A sub-study of the POISE-3 randomized trial examined effects of a perioperative hypotension-avoidance strategy versus a hypertension-avoidance strategy on the risk of acute kidney injury

In this pre-specified sub-study of the POISE-3 trial, we examined the effect of a perioperative hypotension-avoidance strategy versus a hypertension-avoidance strategy on the risk of postoperative acute kidney injury (AKI). Altogether, 7307 patients were included from 110 hospitals in 22 countries. Patients were 45 years and older, had or were at risk of atherosclerotic disease, took at least one antihypertensive medication, and were scheduled for noncardiac surgery. Hypotension-avoidance strategy: (i) target intraoperative mean arterial pressure (MAP) 80 mm Hg or over, (ii) on day of surgery and for two days after, hold renin-angiotensin-aldosterone system inhibitors and use other antihypertensives in stepwise fashion if systolic blood pressure (SBP) 130 mm Hg or more. Hypertension-avoidance strategy: (i) target intraoperative MAP 60 mm Hg or more, (ii) continue all antihypertensives before and after surgery. Primary outcome: postoperative AKI, an increase in serum creatinine concentration of either 26.5 μmol/L or more (0.3 mg/dL or more) within 48 hours of randomization or 50% or more within seven days of randomization. The hypotension-avoidance group (3654 patients) used fewer antihypertensive medications than the hypertension-avoidance group (3653 patients); specifically, 6% vs. 38% used an ACEI or ARB on the day of surgery, and 6% vs. 47% and 7% vs. 50% one and two days after surgery, respectively. Patients also spent about half as much intraoperative time with a MAP under 80 mm Hg (27 vs. 60 minutes, respectively), but had little difference in average BP before or after surgery. There was no significant difference in AKI risk (15.1% vs. 14.4%). Results were consistent with other definitions of AKI and in patients with preexisting chronic kidney disease. Thus, a hypotension-avoidance strategy targeting a MAP greater than 80 mm Hg in the operating room and discontinued blood pressure medication during the perioperative period did not confer a lower risk of AKI compared to a hypertension avoidance strategy. Clinical trial registration number: NCT03505723.