Methods:
This single-center prospective observational study was performed between May 2013 and January 2016. A total of 50 consecutive patients indicated to long-term LVAD implantation (48 HeartMate II VADs, 2 HeartMate 3 VADs; Abbott, Abbott Park, IL, USA) as a bridge to heart transplantation were included (INTERMACS profiles: 2 - 19/50, 3 - 18/50, 4 - 13/50). Exclusion criteria were active infection in 48 hours prior to the surgery, known immune disorder, immunosuppressive drugs in medication and previous short-term LVAD or extracorporeal membrane oxygenation. Preoperative characteristics and baseline values before LVAD implantation are summarized in table 1.
PCT and PSEP levels were assessed before the surgery and during the post-operative period – on the first, second, 14thand 30th post-operative day (POD). PCT (reference range <0.5 µg/L; intermediate precision <2.5%) was measured on a Roche Cobas 6000 analyser (Roche Diagnostics, Rotkreuz, Switzerland) with the Elecsys Brahms Procalcitonin kit (cat. no. 05056888;  Roche Diagnostics, Mannheim, Germany). PSEP (reference range 60-365 ng/L; total precision <5%) was measured on a Mitsubishi Pathfast analyser using a Pathfast Presepsin kit (cat. no. PF 1201-K; Mitsubishi Chemical Medience Corporation, Tokyo, Japan).
The PCT and PSEP values were compared according to the presence of IC. The definition of the IC was clinically relevant infection (i.e. single positive urine culture without any other signs or symptoms of the infection was excluded) confirmed by at least two physicians in regard to the complete medical chart (sings, symptoms, body temperature, blood samples, cultures, imaging methods etc.).
Values are presented as a median with interquartile range in µg/L (PCT) or ng/L (PSEP). Statistical analysis using Mann-Whitney test with Bonferroni correction was performed by MedCalc software (version 12.5.0.0) and a p value of 0.05 or less was considered statistically significant. Study protocol has been approved by institutional review board (IRB) and all patients gave written informed consent.