1Herzzentrum der Universität zu Köln Klinik III für Innere Medizin Köln, Deutschland; 2Universitätsklinikum Köln Klinik und Poliklinik für Herz- und Thoraxchirurgie, Herzzentrum Köln, Deutschland; 3Universitätsklinikum Köln Klinik I für Innere Medizin Köln, Deutschland
Background:
Elevated white blood cell counts (WBC), C-reactive protein (CRP) levels, and increased body temperature (BT), are commonly observed following transcatheter aortic valve implantation (TAVI), often resulting in prophylactic antibiotic therapy (ABT) to prevent infections related to the newly implanted prosthesis. However, these elevated markers can reflect a physiological postoperative inflammatory response rather than a true infection. This investigation aimed to refine the differentiation between postoperative inflammatory and infectious states, thereby optimizing rational antibiotic treatment following TAVI.
Methods:
This retrospective analysis included 1275 consecutive patients who underwent TAVI for severe aortic stenosis at a high-volume center in Germany between January 2020 and July 2022. ABT administration and the identification of an infectious focus during the postoperative phase were assessed in all patients. Inflammatory parameters were systematically evaluated over a seven-day period following TAVI and group comparisons were performed using two-way ANOVA. Factors predicting the presence of an infectious focus were examined using multivariable binary logistic regression.
Results:
Within the first three days after TAVI, 15.8% (n=202) of patients developed fever, 32.1% (409) had elevated WBCs (average maximum WBC: 10.4 ± 5.5 x 109/L), and 89.4% (1140) showed increased CRP levels (average maximum CRP level: 47.7 ± 46.2 mg/dL). ABT was initiated in 11.4% (145) of patients within the first week post-TAVI, with a confirmed infectious focus being retrospectively identified in 22.1% (32) of these patients. Although patients receiving ABT had higher average WBCs, CRP levels, and BT, a more severe NYHA class, more frequent atrial fibrillation, COPD, and new pacemaker insertions, only the implantation of a new pacemaker (Odds Ratio (OR) 2.45; 95% Confidence Interval (CI) 1.03, 5.83; P = 0.042) as well as elevated WBCs (OR 2.91; 95% CI 1.29, 6.56; P = 0.010) and CRP levels exceeding 65 mg/dL (OR 6.59; 95% CI 2.25, 18.23; P < 0.001) within the first three days were significant predictors of an actual infection. Additionally, patients with a confirmed focus exhibited a delayed decline or a biphasic rise in WBCs, CRP levels and BT.
Conclusions:
In this clinical TAVI cohort, symptoms mimicking postoperative infection prompted frequent ABT administration. Yet, an infectious focus was confirmed in only a small proportion of these patients. Elevated WBCs, CRP levels of >65 mg/dL, and new pacemaker implantation were identified as significant predictors of infection, with CRP levels of >65 mg/dL being the strongest predictor. Additionally, a pattern showing a declining trend in WBCs, CRP levels, and BT after the first three days following TAVI, without a subsequent increase, emerged as a potential additional guide for differentiating between inflammatory responses and infectious complications.