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Published on: February 10, 2023
Effect of dual versus mono antiplatelet therapy on recurrent stroke modulated by activated partial thromboplastin
X Xie1,2,3,4, X Wang1,2,3,4, D T Laskowitz5
1Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China.
Insights
Dual antiplatelet therapy with clopidogrel and aspirin is effective in reducing recurrent stroke in patients with high or medium admission activated partial thromboplastin time (aPTT). However, this benefit was not observed in patients with low aPTT levels.
Area of Science:
- Neurology
- Cardiology
- Pharmacology
Background:
- Dual antiplatelet therapy (DAPT) efficacy can be influenced by various patient factors.
- Activated partial thromboplastin time (aPTT) is a measure of blood coagulation that may impact antiplatelet treatment effectiveness.
Purpose of the Study:
- To investigate if admission aPTT modifies the effect of clopidogrel plus aspirin versus aspirin alone on recurrent stroke risk.
- To determine the interaction between aPTT levels and DAPT efficacy in acute cerebrovascular events.
Main Methods:
- Analysis of data from the CHANCE trial involving 5074 patients.
- Patients were stratified into three groups based on admission aPTT levels (low, medium, high).
- Recurrent stroke within 90 days was the primary outcome, assessed using Cox proportional hazards models.
Main Results:
- DAPT showed a significant reduction in stroke risk for patients with high aPTT (adjusted HR 0.50) and medium aPTT (adjusted HR 0.62).
- In contrast, DAPT did not significantly reduce stroke risk in the low aPTT group (adjusted HR 1.07).
- A significant interaction (P < 0.05) was found between antiplatelet therapy and aPTT levels around 25 s.
Conclusions:
- Dual antiplatelet therapy (clopidogrel plus aspirin) is superior to aspirin alone for preventing recurrent stroke in patients with high or medium admission aPTT.
- The benefit of DAPT on recurrent stroke prevention is not evident in patients with low admission aPTT.
- Admission aPTT level is a significant factor modulating the efficacy of DAPT in patients with acute nondisabling cerebrovascular events.
Background And Purpose:
The efficacy of dual antiplatelet treatment may be modified by many factors. The aim was to assess whether the effect of clopidogrel plus aspirin versus aspirin alone on recurrent stroke would be affected by admission activated partial thromboplastin time (aPTT).
Methods:
Data were derived from the Clopidogrel in High-Risk Patients with Acute Nondisabling Cerebrovascular Events (CHANCE) trial. A total of 5074 patients were categorized into three groups based on the aPTT distribution according to the 15th and 85th percentile. The primary outcome was any stroke within 90 days. The interaction of aPTT with antiplatelet therapy on stroke risk was assessed with a Cox proportional hazards model with adjustment for covariates.
Results:
In the high aPTT group (defined as ≥35.9 s), stroke occurred in 6.7% of patients in the clopidogrel-aspirin arm and 11.9% in the aspirin arm [adjusted hazard ratio (HR) 0.50; 95% confidence interval (CI) 0.29-0.85]. In the medium aPTT group (24.6-35.8 s), stroke occurred in 7.7% of patients in the clopidogrel-aspirin arm and 11.8% in the aspirin arm (adjusted HR 0.62; 95% CI 0.50-0.75). Furthermore, in the low aPTT group (≤24.5 s), stroke occurred in 11.2% of patients in the clopidogrel-aspirin arm and 9.9% in the aspirin arm (adjusted HR 1.07; 95% CI 0.65-1.62). The interaction P value of antiplatelet therapy with aPTT level at the cut-point of approximately 25 s or below was significant (P < 0.05).
Conclusions:
Dual antiplatelet therapy was superior to single antiplatelet therapy in the high or medium aPTT group but not in the low aPTT group.
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