Echocardiography in infective endocarditis: reassessment of prognostic implications of vegetation size determined by the transthoracic and the transesophageal approach

Staphylococcus aureus bacteraemia in a UK tertiary referral centre: a 'transoesophageal echocardiogram for all' policy

OBJECTIVES

Infective endocarditis (IE) is a feared complication in up to 38% of cases of Staphylococcus aureus bacteraemia (SAB). BSAC guidelines recommend echocardiography in all cases of SAB. The aim of this study was to determine the incidence of IE in SAB using transoesophageal echocardiography (TOE) as the first step in diagnostic imaging. This study also sought to identify clinical predictors that could improve stratification of those with and without IE.

METHODS

A guideline was implemented that any SAB resulted in the microbiology department (i) recommending that the patient be referred for TOE and (ii) notifying the echocardiography department, resulting in streamlined listing of the patient for TOE. All cases of SAB were then assessed prospectively at University Hospitals Birmingham NHS Foundation Trust between September 2011 and October 2012. Previously identified risk factors for complicated S. aureus bacteraemia were recorded.

RESULTS

There were 98 SAB episodes in total. TOE was performed in 58 (59%) with a further 22 episodes imaged by transthoracic echocardiography alone. IE was diagnosed overall in 13 (16%) cases investigated with echocardiography. No risk factor for IE other than presence of a cardiac device was detected in this group (P = 0.013).

CONCLUSIONS

The rate of IE found in SAB is high when TOE is performed first line. There are no clear risk factors to improve yield or the type of echocardiography to be performed. Echocardiography should be performed in all cases and TOE should be considered where it is expected to influence management, as long as local resources allow.

Surgical treatment of infective endocarditis in active intravenous drug users: a justified procedure?

BACKGROUND

Infective endocarditis is a life threatening complication of intravenous drug abuse, which continues to be a major burden with inadequately characterised long-term outcomes. We reviewed our institutional experience of surgical treatment of infective endocarditis in active intravenous drug abusers with the aim of identifying the determinants long-term outcome of this distinct subgroup of infective endocarditis patients.

METHODS

A total of 451 patients underwent surgery for infective endocarditis between January 1993 and July 2013 at the University Hospital of Heidelberg. Of these patients, 20 (7 female, mean age 35 ± 7.7 years) underwent surgery for infective endocarditis with a history of active intravenous drug abuse. Mean follow-up was 2504 ± 1842 days.

RESULTS

Staphylococcus aureus was the most common pathogen detected in preoperative blood cultures. Two patients (10%) died before postoperative day 30. Survival at 1, 5 and 10 years was 90%, 85% and 85%, respectively. Freedom from reoperation was 100%. Higher NYHA functional class, higher EuroSCORE II, HIV infection, longer operating time, postoperative fever and higher requirement for red blood cell transfusion were associated with 90-day mortality.

CONCLUSIONS

In active intravenous drug abusers, surgical treatment for infective endocarditis should be performed as extensively as possible and be followed by an aggressive postoperative antibiotic therapy to avoid high mortality. Early surgical intervention is advisable in patients with precipitous cardiac deterioration and under conditions of staphylococcal endocarditis. However, larger studies are necessary to confirm our preliminary results.

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.

Infective endocarditis

Infective endocarditis is a serious disease of the endocardium of the heart and cardiac valves, caused by a variety of infectious agents, ranging from streptococci to rickettsia. The proportion of cases associated with rheumatic valvulopathy and dental surgery has decreased in recent years, while endocarditis associated with intravenous drug abuse, prosthetic valves, degenerative valve disease, implanted cardiac devices, and iatrogenic or nosocomial infections has emerged. Endocarditis causes constitutional, cardiac and multiorgan symptoms and signs. The central nervous system can be affected in the form of meningitis, cerebritis, encephalopathy, seizures, brain abscess, ischemic embolic stroke, mycotic aneurysm, and subarachnoid or intracerebral hemorrhage. Stroke in endocarditis is an ominous prognostic sign. Treatment of endocarditis includes prolonged appropriate antimicrobial therapy and in selected cases, cardiac surgery. In ischemic stroke associated with infective endocarditis there is no indication to start antithrombotic drugs. In previously anticoagulated patients with an ischemic stroke, oral anticoagulants should be replaced by unfractionated heparin, while in intracranial hemorrhage, all anticoagulation should be interrupted. The majority of unruptured mycotic aneurysms can be treated by antibiotics, but for ruptured aneurysms, endovascular or neurosurgical therapy is indicated.

