Value of transthoracic echocardiography in predicting embolic events in active infective endocarditis. Duke Endocarditis Service

Evaluation of inter-observer variability regarding aortic and mitral valve findings on transesophageal echocardiograms ordered for suspected endocarditis

Background

Transesophageal echocardiography (TEE) is the gold standard for the detection of valvular vegetations (VV). Differentiating small VV from degenerative changes is challenging and prone to inter‐observer variability. We evaluated inter‐observer agreement regarding aortic (AV) and mitral valve (MV) findings on TEEs ordered for suspected infective endocarditis (IE).

Methods

A total of 349 consecutive TEEs were evaluated. Studies were classified as “definite, possible, or no” IE with valve masses classified further by morphology. Nine faculty echocardiographers scored randomly selected TEEs of the AV (N = 38) and MV (N = 35). Inter‐reader variability was calculated using the Fleiss/Scott Kappa (Kf).

Results

Positive blood cultures were present in 81% and 45% had definite IE by the modified Duke criteria. There was moderate reader agreement regarding the presence of a valvular mass for both the AV (Kf = .41, 95% CI [.30–.53]) and MV (Kf = .49, 95% CI [.34–.65]). For diagnosis of IE, there was fair agreement for the AV (Kf = .29, 95% CI [.18–.42]) and moderate agreement for the MV (Kf = .53, 95% CI [.36–.70]). Masses described as large, multi‐lobulated, or pedunculated were more frequently categorized as clinical IE, (p < .006, both valves), however those with filamentous lesions were not (p < .001, both valves).

Conclusions

In a large academic center, the inter‐observer agreement for the presence of a left sided valvular mass was moderate and agreement regarding the final diagnosis of IE was fair to moderate, with better agreement among readers evaluating the MV. Lesion morphology is associated with the clinical diagnosis of IE.

Neurological Complications in Patients with Infective Endocarditis: Insights from a Tertiary Centre

Fundamento:

Complicações neurológicas são comuns em pacientes com endocardite infecciosa (EI). Dados recentes sugerem que os eventos neurológicos são os principais determinantes do prognóstico e que a cirurgia é crítica para melhorar o resultado.

Objetivo:

Caracterizar pacientes com EI e complicações neurológicas e determinar preditores de embolização para o sistema nervoso central (SNC) e mortalidade.

Métodos:

Análise retrospectiva de pacientes internados em centro terciário com diagnóstico de EI no período de 2006 a 2016. Significância estatística foi definida por um valor de p <0,05.

Resultados:

Identificamos 148 episódios de EI, 20% dos quais tinham evidências de embolização do SNC. Em pacientes com embolização do SNC, 76% apresentaram acidente vascular cerebral isquêmico. Durante o seguimento, 35% foram submetidos à cirurgia e a mortalidade hospitalar e em um ano foi de 39%. Esses pacientes tiveram hospitalizações mais longas, mas não houve diferenças significativas em relação à mortalidade em pacientes com e sem embolização do SNC. Os preditores independentes de complicações neurológicas foram diabetes (p = 0,005) e ausência de febre na apresentação (p = 0,049). A cirurgia foi associada a menor mortalidade (0 vs. 58%; p = 0,003), enquanto os pacientes com choque séptico tiveram pior prognóstico (75 vs. 25%; p = 0,014). Na regressão multivariada de Cox, a infecção pelo vírus da imunodeficiência humana (HIV) foi o único preditor independente de mortalidade hospitalar e de 1 ano (p = 0,011 em ambos).

Conclusões:

Nessa população, a embolização para o SNC foi comum, mais frequentemente apresentada como acidente vascular cerebral isquêmico, e esteve associada a maior tempo de internação, embora sem diferenças significativas na mortalidade. Nos pacientes com embolização do SNC, os submetidos à cirurgia tiveram boa evolução clínica, enquanto os pacientes com choque séptico e infecção pelo HIV tiveram pior evolução. Esses resultados devem ser interpretados com cautela, levando em consideração que os pacientes com complicações mais graves ou mais frágeis foram provavelmente menos considerados para a cirurgia, resultando em viés de seleção.

Association of Vegetation Size With Valve Destruction, Embolism and Mortality

AIM

The mortality of patients with infective endocarditis (IE) is high. The management of patients with large vegetations is controversial. This study sought to investigate the association of vegetation size on outcomes including valve destruction, embolism and mortality.

METHODS AND RESULTS

One hundred and forty-two (142) patients with definite IE and transoesophageal echocardiography (TEE) imaging available for analysis were identified and data retrospectively reviewed. Vegetation length, width and area were measured. Severe valve destruction was defined as the composite of one or more of severe valve regurgitation, abscess, pseudoaneurysm, perforation or fistula. Associations with 6-month mortality were identified by Cox regression analysis. Eighty (80) (56.3%) patients had evidence of valve destruction on TEE. Vegetation length ≥10 mm and vegetation area ≥50 mm² were significantly associated with increased risk of valve destruction, (both odds ratio OR 1.21, p=0.03 and p=0.02 respectively). Thirty-nine (39) (72.2%) patients who had an embolic event, did so prior initiation of antibiotics. Six (6)-month mortality was 18.3%. In the surgically managed group, vegetation size was not associated with mortality. In the medically managed group, vegetation area (mm²) was associated with increased mortality (HR 1.01, p<0.01) along with age (HR 1.06, p=0.03).

CONCLUSION

Vegetation length ≥10 mm or area ≥50 mm² are associated with increased risk of valve destruction. Vegetation size may also predict mortality in medically managed but not surgically managed patients with IE. Further studies to evaluate whether surgery in patients with large vegetation size improves outcomes is warranted.

Infections after transcatheter versus surgical aortic valve replacement: mid-term results of 200 consecutive patients

Background

Transcatheter aortic valve implantation (TAVI) is the standard therapy for high-risk patients with aortic stenosis (AS). TAVI-outcomes are widely investigated in comparison to surgical aortic valve replacement (SAVR), but less is known about infectious complications after TAVI. We aimed to compare early and mid-term infectious outcomes of patients undergoing TAVI or SAVR.

