Low Intraoperative Mean Arterial Pressure and Postoperative Outcomes in Older Adults Undergoing Noncardiac Surgery: A Retrospective Cohort Study with Structural Heart Disease Analysis

Abstract

: Objective: The correlation between intraoperative blood pressure thresholds and outcomes in elderly patients undergoing noncardiac surgery remains inadequately characterized. This study aims to assess the association between intraoperative hypotension (IOH) parameters—specifically blood pressure thresholds and duration—and severe adverse outcomes in elderly patients with or without structural or congenital heart disease. Methods: A retrospective evaluation was performed on 846 elderly patients who underwent non-cardiac surgical procedures at Shanghai Songjiang District Hospital in China, from 01 January 2020, to 31 December 2021. Forty-one patients meeting specific exclusion criteria were excluded from the analysis, yielding a final sample size of 805 including 1.5% of congenital heart disease and 5.6% of structural heart disease. The primary endpoint was the occurrence of severe postoperative morbidity associated with perfusion. Secondary endpoints included all-cause postoperative mortality during hospitalization, intensive care unit (ICU) admission, duration of ICU stay, and total hospital stay duration. Results: The propotion of structural heart disease in the MAP < 60 mmHg group (6.7%) was slightly higher than the overall level (5.6%). Postoperative severe perfusion-related complications were observed in 48 cases (6%), with 22 cases (2.7%) of all-cause mortality during hospitalization in total. Multivariable adjusted logistic regression analysis identified MAP < 60 mmHg was strongly associated with postoperative severe perfusion-related morbidity (OR 3.12, 95% CI 1.28–7.56, p = 0.012) and all-cause mortality (OR 4.05, 95% CI 1.53–10.72, p = 0.005) in high-risk surgery and in patients with structural heart disease. MAP < 70 mmHg was associated with increased ICU admission (OR 2.18, 95% CI 1.36–3.49, p = 0.001) in intermediate-risk surgery. The threshold duration for intraoperative hypotension, defined as MAP < 70 mmHg, was established at 6.5 min, while for MAP < 60 mmHg, it was 5.6 min. Regarding the association between all-cause mortality and the accumulated time of different intraoperative blood pressure thresholds, the AUC was 0.907 (95% CI: 0.846–0.967) for MAP < 60 mmHg, and 0.839 (95% CI: 0.773–0.906) for MAP < 70 mmHg. Corresponding cutoff values were identified as 10.5 min, and 12.5 min, respectively. Conclusions: A significant correlation was observed between intraoperative blood pressure and both postoperative severe perfusion-related morbidity and all-cause mortality. Maintaining intraoperative MAP level at ≥ 80 mmHg might be advisable for elderly patients in high-risk surgery and with structural heart disease.