Comparison of Aggregometry with Flow Cytometry for the Assessment of Agonists  -Induced Platelet Reactivity in XXXX on Dual Antiplatelet Therapy.

@entity1 @entity1423 @entity1397 @entity117 @entity156 @entity1426 @entity8729 @entity1427 @entity857 @entity3075
UNASSIGNED: Data on the agreement between aggregometry and platelet activation by flow cytometry regarding the measurement of on-treatment platelet reactivity to @entity1426 (AA) and @entity857 ( @entity857 ) are scarce. We therefore sought to compare three @entity1423 tests with flow cytometry for the assessment of the response to antiplatelet therapy. Platelet aggregation in response to AA and @entity857 was determined by light transmission aggregometry (LTA), the VerifyNow assays, and @entity156 ( @entity156 ) in 316 @entity1 receiving @entity117 and @entity1397 therapy after angioplasty with stent implantation. AA- and @entity857 -induced @entity8729 expression and activated glycoprotein (GP) IIb/IIIa were determined by flow cytometry. LTA, the VerifyNow @entity3075 assay and @entity156 in response to @entity857 correlated significantly (all p<0.001), and the best correlation was observed between LTA and the VerifyNow @entity3075 assay (r = 0.63). @entity857 -induced platelet reactivity by all aggregation tests correlated significantly with @entity857 -induced @entity8729 expression and activated @entity1427 /IIIa (all p<0.001). The best correlation was seen between the VerifyNow @entity3075 assay and activated @entity1427 /IIIa (r = 0.68). The platelet surface expressions of @entity8729 and activated @entity1427 /IIIa in response to @entity857 were significantly higher in @entity1 with high on-treatment residual platelet reactivity (HRPR) to @entity857 by all test systems (all p<0.001). A rather poor correlation was observed between AA-induced platelet reactivity by LTA and the VerifyNow @entity117 assay (r = 0.15, p = 0.007), while both methods did not correlate with @entity156 . AA-induced platelet reactivity by all aggregation tests correlated significantly, but rather poorly with AA-induced @entity8729 expression (all p<0.05), while only AA-induced platelet reactivity by LTA correlated significantly with AA-induced activated @entity1427 /IIIa (r = 0.21, p<0.001). The platelet surface expression of @entity8729 in response to AA was significantly higher in @entity1 with HRPR by LTA AA and @entity156 (both p<0.02). In contrast, @entity8729 expression in response to AA was similar in @entity1 without and with HRPR by the VerifyNow @entity117 assay (p = 0.5), and platelet surface activated @entity1427 /IIIa in response to AA did not differ significantly between @entity1 without and with HRPR to AA by all test systems (all p>0.1). In conclusion, @entity857 -induced platelet reactivity by aggregometry translates partly into flow cytometry. In contrast, AA-induced platelet reactivity correlates poorly between different @entity1423 tests, and between aggregometry and flow cytometry. Overall, both approaches capture different aspects of platelet function and are therefore not interchangeable in the assessment of agonists  -induced platelet reactivity. Clinical outcome data are needed to determine which test systems and settings are associated with different in vivo consequences.
