Insights into the interpretation of light transmission aggregometry for evaluation of platelet aggregation inhibition by clopidogrel Export

@article{citeulike:4498251, abstract = {When studying the efficacy of clopidogrel to inhibit platelet aggregation by light transmission aggregometry, technical decisions must be taken prior to assessment or during analysis, including, but not limited to, concentration of agonist to use and timing of the evaluation of the response on the aggregation curve obtained (peak ADP-stimulated platelet aggregation vs. late aggregation). We investigated how some of these technical modalities affected the results of platelet aggregation obtained after clopidogrel administration. One hundred and twenty stable coronary artery disease patients requiring a diagnostic angiography were recruited prior to pre-treatment with clopidogrel. Blood samples were tested before clopidogrel initiation and immediately preceding coronary angiography using light transmission aggregometry with either 5 or 20 µM of ADP. Aggregation was measured at maximal amplitude (peak), and 5 minutes after agonist addition (late). While measurements of platelet aggregation as either peak or late aggregation were strongly correlated, peak platelet aggregation was significantly higher than late aggregation, by 10.8\% and by 10.3\% with ADP 5 and 20 µM, respectively. Moreover, the use of ADP 20 µM resulted in less spontaneous disaggregation than 5 µM in the absence of clopidogrel (11.8\% and 4.8\% with ADP 5 µM and 20 µM, respectively). When assessing platelet aggregation following clopidogrel, measurement of late aggregation after addition of ADP 20 µM should be preferred. Large clinical trials should be conducted to assess which parameter between residual aggregation or inhibition of platelet aggregation by clopidogrel best predicts clinical efficacy of the drug.}, author = {Lordkipanidz\'{e}, Marie and Pharand, Chantal and Palisaitis, Donald A. and Schampaert, Erick and Diodati, Jean G.}, citeulike-article-id = {4498251}, citeulike-linkout-0 = {http://dx.doi.org/10.1016/j.thromres.2009.04.003}, citeulike-linkout-1 = {http://linkinghub.elsevier.com/retrieve/pii/S0049384809001820}, citeulike-linkout-2 = {http://view.ncbi.nlm.nih.gov/pubmed/19419755}, citeulike-linkout-3 = {http://www.hubmed.org/display.cgi?uids=19419755}, day = {05}, doi = {10.1016/j.thromres.2009.04.003}, issn = {00493848}, journal = {Thrombosis Research}, keywords = {aggregation, clopidogrel, comparison, lta, method, methods, platelet, platelets}, month = {May}, posted-at = {2009-05-09 09:32:38}, priority = {2}, title = {Insights into the interpretation of light transmission aggregometry for evaluation of platelet aggregation inhibition by clopidogrel}, url = {http://dx.doi.org/10.1016/j.thromres.2009.04.003}, year = {2009} }

TY - JOUR ID - citeulike:4498251 L3 - citeulike-article-id:4498251 N2 - When studying the efficacy of clopidogrel to inhibit platelet aggregation by light transmission aggregometry, technical decisions must be taken prior to assessment or during analysis, including, but not limited to, concentration of agonist to use and timing of the evaluation of the response on the aggregation curve obtained (peak ADP-stimulated platelet aggregation vs. late aggregation). We investigated how some of these technical modalities affected the results of platelet aggregation obtained after clopidogrel administration. One hundred and twenty stable coronary artery disease patients requiring a diagnostic angiography were recruited prior to pre-treatment with clopidogrel. Blood samples were tested before clopidogrel initiation and immediately preceding coronary angiography using light transmission aggregometry with either 5 or 20 µM of ADP. Aggregation was measured at maximal amplitude (peak), and 5 minutes after agonist addition (late). While measurements of platelet aggregation as either peak or late aggregation were strongly correlated, peak platelet aggregation was significantly higher than late aggregation, by 10.8% and by 10.3% with ADP 5 and 20 µM, respectively. Moreover, the use of ADP 20 µM resulted in less spontaneous disaggregation than 5 µM in the absence of clopidogrel (11.8% and 4.8% with ADP 5 µM and 20 µM, respectively). When assessing platelet aggregation following clopidogrel, measurement of late aggregation after addition of ADP 20 µM should be preferred. Large clinical trials should be conducted to assess which parameter between residual aggregation or inhibition of platelet aggregation by clopidogrel best predicts clinical efficacy of the drug. JF - Thrombosis Research SN - 00493848 TI - Insights into the interpretation of light transmission aggregometry for evaluation of platelet aggregation inhibition by clopidogrel KW - aggregation KW - clopidogrel KW - comparison KW - lta KW - method KW - methods KW - platelet KW - platelets AU - Lordkipanidzé, Marie AU - Pharand, Chantal AU - Palisaitis, Donald AU - Schampaert, Erick AU - Diodati, Jean PY - 2009/05/05/ UR - http://dx.doi.org/10.1016/j.thromres.2009.04.003 ER -