3- Antiplatelet agents:
Aspirin irreversibly acetylates a serine reside of cyclooxygenase 1,
which ultimately decreases the synthesis and release of the
platelet-activating molecule thromboxane A2 (TxA2). The
aspirin effect is, therefore, permanent and lasts for the lifespan of
the circulating platelet (7-10 days).36 There was no
increased risk among patients taking perioperative ASA undergoing CABG
compared with placebo,37 but it may be associated with
increased transfusion requirements.38
Oral P2Y12 receptor antagonists, such as clopidogrel
(Plavix) , prasugrel (Effient ) and ticagrelor
(Brilinta ), can be more problematic given their more potent
antiplatelet effect. Like aspirin, the thienopyridine
P2Y12 receptor antagonists clopidogrel and prasugrel
covalently modify the receptor and the antiplatelet effect lasts for the
lifespan of the platelet. Ticagrelor; however, is a non-thienopyridine
P2Y12 receptor antagonist and the antiplatelet effect
lasts for approximately 4 days. In patients undergoing urgent CABG with
prior ticagrelor administration, serial platelet aggregometry revealed a
return to normal platelet function within 3-days.39
The intraoperative use of Cytosorb adsorption, previously used in
septic patients, was tested on 55 patients who were on ticagrelor or
rivaroxaban and required emergency cardiac surgery, mostly CABG. It was
effective in reducing bleeding complications as patients had less postop
drainage, with majority not requiring transfusion and none required
re-exploration (compared to 37.5% in the non-Cytosorb
group).40 Further testing to corroborate their
findings and determine its effect on other substrates such as albumin
and antibiotics will be important.