Lp-PLA2 and dual antiplatelet agents in intracranial arterial stenosis

ObjectiveTo evaluate the interaction effect of lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) activity on the efficacy and safety of dual/single antiplatelet therapy in patients with and without intracranial arterial stenosis (ICAS) by the Clopidogrel in High-Risk Patients with Acute Non-disabling Cerebrovascular Events trial.MethodsPatients with both MRI analysis and Lp-PLA(2) testing results were included in the current subanalysis. The interaction of Lp-PLA(2) activity with the effects of dual and single antiplatelet therapy were analyzed through Cox proportional hazards regressions model.ResultsAmong the 797 patients, the mean age was 63.1 10.8 years, 518 (65%) were men, 356 (44.7%) had ICAS, and 441 (55.3%) did not. There were significantly more patients with elevated Lp-PLA(2) activity in the ICAS group than in the non-ICAS group (43.8% vs 35.4%, p = 0.02). There was significant interaction between Lp-PLA(2) activity levels and the 2 antiplatelet therapies for prevention of stroke recurrences and combined vascular events even after adjustment for confounding factors exclusively for patients with ICAS (p = 0.017, 0.017, respectively), but not for those without (p = 0.332, 0.674, respectively). Compared with aspirin alone, dual antiplatelet therapy significantly reduced the risk of stroke recurrences and combined vascular events (adjusted hazard ratio 0.33 [0.12-0.89], p = 0.028; 0.33 [0.12-0.89], p = 0.028, respectively) for patients with ICAS and nonelevated Lp-PLA(2) activity.ConclusionsPresence of both ICAS and nonelevated Lp-PLA(2) activity may predict better response to dual antiplatelet therapy in prevention of recurrent strokes and combined vascular events for patients with minor stroke or high-risk TIA.Clinicaltrials.gov identifierNCT00979589.