The study was designed and conducted prospectively. Between December 2022 and March 2024, we included 344 patients with severe symptomatic AS and increased surgical risk who underwent TAVR at the Heart Center Bonn. Patients had to be older than 18 years. No other inclusion or exclusion criteria were defined. The study was approved by the local ethics committee and written informed consent was obtained from all patients prior to the initial procedure.

Before the TAVR procedure, all patients underwent a careful evaluation including pre-interventional transthoracic and transesophageal echocardiography (including three-dimensional measurements) and had an interdisciplinary discussion with the local, institutional Heart Team. Details about patient screening, procedural techniques, and adjunctive medication have been described elsewhere [6].

In all patients, the internal jugular vein was used as temporary pacemaker access site and the corresponding sheath was inserted electively before TAVR procedure under ultrasound guidance. The TP lead was placed immediately prior to TAVR under sterile conditions in the hybrid operating room.

The TP leads were aseptically removed after 24 h in patients with a balloon-expandable valve and after 48 h in case of a self-expandable valve. Standardized antibiotic treatment with cefuroxime was performed in all patients as long as the TP leads were in place (alternative in case of allergy).

The tips were cut and placed in tubes containing transport medium. These tubes were transported to the microbiology laboratory within 8 h of removal, where they were sonicated. The resulting sonication fluid was then cultured (aerobic and anaerobic) and incubated at 37 °C for 14 days, with daily inspections for bacterial growth.

For standardized blood collection across the study cohort, a central venous (CV) line was used, which was placed prior to the procedure. In the PPM group, rapid pacing was achieved using a pacemaker lead inserted intraprocedural via the groin and removed directly afterward.

The primary endpoint of the study was 30-day all-cause mortality. Secondary endpoints were periprocedural infections, length of the postprocedural hospital stay, 30-day stroke rate and 30-day major vascular complications.

Periprocedural infections were defined by any clinical evidence of infection (including fever, cough, sputum, burning or painful urination, erysipelas, etc.) with additional confirmation through paraclinical pathology such as thoracic X-ray, urine tests, microbial tests etc., followed by subsequent antibiotic therapy.

For the statistical analysis, participants were characterized into three groups: one group had temporary leads without microbial growth, another group had temporary leads with microbial growth, and a comparison group included patients who did not require temporary leads due to a permanent pacemaker therapy. Finally, we compared patients depending on microbial growth (patients without microbial growth versus patients with microbial growth) and PPM therapy (patients with TPI versus patients with PPM).

Data are presented as the mean ± standard deviation, if normally distributed, or as the median and an interquartile range (IQR) (quartile 1/quartile 3), if not normally distributed. Continuous variables were tested for having a normal distribution with the use of the Kolmogorov–Smirnov test. Categorical variables are given as frequencies and percentages. For continuous variables, a Student’s t test or a Mann–Whitney U test, as appropriate, was performed for comparing between two groups. When comparing more than two groups, ANOVA, employing Dunnett’s T with a reference category or the Kruskal–Wallis test was used. Spearman’s correlation coefficients were used to establish associations. The χ2 test was used for analysis of categorical variables.

Statistical significance was assumed when the null hypothesis could be rejected at p < 0.05. The parameters analyzed included, age, body mass index (BMI), New York Heart Association class (NYHA class), left ventricular ejection fraction (LVEF), trans-aortic valve peak velocity, procedure duration, amount of contrast media, dose area product, fluoroscopy time, hospital duration, postprocedural hospital stay, CRP-peak, and leukocytes-peak, which were assessed using t test. Chi-square tests were conducted for 30-day all-cause mortality, periprocedural infections, 30-day major vascular complication, 30-day stroke rate, coronary artery disease (CAD), atrial fibrillation, death, diabetes mellitus and smoker status.

Statistics were performed using IBM SPSS for Windows (IBM SPSS Statistics, version 29.0.0.0).