Safety of dual antiplatelet pre-treatment in ACS patients undergoing unplanned aortocoronary bypass surgery

Major bleedings following coronary artery bypass grafting (CABG) have significant implications on outcomes in acute coronary syndrome (ACS) patients. Owing fears of fatal bleedings in case of urgent CABG, current guidelines recommend a cessation of P2Y12 receptor antagonists (P2Y12-RA) before cardiac surgery and opt against routine pre-treatment with a P2Y12-RA before coronary angiography (CA). However, sparse information exists outside randomized trials on the frequency of urgent CABG and the consequences of inappropriately long cessation of P2Y12-RA treatment in patients presenting with ACS.

In this observational single-center study, ACS patients presenting to an emergency department requiring a CABG were recruited consecutively during a 2-year enrolment period. Baseline characteristics, CABG related bleedings and all-cause mortality were collected from electronical medical records and related to the timing of CABG and P2Y12-RA cessation.

A total of 1,502 ACS patients were included, herein 102 (6.8%) underwent urgent CABG. The majority (76.5%) received a routine P2Y12-RA pre-treatment in addition to low dose aspirin before CA. 31 (30.4%) developed a CABG related bleeding event. Bleeding probability was highest (HR: 4.77, 95%CI: 2.20-10.37, p=0.0001) when CABG was performed within 24 hours after administration of dual anti platelet therapy (DAPT). Despite high utilization rates of DAPT pre-treatment and high prevalence of CABG-related major bleedings, no fatal bleedings occurred.

Need of urgent CABG in ACS is infrequent and does not result in an excess of mortality. However, cessation of P2Y12-RA for at least 48 hours before CABG is required to minimize rates of CABG-related bleedings.