Predictors of in-hospital mortality in coagulase-negative staphylococci bacteraemia: findings from a Spanish multicentre cohort

Abstract

Background Coagulase-negative staphylococci (CoNS) frequently cause hospital-acquired bloodstream infections (BSI), particularly catheter-related (CRBSI). Few recent studies have examined CoNS BSI-related morbidity and mortality. Our study aims to investigate clinical characteristics, all-cause in-hospital mortality, and mortality predictive factors in CoNS BSI. Methods Patients with CoNS BSI from the PROBAC cohort, comprising individuals admitted to 26 Spanish hospitals with BSI from October 2016 to March 2017, were included. Exclusion criteria were blood contaminations and S. lugdunensis infections, due to its distinct traits. Logistic regression models analysed in-hospital mortality as the primary outcome. Results Baseline characteristics are depicted in Table 1. Of the 445 CoNS BSI cases, catheter-related sources were predominant (330/445, 74%), followed by endocarditis (19/445, 4%, including 5 cases on prosthetic valves), and skin/soft tissue infections (17/445, 4%). Staphylococcus epidermidis constituted 75% (332/445), with 74% showing oxacillin resistance. Catheter removal in CRBSI occurred in 59% (193/330) within a median of 3 days (IQR 2-8). Complicated bacteraemia affected 66% (293/445) of cases, comprising persistent bacteraemia (44/445, 10%), fever lasting >72h (77/445, 17%), and septic complications (7/445, 2%). Other complicated BSI were categorised due to the presence of pro sthetic devices, infective endocarditis, or absence of source control. Empiric therapy was initially omitted in 33% (146/445), later transitioning to targeted treatment in 88% (128/146). Median treatment duration was 10 days (IQR 7-17), with 51% adequacy in empiric therapy. In-hospital mortality was at 15% (67/445), with a median duration from BSI onset to discharge of 13 days (IQR 7 ? 28). Multivariate analysis (AUROC 0.78, 95%CI 0.72?0.83) identified advanced age, cerebrovascular disease, immunosuppressive therapy, Pitt score >3, sepsis, and complicated BSI as predictors of increased in-hospital mortality (Table 2). Conclusions Factors associated with in-hospital mortality represent patient frailty or severity, emphasising the necessity for personalised patient assessment. Moreover, recognising the impact of complicated bacteraemia on mortality underscores the importance of differentiating between complicated and uncomplicated cases, akin to S. aureus BSI, as a strategic approach to reduce mortality. Additionally, acknowledging the potential underestimation of CoNS BSI adverse prognosis suggests opportunities to enhance its clinical management.