Risk of endocarditis among patients with coagulase-negative Staphylococcus bacteremia.

Coagulase-negative staphylococci (CoNS) are currently considered typical microorganisms causing infective endocarditis (IE) in patients with prosthetic valves. The objective was to determine variables associated with IE in patients with CoNS bacteremia. We performed an analysis of the clinical characteristics of patients with CoNS bacteremia admitted to a university hospital in Madrid (Spain) from 2021 to December 2022 according to the occurrence of IE. This study is an evaluation of a bacteremia registry. During the study period, 106 patients with CoNS bacteremia were detected. In 85 patients an echocardiogram was performed during hospital admission to rule out IE. Among them, 12 episodes were detected that met IE criteria (14.2%). Of the 6 patients with heart valve prostheses, 5 patients (83.3%) had IE (p < 0.001). Patients with IE more frequently had positive blood cultures more than 12 h after the first draw (58.3% versus 13.4%; p < 0.001). There was a tendency to associate community-acquired bacteremia and to that all blood culture bottles obtained were positive with an increased risk of IE (p = 0.091 and p = 0,057, respectively). Attributable mortality to infection was higher in patients with IE relative to all other patients (16.7% vs. 0%; p = 0.033). The multivariable analysis included having valve prosthesis and persistent bacteremia for more than 12 h. Both were independently associated with IE: valve prosthesis OR 38.6 (95% CI 5.8-258; p < 0.001) and persistent bacteremia OR 2.6 (95% CI 1.1-6.8; p = 0.046). In conclusion, a high percentage of cases of CoNS bacteremia may be due to IE. Some of the variables related to a higher risk of IE, such as having a valvular prosthesis or presenting positive blood cultures for more than 12 h, should lead to rule out or confirm the presence of IE by performing echocardiography.

Sequential oral antibiotic in uncomplicated Staphylococcus aureus bacteraemia: a propensity-matched cohort analysis.

OBJECTIVES: We aimed to analyse the efficacy and safety of oral sequential therapy (OST) in uncomplicated Staphylococcus aureus bacteraemia (SAB). METHODS: Single-centre observational cohort at a tertiary hospital in Spain, including all patients with the first SAB episode from January 2015 to December 2020. We excluded patients with complicated SAB and those who died during the first week. Patients were classified into the OST group (patients who received oral therapy after initial intravenous antibiotic therapy [IVT]), and IVT group (patients who received exclusively IVT). We performed a propensity-score matching to balance baseline differences. The primary composite endpoint was 90-day mortality or microbiological failure. Secondary endpoints included 90-day SAB relapse. RESULTS: Out of 407 SAB first episodes, 230 (56.5%) were included. Of these, 112 (n = 48.7%) received OST and 118 (51.3%) IVT exclusively. Transition to oral therapy was performed after 7 days (interquartile range, 4-11). The primary endpoint occurred in 10.7% (11/112) in OST vs. 30.5% (36/118) in IVT (p < 0.001). SAB relapses occurred in 3.6% (4/112) vs. 1.7% (2/118) (p 0.436). None of the deaths in OST were related to SAB or its complications. After propensity-score matching, the primary endpoint was not more frequent in the OST group (relative risk, 0.42; 95% CI, 0.22-0.79). Ninety-day relapses occurred similarly in both groups (relative risk, 1.35; 95% CI, 0.75-2.39). DISCUSSION: After an initial intravenous antibiotic, patients with uncomplicated SAB can safely be switched to oral antibiotics without apparent adverse outcomes. This strategy could save costs and complications of prolonged hospital stays. Prospective randomized studies are needed.

Unreliability of Clinical Prediction Rules to Exclude without Echocardiography Infective Endocarditis in Staphylococcus aureus Bacteremia.

BACKGROUND: It is unclear whether the use of clinical prediction rules is sufficient to rule out infective endocarditis (IE) in patients with Staphylococcus aureus bacteremia (SAB) without an echocardiogram evaluation, either transthoracic (TTE) and/or transesophageal (TEE). Our primary purpose was to test the usefulness of PREDICT, POSITIVE, and VIRSTA scores to rule out IE without echocardiography. Our secondary purpose was to evaluate whether not performing an echocardiogram evaluation is associated with higher mortality. METHODS: We conducted a unicentric retrospective cohort including all patients with a first SAB episode from January 2015 to December 2020. IE was defined according to modified Duke criteria. We predefined threshold cutoff points to consider that IE was ruled out by means of the mentioned scores. To assess 30-day mortality, we used a multivariable regression model considering performing an echocardiogram as covariate. RESULTS: Out of 404 patients, IE was diagnosed in 50 (12.4%). Prevalence of IE within patients with negative PREDICT, POSITIVE, and VIRSTA scores was: 3.6% (95% CI 0.1-6.9%), 4.9% (95% CI 2.2-7.7%), and 2.2% (95% CI 0.2-4.3%), respectively. Patients with negative VIRSTA and negative TTE had an IE prevalence of 0.9% (95% CI 0-2.8%). Performing an echocardiogram was independently associated with lower 30-day mortality (OR 0.24 95% CI 0.10-0.54, p = 0.001). CONCLUSION: PREDICT and POSITIVE scores were not sufficient to rule out IE without TEE. In patients with negative VIRSTA score, it was doubtful if IE could be discarded with a negative TTE. Not performing an echocardiogram was associated with worse outcomes, which might be related to presence of occult IE. Further studies are needed to assess the usefulness of clinical prediction rules in avoiding echocardiographic evaluation in SAB patients.