3.) Preoperative infection analysis
Of particular interest in the patient analysis was the preoperative
infection status. While none of the patient cohorts showed an elevated
body temperature under initiated antibiotic therapy, statistically
significant differences were detected in the frequency of collected
blood cultures and positive pathogen detections. In advance, the most
common blood samples (92.9%) were taken in the EL group. In the SR
cohort, this measure was carried out in 71.9%, while it was only
performed in the SI group in 35.6% of cases. Pathogens were most
commonly detected in the EL group (78.2%). Consistently, gram-positive,
coagulase-positive cocci (66.7%/40.9%/50%) were predominantly found
in all groups (SR/EL/SI), followed by gram-positive, coagulase-negative
subspecies (26.7%/40.9%/38.9%). Gram-positive lactobacilli
(11.1%/18.2%/11.1%) and gram-negative proteobacteria
(2.2%/0%/11.1%) were also frequently detected in all groups, with
slightly higher frequencies in the SI group than in the other groups.
Multiple pathogens were seen in all groups, with the highest frequency
(11.1%) in the SI group. Finally, blood analyses showed the highest
inflammatory parameters in the EL cohort (leukocytes: 11.2 Ts/µl, CRP:
6.3 mg/dl, PCT: 3.2 ng/dl), while the SI group showed the lowest signs
of inflammation. Echocardiography was able to detect intracardiac lead
vegetations most frequently in the EL group (60.7%).
Furthermore, different primary sources of infection were identified in
the groups. Isolated pocket infections were significantly more frequent
in patients of the SI group (74%), while bloodstream infections
represented the dominant etiology in the other two groups (EL: 60.7%,
SI: 41.6%) (Table 1).