BackgroundData are lacking regarding optimal discontinuation time of preoperative aspirin before coronary artery bypass grafting (CABG). We aimed at assessing the impact of aspirin discontinuation according to time intervals before CABG and its influence on early postoperative outcomes. MethodsIn this retrospective study, we enrolled 652 patients who underwent primary isolated nonemergent CABG between October 2014 and December 2017. Patients were assigned into groups according to the time interval between the last aspirin dose administration and the time of surgery. The first group comprised patients who were given aspirin ≤24-h before CABG (n = 304), whereas the second group consisted of patients who took aspirin between 24 and 48 h before CABG (n = 348). Efficacy endpoints included 30-d mortality rate, incidence of major adverse cardiac and cerebral events (MACCE) and composite rates of 30-d mortality/MACCE. Propensity score matching was used for final comparison. ResultsOverall, multivariate analysis showed that aspirin administration ≤24 h before CABG was associated with reduced 30-d mortality rate and MACCE by 75% and 57%, respectively. Before as well as after propensity score matching, multivariate analysis showed that aspirin administration ≤24-h before CABG was associated with reduced composite rates of 30-d mortality rate and MACCE by 55% and 59%, respectively. Subgroup analysis stratified by the type of surgery showed that aspirin administration ≤24-h significantly reduced composite rates of 30-d mortality/MACCE in patients after off-pump CABG. ConclusionsPreoperative administration of aspirin ≤24-h before CABG is associated with the reduction of postoperative mortality as well as MACCE. The evidence also suggests that aspirin administration ≤24-h is strongly associated with reduced composite rates of 30-d mortality/MACCE in patients submitted to off-pump CABG.