaemic stroke in patients with SAO during 1-year follow-up.

Conclusion: BG-EPVS increased the risk of haemorrhagic stroke in patients already with AIS/TIA within 1 year. Therefore, caution is recommended when selecting antithrombotic agents for secondary stroke prevention in patients with AIS/TIA and more severe BG-EPVS.