Methods

The present study is a prospective single-centre study including 200 consecutive patients between 06/2014-03/2015 undergoing TAVI (either transfemoral or transapical and transaortic, n=47+53=100) or SAVR (either isolated or concomitant with CABG, n=52+48=100). The mean age and log. EuroSCORE were significantly different between both groups (81±6 versus 69±11 years, P<0.001 and 23.1%±13.8% versus 8.7%±9.5%, P<0.001). Primary endpoints included wound healing disorders, respiratory and urinary tract infections and incidence of endocarditis or sepsis within hospital stay. Secondary endpoints included infectious parameters, infectious related rehospitalisation and 2-year mortality.

Results

Primary endpoints showed no difference in overall TAVI- versus SAVR-groups regarding respiratory- (14% versus 19%, P=0.45), urinary-tract (7% versus 4%, P=0.54) infections, sepsis (5% versus 6%, P=1.0), endocarditis (0% versus 1%, P=1.0) or 30-day mortality (10% versus 4%, P=0.09), except for wound disorders, which were significantly lower in the TAVI-group (1% versus 8%, P=0.035), respectively. Secondary endpoints reported no difference regarding infectious related rehospitalisation (4% versus 4%, P=1.0), but significantly higher 2-year mortality (28% versus 16%, P=0.048) in the TAVI-group.

Conclusions

So far, little has been studied about infectious complications after TAVI. This study reports no difference between the overall TAVI and SAVR groups regarding infectious complications. However, SAVR group show more wound healing disorders but less mortality than TAVI group.

[Which patients with infective endocarditis require emergency surgery?]

Half of patients with infectious endocarditis have surgery during the active phase of infective endocarditis (before the end of antibiotic therapy). The American Heart Association and the European Society of Cardiology, independently from each other, have published guidelines in September 2015. As regards surgical indications, these guidelines are similar. The surgical indication must be a common decision of a multidisciplinary team of experts in cardiology, cardiac surgery, imaging and infectious diseases. The main indications are heart failure, non-infectious process control and prevention of embolisms.

Echocardiographic agreement in the diagnostic evaluation for infective endocarditis

Echocardiography is essential for the diagnosis and management of infective endocarditis (IE). However, the reproducibility for the echocardiographic assessment of variables relevant to IE is unknown. Objectives of this study were: (1) To define the reproducibility for IE echocardiographic variables and (2) to describe a methodology for assessing quality in an observational cohort containing site-interpreted data. IE reproducibility was assessed on a subset of echocardiograms from subjects enrolled in the International Collaboration on Endocarditis registry. Specific echocardiographic case report forms were used. Intra-observer agreement was assessed from six site readers on ten randomly selected echocardiograms. Inter-observer agreement between sites and an echocardiography core laboratory was assessed on a separate random sample of 110 echocardiograms. Agreement was determined using intraclass correlation (ICC), coverage probability (CP), and limits of agreement for continuous variables and kappa statistics (κweighted) and CP for categorical variables. Intra-observer agreement for LVEF was excellent [ICC = 0.93 ± 0.1 and all pairwise differences for LVEF (CP) were within 10 %]. For IE categorical echocardiographic variables, intra-observer agreement was best for aortic abscess (κweighted = 1.0, CP = 1.0 for all readers). Highest inter-observer agreement for IE categorical echocardiographic variables was obtained for vegetation location (κweighted = 0.95; 95 % CI 0.92-0.99) and lowest agreement was found for vegetation mobility (κweighted = 0.69; 95 % CI 0.62-0.86). Moderate to excellent intra- and inter-observer agreement is observed for echocardiographic variables in the diagnostic assessment of IE. A pragmatic approach for determining echocardiographic data reproducibility in a large, multicentre, site interpreted observational cohort is feasible.

Cytokine Signature in Infective Endocarditis

Infective endocarditis (IE) is a severe disease with high mortality rate. Cytokines participate in its pathogenesis and may contribute to early diagnosis improving the outcome. This study aimed to evaluate the cytokine profile in IE. Serum concentrations of interleukin (IL)-1β, IL-6, IL-8, IL-10, IL-12 and tumor necrosis factor (TNF)-α were measured by cytometric bead array (CBA) at diagnosis in 81 IE patients, and compared with 34 healthy subjects and 30 patients with non-IE infections, matched to the IE patients by age and gender. Mean age of the IE patients was 47±17 years (range, 15–80 years), and 40 (50%) were male. The IE patients had significantly higher serum concentrations of IL-1β, IL-6, IL-8, IL-10 and TNF-α as compared to the healthy individuals. The median levels of IL-1β, TNF-α and IL-12 were higher in the IE than in the non-IE infections group. TNF-α and IL-12 levels were higher in staphylococcal IE than in the non-staphylococcal IE subgroup. There was a higher proportion of both low IL-10 producers and high producers of IL-1β, TNF-α and IL-12 in the staphylococcal IE than in the non-staphylococcal IE subgroup. This study reinforces a relationship between the expression of proinflammatory cytokines, especially IL-1β, IL-12 and TNF-α, and the pathogenesis of IE. A lower production of IL-10 and impairment in cytokine network may reflect the severity of IE and may be useful for risk stratification.

Transesophageal echocardiography: a complementary view of the heart

Transesophageal echocardiography has been widely used as a diagnostic tool during the past two decades to detect cardiac abnormalities that are not visible or poorly visible with transthoracic echocardiography. At present, transesophageal echocardiography is a cornerstone of modern diagnosis of several cardiac diseases, providing diagnostic, prognostic and therapeutic information. In this review, the present status of transesophageal echocardiography not only as a diagnostic tool, underlining its effects on clinical decision making, but also as a monitoring adjunct for many interventional cardiac procedures is examined.

Neurological Complications of Infective Endocarditis

Background—

The purpose of this study was to assess the incidence of neurological complications in patients with infective endocarditis, the risk factors for their development, their influence on the clinical outcome, and the impact of cardiac surgery.

