People who need cardiac surgery are

People who need cardiac surgery are often receiving ACE inhibitors or ARBs for their cardiac disease. It is unclear whether these people should stop ACE inhibitors or ARBs around the time of cardiac surgery when their blood pressure will be most unstable. Stopping ACE inhibitors or ARBs might cause deterioration of cardiac disease, which is often a concern for cardiology clinicians, but trials of ACE inhibitors and ARBs in cardiac disease have typically excluded patients undergoing cardiac surgery whose condition is unstable. Stopping ACE inhibitors or ARBs at the time of surgery may prevent exacerbation of acute kidney injury in patients whose condition is unstable.A randomised controlled trial is needed in patients on ACE inhibitors or ARBs undergoing cardiac surgery to compare continuing treatment with stopping treatment for 48 hours (24 hours before and after surgery). Outcomes should include the incidence of acute kidney injury, cardiovascular events, all cause mortality, number of patients needing renal replacement therapy and length of hospital stay.