What is the effect of perioperative withdrawal versus continuation of angiotensin-converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARB) on acute kidney injury in patients undergoing elective noncardiac surgery?
Through their effect on blood pressure, concurrent use of ACEi or ARB in the perioperative period may contribute to hypotension and compromised tissue perfusion, leading to poor wound healing, renal injury, myocardial infarction, stroke and death.
A pragmatic, assessor-blinded multicenter randomized clinical trial.
Patients who use ACEi or ARB chronically for the treatment of hypertension, and who are scheduled for elective intermediate to high risk noncardiac surgery.
Withdrawal ACEi and ARB in the perioperative period. This intervention will be compared to perioperative continuation of ACEi and ARB.
The primary outcome is postoperative acute kidney injury.
Secondary outcomes include intra- and postoperative hypotension, postoperative myocardial injury, length of hospital stay, and end-stage renal failure, major cardiovascular complications, mortality and quality of life at three months after surgery.
The incidence of the primary outcome 10%. To detect a risk reduction from 10 to 7% (i.e. a relative risk reduction of 30%) with a type 1 error rate of 0.05, power of 80%, and 10% loss-to-follow up, in total approximately 3200 patients are needed (n=1600 per arm).
The difference in the occurrence of postoperative acute kidney injury between the groups will be expressed in terms of a risk ratio (RR) with accompanying 95% confidence interval.