Methods and Results—

This was a retrospective analysis of prospectively collected data on a multicenter cohort of 1345 consecutive episodes of left-sided infective endocarditis from 8 centers in Spain. Cox regression models were developed to analyze variables predictive of neurological complications and associated mortality. Three hundred forty patients (25%) experienced such complications: 192 patients (14%) had ischemic events, 86 (6%) had encephalopathy/meningitis, 60 (4%) had hemorrhages, and 2 (1%) had brain abscesses. Independent risk factors associated with all neurological complications were vegetation size ≥3 cm (hazard ratio [HR] 1.91), Staphylococcus aureus as a cause (HR 2.47), mitral valve involvement (HR 1.29), and anticoagulant therapy (HR 1.31). This last variable was particularly related to a greater incidence of hemorrhagic events (HR 2.71). Overall mortality was 30%, and neurological complications had a negative impact on outcome (45% of deaths versus 24% in patients without these complications; P <0.01), although only moderate to severe ischemic stroke (HR 1.63) and brain hemorrhage (HR 1.73) were significantly associated with a poorer prognosis. Antimicrobial treatment reduced (by 33% to 75%) the risk of neurological complications. In patients with hemorrhage, mortality was higher when surgery was performed within 4 weeks of the hemorrhagic event (75% versus 40% in later surgery).

Conclusions—

Moderate to severe ischemic stroke and brain hemorrhage were found to have a significant negative impact on the outcome of infective endocarditis. Early appropriate antimicrobial treatment is critical, and transitory discontinuation of anticoagulant therapy should be considered.

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.

Profile of infective endocarditis at a tertiary care center in Brazil during a seven-year period: prognostic factors and in-hospital outcome

OBJECTIVES

To describe the epidemiological, clinical, and laboratory profile of infective endocarditis (IE) at a Brazilian tertiary care center, and to identify the predictors of in-hospital mortality.

METHODS

Data from 62 patients who fulfilled the modified Duke's criteria for IE during a seven-year period were gathered prospectively. The Cox proportional hazards model was used to identify predictive factors for death.

RESULTS

The mean age of patients was 45 years, and 39 patients (63%) were male. The median time from admission to diagnosis was 15 days. Rheumatic heart disease was the predominant underlying heart condition (39%), followed by valvular prosthesis (31%). Neurological complications were observed in 12 patients (19%). Echocardiography demonstrated one or more vegetations in 84% of cases. The infective agent was identified in 65% of cases, and the most frequent causative agents were staphylococci (48%), followed by streptococci (20%). The median duration of hospitalization was 39 days. Surgery was performed during the acute phase of the IE in 53% of cases. The overall in-hospital mortality was 31%. On multivariate analysis, vegetation length >13mm remained the only independent predictor of in-hospital mortality (hazard ratio 1.05 per millimeter, 95% confidence interval 1.003-1.110, p=0.038).

CONCLUSIONS

IE remains a severe disease affecting the young population in Brazil, and rheumatic heart disease continues to be the most common underlying heart condition. Large vegetation size, assessed early in the course of IE by transesophageal echocardiography, along with the clinical and microbiological features, may predict in-hospital death.

Relative value of clinical and transesophageal echocardiographic variables for risk stratification in patients with infective endocarditis

BACKGROUND

Infective endocarditis remains a life-threatening disease, and its optimal management is of paramount importance. Transesophageal echocardiography (TEE) is useful for the diagnosis of endocarditis-induced lesions, but the prognostic significance of the method remains controversial.

HYPOTHESIS

The purpose of this study was to relate clinical and TEE characteristics to the occurrence of mortality and/or systemic embolization in a consecutive series of 45 patients with a diagnosis of infective endocarditis.

METHODS

All patients underwent at least one monoplane TEE. Clinical data, episodes of embolization, and echocardiographic characteristics were prospectively recorded. Stepwise logistic discriminant analysis was performed to identify the independent variables that best predicted three binary outcomes: systemic embolization, death, and systemic embolization and/or death.

RESULTS

Twelve of the 45 patients (27%) died from the endocarditis. Significant univariate predictors of death were the presence of paravalvular abscess (p = 0.025), number of vegetations (p = 0.021), Staphylococcus aureus isolated in blood cultures (p = 0.002), medical treatment alone (p < 0.002), and systemic embolism (p < 0.001). In multivariate analysis, systemic embolism (chi 2 = 29.3; p < 0.01), echocardiographic evidence of paravalvular abscess (chi 2 = 5.6; p = 0.018), Staphylococcus aureus endocarditis (chi 2 = 5.5; p = 0.016), and medical treatment alone (chi 2 = 5.11; p = 0.024) emerged as optimal predictors of death. Systemic embolization occurred in 12 patients. Independent variables predicting systemic embolization were a total length of vegetations > 14 mm (p = 0.01), greater age (p = 0.02), and medical treatment alone (p = 0.03). When two or more vegetations were observed, the total length is the sum of the individual sizes. Independent risk factors for the development of systemic emboli and/or death as a combined end point were total length of vegetations on TEE (chi 2 = 6.4; p = 0.003) and medical treatment alone (chi 2 = 4.1; p = 0.047).

CONCLUSIONS

High-risk patients may be identified by the combination of clinical variables and TEE characteristics.

[Timing and indications for surgical intervention in infective endocarditis]

This paper reviews current knowledge on the indications for and timing of cardiac surgery in patients with infective endocarditis. The main indications for surgery are haemodynamic compromise, persisting infection, peripheral embolisation, large size of vegetations, large valvular and paravalvular damage and infections caused by certain microorganisms.

Complexity and subtlety of infective endocarditis

Infective endocarditis (IE) is an uncommon clinical entity that, if unrecognized, leads to serious morbidity and mortality. Approximately 15,000 new cases of IE occur in the United States each year. Despite advances in early diagnosis, antimicrobial treatment, and surgical techniques, reported mortality from referral centers has changed little throughout several decades. Early recognition of IE requires understanding of its epidemiology, risk factors, clinical presentations, physical examination signs, microbiological associations, and electrocardiographic and chest radiographic findings. Once IE is suspected, further testing with blood cultures and echocardiography can confirm the diagnosis and lead to early treatment with bactericidal antibiotics and surgery when appropriate, thus reducing the morbidity and mortality of IE. Unrecognized and untreated, IE is invariably fatal. Early recognition of IE and an in-depth understanding of the clinical vagaries of IE are mandatory for all patient care providers.

