Abstract Background Previous studies have shown the safety of intravenous glycoprotein (GP) IIbIIIa inhibitors used as a bridging after ADP receptor blocker withdrawal in patients with stable coronary artery disease and previous percutaneous coronary interventions (PCI) undergoing cardiac or non-cardiac surgeries. However, there are few data analyzing GP IIbIIIa inhibitor bridging among patients with acute coronary syndromes (ACS) scheduled for coronary artery bypass graft (CABG) during the same hospitalization. Purpose To evaluate the safety of tirofiban bridging after clopidogrel withdraw in post-ACS patients schedule for CABG during the same hospitalization. Methods Fifty-six patients who underwent CABG after tirofiban bridging post-ACS (bridge group - BG) were compared to 56 sex and age-matched controls also submitted to same-hospitalization CABG post-ACS without bridging (control group - CG). All patients received aspirin plus clopidogrel for ACS; clopidogrel was withdrawn 5 to 7 days before CABG and aspirin was maintained during the whole perioperative period. The primary endpoint was chest tube output in the first 24h after CABG (CTO24h). We hypothesized that BG would be non-inferior to CG, with a non-inferiority margin of 25% in excess of CTO24h in the BG compared to the CG, based on prior literature data. Other exploratory analyses were: blood transfusions, number of red blood cells/patient and re-thoracotomy 24h after surgery. A multivariable linear regression model was developed considering CTO24h as dependent variable and adjusted for other eight co-variates, described in the figure. Results From the 112 patients included (75% men; mean age 60.2±9.3 years), in comparison with CG, BG had higher proportion of STEMI (80.0% vs. 28.6%, p<0.01), fibrinolytic utilization (25% vs. 7.1%, p<0.05), PCI in the acute phase (92.9% vs. 0%, p<0.01) and LMCA stenosis (30.4% vs. 7.1% p<0.01). Tirofiban was utilized by clinician discretion due to PCI in the same hospitalization previously to CABG (n=52), previous PCI up to 3 months before index event (n=3) or severe LMCA stenosis (n=1). BG patients received tirofiban for a mean of 4.3±2.1 days and it was withdrawn at a mean of 6.6±4.3 hours before CABG. After adjustments, BG was non-inferior to CG regarding CTO24h (figure) There were no significant differences between BG and CG regarding need for blood transfusion (26.8% vs. 26.8%, p>0.99), mean number of red blood cells/patient (0.3±0.8 vs 0.5±1.2, p=0.35) or re-thoracotomy due to bleeding (5.4% vs 0%, p=0.24). Conclusion Among ACS patients submitted to urgent CABG after clopidogrel withdrawal, tirofiban bridging, compared to no bridging, was not associated with higher risk of bleeding in the first 24 hours after surgery. Our study suggests that tirofiban may be a safe therapy to patients with high risk of thrombotic complication (such as stent thrombosis or re-infarction) after clopidogrel withdraw. Figure 1 Funding Acknowledgement Type of funding source: None