Abstract 11618: Angiopoietin-2 is Associated With Capillary Leak and Complications After Cardiac Surgery

Abstract

Introduction: Patients undergoing cardiac surgery are prone to numerous complications. Increased vascular permeability may be associated with morbidity and mortality due to hemodynamic instability, fluid overload, and edema formation. Hypothesis: Markers of endothelial injury and inflammation are associated with capillary leak (CLS), ultimately increasing the risk of perioperative complications. Methods: In a prospective, observational trial 405 cardiac surgery patients were evaluated using daily body impedance electrical analysis, ultrasound, sublingual intravital microscopy, and analysis of biomarkers. Multivariable models and machine learning (ML) were used to study the association of angiopoietin-2 (Ang-2) with extracellular water (ECW) as well as common complications after cardiac surgery. Results: Across all surgical groups, ECW increased postoperatively (20±6 preoperatively to 29±7L on POD2; P <0.001). Concomitantly, the levels of Ang-2 rose, showing a strong correlation based on the time points of measurements (r=0.959, P =0.041). Inflammatory (IL-6, IL-8, CRP) and endothelial biomarkers (VE-Cadherin, syndecan-1, ICAM-1) suggestive of CLS were increased. After accounting for common risk factors of edema formation in cardiac surgery, we found a significant association of Ang-2 and ECW (Table 1). Furthermore, high Ang-2 patients showed an increased odds for developing acute kidney injury (OR 1.095 [1.032-1.169]; P =0.004), and high Ang-2 was associated with delayed extubation, longer time in the ICU, and a higher chance of prolonged dependence on vasoactive medication. ML predicted postoperative complications well if CLS was added to standard risk factors. Conclusions: CLS is a relevant problem after cardiac surgery. Ang-2 in combination with ECW shows promising potential to reliably anticipate CLS and postoperative complications after cardiac surgery.