Definition of Acetylsalicylic Acid Resistance Using Whole Blood Impedance Aggregometry in Patients Undergoing Coronary Artery Surgery

A beneficial effect of acetylsalicylic acid (ASA) on vein graft patency has been described, but some patients experience adverse cardiac events despite appropriate ASA treatment. Study aim was to define ASA resistance using Multiple elec- trode aggregometry (MEA) preoperatively in group of patients undergoing coronary artery bypass grafting (CABG). Pro- spective observational trial at University Hospital Center Zagreb enrolled 131 patients scheduled for CABG, and divided them into 4 groups with respect to preoperative antiplatelet therapy (APT). Group 1 received 100 mg ASA per day, Group 2 100 mg ASA + 75 mg clopidogrel per day, Group 3 75 mg clopidogrel per day, and Group 4 did not receive any APT. MEA with ASPI test (sensitive to ASA) and ADP test (sensitive to clopidogrel) was performed prior to surgery. In Group 1, patients were characterized as ASA resistant if their ASPI test value exceeded the 75 th percentile distribution. Study en- rolled 131 patients. Significant differences both in the ASPI (p<0.001) and the ADP test (p=0.038) were observed be- tween patients in different APT groups. In Group (1) ASPI test value of 30 AUC presented 75 th percentile of distribution, thus indicating ASA resistance. Group 2 patients had slightly lower ADP test values, but no significant difference oc- curred (mean 60.05 vs. 63.32 AUC, p=0.469). In Group 1 and 2, significant correlations between the ADP test and both, platelet count (r=0.347, p<0.001) and fibrinogen level (r=0.364, p<0.001) were observed. Association between low re- sponse to ASA and post-CABG major adverse ischemic events risk increase has been described thus indicating need for ASA resistant patients detection. In patients with preoperative ASPI test exceeding 30 AUC postoperative, ASA dose ad- justment or clopidogrel addition according to MEA results should be considered

Relationship between level of glycosylated hemoglobin and platelet reactivity in patients with diabetes mellitus undergoing elective coronary artery bypass grafting

Uvod. S obzirom na središnju ulogu trombocita u razvoju tromboze, koja je glavni uzrok ranog poslijeoperacijskog zatajenja grafta, te povećanu sklonost dijabetičara hiperreaktivnosti trombocita, cilj ovog istraživanja je utvrditi utjecaj prijeoperacijskog HbA1c na reaktivnost trombocita i klinički ishod ovih bolesnika. ----- Metode. U prospektivnu opservacijsku studiju je uvršteno 225 bolesnika. Svim je bolesnicima prije operacije određena razina HbA1c, kao i funkcija trombocita, koja je reevaluirana četvrti poslijeoperacijski dan. Bolesnici su podijeljeni u dvije skupine: HbA1c < 7 % i HbA1c ≥ 7 %. Primarna mjera ishoda je procijeniti je li povećana razina prijeoperacijskog HbA1c predskazatelj veće prevalencije aspirinske rezistencije. Kao sekundarnu mjeru ishoda uspoređivali smo pojavu MACCE-a između dvije HbA1c skupine. ----- Rezultati. U dvjema HbA1c skupinama možemo uočiti konzistentan porast poslijeoperacijske aspirinske rezistencije za otprilike 10 %. Osim toga, za 10 % je veća prevalencija aspirinske rezistencije u skupini bolesnika s HbA1c < 7 % prije i nakon operacije. Ovom studijom nismo dokazali razlike u kliničkim ishodima između HbA1c skupina. ----- Zaključak. Kod bolesnika s dijabetesom neophodno je procijeniti poslijeoperacijsku reaktivnost trombocita kako bismo detektirali one s aspirinskom rezistencijom u svrhu primjene potentnije antiagregacijske terapije te na taj način reducirali stopu neželjenih ishemijskih događaja nakon kirurške revaskularizacije miokarda.Introduction. It is known that early thrombosis is a major cause of early postoperative graft failure and that patients with diabetes have an increased tendency for platelet hyperreactivity. Therefore, the aim of this study was to determine the impact of preoperative HbA1c on platelet reactivity and clinical outcome in these patients. ----- Methods. All 225 patients had HbA1c levels as well as platelet function before surgery, which was reevaluated on the fourth postoperative day. Patients were divided into two groups: HbA1c < 7% and HbA1c ≥ 7%. The primary outcome measure is to assess whether an increased preoperative HbA1c level is a predictor of a higher prevalence of aspirin resistance. ----- Results. In the two HbA1c groups, a consistent increase in postoperative aspirin resistance by approximately 10% can be observed. The prevalence of aspirin resistance was 10% higher in the group of patients with HbA1c < 7% before and after surgery. We did not demonstrate differences in clinical outcomes between HbA1c groups. ----- Conclusion. In patients with diabetes, it is necessary to assess the postoperative platelet reactivity in order to detect those with aspirin resistance in order to apply more potent antiplatelet therapy and thus reduce the rate of adverse ischemic events after surgical myocardial revascularization

