Lp-PLA₂ and dual antiplatelet agents in intracranial arterial stenosis.

Abstract

To evaluate the interaction effect of lipoprotein-associated phospholipase A₂ (Lp-PLA₂) 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. Patients with both MRI analysis and Lp-PLA₂ testing results were included in the current subanalysis. The interaction of Lp-PLA₂ activity with the effects of dual and single antiplatelet therapy were analyzed through Cox proportional hazards regressions model. Among 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-PLA₂ activity in the ICAS group than in the non-ICAS group (43.8% vs 35.4%, <i>p</i> = 0.02). There was significant interaction between Lp-PLA₂ 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 (<i>p</i> = 0.017, 0.017, respectively), but not for those without (<i>p</i> = 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], <i>p</i> = 0.028; 0.33 [0.12-0.89], <i>p</i> = 0.028, respectively) for patients with ICAS and nonelevated Lp-PLA₂ activity. Presence of both ICAS and nonelevated Lp-PLA₂ 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. NCT00979589.