Small vessel disease burden and prognosis of recent subcortical ischaemic stroke differ by parent artery atherosclerosis

Background and purpose Parent artery atherosclerosis is an important aetiology of recent subcortical ischaemic stroke (RSIS). However, comparisons of RSIS with different degrees of parent artery atherosclerosis are lacking. Methods Prospectively collected data from our multicentre cohort (all were tertiary centres) of the Stroke Imaging Package Study between 2015 and 2017 were retrospectively reviewed. The patients with RSIS defined as a single clinically relevant diffusion‐weighted imaging positive lesion in the territory of lenticulostriate arteries were categorized into three subgroups: (1) normal middle cerebral artery (MCA) on magnetic resonance angiography and high‐resolution magnetic resonance imaging (HR‐MRI); (2) low‐grade MCA atherosclerosis (normal or 2). The clinical and imaging findings were compared between subgroups. Results A total of 239 patients (median age 60.0 [52.0–67.0] years, 72% male) were enrolled, including 140 with normal MCA, 64 with low‐grade MCA atherosclerosis and 35 with steno‐occlusive MCA atherosclerosis. Patients with steno‐occlusive MCA atherosclerosis had the largest infarct volume. Low‐grade MCA atherosclerosis was independently associated with cerebral microbleeding, more severe perivascular spaces in basal ganglia and higher total cerebral small vessel disease burden. Low‐grade MCA atherosclerosis was an independent determinant of 90‐day functional dependence (odds ratio 3.897; 95% confidence interval 1.309–11.604). Conclusions Our study suggested RSIS with varying severity of parent artery atherosclerosis exhibits distinctive clinical and neuroimaging characteristics, with low‐grade MCA atherosclerosis associating with higher cerebral small vessel disease burden and worse prognosis.