A Markov model to compare the long-term effect of aspirin, clopidogrel and clopidogrel plus aspirin on prevention of recurrent ischemic stroke due to intracranial artery stenosis

Background: Given the importance of intracranial stenosis as a cause of recurrent ischemic stroke and the lack of evidence supporting a clear choice for prevention of recurrent ischemic events, a computer simulation model for prognostic prediction could be used to improve decision making. Aims: The aim of the following study is to compare the long-term effect of aspirin, clopidogrel and clopidogrel plus aspirin for prevention of recurrent stroke due to atherosclerotic intracranial artery stenosis. Setting and Design: The cohort consisted of 206 patients from 2006 to 2011. Materials and Methods: A two-state Markov model was used to predict the prognosis of patients with stroke or transient ischemic attack (TIA) caused by angiographically verified 50-99% stenosis of a major intracranial artery to receive aspirin, clopidogrel, or dual therapy. Statistical Analysis: Two tests were used: Pearson Chi-square test or Fisher's exact test (for percentages) and Kruskal Wallis test (for rank order data). Results: In the 10-year Markov cohort analysis, 36.24% of patients who were treated with clopidogrel plus aspirin developed to recurrent stroke while the probability for patients in the aspirin group and clopidogrel group was 42.60% and 48.39% respectively. Patients with clopidogrel plus aspirin had the highest quality-adjusted life years, followed by aspirin and clopidogrel. Conclusion: To prevent recurrent stroke in patients with intracranial artery stenosis, especially in those patients with a history of TIA or coronary artery disease, medical therapy with clopidogrel plus aspirin should be considered in preference to aspirin alone.