BACKGROUND: Perioperative hemodynamic abnormalities have been associated with neurocognitive outcomes after noncardiac surgery.

OBJECTIVE: To compare the effects of perioperative hypotension-avoidance versus hypertension-avoidance strategies on delirium and 1-year cognitive decline after noncardiac surgery.

DESIGN: Randomized controlled trial. (ClinicalTrials.gov: NCT03505723).

SETTING: 54 centers, 19 countries.

PARTICIPANTS: 2603 high-vascular-risk patients undergoing noncardiac surgery, receiving 1 or more chronic antihypertensive medications (mean age, 70 years).

INTERVENTION: In the hypotension-avoidance strategy, the intraoperative mean arterial pressure (MAP) target was 80 mm Hg or greater; before and for 2 days after surgery, renin-angiotensin-aldosterone system inhibitors were withheld, and other chronic antihypertensive medications were administered for systolic blood pressures of 130 mm Hg or greater following an algorithm. In the hypertension-avoidance strategy, the intraoperative MAP target was 60 mm Hg or greater; all chronic antihypertensive medications were continued perioperatively.

MEASUREMENTS: Delirium on postoperative day 1 to 3 (primary outcome); decline of 2 points or more at the Montreal Cognitive Assessment (MoCA) 1 year after surgery compared with baseline (secondary outcome).

RESULTS: 95 of 1310 patients (7.3%) in the hypotension-avoidance and 90 of 1293 patients (7.0%) in the hypertension-avoidance group had delirium (relative risk [RR], 1.04 [95% CI, 0.79 to 1.38]). Among 701 patients who completed 1-year MoCA (full or telephone version), 129 of 347 (37.2%) in the hypotension-avoidance and 117 of 354 (33.1%) in the hypertension-avoidance group had a decline of 2 or more points (RR, 1.13 [CI, 0.92 to 1.38]). Nineteen percent in the hypotension-avoidance and 27% in the hypertension-avoidance strategy had hypotension requiring an intervention (RR, 0.63 [CI, 0.52 to 0.76]), mostly intraoperatively; only 5%, in both groups, had hypotension postoperatively.

LIMITATION: The COVID-19 pandemic challenged site participation in the substudy; although large, the sample size was lower than expected.

CONCLUSION: There was no evidence of a difference in neurocognitive outcomes between the hypotension-avoidance and hypertension-avoidance strategies.

PRIMARY FUNDING SOURCE: Canadian Institutes of Health Research, Canada; National Health and Medical Research Council, Australia; Research Grant Council, Hong Kong SAR, China.