Kinetics of Procalcitonin, CRP, IL-6, and Presepsin in Heart Transplant Patients Undergoing Induction with Thymoglobulin (rATG)

Background/Objectives: Heart transplantation (HTx) is a lifesaving procedure for end-stage heart failure patients; however, postoperative infections remain a major challenge due to immunosuppressive therapy and surgical complications. Traditional biomarkers such as C-reactive protein (CRP) and procalcitonin (PCT) have limitations in distinguishing infections from systemic inflammatory response syndrome (SIRS). Emerging markers such as Presepsin and interleukin-6 (IL-6) may improve diagnostic accuracy. This study aimed to evaluate the kinetics and reliability of these four inflammatory biomarkers in heart transplant recipients in the immediate postoperative period. Methods: This retrospective observational study included 126 patients who underwent HTx at Policlinic of Bari between January 2022 and November 2024. Patients were categorized into infected (n = 26) and non-infected (n = 100) groups based on clinical and microbiological criteria. Biomarkers (CRP, PCT, Presepsin, and IL-6) were measured preoperatively and on postoperative days (PODs) 1, 2, 3, 4, 5, and 10. Statistical analyses included the Mann–Whitney U test and logistic regression to identify the independent predictors of infection. Results: CRP and PCT levels differed significantly between the groups only on day 10, limiting their use as early infection markers. In contrast, Presepsin levels were significantly elevated in infected patients from day 1 (p < 0.001), whereas IL-6 levels showed significant differences from day 3 onward. Presepsin showed the strongest association with infection in the early postoperative phase. Conclusions: Presepsin and IL-6 outperformed CRP and PCT in detecting early postoperative infections in heart transplant recipients. Their early elevation supports their use as reliable markers for guiding timely clinical intervention and improving patient outcomes. Further research is needed to validate these findings in larger cohorts and with different immunosuppressive regimens.