Predictors of Stroke Outcomes in Conservatively Treated Patients With Moyamoya Disease: A Follow-up MRI Study

Abstract

Background: Little is known about the association between stroke and imaging and clinical features in conservatively treated patients with moyamoya disease (MMD).

Purpose: To investigate independent risk factors for stroke in conservatively treated patients with MMD during a long-term follow-up.

Study type: Prospective study.

Subjects: One hundred sixty conservatively managed patients with MMD (median age 46 years, 89 male).

Field strength/sequence: Time of flight, turbo inversion recovery magnitude T1WI, turbo spin echo (TSE) T2WI, echo-planar imaging DWI, T2-fluid attenuated inversion recovery, dynamic susceptibility contrast-magnetic resonance imaging, and pre- and post-contrast 3D TSE T1WI sequences at 3.0 Tesla.

Assessment: Patients were assessed at baseline and followed yearly. Ischemic and hemorrhagic stroke incidence rates were determined. Multiple demographic, clinical (modified Rankin score [mRS]), and cerebral imaging (cerebral blood volume [CBV] and concentric enhancement of arterial wall) factors at baseline were considered as potential predictors of stroke during the follow-up period.

Statistical tests: Univariable and multivariable Cox proportional hazards models to calculate the hazard ratios (HRs) and corresponding 95% confidence interval (CI) for stroke. Cumulative risk of stroke was estimated by the Kaplan-Meier product-limit method. A P value <0.05 was considered statistically significant.

Results: The median follow-up duration was 47 months. During the follow-up period, 18 (11.25%) patients experienced stroke events (13 [8.13%] ischemic, 5 [3.12%] hemorrhagic). Univariable analysis showed that 11 factors were significantly associated with stroke. After adjustment for clinical characteristics, multivariable analysis showed that mRS score ≥3 (HR, 1.99; 95% CI, 1.26-3.14), decreased CBV (HR, 5.31; 95% CI, 2.32-12.13), and concentric enhancement of the arterial wall (HR, 4.16; 95% CI, 1.55-11.15) were significantly associated with stroke.

Data conclusion: Decreased CBV, mRS score ≥ 3, and concentric enhancement of the arterial wall were significantly associated with increased incidence of stroke in conservatively treated MMD.

Evidence level: 2 TECHNICAL EFFICACY: Stage 4.

Keywords: magnetic resonance imaging; moyamoya disease; risk factors; stroke.