The effect of off-pump coronary artery bypass grafting on platelet activation in patients on aspirin therapy until surgery day.
OBJECTIVE
Antiplatelet therapy is a class I indication in perioperative care after coronary artery bypass grafting to prevent graft occlusion. We sought to determine whether continuation of aspirin until surgery day suppresses platelet activity in the early period after off-pump coronary artery bypass grafting (OPCAB).


METHODS
Forty-two patients at mean age of 62.5 (+/-7.9) years were included. Average risk rate (EuroScore logistic) was 2.2 (+/-1.7) %. In all patients collagen/epinephrine stimulated platelet plug formation (closure time, CT) (CEPI-CT, s) using a platelet function analyzer (PFA-100), troponin I (TnI), creatine kinase-MB (CK-MB), ST segment elevation were evaluated a day before surgery, 4h after chest closure, 24 and 120 h after surgery.


RESULTS
Preoperative mean CEPI-CT was 224.8 (+/-79.7)s. In 13 (30%) patients aspirin resistance (CEPI-CT<163 s.) was observed. In 4, 24 and 120 h time points CEPI-CT was significantly reduced: 164.4 (+/-79), 168.5 (+/-83.3) and 167.5 (+/-80.4), respectively (p<0,001). TnI and CK-MB (ng/ml) levels raised in respective time points: 4 h (0.26 range 4; 1.9 range 6), 24 h (0.2 range 6; 2.6 range 8), 120 h (0.04 range 2; 0.6 range 5). ST segment elevation (mV) changed in time: 4h (0.7 range 3.5), 48 h (0.7 range 2.8) and 120 h after surgery (0.2 range 1.5). There were no significant correlations between CEPI-CT and TnI, CK-MB, ST segment elevation found.


CONCLUSIONS
Aspirin therapy continued until surgery day does not protect against acute platelet activation in patients after OPCAB.
Department of Cardiac Surgery, Ist Chair of Cardiology, Medical University of Warsaw, Banacha 1a Street, Warsaw, Poland. grzegorz.suwalski@wp.pl
Grzegorz
G
Suwalski
Piotr
P
Suwalski
Krzysztof J
KJ
Filipiak
Marek
M
Postuła
Franciszek
F
Majstrak
Grzegorz
G
Opolski
D000328:Adult; D000368:Aged; D001241:Aspirin / Q000008:administration & dosage / Q000494:pharmacology*; D047549:Coronary Artery Bypass, Off-Pump / Q000379:methods*; D004334:Drug Administration Schedule; D004351:Drug Resistance; D006400:Hematocrit; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000517:prevention & control; D015539:Platelet Activation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000494:pharmacology*; D011182:Postoperative Care / Q000379:methods; D011184:Postoperative Period; D011300:Preoperative Care / Q000379:methods; D011446:Prospective Studies
D006454:Hemoglobins; D010975:Platelet Aggregation Inhibitors; D001241:Aspirin