Objective: To investigate whether different infarction patterns of single acute infarction (SAI) and multiple acute infarctions (MAIs) respectively have different risk of stroke recurrence after minor stroke.
Methods: We derived data from the imaging subgroup of the Clopidogrel in High-risk Patients with Acute Nondisabling Cerebrovascular Events (CHANCE) trial. Minor stroke were categorized into SAI and MAIs according to infarction patterns in diffusion weighted imaging. SAI were classified as 1.Cortical lesion; 2.Subcortical lesion with diameter>15mm; 3.Subcortical lesion with diameter≤15mm; 4.Corticosubcortical lesion. MAIs were classified as 1.Unilateral anterior circulation; 2.Posterior circulation; 3.Multiple circulations; 4.Border-zone territories. The primary outcome was stroke recurrence at one-year follow-up.
Results: A total of 834 patients with minor stroke from 45 of 114 participating centers of the trial undergoing baseline MRI were included in this imaging subgroup. SAI was observed in 553 and MAIs in 281, the risk of stroke recurrence was 9.9% and 15.3% in SAI and MAIs respectively. After adjustment for potential confounders, different infarction patterns in SAI (cortical lesion, subcortical lesion with diameter>15mm, subcortical lesion with diameter≤15mm, and corticosubcortical lesion) had different risk of stroke recurrence (5.0%, 16.3%, 7.6% and 20.0%, respectively) (p=0.018), however, different infarction patterns in MAIs (unilateral anterior circulation, posterior circulation, multiple circulations and border-zone territories) had no different risk of stroke recurrence (14.8%, 11.8%, 19.5% and 18.5%, respectively) (p>0.05).
Conclusions: Patients with different infarction patterns had different risk of stroke recurrence in SAI but not in MAIs. Some specific infarction patterns of SAI had similar risk of stroke recurrence as MAIs.