Does extraction of cardiac implantable electronic devices improve outcome in patients with Staphylococcus aureus bacteraemia?

Abstract

Background: Staphylococcus aureus bacteraemia (SAB) is recognized as an infection that is difficult to treat and with high risk of device related infection. Extraction/explantation of cardiac implantable electronic devices (CIED) is recommended in SAB patients but studies evaluating long-term prognosis are scarce.

Materials and methods: In this retrospective cohort study, 626 consecutive SAB patients were identified in routine diagnostics (November 2014-October 2016). Patient characteristic, infective endocarditis (IE) incidence and mortality were compared for patients with and without CIED.

Results: SAB patients with CIED (n = 33) compared to non-CIED patients (n = 593) were older (83 versus 70 years, p = .0001), had a higher 30-day mortality (12/33, 36% versus 119/593, 20%, p = .044) and higher incidence of IE (9/33, 27% versus 41/593, 7%, p = .0006). One-year mortality was 19/33 (58%) among the SAB CIED patients. Echocardiography was performed in all nine patients with CIED-IE but only in 14/24 (58%) of the 24 SAB CIED patients that were considered not having IE. However, if patients with very early mortality were excluded, echocardiography was performed in 14/17 (82%) of SAB CIED-non-IE patients. CIED extraction/explantation during intravenous antibiotic treatment was only performed in three patients with SAB CIED-IE and in one non-IE patient. One year post treatment initiation, 14 out of 33 SAB CIED patients were alive of whom only one had CIED extraction/explantation performed as part of treatment.

Conclusion: Staphylococcus aureus bacteraemia in CIED patients is associated with poor prognosis but in a subgroup of patients survival beyond one year was seen despite retainment of the electronic device.

Keywords: Staphylococcus aureus; bacteraemia; cardiac implantable electronic device; extraction; infective endocarditis.