Preoperative depressive symptoms predict sustained postoperative inflammation and longer hospital stay after cardiac surgery

Introduction: Psychological distress is common among patients undergoing cardiac surgery and may influence postoperative recovery and inflammation. This retrospective study examined whether preoperative depressive symptoms predict the postoperative inflammatory response and the length of hospital stay (LOS) in elective cardiac surgery patients. Methods: Routine clinical data from 951 individuals treated at the Department of Cardiac Surgery, University Hospital Düsseldorf between August 2021 and December 2023 were analyzed. All patients completed the PHQ-4 screening questionnaire prior to surgery, yielding PHQ-2 (depressive symptoms) and GAD-2 (anxiety) subscores. Early and late postoperative C-reactive protein (CRP) indices were derived from routinely collected laboratory measurements. Multivariable regression models adjusted for age, sex, left ventricular ejection fraction, type of surgery, baseline CRP, and anxiety symptoms were estimated, followed by a parallel mediation model to test whether postoperative CRP responses mediated the association between depressive symptoms and postoperative LOS. Results: Higher preoperative depressive symptoms significantly predicted longer postoperative LOS. They also independently predicted both early and late CRP responses, indicating heightened postoperative inflammation. In the mediation model, late postoperative CRP-but not early CRP-showed a positive association with LOS. Depressive symptoms remained directly associated with prolonged LOS even after accounting for inflammatory pathways, suggesting both direct and indirect mechanisms linking psychological distress to recovery trajectories. Conclusion: These findings show that preoperative depressive symptoms are linked to postoperative inflammation and recovery. Even brief 2-item measures provides clinically relevant prognostic information. Incorporating such concise psychological screenings into perioperative care could enhance risk stratification and support targeted interventions.