What question did this study set out to answer?

Evaluate the diagnostic performance of procalcitonin and interleukin-6 in cardiac surgery patients with suspected early infection.

February 22, 2026BJA Open0 citationsOpen Access

Procalcitonin and interleukin-6 to diagnose infection in cardiac surgery patients with hyperinflammation: a two-centre, prospective cross-sectional study

TRTed Reniers NPNoordzij Pg EHEline Harding

Key Points

Evaluate the diagnostic performance of procalcitonin and interleukin-6 in cardiac surgery patients with suspected early infection.
Conducted a two-centre, prospective cross-sectional study.
Included elective cardiac surgery patients with suspected infection based on clinical criteria.
Assessed diagnostic thresholds for procalcitonin and interleukin-6 using likelihood ratios.
Infection confirmed in 21 out of 284 patients (7%).
Procalcitonin showed an area under the curve (AUC) of 0.59, insufficient for clinical use.
Interleukin-6 demonstrated a better AUC of 0.70, indicating potential for ruling out infection.

Abstract

AbstractBackground Inflammation after cardiac surgery complicates infection diagnosis. The diagnostic value of procalcitonin (PCT) in patients with suspected infection remains unclear. We studied the diagnostic performance of PCT in elective cardiac surgery patients suspected of early-onset infection. Secondarily, we analysed C-reactive protein (CRP), leucocytes, interleukin-6 (IL-6), and neutrophil/lymphocyte ratio (NLR). Methods A two-centre, prospective study was conducted. Patients were suspected of infection if they developed abnormal body temperature (38.0°C), had blood cultures drawn, or received antibiotic treatment within the first 3 postoperative days. A positive and negative diagnostic threshold was assessed at the time infection was suspected, with a negative likelihood ratio (–LR) 5 deemed clinically relevant for ruling out and ruling in infection, respectively. Results Infection was confirmed in 21/284 (7%) patients. The area under the curve (AUC) for PCT was 0.59 (95% confidence interval CI 0.47–0.71). No PCT threshold met predefined clinical relevance criteria, with a minimum –LR of 0.25 at 0.15 μg L–1 and maximum +LR of 2.07 at 7.16 μg L–1. The AUC for IL-6 was 0.70 (95% CI 0.59–0.80), achieving a –LR of 0.15 and a +LR of 5.37 at thresholds of 73 and 531 pg ml–1, respectively. This enabled infection to be ruled out for 82 (29%) patients and ruled in for three (1%) patients. CRP, leukocytes, and NLR did not differentiate between infected and non-infected patients. Conclusions PCT did not meet clinically important thresholds, offering no valuable diagnostic information in patients with suspected infection early after cardiac surgery, whereas IL-6 did. IL-6 appears promising for ruling out infection, warranting further investigation. Trial registration number clinicaltrials.gov, registration number NCT05199025, Open Science Framework (OSF) (https://doi.org/10.17605/OSF.IO/6DGJS.

اسأل الذكاء الاصطناعي

Bookmark

View Full Paper