# Early Use of Innovative Biomarkers Such as Mid-Regional Pro-Adrenomedullin and SeptiCyte® RAPID in Post-Cardiac Surgery Patients: Pilot Case Series

## TL;DR

This study explores new biomarkers for detecting sepsis in patients after heart surgery, showing promising results in those with infective endocarditis.

## Contribution

The study introduces the early use of MR-proADM and SeptiCyte® RAPID in post-cardiac surgery patients to improve sepsis detection.

## Key findings

- MR-proADM and SeptiCyte® RAPID showed increased levels in patients with infective endocarditis.
- Innovative biomarkers performed well in patients with organ dysfunction and cardiovascular or pulmonary damage.
- No biomarker changes were observed in patients with standard elective surgery.

## Abstract

Prognostic uncertainty and missed diagnoses of sepsis remain frequent after cardiopulmonary bypass (CPB) surgery, where systemic inflammatory response (SIRS) arises from surgical trauma, blood activation in the extracorporeal circuit, ischemia/reperfusion injury, and endotoxin release. Among innovative biomarkers, pro-adrenomedullin (pro-ADM), particularly its stable fragment mid-regional pro-adrenomedullin (MR-proADM), has shown promise for detecting endothelial dysfunction and predicting organ failure in sepsis. SeptiCyte® RAPID (Seattle, WA, USA) also represents a novel diagnostic tool that assesses the host immune response by quantifying PLA2G7 and PLAC8 gene expression in whole blood, offering potential for early differentiation between sepsis and sterile inflammation. We analyzed traditional and innovative biomarkers within 24 h post-CPB in a pilot group of patients admitted to the cardiac Intensive Care Unit of the “Città della Salute e della Scienza” University Hospital (Turin, Italy) between June and November 2023. Data from the following 14 patients were collected: 7 undergoing surgery for infective endocarditis (IE, Group 1) and 7 having standard elective cardiac surgery (Group 2). Procalcitonin (PCT), lactate, and pro-ADM increased in Group 1 but not in Group 2. SeptiCyte® RAPID showed a moderate, borderline increase in Group 1. The innovative biomarkers had a good performance in patients exhibiting signs of organ dysfunction and in subjects demonstrating at least cardiovascular and/or pulmonary damage and under vasopressor and inotropic support. Although limited by the small sample, our preliminary data suggest no biomarker alterations in patients with standard elective cardiac surgery, unlike in those with IE.