Infective endocarditis: diagnosis, antimicrobial therapy, and management of complications: a statement for healthcare professionals from the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease, Council on Cardiovascular Disease in the Young, and the Councils on Clinical Cardiology, Stroke, and Cardiovascular Surgery and Anesthesia, American Heart Association: endorsed by the Infectious Diseases Society of America

BACKGROUND

Despite advances in medical, surgical, and critical care interventions, infective endocarditis remains a disease that is associated with considerable morbidity and mortality. The continuing evolution of antimicrobial resistance among common pathogens that cause infective endocarditis creates additional therapeutic issues for physicians to manage in this potentially life-threatening illness.

METHODS AND RESULTS

This work represents the third iteration of an infective endocarditis "treatment" document developed by the American Heart Association under the auspices of the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease, Council on Cardiovascular Disease of the Young. It updates recommendations for diagnosis, treatment, and management of complications of infective endocarditis. A multidisciplinary committee of experts drafted this document to assist physicians in the evolving care of patients with infective endocarditis in the new millennium. This extensive document is accompanied by an executive summary that covers the key points of the diagnosis, antimicrobial therapy, and management of infective endocarditis. For the first time, an evidence-based scoring system that is used by the American College of Cardiology and the American Heart Association was applied to treatment recommendations. Tables also have been included that provide input on the use of echocardiography during diagnosis and treatment of infective endocarditis, evaluation and treatment of culture-negative endocarditis, and short-term and long-term management of patients during and after completion of antimicrobial treatment. To assist physicians who care for children, pediatric dosing was added to each treatment regimen.

CONCLUSIONS

The recommendations outlined in this update should assist physicians in all aspects of patient care in the diagnosis, medical and surgical treatment, and follow-up of infective endocarditis, as well as management of associated complications. Clinical variability and complexity in infective endocarditis, however, dictate that these guidelines be used to support and not supplant physician-directed decisions in individual patient management.

Analysis of mortality and risk factors associated with native valve endocarditis in drug users: the importance of vegetation size

BACKGROUND

Native valve endocarditis in drug-user patients had a microbiology, a frequency of involvement of different cardiac valves, and a prognosis that differ from those in non-drug users. A retrospective study of native valve endocarditis cases in intravenous drug users diagnosed from 1985 to 1999 in our institution was performed to analyze the inhospital mortality of drug users with native valve endocarditis and to identify factors predictive of mortality.

METHODS

All patients fulfilled the Duke's criteria for definite or probable endocarditis. Analysis of predictors of inhospital mortality was restricted to right-sided infective endocarditis (IE) with definite diagnosis and echocardiographic data. The following variables were analyzed: sex, HIV serostatus, CD4 cell count < 200/mm3, time of IE diagnosis (before 1993 or after 1993), previous valvulopathy, polymicrobial IE, fungal etiology (mixed or alone), neurological complication, arterial emboli, pulmonary emboli, congestive heart failure, vegetation size (VS) > 2 cm, and inhospital cardiac surgery. Logistic regression was used in a multivariate model to identify factors independently associated with mortality. Adjusted odds ratios (OR) and 95% CIs were examined.

RESULTS

Four hundred ninety-three cases of IE were diagnosed in this period. Two hundred twenty cases of native valve endocarditis in intravenous drug users were identified. Fourteen cases in this group died (6%). Mean time from diagnosis to death was 18.5 +/- 15 days (range, 3-52). Vegetation size was available in 111 cases. Univariate analysis identified the following variables associated with inhospital mortality in right-sided cases: VS > 2 cm and fungal etiology. In multivariate analysis, the variables associated with mortality that achieved statistical significance were size of vegetation > 2 cm (P = .014, OR 10.2, 95% CI 1.6-78.0) and fungal etiology (P = .009, OR 46.2, 95% CI 2.4-1100.9).

CONCLUSIONS

The main prognostic factors of inhospital mortality in right-sided IE in drug users in our series were VS > 2 cm and fungal etiology. The role of early surgery in these patients should be reevaluated.

Risk of Embolism and Death in Infective Endocarditis: Prognostic Value of Echocardiography

Background— The incidence of embolic events (EE) and death is still high in patients with infective endocarditis (IE), and data about predictors of these 2 major complications are conflicting. Moreover, the exact role of echocardiography in risk stratification is not well defined.

Methods and Results— In a multicenter prospective European study, including 384 consecutive patients (aged 57±17 years) with definite IE according to Duke University criteria, we tested clinical, microbiological, and echocardiographic data as potential predictors of EE and 1-year mortality. Transesophageal echocardiography was performed in all patients. Embolism occurred before or after IE diagnosis (total-EE) in 131 patients (34.1%) and after initiation of antibiotic therapy (new-EE) in 28 patients (7.3%). Staphylococcus aureus and Streptococcus bovis were independently associated with total-EE, whereas vegetation length >10 mm and severe vegetation mobility were predictors of new-EE, even after adjustment for S aureus and S bovis . One-year mortality was 20.6%. In multivariable analysis, independently of the other predictors of death (age, female sex, creatinine serum >2 mg/L, moderate or severe congestive heart failure, and S aureus ) and comorbidity, vegetation length >15 mm was a predictor of 1-year mortality (adjusted relative risk=1.8; 95% CI, 1.10 to 2.82; P =0.02).

Conclusions— In IE, vegetation length is a strong predictor of new-EE and mortality. In combination with clinical and microbiological findings, echocardiography may identify high-risk patients who will need a more aggressive therapeutic strategy.

