Analysis of findings on cranial magnetic resonance imaging (MRI) on the first 900 participants in the secondary prevention of small subcortical strokes (SPS3) trial

Abstract

Background: Cranial MRI findings of cerebral small vessel disease comprise: lacunar infarcts, cerebral hemorrhages and white matter abnormalities (WMA). Several studies have attempted to characterize these findings in lacunar stroke patients. However, the data is inconclusive due to lack of a uniform definition of lacunar stroke and to the inclusion of different stroke subtypes. The SPS3 study is enrolling a well-characterized cohort of MRI proven lacunar stroke patients without prior cortical infarcts, cardioembolic source or carotid stenosis. Methods: MRI data are from the SPS3 participants. MRIs and MRAs were centrally read and the interpreter was unaware of the clinical data. Results: Data from the first 984 patients enrolled were included in this analysis. The anatomical distribution of the index infarct was as follow: basal ganglia (18%), corona radiata (28%), centrum semiovale (2%), thalamus (26%) and brainstem (26%). Mean size of the acute infarct on DWI was 1.4 cm (SD=0.54). Moderate to severe WMAs on the ARWMC and Fazekas scales (periventricular and subcortical) were present on 47% and 54% respectively. Multiple subcortical infarcts were found in 17% of the cases. History of hypertension was significantly associated with multiple strokes (p=0.003) and with an increase in severity ofWMAs (p<0.001). In addition, the degree of WMA was correlated with severity of systolic hypertension at baseline (p<0.001). At least one intracranial vessel with ≥50% of stenosis was present in 21% of the cases. History of diabetes was associated with intracranial atherosclerotic stenosis (p=0.03). Conclusions: This preliminary analysis shows a wide spectrum of MRI/MRA findings in lacunar stroke patients. Characterization of these findings is crucial to stratify patients at different risks for stroke recurrence and cognitive decline, as well as to responses to stroke prevention therapies. Outcome data from SPS3 will help further elucidate these issues.