Elevated preoperative suPAR is a strong and independent risk marker for postoperative complications in patients undergoing major noncardiac surgery (SPARSE)

BACKGROUND: Patients 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.

METHODS: In 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.

RESULTS: Preoperative 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).

CONCLUSION: Preoperative soluble urokinase plasminogen activator receptor provided strong and independent predictive value on postoperative complications in White patients undergoing major noncardiac surgery.