The ultegra rapid platelet-function assay: Comparison to standard platelet function assays in patients undergoing percutaneous coronary intervention with abciximab therapy

Background Despite the proven benefit of glycoprotein IIb/IIIa inhibitors during percutaneous coronary intervention, significant interpatient variability exists in antiplatelet response. Furthermore, a diminished degree of platelet inhibition is an independent predictor of adverse cardiac events, highlighting the need for accurate and precise monitoring of platelet function. Methods Patients (n = 192) who underwent elective percutaneous coronary intervention at 4 centers were enrolled. The following 3 time points were studied: 1, baseline, before abciximab bolus administration; 2, during, within 1 hour of abciximab bolus administration; and 3, post, 24 hours after abciximab bolus administration or at the time of patient discharge, whichever occurred first. The following 3 assays were compared at all time points: Ultegra rapid platelet-function assay (Ultegra RPFA), conventional turbidometric platelet aggregometry, and receptor binding assay with [ 125I]-abciximab. Variability in Ultegra RPFA measurements between operators was determined with performance of the assays at the point of care and in the laboratory. A sub-study of 22 patients at 1 center was performed in which the laboratory scientist performed all 3 assays in duplicate at each time point. Results Comparison with the receptor binding assay and conventional platelet aggregometry in 120 patients showed that the Ultegra RPFA correlated with aggregometry ( r = 0.89) and with the receptor binding assay ( r = 0.89). There was good agreement ( r = 0.80) between values obtained by intended users and those obtained by laboratory scientists. Furthermore, Ultegra RPFA values had equivalent precision to the standard assays. Conclusion The Ultegra RPFA has equivalent accuracy and precision when compared with the 2 reference assays studied. Ultegra RPFA measurements are not operator-dependent and are not influenced by concomitant medications, hematologic parameters, or demographics. (Am Heart J 2002;143:602-11.)