Relation between elevated first SBP from baseline (delta SBP) and postoperative outcome

Abstract

Background: Hypertension is associated with increased postoperative risk. However, no consensus was accepted whether elevated blood pressure in the operating room with normal blood pressure at rest related to additional cardiovascular risk.

Methods: This was a single-center retrospective cohort study based on patients who underwent elective noncardiac surgery from 1 January 2012, to 31 December 2018. We evaluated the relationship between the delta SBP (the difference between first operating room blood pressure and baseline blood pressure) and the development of postoperative major adverse cardiac events (MACEs) in patients with normal baseline blood pressure. Multivariate logistic regression before and after propensity score weighting was performed to adjust for perioperative variables, and the minimum P value approach was used to identify the possible threshold of delta SBP that independently indicated the risk of MACE.

Results: Of the 55 563 surgeries, in 4.1%, postoperative MACE occurred. The threshold for the delta SBP was 49 mmHg. The adjusted odds ratio for MACE before and after propensity score weighting for the delta SBP threshold was 1.35 (95% CI, 1.11--1.59); P less than 0.001 and 1.28 (1.03-1.60); P = 0.028, respectively.

Conclusion: Delta SBP contributed to the elevated risk over and beyond the SBP at rest in patients who underwent elective noncardiac surgery. A rise of SBP of more than 49 mmHg from baseline in the operating room was significantly associated with an increased risk of postoperative MACE.