Differential impact of inflammation on six laboratory assays measuring residual arachidonic acid-inducible platelet reactivity during dual antiplatelet therapy.

AIMS

Inflammation has been postulated to modify the platelet response to aspirin treatment, thereby causing high on-treatment residual platelet reactivity (HRPR). Both high levels of inflammatory markers and HRPR have been linked to adverse cardiovascular events. We aimed to study the impact of inflammation on residual arachidonic acid (AA)-inducible platelet reactivity.

METHODS

In 288 patients receiving dual antiplatelet therapy, residual AA-inducible platelet reactivity was assessed using light transmission aggregometry (LTA), the VerifyNow assay, multiple electrode aggregometry (MEA) and the Impact-R. The levels of urinary 11-dehydro-thromboxane B2 (D-TXB2), serum thromboxane B2 (TXB2), interleukin-6 (IL-6) and high-sensitivity C-reactive protein (hsCRP) were determined using immunoassays.

RESULTS

The IL-6 level was found to be an independent predictor of platelet reactivity as determined according to LTA and D-TXB2 using a multiple linear regression analysis. Accordingly, patients with supramedian IL-6 levels exhibited significantly higher platelet reactivity than patients with inframedian IL-6 levels when determined according to LTA and D-TXB2 (both p ≤0.02). High IL-6 levels were associated with a 3.6-fold (95%CI 2.1-6.4) increased risk of HRPR, as defined according to D-TXB2, and a 3.4-fold (95%CI 1.4-8.3) increased risk of HRPR, as defined according to MEA. The HsCRP level was found to be an independent predictor of platelet reactivity when determined according to LTA, D-TXB2, the Impact-R and TXB2 using a multiple linear regression analysis. High hsCRP levels were associated with a 3.6-fold (95%CI 1.3-10) increased risk of HRPR, as defined according to LTA, and a 2.5-fold (95%CI 1.3-4.6) increased risk of HRPR, as defined according to TXB2.

CONCLUSIONS

Increased levels of inflammatory markers are independently associated with residual AA-inducible platelet reactivity in patients receiving dual antiplatelet treatment.