Early identification of patients with native valve infectious endocarditis at risk for major complications by initial clinical presentation and baseline echocardiography

What size of vegetation is an indication for surgery in endocarditis?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether the of vegetations in endocarditis is an indication for surgery. Altogether, 102 papers were found using the reported search; 16 papers were identified that provided the best evidence to answer the question. The authors, journal, date, country of publication, patient group, study type, relevant outcomes and results were tabulated. The vegetation size was classified into small (<5 mm), medium (5-9 mm), or large (≥10 mm) using echocardiography and a vegetation size of ≥10 mm was a predictor of embolic events and increased mortality in most of the studies with left-sided infective endocarditis. For large vegetations--that commonly resulted from the failure of antibiotics to decrease the vegetation size during 4-8 weeks' therapy--and complications such as perivalvular abscess formation, valvular destruction and persistent pyrexia necessitated surgical intervention. In a multicentre prospective cohort study of 384 consecutive patients with infective endocarditis, it was observed that a vegetation size of >10 mm and severe vegetation mobility were predictors of new embolic events. Equally, a meta-analysis showed that the echocardiographic detection of a vegetation size of ≥10 mm in patients with left-sided infective endocarditis posed significantly increased risk of embolic events. In another prospective cohort study of 211 patients, it was observed that there was an increased risk of embolization with vegetations of ≥10 mm. In similarly another study of 178 consecutive patients with infective endodarditis assessed by echocardiographic study, it was found out that there was a significantly higher incidence of embolism with a vegetation size >10 mm (60%, P<0.001). When using the area of the vegetation, a vegetation size of >1.8 cm(2) predicted the development of a complication. Assuming that the vegetation was a sphere, the calculated diameter will be 8 mm when using 4Ωr(2) for the area. However, for right-sided infection endocarditis, a vegetation size of >20 mm was associated with a higher mortality when compared with a vegetation size of ≤20 mm. There is strong evidence to suggest that a vegetation size of ≥10 mm especially for left-sided infective endocarditis is an indication for surgery.

Prognostic stratification of patients with left-sided endocarditis determined at admission

BACKGROUND

The prognosis of patients with left-sided endocarditis remains poor despite the progress of surgical techniques. Identification of high-risk patients within the first days after admission to the hospital would permit a more aggressive therapeutic approach.

METHODS

We designed a prospective multicenter study to find out the clinical, microbiologic, and echocardiographic characteristics available within 72 hours of admission that might define the profile of high-risk patients. Of 444 episodes, 317 left-sided endocarditis cases were included and 76 variables were assessed. Events were surgery in the active phase of the disease and in-hospital death. A stepwise logistic regression analysis was undertaken to determine variables predictive of events.

RESULTS

Multivariate analysis of the clinical variables found to have statistical significance in the univariate analysis identified the following as predictive: patient referred from another hospital (odds ratio [OR]: 1.8; confidence interval [CI], 1.1-2.9), atrioventricular block (OR: 2.5; CI, 1.1-5.9), acute onset (OR: 1.7; CI, 1.1-2.9), and heart failure at admission (OR: 2.3; CI, 1.4-3.8). When the echocardiographic and microbiological variables statistically significant in the univariate analysis were introduced, the presence of heart failure at admission (OR: 2.9; CI, 1.8-4.8), periannular complications (OR: 1.8; CI, 1.1-3.1), and Staphylococcus aureus infection (OR: 2.0; CI, 1.1-3.8) retained prognostic power. Risk could be accurately stratified when combining the 3 variables with predictive power: 0 variables present: 25% of risk; 1 variable present: 38% to 49% of risk; 2 variables present: 56% to 66% of risk; and 3 variables present: 79% of risk.

CONCLUSIONS

The risk of patients with left-sided endocarditis can be accurately stratified with the assessment of variables easily available within 72 hours of admission to the hospital.

Risk factors for "major" embolic events in hospitalized patients with infective endocarditis

BACKGROUND

Infective endocarditis often is complicated by embolic events after hospital admission. Identifying patients at higher risk may improve the disease outcome. This study was aimed at identifying predictors of embolic risk among the clinical and laboratory data obtained on hospital admission in patients diagnosed as having definite infective endocarditis according to the Duke criteria.

