BackgroundPatients undergoing major surgery are often at risk of developing postoperative complications. We investigated whether a preoperative marker of chronic inflammation, soluble urokinase plasminogen activator receptor, can aid in identifying patients at high risk for postoperative complications, morbidity, and mortality. MethodsIn this prospective observational study (ClinicalTrials.gov identifier: NCT03851965), EDTA blood was collected from consecutive adult White patients scheduled for major noncardiac surgery with expected duration ≥2 hours under general anesthesia. Inclusion criteria were age ≥18 years and American Society of Anesthesiologists physical status I to IV. Plasma soluble urokinase plasminogen activator receptor levels were determined using the suPARnostic quick triage lateral flow assay. The primary endpoint was postoperative complications defined as presence of any complication and/or admission to intensive care unit and/or mortality within the first 90 postoperative days. ResultsPreoperative soluble urokinase plasminogen activator receptor had an odds ratio of 1.50 (95% confidence interval: 1.24–1.82) for every ng/mL increase. When including age, sex, American Society of Anesthesiologists score, C-reactive protein, and grouped soluble urokinase plasminogen activator receptor in multivariate analysis, patients with soluble urokinase plasminogen activator receptor between 5.5 and 10 ng/mL had an odds ratio of 11.2 (confidence interval: 3.1–40.8) and patients with soluble urokinase plasminogen activator receptor >10 ng/mL had an odds ratio of 19.9 (95% confidence interval: 4.3–92.9) compared to patients with soluble urokinase plasminogen activator receptor ≤5.5 ng/mL, respectively. Receiver operating characteristic analysis of soluble urokinase plasminogen activator receptor showed an area under the curve of 0.82 (confidence interval: 0.72–0.91). Receiver operating characteristic analysis combining age, sex, C-reactive protein levels, and American Society of Anesthesiologists score and had an area under the curve of 0.71 (95% confidence interval: 0.61–0.82). Adding soluble urokinase plasminogen activator receptor to this model increased the area under the curve to 0.83 (95% confidence interval: 0.74–0.92) (P = .033). ConclusionPreoperative soluble urokinase plasminogen activator receptor provided strong and independent predictive value on postoperative complications in White patients undergoing major noncardiac surgery.