BACKGROUND: In this study, we explored whether antiplatelet medications impair whole blood impedance aggregometry after cardiac surgery and cardiopulmonary bypass (CPB) compared with classical light transmission aggregometry (LTA). METHODS: Multiplate (M) assays measuring changes in electrical resistance as aggregation units over time, and LTA assays (% aggregation) induced by collagen (COL), adenosine diphosphate (ADP), or arachidonic acid were performed simultaneously using arterial blood samples obtained before induction of anesthesia, 15 min and 3 h after neutralization of heparin in 70 consecutive patients scheduled for elective coronary artery bypass grafting. Patients in Group A (n = 48) discontinued intake of antiplatelet drugs for at least 7 days and served as controls, patients in Group B (n = 11) received aspirin 100 mg/d and those in Group C (n = 11) aspirin 100 mg/d and clopidogrel 75 mg/d (dual antiplatelet therapy) until the day before surgery. RESULTS: In patients without antiplatelet therapy, 15 min and 3 h after protamine a significant decrease in platelet aggregation was observed with all three agonists and both aggregation methods. In patients receiving aspirin alone, LTA-COL, LTA-ADP and M-ADP changed significantly over time, and ADP assays of both aggregation methods showed a significant decrease in platelet aggregation 15 min after protamine in patients receiving dual antiplatelet therapy. When calculating the areas under the receiver-operating characteristic curves for discrimination of antiplatelet agents, LTA-COL was able to discriminate between controls and patients receiving aspirin or dual antiplatelet therapy 15 min and 3 h after CPB and the M-ADP assay was able to discriminate between controls and patients receiving dual antiplatelet therapy 3 h after protamine. CONCLUSION: Whole blood and classical LTA performed with all commonly used agonists enable detection of CPB-induced changes in platelet aggregation in patients not taking antiplatelet medication, whereas in patients receiving antiplatelet therapy, ADP-induced antiplatelet assays are preferable for detecting CPB-induced impairment of platelet aggregation.
BACKGROUND: In this study, we explored whether antiplatelet medications impair whole blood impedance aggregometry after cardiac surgery and cardiopulmonary bypass (CPB) compared with classical light transmission aggregometry (LTA). METHODS: Multiplate (M) assays measuring changes in electrical resistance as aggregation units over time, and LTA assays (% aggregation) induced by collagen (COL), adenosine diphosphate (ADP), or arachidonic acid were performed simultaneously using arterial blood samples obtained before induction of anesthesia, 15 min and 3 h after neutralization of heparin in 70 consecutive patients scheduled for elective coronary artery bypass grafting. Patients in Group A (n = 48) discontinued intake of antiplatelet drugs for at least 7 days and served as controls, patients in Group B (n = 11) received aspirin 100 mg/d and those in Group C (n = 11) aspirin 100 mg/d and clopidogrel 75 mg/d (dual antiplatelet therapy) until the day before surgery. RESULTS: In patients without antiplatelet therapy, 15 min and 3 h after protamine a significant decrease in platelet aggregation was observed with all three agonists and both aggregation methods. In patients receiving aspirin alone, LTA-COL, LTA-ADP and M-ADP changed significantly over time, and ADP assays of both aggregation methods showed a significant decrease in platelet aggregation 15 min after protamine in patients receiving dual antiplatelet therapy. When calculating the areas under the receiver-operating characteristic curves for discrimination of antiplatelet agents, LTA-COL was able to discriminate between controls and patients receiving aspirin or dual antiplatelet therapy 15 min and 3 h after CPB and the M-ADP assay was able to discriminate between controls and patients receiving dual antiplatelet therapy 3 h after protamine. CONCLUSION: Whole blood and classical LTA performed with all commonly used agonists enable detection of CPB-induced changes in platelet aggregation in patients not taking antiplatelet medication, whereas in patients receiving antiplatelet therapy, ADP-induced antiplatelet assays are preferable for detecting CPB-induced impairment of platelet aggregation.
Authors: A Westbrook; V Pettilä; A Nichol; M J Bailey; G Syres; L Murray; R Bellomo; E Wood; L E Phillips; A Street; C French; N Orford; J Santamaria; D J Cooper Journal: Intensive Care Med Date: 2010-05-04 Impact factor: 17.440
Authors: Max V Wohlauer; Ernest E Moore; Scott Thomas; Angela Sauaia; Ed Evans; Jeffrey Harr; Christopher C Silliman; Victoria Ploplis; Francis J Castellino; Mark Walsh Journal: J Am Coll Surg Date: 2012-05 Impact factor: 6.113
Authors: Nicole M J Zwifelhofer; Rachel S Bercovitz; Regina Cole; Ke Yan; Pippa M Simpson; Alyssa Moroi; Peter J Newman; Robert A Niebler; John P Scott; Eckehard A D Stuth; Ronald K Woods; D Woodrow Benson; Debra K Newman Journal: Thromb Haemost Date: 2019-11-21 Impact factor: 5.249
Authors: Andrew D Mumford; Jessica Harris; Zoe Plummer; Kurtis Lee; Veerle Verheyden; Barnaby C Reeves; Chris A Rogers; Gianni D Angelini; Gavin J Murphy Journal: Res Pract Thromb Haemost Date: 2017-07-25