The influence of mean arterial pressure on the efficacy and safety of dual antiplatelet therapy in minor stroke or transient ischemic attack patients

Mean arterial pressure (MAP) is the strongest predictor of stroke. The combination of clopidogrel and aspirin within 24 hours after onset has been suggested by the Clopidogrel in High-Risk Patients with Acute Nondisabling Cerebrovascular Events (CHANCE) study to be superior to aspirin alone. However, it is not clear whether poststroke blood pressure has an influence on the efficacy and safety of dual antiplatelet treatment. We have performed a post hoc analysis from the CHANCE trial. Patients were stratified into three groups based on MAP levels. Among patients with MAP <102 mm Hg, there was no significant difference in stroke recurrence between the clopidogrel-aspirin group and the aspirin group (7.7% vs 7.5%; hazard ratio [HR], 1.03; 95% confidence interval [CI], 0.73-1.45). However, compared to aspirin treatment, the clopidogrel-aspirin dual treatment was more effective at reducing the risk of stroke in patients with MAP >= 113 mm Hg (6.9% vs 12.3%, HR, 0.55; 95% CI, 0.39-0.78) or 102-113 mm Hg (9.5% vs 14.9%, HR, 0.62; 95% CI, 0.48-0.81). There was a significant interaction between MAP and antiplatelet therapy as it relates to stroke recurrence (P for interaction = 0.037), and a similar result was found for combined vascular events (P for interaction = 0.027). In conclusion, dual antiplatelet therapy may be more effective at reducing combined vascular events in patients with higher MAP after minor stroke or transient ischemic attack.