Infective endocarditis in neutropenic patients with viridans streptococci bacteraemia

Clinicomicrobiological risk factors for infective endocarditis in viridans group streptococci bacteraemia

BACKGROUND

When to perform echocardiography to rule out infective endocarditis (IE) in patients with viridans group streptococci (VGS) bloodstream infections (BSIs) is unclear.

OBJECTIVES

We aimed to identify independent risk factors for IE in patients with VGS BSI.

METHODS

This retrospective study conducted at Seoul National University Hospital from January 2013 to December 2022 involved patients with VGS and nutritionally variant streptococcal BSI, excluding single positive blood cultures and polymicrobial BSI cases. Independent risk factors were identified by multivariate logistic regression and sensitivity analyses according to echocardiography results, VGS species or the inclusion of possible IE cases.

RESULTS

Of 845 VGS BSI cases, 349 were analysed and 86 IE cases were identified (24.6%). In the multivariate analysis, heart valve disease [adjusted odds ratio (aOR), 14.14, 95% CI, 6.14-32.58; P < 0.001], persistent bacteraemia (aOR, 5.12, 95% CI, 2.03-12.94; P = 0.001), age (per year, aOR, 0.98; 95% CI, 0.96-1.00; P = 0.015), solid cancer (aOR, 0.26; 95% CI, 0.13-0.53; P < 0.001) and haematologic malignancy (aOR, 0.04; 95% CI, 0.01-0.41; P = 0.006) were independently associated with IE. Sensitivity analyses yielded consistent results; also, infection by a member of the mitis group was independent risk factor for IE (aOR, 6.50; 95% CI, 2.87-14.68; P < 0.001).

CONCLUSIONS

Younger age, heart valve disease, persistent bacteraemia, absence of underlying malignancy and BSI by a member of the mitis group were independent risk factors for IE in patients with VGS BSI. Echocardiographic evaluation could be prudently considered based on these clinicomicrobiological risk factors.

Infective endocarditis is rare in patients with hematologic malignancy and neutropenia

BACKGROUND

Infective endocarditis (IE) is a serious complication of bloodstream infections (BSIs) that occurs at variable rates depending on the pathogen and clinical setting. There is a paucity of data describing the risk of IE in patients with hematologic malignancy who develop bacteremia while neutropenic.

METHODS

Adult patients on the hematology ward from January 2018 to December 2020 with hematologic malignancy and bacteremia were evaluated retrospectively for endocarditis by applying the 2023 Duke-ISCVID criteria. Charts of possible cases were evaluated 90 days after the initial BSI for new infectious complications that could indicate missed IE. Descriptive statistics compared patients admitted for hematopoietic stem cell transplantation (HSCT) to those admitted for alternative reasons (non-HSCT).

RESULTS

Among the 1005 positive blood cultures initially identified, there were 66 episodes in 65 patients with hematologic malignancy and at least grade 3 neutropenia for a mean duration of 11.4 days during their admission. Transthoracic echocardiography (TTE) was performed in 34.8% of BSIs, and transesophageal echocardiography (TEE) in 6.1%. There were no new infectious complications in possible cases 90 days after their initial BSI. No cases of endocarditis were identified.

CONCLUSIONS

Endocarditis is rare amongst patients with hematologic malignancy, bacteremia, and neutropenia, and no cases were identified in this cohort. The use of routine TTE in this setting seems unwarranted, and the addition of TEE is unlikely to improve patient-centered outcomes.

Risk of Infective Endocarditis in Streptococcus mitis Bloodstream Infections Among Patients with Neutropenia from Hematologic Malignancies

Streptococcus mitis commonly causes bloodstream infections (BSIs) in neutropenic patients but infrequently results in infective endocarditis (IE) in this population. Among 210 patients with neutropenia and S. mitis BSI, 55% underwent cardiac imaging. None were diagnosed with S. mitis IE; 3 had recurrent S. mitis BSI within 12 weeks.

Contemporary Experience of Abiotrophia, Granulicatella and Gemella Bacteremia

BACKGROUND

Abiotrophia, Granulicatella, and Gemella are gastrointestinal microbiota, gram-positive cocci that behave like viridans group streptococci. Despite the low incidence of bacteremia from these organisms, they can lead to infective endocarditis (IE) and other clinical syndromes. Due to scant data, we aim to describe detailed clinical features, management, and outcomes of patients with bacteremia from these organisms.

METHODS

We reviewed all adult patients who developed Abiotrophia, Granulicatella, or Gemella bacteremia from 2011 to 2020, at Mayo Clinic.

