NEJM  "Aspirin in Patients Undergoing Noncardiac Surgery"  
http://www.nejm.org/doi/full/10.1056/NEJMoa1401105?query=featured_home
"CONCLUSIONS

Administration of aspirin before surgery and throughout the early postsurgical period had no significant effect on the rate of a composite of death or nonfatal myocardial infarction but increased the risk of major bleeding. (Funded by the Canadian Institutes of Health Research and others; POISE-2 ClinicalTrials.gov number,NCT01082874.)"