Abstract TP178: Pre-existing Volume of White Matter Disease Predicts Ischemic Stroke

Background: Patients are more likely to develop white matter disease (WMD) and microhemorrhage (MH) after ischemic stroke. Little is known about whether stroke patients had an increased prevalence of these findings before a stroke compared to patients who did not go on to develop a stroke. Methods: We retrospectively identified patients admitted to our institution with ischemic stroke between 5/16 - 12/17 who had magnetic resonance imaging (MRI) of the brain between 30 days-2 years prior to their stroke. Age and gender-matched controls for the initial MRI were identified for pair-wise comparison. Automatic segmentations of gray and white matter volumes and manual segmentation of WMD and MH (size<10mm) were completed using 3D Slicer 4.5 and 4.9, respectively. Univariate analyses and multivariate models were performed to determine factors associated with stroke. This included demographic factors and traditional vascular risk factors. Results: Among the 96 patients in our study, stroke patients (n=48, mean age 68, 50% female) had lower rates of cancer (p=0.03) but higher rates of hyperlipidemia (p=0.024) compared to controls. Stroke patients exhibited greater WMD volume (15.7±20.2 vs 7.3±10.4 mL, p= 0.012) compared to controls, but not MH number (p=0.29) or total MH volume (p=0.26). Although history of stroke was associated with new presentation of stroke (72.9% vs 22.9%, p<0.001), prior stroke was not linked to an overall difference in WMD volume (13.7±17.6 vs 9.4±15.3mL, p=0.20), gray to white matter ratio (1.27±0.54 vs 1.21±0.74 mL, p=0.68), MH number (p=0.36) or total MH volume (p=0.39). After adjusting for confounders, pre-existing WMD volume remained an independent predictor of stroke (adjusted OR 1.042 per one point increase, 95% CI 1.001-1.086, p=0.046). Conclusion: Increased volume of white matter disease correlates with a greater risk of future ischemic stroke. These results should be validated in subsequent studies.