If you are taking daily aspirin and are about to have a non-cardiac surgery we now have a firm answer: 7 days.
Many of you scheduled to undergo surgery are taking aspirin for prevention of cardiovascular disease. The risk of aspirin prior to surgery was just confirmed in a large trial called the POISE-2 trial. There was no benefit to taking an aspirin up until surgery and there were, not surprisingly, risks. As expected, major bleeding was more common in the aspirin group (4.6 versus 3.8 percent). Patients with an indication for long-term aspirin usage who stop taking aspirin prior to surgery should have their aspirin re-started when the risk of major bleeding after surgery has passed.
Prior to POISE-2, the potential harm from taking aspirin up until your surgery was not well studied, and there was evidence from small studies both against and in favor of its use. Now we know. Stop your aspirin seven days before your surgery.