Intraoperative Hypotension and Major Adverse Cardiac Events Among Older Adult Patients Undergoing Noncardiac Surgery: Retrospective Cohort Study.

Abstract

Background: Intraoperative hypotension (IOH) is an important risk factor for major adverse cardiac events (MACE) in patients undergoing noncardiac surgery. However, the IOH threshold in older adult patients remains controversial.

Objective: This study aimed to explore an appropriate IOH threshold in older adult patients to decrease the risk of MACE.

Methods: This study involved older adult patients undergoing noncardiac surgery (age ≥65 y) from January 2012 to August 2019 in the Chinese People's Liberation Army General Hospital (PLAGH; 35,262 patients) and Shanghai Changhai Hospital from January 2024 to December 2024 (13,418 patients). Univariate moving-average plots and multivariate restricted cubic splines were used to determine the IOH thresholds associated with an increased risk of MACE. The relationship between the IOH threshold and MACE was assessed using univariate and multivariate logistic regression analyses by 3 different hypotension exposure forms (duration, area, and time-weighted average mean arterial pressure [MAP]).

Results: Out of 35,262 patients, 874 developed MACE in PLAGH, and 296 of 13,418 patients developed MACE in Changhai Hospital. In PLAGH, MAP below an absolute threshold of 70 mm Hg was associated with MACE. When the IOH absolute threshold was 70 mm Hg, the risk of MACE demonstrated a "dose-increasing" effect with changes in IOH exposure, and the risk of MACE was significantly increased when the duration lasted >15 minutes (odds ratio 1.51, 95% CI 1.22-1.88; P<.001). The stratified analysis showed that in patients younger than 80 years, when intraoperative MAP dropped below 70 mm Hg for more than 15 minutes, the odds ratio was 1.38 (95% CI 0.86-2.28), P<.01. In Changhai hospital, intraoperative MAP <70 mm Hg was also significantly associated with MACE. Furthermore, IOH lasting longer than 15 minutes substantially increased the risk of MACE.

Conclusions: For older adult patients undergoing noncardiac surgery, intraoperative MAP should be kept above 70 mm Hg to reduce the risk of postoperative MACE.