Influence of lipoprotein-associated phospholipase A2 mass on prognosis value of baseline platelet count for clinical outcomes after acute ischemic stroke

Background and aims: We aimed to examine the association between baseline platelet count (PLT) and prognosis of acute ischemic stroke according to lipoprotein-associated phospholipase A2 (Lp-PLA2) mass. Methods: A total of 3254 patients with acute ischemic stroke were included in this analysis. The primary out-come was a combination of major disability and all-cause mortality (modified Rankin Scale score >= 3) at 3 months after stroke. Secondary outcome was major disability and all-cause mortality, respectively. Results: The prognosis value of PLT for primary outcome was significantly modified by Lp-PLA(2) mass (p(interaction) = 0.002). After multivariate adjustment, elevated PLT was associated with the increased risk of primary outcome in patients with high Lp-PLA(2) mass (odds ratio [OR], 1.64; 95% confidence interval [CI], 1.09-2.48; p(trend) = 0.002), but not in those with low Lp-PLA2 mass (OR, 0.94; 95%CI, 0.62-1.42; p(trend) = 0.181), when comparing two extreme PLT quartiles. A similar association was found between elevated PLT and major disability (p(interaction) = 0.001). Elevated PLT was associated with increased risk of major disability only in patients with high Lp-PLA2 mass (OR, 1.54; 95%CI, 1.03-2.31; p(trend) = 0.007), for the highest quartile vs the lowest quartile. Each 100 x 10(9)/L increment in PLT was associated with 42% (95%CI, 12%-79%) increased risk of primary outcome and 33% (95%CI, 6%-68%) increased risk of major disability in those with high Lp-PLA2 mass. Conclusions: The elevated PLT was associated with poor prognosis of acute ischemic stroke only in patients with high Lp-PLA2 mass. Lp-PLA2 might be an important factor influencing the prognosis value of PLT for clinical outcomes in acute ischemic stroke patients.