METHODS

Ninety-four patients were enrolled in a prospective study. The results of hematologic, echocardiographic, and microbiological investigations were analyzed, using statistical methods as appropriate. Multivariate analysis was applied to variables significantly associated with embolism in univariate analysis.

RESULTS

Forty-six percent of patients had a major embolic complication after admission. No association was found between embolism and sex, site of infection, or microorganism involved. Patients with embolism were significantly younger, had larger vegetation, and showed a significantly higher level of serum C-reactive protein and lower albumin concentrations than those without embolism. Young age, larger vegetation size, and high levels of C-reactive protein were the independent variables associated with an increased incidence of embolic events in the multivariate logistic regression analysis.

CONCLUSIONS

Our data indicate that patients with infective endocarditis with young age and/or with large vegetation and/or with high serum levels of C-reactive protein are at increased risk of major embolic complications during the in-hospital course of the disease.

Infective endocarditis in the injection drug user

Although infective endocarditis is certainly not the most common infection seen in injecting drug users, it is the infection that clinicians most commonly think of when they consider infectious complications of injected drug use. The microbiology of infective endocarditis in injection drug users has remained relatively stable over the last several decades. Tricuspid valve endocarditis has been associated most frequently with injection drug use, but recent reports have suggested that involvement of left-sided valves is seen more often now than in the past. The use of transesophageal echocardiography has greatly advanced the ability to diagnose infective endocarditis and the cardiac complications of valvular infection.

Effect of penicillin resistance of Streptococcus pneumoniae on the presentation, prognosis, and treatment of pneumococcal endocarditis in adults

We performed a clinical study of pneumococcal endocarditis (PE) in adults at 15 major Spanish hospitals during a 21-year period (1978-1998). During this time, 63 patients had PE due to Streptococcus pneumoniae diagnosed. Of the 63 isolates recovered from these patients, 24 (38%) and 6 (10%) showed resistance to penicillin (minimum inhibitory concentration [MIC], 0.1-4 microg/mL) and cefotaxime (MIC, 1 microg/mL), respectively. Twenty-two (35%) of the patients died. Left-side heart failure, but not penicillin resistance, was independently associated with a higher risk of death (odds ratio, 1.33; 95% confidence interval, 1.04-1.71; P=.026). Patients without meningitis who had PE due to penicillin-resistant S. pneumoniae could be treated with high-dose penicillin or a third-generation cephalosporin if the MIC for penicillin was < or =1 microg/mL. For patients with concurrent meningitis, high doses of cefotaxime could be used if the MIC for cefotaxime was < or =1 microg/mL. Early recognition of heart failure and surgery may help to decrease mortality.

Patient selection criteria and management guidelines for outpatient parenteral antibiotic therapy for native valve infective endocarditis

Outpatient parenteral antibiotic therapy (OPAT) for infective endocarditis (IE) is being applied widely, despite the absence of controlled data that demonstrates that outcomes are equivalent to those with standard inpatient antibiotic therapy. We review existing OPAT guidelines, published data on the timing of complications from IE, and data on risk factors that can be used to predict complications. These data are used to propose more stringent criteria for patient selection and clinical management of OPAT for native valve IE. We recommend a conservative approach (inpatient or daily outpatient follow-up) during the critical phase (weeks 0-2 of treatment), when complications are most likely, and we recommend consideration of OPAT for the continuation phase (weeks 2-4 or 2-6 of treatment) when life-threatening complications are less likely.

[Isolated pulmonary endocarditis on native valve in elderly patient without predisposing factors]

Isolated infective endocarditis in the native pulmonary valve is an unusual clinical entity in patients without predisposing factors and in non-intravenous drugs users. We present the case of a 75-year-old patient, with a subacute clinical picture of fever and pulmonary cavity nodules, admitted to our hospital with an initial suspected diagnosis of pulmonary tuberculosis. The presence of Enterococcal bacteremia in hemocultive and the documentation of a large vegetation in pulmonary valve by transtoracic and transesophageal echocardiography were key factors for final diagnosis.