Postoperative Vasoactive Exposure Patterns and Outcomes After Non-Cardiac Surgery: A Prespecified Analysis of the SQUEEZE Cohort

Background: Postoperative vasoactive therapy is usually summarised by its presence or duration, although haemodynamic support evolves over time. We investigated whether reproducible postoperative vasoactive exposure patterns provide prognostic information beyond the duration of postoperative vasoactive therapy. Methods: We performed a prespecified substudy of the international SQUEEZE cohort. Adults receiving postoperative vasoactive infusion within seven postoperative days after non-cardiac surgery were included. Unsupervised k-means clustering identified exposure patterns using duration of postoperative vasoactive infusion, cumulative vasoactive agent-days, and peak number of concurrent agents. Associations with 30-day mortality, acute kidney injury (AKI), and hospital length of stay were assessed using multivariable regression. A prespecified landmark analysis evaluated early postoperative vasoactive exposure burden during postoperative days 0-1. Results: Among 25,672 patients, 6676 (26.0%) received postoperative vasoactive infusion. Four reproducible exposure patterns were identified. Adjusted 30-day mortality ranged from 9.7% in the low-burden pattern to 35.3% in the high-burden pattern but was not strictly monotonic, whereas adjusted AKI risk increased from 28.0% to 56.0% across patterns. In covariate-adjusted models fitted to the same complete-case cohort, discrimination was higher when exposure pattern rather than duration was included (AUC 0.818 vs. 0.795), while adding duration to pattern classification resulted in little additional discrimination (AUC 0.819). Findings were consistent in the early postoperative landmark analysis. Conclusions: Postoperative vasoactive exposure follows reproducible patterns characterised by persistence and overall treatment burden rather than binary classification alone. These patterns were associated with mortality, AKI, and hospital length of stay, and provided prognostic information beyond duration alone. Editorial comment: This substudy and analysis of the SQUEEZE cohort, which represents a large sample of cases with focus on post-operative vasopressor treatments, shows that more intensive vasopressor therapy was associated with worse postoperative outcomes, including for mortality and 30 days and postoperative acute kidney injury occurrence. Trial registration: ClinicalTrials.gov identifier: NCT03805230.