Dynamics of bacterial pathogens at the driveline exit site in patients with ventricular assist devices: A prospective, observational, single-center cohort study

Background: Driveline infections (DLIs) at the exit site are frequent in patients with left ventricular assist devices (LVADs). The dynamics from colonization to infection are yet to be investigated. We combined systematic swabbing at the driveline exit site and genomic analyses to study the dynamics of bacterial pathogens and get insights into DLIs pathogenesis.

Methods: A prospective, observational, single-center cohort study at the University Hospital of Bern, Switzerland was performed. Patients with LVAD were systematically swabbed at the driveline exit site between June 2019 and December 2021, irrespective of signs and symptoms of DLI. Bacterial isolates were identified and a subset was whole-genome sequenced.

Results: Fifty-three patients were screened, of which 45 (84.9%) were included in the final population. Bacterial colonization at the driveline exit site without manifestation of DLI was frequent and observed in 17 patients (37.8%). Twenty-two patients (48.9%) developed at least one DLI episode over the study period. Incidence of DLIs reached 2.3 cases per 1000 LVAD days. The majority of the organisms cultivated from exit sites were Staphylococcus species. Genome analysis revealed that bacteria persisted at the driveline exit site over time. In four patients, transition from colonization to clinical DLI was observed.

Conclusions: Our study is the first to address bacterial colonization in the LVAD-DLI setting. We observed that bacterial colonization at the driveline exit site was a frequent phenomenon, and in a few cases, it preceded clinically relevant infections. We also provided acquisition of hospital-acquired multidrug-resistant bacteria and the transmission of pathogens between patients.