Relationship between level of glycosylated hemoglobin and platelet reactivity in patients with diabetes mellitus undergoing elective coronary artery bypass grafting

Uvod. S obzirom na središnju ulogu trombocita u razvoju tromboze, koja je glavni uzrok ranog poslijeoperacijskog zatajenja grafta, te povećanu sklonost dijabetičara hiperreaktivnosti trombocita, cilj ovog istraživanja je utvrditi utjecaj prijeoperacijskog HbA1c na reaktivnost trombocita i klinički ishod ovih bolesnika. ----- Metode. U prospektivnu opservacijsku studiju je uvršteno 225 bolesnika. Svim je bolesnicima prije operacije određena razina HbA1c, kao i funkcija trombocita, koja je reevaluirana četvrti poslijeoperacijski dan. Bolesnici su podijeljeni u dvije skupine: HbA1c < 7 % i HbA1c ≥ 7 %. Primarna mjera ishoda je procijeniti je li povećana razina prijeoperacijskog HbA1c predskazatelj veće prevalencije aspirinske rezistencije. Kao sekundarnu mjeru ishoda uspoređivali smo pojavu MACCE-a između dvije HbA1c skupine. ----- Rezultati. U dvjema HbA1c skupinama možemo uočiti konzistentan porast poslijeoperacijske aspirinske rezistencije za otprilike 10 %. Osim toga, za 10 % je veća prevalencija aspirinske rezistencije u skupini bolesnika s HbA1c < 7 % prije i nakon operacije. Ovom studijom nismo dokazali razlike u kliničkim ishodima između HbA1c skupina. ----- Zaključak. Kod bolesnika s dijabetesom neophodno je procijeniti poslijeoperacijsku reaktivnost trombocita kako bismo detektirali one s aspirinskom rezistencijom u svrhu primjene potentnije antiagregacijske terapije te na taj način reducirali stopu neželjenih ishemijskih događaja nakon kirurške revaskularizacije miokarda.Introduction. It is known that early thrombosis is a major cause of early postoperative graft failure and that patients with diabetes have an increased tendency for platelet hyperreactivity. Therefore, the aim of this study was to determine the impact of preoperative HbA1c on platelet reactivity and clinical outcome in these patients. ----- Methods. All 225 patients had HbA1c levels as well as platelet function before surgery, which was reevaluated on the fourth postoperative day. Patients were divided into two groups: HbA1c < 7% and HbA1c ≥ 7%. The primary outcome measure is to assess whether an increased preoperative HbA1c level is a predictor of a higher prevalence of aspirin resistance. ----- Results. In the two HbA1c groups, a consistent increase in postoperative aspirin resistance by approximately 10% can be observed. The prevalence of aspirin resistance was 10% higher in the group of patients with HbA1c < 7% before and after surgery. We did not demonstrate differences in clinical outcomes between HbA1c groups. ----- Conclusion. In patients with diabetes, it is necessary to assess the postoperative platelet reactivity in order to detect those with aspirin resistance in order to apply more potent antiplatelet therapy and thus reduce the rate of adverse ischemic events after surgical myocardial revascularization

Definition of acetylsalicylic acid resistance using whole blood impedance aggregometry in patients undergoing coronary artery surgery [Definicija rezistencije na acetilsalicilnu kiselinu upotrebom impedancijske agregometrije kod bolesnika koji se podvrgavaju operaciji koronarnog premoštenja]

A beneficial effect of acetylsalicylic acid (ASA) on vein graft patency has been described, but some patients experience adverse cardiac events despite appropriate ASA treatment. Study aim was to define ASA resistance using Multiple electrode aggregometry (MEA) preoperatively in group of patients undergoing coronary artery bypass grafting (CABG). Prospective observational trial at University Hospital Center Zagreb enrolled 131 patients scheduled for CABG, and divided them into 4 groups with respect to preoperative antiplatelet therapy (APT). Group 1 received 100 mg ASA per day, Group 2 100 mg ASA + 75 mg clopidogrel per day, Group 3 75 mg clopidogrel per day, and Group 4 did not receive any APT. MEA with ASPI test (sensitive to ASA) and ADP test (sensitive to clopidogrel) was performed prior to surgery. In Group 1, patients were characterized as ASA resistant if their ASPI test value exceeded the 75th percentile distribution. Study enrolled 131 patients. Significant differences both in the ASPI (p < 0.001) and the ADP test (p = 0.038) were observed between patients in different APT groups. In Group (1) ASPI test value of 30 AUC presented 75th percentile of distribution, thus indicating ASA resistance. Group 2 patients had slightly lower ADP test values, but no significant difference occurred (mean 60.05 vs. 63.32 AUC, p = 0.469). In Group 1 and 2, significant correlations between the ADP test and both, platelet count (r = 0.347, p < 0.001) and fibrinogen level (r = 0.364, p < 0.001) were observed. Association between low response to ASA and post-CABG major adverse ischemic events risk increase has been described thus indicating need for ASA resistant patients detection. In patients with preoperative ASPI test exceeding 30 AUC postoperative, ASA dose adjustment or clopidogrel addition according to MEA results should be considered

