The association of white matter hyperintensities with stroke outcomes and antiplatelet therapy in minor stroke patients.

Background: To characterize the severity and distribution of white matter hyperintensities (WMHs) and to assess the relationship of WMHs with initial stroke severity, 3-month functional outcome, stroke recurrence and response to antiplatelet therapies.

Methods: In Clopidogrel High-risk Patients with Acute Nondisabling Cerebrovascular Events (CHANCE) trial, 787 minor stroke patients with baseline magnetic resonance imaging (MRI) information were included in this analysis. Deep and periventricular WMHs (DWMHs and PVWMHs) were rated using the Fazekas scale and categorized into mild (grades 0-2), moderate (grades 3-4) and severe (grades 5-6). Multivariable logistic regression was used to examine the associations between WMHs severities and outcomes, including initial stroke severity by the National Institutes of Health Stroke Scale (NIHSS) scores, 3-month functional outcome by modified Rankin Scale (mRS), and stroke recurrence. Cox proportional hazards model was used to assess the treatment-by-subgroup interaction effect.

Results: Among the 787 patients in this analysis, 432 (54.9%) had moderate or severe WMHs (3-6). Compared with mild WMHs, the adjusted odds ratio (OR) of severe WMHs for risk of higher NIHSS was 2.10, 95% confidence interval (CI), 1.26-3.48 (P=0.004). Both severities of SDWMHs (OR 1.66; 95% CI, 1.15-2.40; P=0.007) and PVWMHs (OR 1.47; 95% CI, 1.02-2.10; P=0.04) were associated with higher NIHSS scores. There were no statistically significant associations of WMHs with 3-month functional outcome and stroke recurrence. There were no significant interactions between WMHs and antiplatelet therapy.

Conclusions: In patients with minor stroke, both SDWMHs and PVWMHs might related with initial stroke severity. No interaction was detected between the severity of WMHs and antiplatelet treatment. ClinicalTrials.gov identifier: NCT00979589. Date of registration: Sep 18, 2009.