High-sensitivity C-reactive protein modifies the prognostic value of platelet count for clinical outcomes after ischemic stroke

BackgroundPlatelets play a critical role in the formation of thrombosis and embolism, and high-sensitivity C-reactive protein (HS-CRP) is an important indicator of inflammation, which contribute to the development of ischemic stroke development. This study aimed to examine whether the relationship between baseline platelet count and adverse clinical outcomes is modulated by HS-CRP in patients with ischemic stroke. MethodsA total of 3267 patients with ischemic stroke were included in the analysis. The primary outcome was a combination of death and major disability (modified Rankin Scale [mRS] score [&ge;]3) at 1 year after ischemic stroke. Secondary outcomes included major disability, death, vascular events, composite outcome of vascular events or death, and an ordered 7-level categorical score of the mRS at 1 year. Multivariate logistic regression and Cox proportional hazards regression models were used to assess the association between the baseline platelet count and clinical outcomes stratified by HS-CRP levels when appropriate, odds ratio (OR) or hazard ratio (HR) and 95% confidence interval (CI) were calculated for the highest quartiles of platelet counts compared with the lowest quartile. ResultsThe elevated platelet count was associated with the primary outcome (OR, 3.14;95% CI, 1.77-5.58), major disability (OR, 2.07;95%CI, 1.15-3.71), death (HR, 2.75;95%CI, 1.31-5.79), composite outcome of vascular events or death (HR, 2.57;95%CI, 1.38-4.87), and the ordered 7-level categorical score of the mRS at 1 year (OR, 2.01 [95%CI, 1.33-3.04]) among patients with high HS-CRP levels (all P trend <0.05). However, platelet count was not associated with the primary outcome (OR, 1.13; 95%CI, 0.75-1.71), major disability (OR, 1.34; 95%CI, 0.87-2.08), death (HR, 0.48; 95%CI, 0.19-1.24), composite outcome of vascular events or death (HR, 0.79; 95%CI, 0.45-1.37), and the ordered 7-level categorical score of the mRS at 1 year (OR, 1.17; 95%CI, 0.91-1.49) (all P trend >0.05) in those with low HS-CRP levels. There was an interaction effect of platelet count and HS-CRP on the primary outcome, death, composite outcome of vascular events or death, and the ordered 7-level categorical score of the mRS at 1 year after ischemic stroke (all P interaction <0.05). ConclusionsAn elevated platelet count was associated with adverse clinical outcomes in ischemic stroke patients with high HS-CRP levels but not in those with low HS-CRP levels, the HS-CRP level had a modifying effect on the association between platelet count and clinical outcomes in patients with ischemic stroke, suggesting that strategies for anti-inflammatory and antiplatelet therapy should be developed according to the results of both platelet and HS-CRP testing.