Impact of Basal Ganglia Perivascular Spaces on Ischemic and Hemorrhagic Risks in Patients Taking Antithrombotic Therapies.

BACKGROUND AND

objectivesEnlarged perivascular spaces (ePVSs) are considered to increase the risk of stroke. However, data regarding the benefits and risks of antithrombotic therapy in patients with ePVSs are currently limited. This study assessed the association between ePVSs and the risks of hemorrhagic or ischemic events in patients taking antithrombotic agents.

methodsThis prospective, multicenter observational study enrolled patients with cerebrovascular or cardiovascular diseases who had newly started or were continuing to take oral antithrombotic agents at 52 hospitals across Japan between 2016 and 2019. Baseline multimodal MRI was performed for all of the study participants. The images were then centrally evaluated for cerebral small vessel disease (SVD), including white matter hyperintensities, cerebral microbleeds, lacunes, and basal ganglia-enlarged perivascular spaces (BGPVSs). BGPVSs were categorized as 0, 1-10, 11-20, or ≥21. Outcomes included major bleeding, intracranial hemorrhage, ischemic events, ischemic stroke, and mortality. Multivariable Cox proportional hazards models were used for the BGPVSs (in categorical and ordinal forms), adjusted for patient demographics, vascular risk factors, and other SVD markers.

resultsOf the total 5,065 patients (1,663 women; median age 74 [interquartile range 67-81] years), antiplatelets and anticoagulants were administered at the baseline to 3,820 (75.4%) and 1,502 (29.7%) patients, respectively. Their BGPVS distributions were as follows: 0, 475 (9.4%); 1-10, 2,615 (51.6%); 11-20, 1,267 (25.0%); and 21+, 708 patients (14.0%). Over a median follow-up period of 2.0 (interquartile range 1.8-2.0) years, we noted 266 ischemic events, 188 ischemic strokes, 92 major bleeding events, 54 intracranial hemorrhages, and 198 deaths. Higher BGPVS was associated with an increased risk of major bleeding (BGPVS ≥21: adjusted hazard ratio [aHR] 4.04, 95% CI 1.17-13.92; per-unit increase: aHR 1.38, 95% CI 1.07-1.77) and ischemic stroke (BGPVS ≥21: aHR 2.58, 95% CI 1.21-5.50; per-unit increase: aHR 1.28, 95% CI 1.07-1.53) but was not significantly associated with higher risks of ischemic events, intracranial hemorrhage, or mortality. DISCUSSION: Higher BGPVS burdens are associated with higher risks of ischemic stroke and major bleeding in patients receiving antithrombotic therapy. BGPVSs may serve as useful imaging biomarkers for vascular risk assessment and personalized therapy.