Definicija rezistencije na acetilsalicilnu kiselinu upotrebom impedancijske agregometrije kod bolesnika koji se podvrgavaju operaciji koronarnog premoštenja

A beneficial effect of acetylsalicylic acid (ASA) on vein graft patency has been described, but some patients experience adverse cardiac events despite appropriate ASA treatment. Study aim was to define ASA resistance using Multiple electrode aggregometry (MEA) preoperatively in group of patients undergoing coronary artery bypass grafting (CABG). Prospective observational trial at University Hospital Center Zagreb enrolled 131 patients scheduled for CABG, and divided them into 4 groups with respect to preoperative antiplatelet therapy (APT). Group 1 received 100 mg ASA per day, Group 2 100 mg ASA + 75 mg clopidogrel per day, Group 3 75 mg clopidogrel per day, and Group 4 did not receive any APT. MEA with ASPI test (sensitive to ASA) and ADP test (sensitive to clopidogrel) was performed prior to surgery. In Group 1, patients were characterized as ASA resistant if their ASPI test value exceeded the 75th percentile distribution. Study enrolled 131 patients. Significant differences both in the ASPI (p < 0.001) and the ADP test (p = 0.038) were observed between patients in different APT groups. In Group (1) ASPI test value of 30 AUC presented 75th percentile of distribution, thus indicating ASA resistance. Group 2 patients had slightly lower ADP test values, but no significant difference occurred (mean 60.05 vs. 63.32 AUC, p = 0.469). In Group 1 and 2, significant correlations between the ADP test and both, platelet count (r = 0.347, p < 0.001) and fibrinogen level (r = 0.364, p < 0.001) were observed. Association between low response to ASA and post-CABG major adverse ischemic events risk increase has been described thus indicating need for ASA resistant patients detection. In patients with preoperative ASPI test exceeding 30 AUC postoperative, ASA dose adjustment or clopidogrel addition according to MEA results should be considered.Povoljan učinak acetilsalicilne kiseline na prohodnost venskih graftova već je opisana, ali određeni broj bolesnika poslijeoperacijski doživi nepovoljna ishemijska zbivanja unatoč adekvatnom liječenju acetilsalicilnom kiselinom. Cilj studije je prijeoperacijski definirati rezistenciju na acetilsalicilnu kiselinu upotrebom impedancijske agregometrije (MEA) u skupini bolesnika koji se podvrgavaju operaciji koronarnog premoštenja (CABG). Prospektivna opservacijska studija u Kliničkom bolničkom centru Zagreb uključila je 131 bolesnika kod kojih je planiran CABG. Bolesnici su podijeljeni u 4 skupine obzirom na prijeoperacijski ordiniranu antiagregacijsku terapiju. Skupina 1 je primala acetilsalicilnu kiselinu 100 mg/dnevno, skupina 2 100 mg acetilsalicilne kiseline te 75 mg klopidogrel dnevno, skupina 3 je primala klopidogrel 75 mg dnevno dok skupina 4 nije primala antiagregacijsku terapiju prije operacije. MEA s ASPI testom (koji je senzitivan na učinak acetilsalicilne kiseline) i ADP testom (senzitivan na učinak klopidogrela) je izvedena prije operacije. U skupini 1, bolesnici kojima je vrijednost ASPI testa iznosila vise od 75. percentile distribucije vrijednosti ASPI testa su okarakterizirani kao rezistentni na acetilsalicilnu kiselinu. Značajne razlike u vrijednostima ASPI (p<0.001) i ADP testa (p=0.038)uočene su između skupina bolesnika definiranih prema režimu prijeoperacijskog antiagregacijskog liječenja. U skupini 1, vrijednost ASPI testa od 30 AUC (engl. area under curve) je predstavljala vrijednost 75-te percentile, označavajući graničnu vrijednos za definiciju rezistencije na acetilsalicilnu kiselinu.U skupini 2 (izloženi klopidogrelu) izmjerene su niže vrijednosti ADP testa, međutim bez statistički značajne razlike (srednja vrijednost 60.05 vs. 63.32 AUC, p=0.469). U skupini 1 i 2,uočene su značajne korelacije između vrijednosti ADP testa i broja trombocita (r=0.347, p<0.001) te razine fibrinogena (r=0.364, p<0.001).Povezanost između izostanka odgovora na acetilsalicilnu kiselinu i povećanog rizika za neželjena poslijeoperacijska ishemijska zbivanja je već opisana što naglašava potrebu za brzim i lakoizvedivim definiranjem bolesnika s rezistencijom na acetilsalicilnu kiselinu. Kod bolesnika s prijeoperacijskim vrijednostima ASPI testa većim od 30 AUC, trebalo bi razmotriti prilagodbu doze acetilsalicilne kiseline ili dodavanje klopidogrela (tzv. dvojna antiagregacijska terapija) na osnovi MEA monitoriranja