Embolic risk in subacute bacterial endocarditis: Determinants and role of transesophageal echocardiography

Embolic events are a frequent and life-threatening complication of subacute bacterial endocarditis (SBE) and are associated with a high mortality and morbidity. The prediction of the embolic risk in an individual patient remains a challenge. Echocardiography plays a key role in the management of infective endocarditis both for the diagnostic and prognostic assessment of these patients, but its value in predicting embolic events is still debated. This review focuses on the characteristics of embolic events in SBE, and on the role of echocardiography, especially transesophageal echocardiography (TEE), in the prediction of embolic events. The review confirms that, among other factors, TEE may be helpful in both the prediction of the embolic risk and the decision to perform early surgery.

Embolic events in infective endocarditis: a review and report of 4 cases

Infective endocarditis (IE) remains a dangerous disease in terms of morbidity and mortality. Valve damage with or without congestive heart failure, paravalvular extension, embolization of vegetation, damage due to immunological involvement and septic shock are the main complications of IE. Embolic events are frequent and life-threatening complications of IE. In previous series, the reported figures of embolic complication vary from 10 to 50%. We describe four cases of patients with IE and peripheral embolization. In this paper, we will briefly discuss the role of echocardiography, infective microorganisms and clinical aspects in the prediction of an embolic event. Therapeutic strategies are discussed.

Risk of endocarditis among patients with prosthetic valves and Staphylococcus aureus bacteremia

PURPOSE

Staphylococcus aureus is a common cause of bacteremia and of native valve infective endocarditis. However, the risk of endocarditis in patients with a prosthetic valve who develop S. aureus bacteremia is unclear. The aim of this study was to define the risk of prosthetic valve endocarditis in patients with S. aureus bacteremia.

SUBJECTS AND METHODS

All patients with a prosthetic valve or ring who developed S. aureus bacteremia during the 94-month study period were prospectively evaluated. The modified Duke criteria were used for the diagnosis of endocarditis. Patients were followed up for 12 weeks after the initial diagnosis of S. aureus bacteremia.

RESULTS

The overall rate of definite prosthetic valve endocarditis among the study patients was 26/51 (51%). The risk of endocarditis was similar in patients with late (>or=12 months after valve implantation) vs. early S. aureus bacteremia (<12 months after prosthetic valve implantation) (50% vs. 52%, P=1.0), mitral vs. aortic prostheses (62% vs. 48%, P=0.24), and mechanical vs. bioprosthetic valves (62% vs. 44%, P=0.29). The 12-week mortality was higher among patients with definite vs. possible endocarditis (62% vs. 28%, P=0.019).

CONCLUSION

In this investigation, approximately half of all patients with prosthetic valves who developed S. aureus bacteremia had definite endocarditis. The risk of endocarditis was independent of the type, location, or age of the prosthetic valve. The mortality of prosthetic valve endocarditis is high. All patients with a prosthetic valve who develop S. aureus bacteremia should be aggressively screened and followed for endocarditis.

Early predictors of in-hospital death in infective endocarditis

BACKGROUND

Data on early determinants of outcome in infective endocarditis (IE) are limited. We evaluated the prognostic significance of early clinical characteristics in a large, prospective cohort of patients with IE.

METHODS AND RESULTS

Two hundred sixty-seven consecutive patients with definite or possible IE by modified Duke criteria and echocardiography performed within 7 days of presentation were evaluated. Acute physiology was assessed by the Acute Physiology, Age, Chronic Health Evaluation II (APACHE II) score at the time of presentation, and early heart failure was diagnosed by Framingham criteria. In-hospital mortality rate in the cohort was 19% and similar for patients with definite or possible IE (20% versus 16%, respectively; P=0.464). Independent predictors of death determined by logistic regression modeling were diabetes mellitus (OR 2.48; 95% CI, 1.24 to 4.96), Staphylococcus aureus as causative organism (OR, 2.06; 95% CI, 1.01 to 4.20), APACHE II score (OR, 1.07; 95% CI, 1.01 to 1.12), and embolic event (OR, 2.79; 95% CI, 1.15 to 6.80). Early echocardiographic findings of the Duke criteria were not predictive of death.

CONCLUSIONS

Early in the course of IE, readily available clinical characteristics that reflect the host-pathogen interaction are predictive of in-hospital death. These factors may identify those patients with IE for more aggressive treatment.

Risk factors for systemic emboli in infective endocarditis

A retrospective study was undertaken to analyse the risk factors for systemic emboli in infective endocarditis. Patients (n = 80; 70% males; mean age 65 years; range 20-91 years) with infective endocarditis, as defined by the Duke criteria and diagnosed using transoesophageal echocardiography during the period January 1995 to March 2001, were included. The average time between the start of the illness and the beginning of antibiotic treatment was 55 days (range 0-405 days). The pathogens identified were streptococci (n = 47), staphylococci (n = 11), enterococci (n = 9), and others (n = 4). In nine cases, blood cultures were sterile. Thirty patients with at least one embolic episode were compared with 50 control patients. According to univariate analysis, the main risk factor for systemic emboli was the size of the vegetation (12.4 mm vs. 7.8 mm; p = 0.0005). The risk of emboli was 57% when the vegetation measured > 10 mm and only 22% when it was < 10 mm (p = 0.003). The mobility of the vegetation was also a risk factor: 48% if the vegetation was mobile; and 9% if fixed (p = 0.003). Sex, age, pathogen, antibiotic treatment, type of valve and the number and position of the vegetations were not found to be risk factors. With multivariate analysis, only mobility was identified as a risk factor. Overall, mobile vegetations > 10 mm in size were associated with an increased risk of embolic episodes in infective endocarditis.

Stroke location, characterization, severity, and outcome in mitral vs aortic valve endocarditis

OBJECTIVE

To characterize the incidence and clinical features of patients with infective endocarditis (IE) and stroke.

METHODS

The authors reviewed the records of 707 patients diagnosed with definite or possible IE between January 1984 and November 1999. Stroke was confirmed by application of strict definitions and classified by type, pathophysiology, vascular territory, and severity. The authors determined mortality rates for the initial hospitalization and 12 months after admission.