RESULTS

We identified 238 patients with positive blood culture for these organisms. Of those, 161 (67.6%) patients were deemed to have bacteremia of clinical significance; 62 (38.5%) were neutropenic, - none of whom were diagnosed with IE. The primary source of bacteremia for the neutropenic group was the gastrointestinal tract. Among 161 patients, echocardiography was obtained in 88 (54.7%) patients, especially those with unknown sources of bacteremia. A total of 19 cases had IE: 5 (26.3%) Abiotrophia, 11 (57.9%) Granulicatella, and 3 (15.8%) Gemella. Based on known IE scoring systems, the negative predictive value at established cutoffs for these scores, performed with our cohort were 95.9%, 100% and 97.9% for NOVA, HANDOC and DENOVA scores, respectively. We also found that the penicillin-non-susceptible rate was high in Abiotrophia (66.7%) and Granulicatella (53.7%).

CONCLUSIONS

We described unique characteristics of Abiotrophia, Granulicatella, and Gemella bacteremia at our institution. Clinical significance, clinical syndrome, their proclivity of endocarditis, and susceptibility pattern should be thoroughly reviewed when encountering these organisms.

A comparison of different antibiotic regimens for the treatment of infective endocarditis

BACKGROUND

Infective endocarditis is a microbial infection of the endocardial surface of the heart. Antibiotics are the cornerstone of treatment, but due to the differences in presentation, populations affected, and the wide variety of micro-organisms that can be responsible, their use is not standardised. This is an update of a review previously published in 2016.

OBJECTIVES

To assess the existing evidence about the clinical benefits and harms of different antibiotics regimens used to treat people with infective endocarditis.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase Classic and Embase, LILACS, CINAHL, and the Conference Proceedings Citation Index - Science on 6 January 2020. We also searched three trials registers and handsearched the reference lists of included papers. We applied no language restrictions.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) assessing the effects of antibiotic regimens for treating definitive infective endocarditis diagnosed according to modified Duke's criteria. We considered all-cause mortality, cure rates, and adverse events as the primary outcomes. We excluded people with possible infective endocarditis and pregnant women.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, 'Risk of bias' assessment, and data extraction in duplicate. We constructed 'Summary of findings' tables and used GRADE methodology to assess the quality of the evidence. We described the included studies narratively.

MAIN RESULTS

Six small RCTs involving 1143 allocated/632 analysed participants met the inclusion criteria of this first update. The included trials had a high risk of bias. Three trials were sponsored by drug companies. Due to heterogeneity in outcome definitions and different antibiotics used data could not be pooled. The included trials compared miscellaneous antibiotic schedules having uncertain effects for all of the prespecified outcomes in this review. Evidence was either low or very low quality due to high risk of bias and very low number of events and small sample size. The results for all-cause mortality were as follows: one trial compared quinolone (levofloxacin) plus standard treatment (antistaphylococcal penicillin (cloxacillin or dicloxacillin), aminoglycoside (tobramycin or netilmicin), and rifampicin) versus standard treatment alone and reported 8/31 (26%) with levofloxacin plus standard treatment versus 9/39 (23%) with standard treatment alone; risk ratio (RR) 1.12, 95% confidence interval (CI) 0.49 to 2.56. One trial compared fosfomycin plus imipenem 3/4 (75%) versus vancomycin 0/4 (0%) (RR 7.00, 95% CI 0.47 to 103.27), and one trial compared partial oral treatment 7/201 (3.5%) versus conventional intravenous treatment 13/199 (6.53%) (RR 0.53, 95% CI 0.22 to 1.31). The results for rates of cure with or without surgery were as follows: one trial compared daptomycin versus low-dose gentamicin plus an antistaphylococcal penicillin (nafcillin, oxacillin, or flucloxacillin) or vancomycin and reported 9/28 (32.1%) with daptomycin versus 9/25 (36%) with low-dose gentamicin plus antistaphylococcal penicillin or vancomycin; RR 0.89, 95% CI 0.42 to 1.89. One trial compared glycopeptide (vancomycin or teicoplanin) plus gentamicin with cloxacillin plus gentamicin (13/23 (56%) versus 11/11 (100%); RR 0.59, 95% CI 0.40 to 0.85). One trial compared ceftriaxone plus gentamicin versus ceftriaxone alone (15/34 (44%) versus 21/33 (64%); RR 0.69, 95% CI 0.44 to 1.10), and one trial compared fosfomycin plus imipenem versus vancomycin (1/4 (25%) versus 2/4 (50%); RR 0.50, 95% CI 0.07 to 3.55). The included trials reported adverse events, the need for cardiac surgical interventions, and rates of uncontrolled infection, congestive heart failure, relapse of endocarditis, and septic emboli, and found no conclusive differences between groups (very low-quality evidence). No trials assessed quality of life.

AUTHORS' CONCLUSIONS

This first update confirms the findings of the original version of the review. Limited and low to very low-quality evidence suggests that the comparative effects of different antibiotic regimens in terms of cure rates or other relevant clinical outcomes are uncertain. The conclusions of this updated Cochrane Review were based on few RCTs with a high risk of bias. Accordingly, current evidence does not support or reject any regimen of antibiotic therapy for the treatment of infective endocarditis.