Platelet aggregation response to cyclooxygenase inhibition and thromboxane receptor antagonism using impedance aggregometry: A pilot study

Impedance aggregometry is an alternative to light transmission aggregometry that allows analysis of platelet function in whole blood samples. We hypothesized (1) impedance aggregometry would produce repeatable results, (2) inhibition of cyclooxygenase with aspirin would attenuate aggregation responses to collagen and abolish the aggregation response to arachidonic acid (AA), and (3) thromboxane receptor antagonism (terutroban) would attenuate the aggregation response to AA. Venous blood was obtained from 11 participants three times separated by at least 2 weeks. One sample followed 7‐day‐aspirin intervention (81 mg once daily; ASA), the others no intervention (control). Aggregation was induced using 1 μg/mL collagen ([col 1]), 5 μg/mL collagen ([col 5]), and 50 mM AA via impedance aggregometry to determine total aggregation (AUC) analyzed for intra‐test repeatability, inter‐test repeatability, intervention (ASA or control), and incubation (saline or terutroban). [col 1] showed high intra‐test (p ≤ 0.03 visit 1 and 2) and inter‐test repeatability (p