Aminotransferase Level and the Effects of Dual Antiplatelet in Minor Stroke or Transient Ischemic Attack: A post hoc Analysis of a Randomized Control Trial

Introduction: This study was intended to evaluate whether the safety and efficacy of dual antiplatelet treatment in patients with minor ischemic stroke (MIS) or transient ischemic attack (TIA) could be modified by the aminotransferase level. Also, we sought to assess the interaction between aminotransferase level and CYP2C19 loss-of-function status on the efficacy of dual antiplatelet therapy. Methods: This study is a post hoc analysis of the Clopidogrel in High-Risk Patients With Acute Nondisabling Cerebrovascular Events (CHANCE) study, a double-blinded randomized control trial. We included 5,133 patients with a complete workup of baseline alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels. The primary outcome is stroke or TIA recurrence within 90 days. Cox proportional hazard models were used in the evaluation of the efficacy of antiplatelet treatment in patients with different aminotransferase levels and subgroups categorized by the aminotransferase level × CYP2C19 loss-of-function status. Results: The median age of all the included patients was 62 years; 66.3% of the patients were male. More recurrent stroke or TIA occurred in patients with elevated ALT and AST levels within 90 days compared to patients with normal ALT and AST levels (14.5 vs. 11.2%, p = 0.029). Dual antiplatelet treatment with aspirin and clopidogrel reduced recurrence compared with aspirin alone in patients with both normal (adjusted hazard ratio [HR], 95% confidence interval [CI]: 0.72 [0.60–0.86], p < 0.001) and elevated (adjusted HR [95% CI]: 0. 57 [0. 35–0. 92], p = 0. 020) ALT and AST levels (p = 0.64 for interaction). No significant difference in treatment efficacy on 90-day all-cause death or bleeding events was found. Conclusions: Dual antiplatelet treatment was safe for minor stroke or high-risk TIA patients with mildly elevated aminotransferase. Mild elevation of ALT or AST did not undermine the protective efficacy of the dual antiplatelet regimen in reducing recurrent stroke or TIA within 90 days after MIS or TIA. The interaction between the CYP2C19 loss-of-function allele carrier status and aminotransferase level on the efficacy of dual antiplatelet treatment was not observed.