RESULTS

Strokes occurred in 68 (9.6%) of 707 patients with IE, 38 (17%) of 218 patients with mitral valve endocarditis (MVE), 14 (9%) of 149 patients with aortic valve endocarditis (AVE), and 16 (5%) of 340 patients with other forms of IE (OR for MVE vs AVE = 2.0, 95% CI 1.1 to 3.9). Among the patients with MVE or AVE and stroke, there were no significant relationships between site of vegetation and length of hospitalization, stroke severity, mortality during the initial hospitalization, or 12-month mortality. Fifty-two percent of patients with stroke and IE died within 1 year of admission.

CONCLUSIONS

The overall incidence of stroke in patients with IE (9.6%) is lower than previous reports (21 to 39%). Patients with MVE had a greater risk of stroke than patients with AVE. Fifty-two percent of patients died within 1 year of admission for IE.

A randomized trial of aspirin on the risk of embolic events in patients with infective endocarditis

OBJECTIVES

This study examined the effect of aspirin on the risk of embolic events in infective endocarditis (IE).

BACKGROUND

Embolism is a major complication of IE, and studies in animal models have shown that platelet inhibition with aspirin can lead to more rapid vegetation resolution and a lower rate of embolic events.

METHODS

We conducted a randomized, double-blinded, placebo-controlled trial of aspirin treatment (325 mg/day) for four weeks in patients with IE to test the hypothesis that the addition of aspirin would reduce the incidence of clinical systemic embolic events. Patients with perivalvular abscess were excluded. Serial cerebral computed tomograms and transesophageal echocardiograms were obtained in a subset of patients.

RESULTS

During the four-year study period, 115 patients were enrolled: 60 assigned to aspirin and 55 assigned to placebo. Embolic events occurred in 17 patients (28.3%) on aspirin and 11 patients (20.0%) on placebo, with an odds ratio (OR) of 1.62 (95% confidence interval [CI] 0.68 to 3.86, p = 0.29). There was a trend toward a higher incidence of bleeding in the patients taking aspirin versus placebo (OR 1.92, 95% CI 0.76 to 4.86, p = 0.075). Development of new intracranial lesions was similar in both groups. Aspirin had no effect on vegetation resolution and valvular dysfunction.

CONCLUSIONS

In endocarditis patients already receiving antibiotic treatment, the addition of aspirin does not appear to reduce the risk of embolic events and is likely associated with an increased risk of bleeding. Aspirin is not indicated in the early management of patients with IE.

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.

A clinical study of culture-negative endocarditis

Culture-negative infective endocarditis (CNE) is a diagnostic problem in spite of improved echocardiographic and blood culturing techniques. We conducted the present study to estimate the proportion of CNE in patients with infective endocarditis, to investigate data regarding risk factors, and to evaluate the Duke and the modified Beth Israel criteria in patients with CNE. We evaluated 820 consecutive suspected episodes of infective endocarditis in adults at the Departments of Infectious Diseases in Göteborg and Borås, Sweden (1984-1996). All patients were diagnosed and treated according to a protocol; 487 episodes were identified as infective endocarditis. Episodes with absence of bacterial growth at blood culture were defined as CNE and were classified with the Duke and the modified Beth Israel criteria. We identified 116 CNE episodes (median age, 67 yr). Mortality was 7%, and in 15%, cardiac surgery was performed. The Duke criteria classified 20 definite, 80 possible, and 16 reject episodes. The modified Beth Israel criteria distinguished 13 definite, 15 probable, 27 possible, and 61 reject episodes. The proportion of CNE among patients with infective endocarditis varied from 19% to 27% at the 2 departments. Antibiotic treatment preceded blood culture in 45% of the CNE episodes. About 20% in a Scandinavian population of infective endocarditis patients have CNE. Antibiotic pretreatment explains less than 50% of all CNE episodes. The Duke criteria are more sensitive but less specific than the modified Beth Israel criteria in classifying patients with CNE.

Imaging techniques for diagnosis of infective endocarditis

Cardiac imaging, specifically echocardiography, has greatly enhanced the ability of clinicians to effectively diagnose and manage IE. Echocardiograms should generally be obtained in all patients suspected of having IE, both to establish the diagnosis and to identify complicated cardiac involvement that may warrant surgical intervention. Transesophageal imaging is more sensitive and specific than the transthoracic approach and currently represents the optimal approach to echocardiographic imaging. Manifestations of endocardial involvement include vegetations, abscesses, aneurysms, fistulae, leaflet perforations, and valvular dehiscence. The roles of other imaging modalities including CT, MRI, and nuclear imaging have yet to be fully established.

Current best practices and guidelines. Indications for surgical intervention in infective endocarditis

Optimal diagnosis and management of patients with infective endocarditis requires sound clinical judgment based on extensive experience. This is especially important in regard to the indications and timing for surgery. To achieve the best possible outcomes, surgical intervention during treatment is required in 25% to 30% of patients with infective endocarditis. Heart failure and progressive left-sided valvular dysfunction are the most common indications for operation. Valve repair should be considered as an alternative to valve replacement whenever feasible, especially in younger patients. Successful management of perivalvular abscesses and prosthetic valve infections requires radical removal of infected tissue followed by reconstructive procedures performed by experienced surgeons. Emergency or urgent surgery should seldom be delayed.

[Mitral regurgitation in infective endocarditis]

Endocarditis affecting the mitral valve is frequent and is associated with specific features. Mitral prolapse is the most frequent underlying disease and the mechanism of mitral regurgitation secondary to infective endocarditis is frequently complex and multiple. Echocardiography plays a key-role in both the diagnosis, the prognostic assessment and the choice of the best therapeutic option in patients with mitral valve endocarditis. Surgery is frequently necessary, and must be performed early in the course of the disease. Mitral valve repair is the best therapeutic option, when technically possible.

Embolic risk in subacute bacterial endocarditis: determinants and role of transesophageal echocardiography

Embolic events are a frequent and life-threatening complication of subacute bacterial endocarditis (SBE), and are associated with a high mortality and morbidity. The prediction of the embolic risk in an individual patient remains a challenge. Echocardiography plays a key role in the management of infective endocarditis both for the diagnostic and prognostic assessment of these patients, but its value in predicting embolic events is still debated. This review focuses on the characteristics of embolic events in SBE, and on the role of echocardiography, especially transesophageal echocardiography (TEE), in the prediction of embolic events. The review confirms that, among other factors, TEE may be helpful in both the prediction of the embolic risk, and the decision to perform early surgery.

