Background: We aim to investigate the effects and safety of
clopidogrel plus
aspirin in patients with different types of single small
subcortical infarction (SSSI) in the
Clopidogrel in High-risk patients with Acute Non-disabling Cerebrovascular Events (CHANCE) trial. Methods: SSSI was defined as single DWI lesion of ≤2.0 cm. Patients with SSSI were divided into SSSI + PAD (parent artery disease) and SSSI - PAD, according to the
stenosis of the parent artery. The efficacy outcome was
stroke recurrence during 90-day follow-up. Cox proportional hazards models or logistic regression models were used to assess the interaction of the treatment effects of
clopidogrel plus
aspirin vs.
aspirin alone among patients with and without PAD. Results: Among 338 patients with SSSI included in the subanalysis, 105 were with PAD and 233 without. The efficacy of
clopidogrel plus
aspirin compared with
aspirin alone on any
stroke was consistent between patients with [adjusted hazard ratio (HR) 0.84; 95% confidence interval (CI), 0.25-2.75] and without PAD (adjusted HR 1.03; 95% CI, 0.40-2.68, interaction P = 0.83). In patients with SSSI + PAD, the rate of
stroke recurrence in those treated with dual antiplatelet
therapy and mono antiplatelet
therapy was not significantly different (10.9 vs. 13.6%, P = 0.77). The number of
bleeding events was similar between the
clopidogrel-
aspirin group and
aspirin group regardless of SSSI + PAD or SSSI - PAD. Conclusions: There was no significant difference in the efficacy of
clopidogrel plus
aspirin compared with
aspirin alone between patients with SSSI + PAD and SSSI - PAD in the CHANCE trial. Studies in other populations and with adequate power are needed to further verify such findings.