Background
Although cerebral lesions ≥3mm on imaging are associated with incident stroke, lesions < 3mm are typically ignored.
Objective
To examine stroke risks associated with subclinical brain lesions by size (< 3 mm only, lesions ≥3 mm only, both < 3 mm and ≥3 mm) and white matter hyperintensities (WMH).
Design
Community cohort, Atherosclerosis Risk in Communities (ARIC) Study
Setting
Two ARIC sites with magnetic resonance imaging (MRI) data (1993–95)
Participants
1,884 (99%) adults (50–73 years, 40% men; 50% black) with MRI and no prior stroke; average 14.5 years follow-up.
Measurements
MRI lesions: none (n=1611), < 3 mm only (n=50), ≥3 mm only (n=185), or both < 3 and ≥3 mm lesions (n=35); WMH score (0–9 scale). Outcomes: incident stroke (n=157), overall mortality (n=576), stroke mortality (n=50). Hazard Ratios (HR) estimated with proportional hazards models.
Results
Compared to no lesions, stroke risk was tripled with lesions < 3mm only (HR=3.47, 95% CI:1.86-6.49), doubled with lesions ≥3 mm only (HR=1.94, 95% CI:1.22-3.07), and was 8-fold higher with both < 3 mm and ≥3 mm-sized lesions (HR=8.59, 95% CI:4.69-15.73). Stroke risk doubled with WMH ≥3 (HR=2.14, 95% CI:1.45-3.16). Stroke mortality risk tripled with lesions < 3 mm only (HR=3.05, 95% CI:1.04-8.94), doubled with lesions ≥3 mm (HR=1.9, 95% CI:1.48-2.44) and was seven-times higher with both lesion sizes (HR=6.97, 95% CI:2.03-23.93).
Limitations
Few stroke events (n=147), especially hemorrhagic (n=15); limited numbers of participants with only lesions ≤3mm (n=50) or with both lesions ≤3mm and 3–20mm (n=35).
Conclusions
Very small cerebrovascular lesions may be associated with increased risks of stroke and mortality; having both < 3 mm and ≥3 mm lesions may represent a particularly striking risk increase. Larger studies are needed to confirm findings and provide more precise estimates.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.