The effect of continuation versus withholding angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers on mortality and major adverse cardiovascular events in hypertensive patients undergoing elective non-cardiac surgery: An open-label randomised controlled trial

The incidence of hypertension is increasing in the population and hypertensive patients routinely present for surgery and anesthesia. Angiotensin converting enzyme inhibitors (ACEI) or angiotensin II receptor blockers (ARB)s are commonly prescribed as first line antihypertensive agents to patients suffering from hypertension. These drugs are considered cardio protective and improve long term outcomes. However, patients who continue their ACEI/ARBs during surgery may have significant hypotension due to the effects of anesthesia and such hypotension is often difficult to treat. In addition, hypotension may worsen the postoperative outcomes  and patients may have stroke, sepsis or acute kidney injury. However, withholding these drugs before surgery to minimise the incidence of hypotension and angioneurotic edema is also potentially risky as the continued benefits of cardio protection may be lost and patients may have major adverse cardiovascular events. Until date, there is no clear cut consensus on whether ACEI/ ARBs should be continued or withheld before surgery. Even multiple guidelines have differing recommendations with regards to continuation or withholding of ACEI/ARBs before surgery. Thus, this multi-centric open-label randomised controlled trial will look to address the issue by recruiting approximately 2100 patients, half of whom will be randomised to have their ACEI/ARBs withheld before surgery and the other half randomised to continue their medications on the day of surgery. The primary outcome that this trial will seek to address is the 30-day all cause mortality, incidence of major adverse cardiovascular and non-cardiovascular events in an effort to generate the evidence for best practices in this cohort of patients and address definitively the clinical conundrum that has vexed clinicians for more than two decades now.