Role of echocardiography in the diagnosis and management of infective endocarditis

Infective endocarditis is a life-threatening disease with significant morbidity and mortality. Accurate and early diagnosis for initiation of effective treatment is essential in improving patient outcome. Echocardiography is currently the primary modality for the detection of vegetations and cardiac complications that result from endocarditis. Technological advances in echocardiography, particularly the development of transesophageal echocardiography (TEE), have revolutionized the diagnosis and management of infective endocarditis. With the enhanced resolution provided by TEE, vegetations and paravalvular complications can be reliably detected. Transthoracic and transesophageal echocardiography provides complementary information for patient management and follow-up, and is best used in conjunction with clinical data. By means of its high sensitivity and negative predictive value, TEE is essential in the evaluation of prosthetic valve endocarditis and the paravalvular complications of IE. All patients with suspected infective endocarditis should undergo transthoracic echocardiography, and most of these patients should also undergo TEE evaluation. The role of new technology such as harmonic and three-dimensional imaging is yet to be determined.

Current best practices and guidelines indications for surgical intervention in infective endocarditis

Optimal diagnosis and management of patients with infective endocarditis requires sound clinical judgment based on extensive experience. This is especially important in regard to the indications and timing for surgery. To achieve the best possible outcomes, surgical intervention during treatment is required in 25% to 30% of patients with infective endocarditis. Heart failure and progressive left-sided valvular dysfunction are the most common indications for operation. Valve repair should be considered as an alternative to valve replacement whenever feasible, especially in younger patients. Successful management of perivalvular abscesses and prosthetic valve infections requires radical removal of infected tissue followed by reconstructive procedures performed by experienced surgeons. Emergency or urgent surgery should seldom be delayed.

Imaging techniques for diagnosis of infective endocarditis

With the ability to structurally characterize cardiac manifestations, echocardiography is used for the diagnosis and management of infective endocarditis. In establishing the diagnosis according to the Duke criteria, the findings of endocardial involvement (vegetation, abscess, prosthetic valve dehiscence) or new valvular regurgitation represent "major" diagnostic criteria. As echocardiography cannot reliably differentiate noninfective from infective lesions, however, proper diagnosis lies in correlating echocardiography with clinical findings. The more invasive transesophageal approach provides substantially greater image resolution; this approach should be considered first in the evaluation of patients with higher prior probabilities of endocarditis and those with potential endocardial complications.

The risk of stroke and death in patients with aortic and mitral valve endocarditis

BACKGROUND

Previous studies have generated inconsistent results when attempting to define predictors of stroke and death in patients with endocarditis. We sought to examine the relationship between vegetation 2-dimensional size and stroke in those with infective endocarditis (IE) and to identify differences between aortic valve (AV) and mitral valve (MV) IE with regard to clinical characteristics, echocardiographic findings, stroke, and death.

METHODS

We used the Duke Endocarditis Database to examine 145 episodes of definite IE involving the AV, n = 62, or MV, n = 83. A logistic regression model was developed to analyze important variables in predicting stroke, and a Cox proportional hazards model was used in predicting mortality.

RESULTS

The mitral valve was infected in 57% of the cases. Vegetations were more commonly detected in patients with MV IE (92.8% vs 66.1%, P =.001) and these MV vegetations were significantly larger (P <.05). Thirty-four of 145 episodes (23.4%) were complicated by stroke. MV IE was associated with a greater stroke rate, 32.5% versus 11.3% (P =.003). Strokes tended to occur early in the course of illness, particularly in MV IE. In the multivariable model, the independent predictors of stroke were MV IE (P =.04) and vegetation length (P =.03). Independent predictors of 1-year mortality were age (P =.02) and vegetation area (P =.048).

CONCLUSION

Stroke is more common in patients with MV IE. Vegetation 2-dimensional size and characteristics are important predictors of stroke and mortality. These findings may lead to predictive models that allow physicians to identify high-risk patients who need aggressive treatment strategies to prevent long-term morbidity and mortality.

Echocardiography predicts embolic events in infective endocarditis

OBJECTIVES

The aim of our study was to assess the value of transesophageal echocardiography (TEE) in predicting embolic events (EEs) in a large group of patients with definite endocarditis according to the Duke criteria, including silent embolism.

BACKGROUND

The value of echocardiography in predicting embolism in patients with endocarditis remains controversial. Some studies reported an increased risk of embolism in patients with large and mobile vegetations, whereas other studies failed to demonstrate such a relationship.

METHODS

Multiplane transesophageal echocardiograms of 178 consecutive patients with definite infective endocarditis (IE) were analyzed. The incidence of embolism was compared with the echocardiographic characteristics (localization, size and mobility) of the vegetations. To detect silent embolism, cerebral and thoraco-abdominal scans were performed in 95% of patients.

RESULTS

Among 178 patients, 66 (37%) had one or more EEs. There was no difference between patients with and without embolism in terms of age, gender and left valve involved. On univariate analysis, Staphylococcus infection, right-side valve endocarditis and vegetation length and mobility were significantly related to EEs. A significant higher incidence of embolism was present in patients with vegetation length >10 mm (60%, p < 0.001) and in patients with mobile vegetations (62%, p < 0.001). Embolism was particularly frequent among 30 patients with both severely mobile and large vegetations (> 15 mm) (83%, p < 0.001). On multivariate analysis, the only predictors of embolism were vegetation length (p = 0.03) and mobility (p = 0.01).

CONCLUSIONS

Our study shows that the presence of vegetations on TEE is predictive of embolism and that the morphologic characteristics of vegetations are helpful in predicting EEs in both mitral and aortic valve IE. It also suggests that early operation may be recommended in patients with vegetations > 15 mm and high mobility, irrespective of the degree of valve destruction, heart failure and response to antibiotic therapy.

