Taking aspirin before non-cardiac surgery does most patients more harm than good, says an Australian anaesthetist involved in a 23-country study.
It does not prevent heart attacks and it causes bleeding, says Professor Kate Leslie.
Millions of people in Australia and New Zealand undergo non-cardiac surgery every year and, until now, around 20 per cent have been advised to take aspirin.
This is a dramatic change and will lead to new medical guidelines, says Prof Leslie, who led the Australian part of the 10,000-patient study published in the New England Journal of Medicine.
The results also show doctors should not prescribe the blood pressure drug clonidine as a preventative measure before surgery.