Summary
In a blinded trial of 2,012 older patients having non-cardiac surgery, omitting an ACE inhibitor or ARB on the morning of surgery reduced treated perioperative hypotension. Postoperative hypertension was more frequent during the first three days, while 30-day complications and mortality did not differ significantly.
A randomised, double-blind trial at five hospitals in China found that older patients who skipped their usual ACE inhibitor or angiotensin receptor blocker (ARB) on the morning of non-cardiac surgery had fewer episodes of treated perioperative hypotension than patients who took the medicine. The study included 2,012 patients aged 60-80 undergoing surgery under general anaesthesia. The researchers also recorded more postoperative hypertension among those who skipped the dose.
What the trial compared
Participants had hypertension and had used an ACE inhibitor or ARB for at least two weeks. They were assigned to take either their usual medicine or an identical placebo on the morning of surgery. The drugs were scheduled to restart on the morning of the first postoperative day, with restart delayed in specified circumstances, including recent treated low blood pressure, vasopressor use or acute kidney injury.
The primary outcome was perioperative hypotension: mean blood pressure below 65 mm Hg, or a fall of at least 30% from baseline, that required intravenous fluids or a vasopressor. In other words, the outcome captured low blood pressure that prompted treatment during surgery or recovery, rather than every low reading.
Of the 2,012 patients in the intention-to-treat analysis, 1,008 were assigned to skip the medicine and 1,004 to continue it. Treated perioperative hypotension occurred in 31.2% of the no-medicine group and 45.5% of the continuation group. After adjustment for prespecified factors, including age, health status and trial centre, the odds ratio was 0.52 (95% confidence interval 0.43 to 0.63). The absolute risk difference was -14.4 percentage points (95% CI -18.5 to -10.1).
The group that skipped the dose also had a shorter duration of hypotension, by an adjusted mean of 1.3 minutes, and was less likely to require a vasopressor: 28.5%, compared with 41.1% among those who continued treatment.
Postoperative blood pressure and study boundaries
The pattern differed after surgery. Within the first three postoperative days, hypertension occurred in 15.2% of patients who skipped the morning dose and 7.9% of those who took their medicine. The researchers described these episodes as brief; 98% were managed with oral or enteral nifedipine or captopril. Hypotension after surgery was not significantly different between groups.
The trial found no significant between-group differences in 30-day complications—including perioperative neurocognitive disorder and major cardiocerebral events—or mortality. These findings concern the measured outcomes and follow-up period; they do not show that the two approaches have identical effects in every patient or over longer periods.
The study provides evidence about a specific, short interruption under monitored perioperative care, not a general medication instruction. Participants were 60-80 years old, had hypertension, and underwent non-cardiac surgery at five tertiary hospitals in China. Patients with several severe conditions, including heart failure and advanced kidney impairment, were excluded; operations were predominantly short to moderate in duration. The findings therefore have a more direct bearing on patients resembling the trial population than on those groups not represented.
For that population, the trial found that omitting the dose on surgery morning reduced treated perioperative hypotension and vasopressor use, while postoperative hypertension was more frequent. Decisions about an individual patient’s medicines remain part of their clinical perioperative plan.