Individual value of each of the Duke criteria for the diagnosis of infective endocarditis

OBJECTIVES: To assess the value of each of the Duke criteria for the diagnosis of infective endocarditis (IE). METHODS: Detailed review was done of charts of all cases discharged with the diagnosis of IE, and classification as 'definite', 'possible' and 'rejected' cases was made according to the Duke criteria. The diagnostic impact of each criterion was assessed by reclassifying each 'definite' case after subtraction of each individual criterion and by reclassifying each 'possible' and 'rejected' case after addition of each individual criterion. RESULTS: From 1983 to 1993, 179 cases were identified in the databases of two hospitals. When the Duke criteria were applied, 124 (6967%) were classed as 'definite', 43 (2466%) as 'possible' and 12 (763%) as 'rejected' cases. Of the 67 pathologically proven cases, 52 (78610%) were 'definite' cases when the criteria were applied before pathology. If the major microbiological criterion is subtracted, 53% (69%) of the 'definite' cases become 'possible' or 'rejected'. When the echocardiographic criterion is subtracted, 34% (68%) of the 'definite' cases become possible or rejected. Among minor criteria, fever and predisposition, contributing to the classification of respectively 31% (68%) and 27% (68%) of the 'definite' cases, were the most powerful. On the other hand, the minor microbiological criterion and immunologic phenomena were responsible for the classification of only 2% (62%) and 6% (64%) respectively, of the 'definite' cases. CONCLUSIONS: Depending on the criterion examined, 47-98% of the 'definite' cases of IE would remain 'definite' if this particular criterion were absent. The major microbiological criterion had the highest relative importance. In this retrospective study, in which only 32 (18%) patients had a transesophageal echocardiogram, the echocardiogram contributed to 15% (66%) of the 'definite' cases according to the major criterion and to 19% (66%) according to the minor criterion. This study illustrates that the degree of certainty of the diagnosis of IE often depends on the presence/absence of only one criterion.

Pediatric bacterial endocarditis. Treatment and prophylaxis

Endocarditis is a rare but serious complication often related to complex CHD. The incidence, particularly among smaller infants with cyanotic heart disease, seems to be increasing. The pathophysiology is related to a combination of host and bacterial factors that predispose to endothelial colonization and infection. Diagnosis, although occasionally difficult, is life saving, but the treatment is prolonged. Prophylaxis before appropriate procedures may significantly decrease the risk for development in appropriate patients.

Transesophageal ultrasonographic imaging in rat hearts: visualization of aortic valve vegetations in non-bacterial thrombotic endocarditis

The aim of this study was to test the feasibility of transesophageal ultrasonography in rats by using an intravascular ultrasound system for visualization of vegetations at the aortic valve in the animal model of experimental endocarditis. After anesthesia and preparation of the right carotid artery, a polyethylene catheter was advanced across the aortic valve into the left ventricle in 91 rats. For transesophageal ultrasonography an intravascular ultrasound catheter (3.5 French; 30 MHz) linked to an imaging system was introduced into the esophagus. Sonographic investigations were performed every 24 hours until death. The presence, size, and echogenicity of vegetations were evaluated. Presence and size were compared to autopsy findings. No complications occurred as a result of the sonographic investigation. Left-sided valvular structures were imaged regularly. For detection of vegetations, sensitivity and specificity were 93% and 88%, respectively. Comparing the measurements of the vegetation size the following regression equation was obtained: y = 0.74x + 0.04 (r = 0.89; standard error of estimate = 0.02 cm). Inter- and intraobserver variabilities for sonographic measurements were 8.3% and 6.2%, respectively. Transesophageal ultrasonography permits reliable detection and repetitive accurate quantification of vegetations in the rat model of endocarditis. The technique enhances longitudinal studies of the dynamic process of the growth of vegetations under defined microbial conditions.

Role of transthoracic and transesophageal echocardiography in predicting embolic events in patients with active infective endocarditis involving native cardiac valves

Some studies describe an increased risk for emboli in infective endocarditis patients with large (>10 mm) and mobile vegetations. Other studies fail to demonstrate the above relation. Most studies have been performed using transthoracic echocardiography or with a monoplane transesophageal approach. The present study examines whether distinctive characteristics of vegetative lesions detected by transthoracic and multiplane transesophageal echocardiography are predictive of embolic risk. We reviewed both transthoracic and transesophageal echocardiograms of 57 patients with diagnosis of acute infective endocarditis and no documented or suspected previous embolic events. We evaluated site, length, width, mobility, and echodensity of vegetations. Twenty-five patients (44%) had embolic events. No statistical differences in age, sex distribution, location of endocarditis, or offending pathogens between embolic (n = 25) and nonembolic (n = 32) patients were found. There were no differences in any of the echo characteristics of vegetations detected by transthoracic and transesophageal approach in embolic and nonembolic groups. Thus, transthoracic and transesophageal characteristics of vegetations are not helpful in defining embolic risk in patients with infective endocarditis.

The ability of vegetation size on echocardiography to predict clinical complications: a meta-analysis

To clarify whether echocardiographic detection of a vegetation 10 mm or larger in size in patients with left-sided infective endocarditis poses an increased risk for complications, we performed a meta-analysis of English-language publications identified by a computerized search of the key words infective endocarditis and echocardiography. A pooled odds ratio was calculated by using the Robins, Greenland, and Breslow estimate of variance. The pooled odds ratio for increased risk of systemic embolization in the presence of a vegetation >10 mm (10 studies, 738 patients) was 2.80 (95% confidence interval [CI] 1.95 to 4.02; p < 0.01). The odds ratio of requiring valve-replacement surgery (seven studies, 549 patients) was 2.95 (95% CI 1.90 to 4.58; p < 0.01). The odds ratio of death (six studies, 476 patients) was 1.55 (95% CI 0.92 to 2.60; p = 0.10). Thus this analysis supports the hypothesis that echocardiographically detected left-sided vegetations >10 mm pose a significantly increased risk of (1) systemic embolization and (2) a need for valve-replacement surgery than cases where either no or smaller vegetations are detected.