Cardiac computed tomography angiography results in diagnostic and therapeutic change in prosthetic heart valve endocarditis

Echocardiography may miss prosthetic heart valve (PHV) endocarditis which advocates for novel imaging techniques to improve diagnostic accuracy and patient outcome. The purpose of this study was to determine the complementary diagnostic value of cardiac computed tomography angiography (CTA) to the clinical routine workup including transthoracic and transesophageal echocardiography (TTE/TEE) in patients with suspected PHV endocarditis and its impact on patient treatment. A diagnostic prospective cross-sectional study was chosen as design. Besides clinical routine workup (including TTE/TEE), CTA was performed to assess its diagnostic accuracy and complementary diagnostic/therapeutic value. For the diagnostic accuracy, the reference standard was surgical findings or clinical follow-up. To determine the complementary diagnostic/therapeutic value an expert-panel was used as reference standard. Twenty-eight patients were included. CTA resulted in a major diagnostic change in six patients (21 %) mainly driven by novel detection of mycotic aneurysms by CTA. Furthermore, treatment changes occurred in seven patients (25 %) compared to clinical routine workup. Diagnostic accuracy of routine clinical workup plus CTA was superior to clinical routine workup alone for the detection of PHV endocarditis in general, vegetations and peri-annular extension. This study demonstrates that CTA and clinical workup including TTE and TEE are complementary in patients with PHV endocarditis. Therefore, CTA imaging has to be considered after clinical routine workup in patients with a high suspicion on PHV endocarditis.

Evaluation of vegetation size and its relationship with embolism in infective endocarditis: a real-time 3-dimensional transesophageal echocardiography study

BACKGROUND

Two-dimensional (2D) echocardiography studies have shown that the maximum length of vegetation (MLV)≥10 mm is a predictor of embolic events (EEs) in patients with infective endocarditis. However, 2D measurements probably underestimate the vegetation dimensions. In this study, we evaluated the feasibility of real-time 3-dimensional transesophageal echocardiography (RT3DTEE) in determining MLV and its accuracy in identifying the risk for EEs compared with 2D transesophageal echocardiography (2DTEE).

METHODS AND RESULTS

We analyzed 60 patients with vegetations. RT3DTEE measurement of MLV was obtained with Advanced QLAB Quantification Software by cropping the 3D volume with the appropriate 2D plane to obtain the largest value. The standard 2DTEE images were also evaluated to determine the MLV. Major EEs were registered from medical records, and a logistic regression analysis was performed to determine the association between MLV and EEs. The RT3DTEE MLV was larger than the 2DTEE value with a mean difference of 3.2 mm (95% confidence interval, 2.1-4.2 mm). The best cut-off value for prediction of EEs was MLV≥20 mm with RT3DTEE and MLV≥16 mm with 2DTEE. The positive predictive value increased from 59.1% to 65.2% when RT3DTEE was used. The accuracy of classification of patients with EEs increased from 65% to 70% with this new technique.

CONCLUSIONS

RT3DTEE is a feasible technique for the analysis of vegetation morphology and size that may overcome the shortcoming of 2DTEE, leading to a better prediction of the embolism risk in patients with infective endocarditis.

Long-term outcomes and cardiac surgery in critically ill patients with infective endocarditis

AIMS

To assess long-term outcomes and the management of critical left-sided infective endocarditis (IE) and evaluate the impact of surgery.

METHODS AND RESULTS

Among the 198 patients included prospectively for IE across 33 adult intensive care units (ICU) in France from 1 April 2007 to 1 October 2008, 137 (69%) were dead at a median follow-up time of 59.5 months. Characteristics significantly associated with mortality were: Sepsis-related Organ-Failure Assessment (SOFA) score at ICU admission [Hazard ratio (HR), 95% Confidence Interval (CI) of 1.43 (0.79-2.59) for SOFA 5-9; 2.01 (1.05-3.85) for SOFA 10-14; 3.53 (1.75-7.11) for SOFA 15-20; reference category SOFA 0-4; P = 0.003]; prosthetic mechanical valve IE [HR 2.01; 95% CI 1.09-3.69, P = 0.025]; vegetation size ≥15 mm [HR 1.64; 95% CI 1.03-2.63, P = 0.038]; and cardiac surgery [HR (95%CI), 0.33 (0.16-0.67) for surgery ≤1 day after IE diagnosis; 0.61 (0.29-1.26) for surgery 2-7 days after IE diagnosis; 0.42 (0.21-0.83) for surgery >7 days after IE diagnosis; reference category no surgery; P = 0.005]. One hundred and three (52%) patients underwent cardiac surgery after a median time of 6 (16) days. Independent predictors of surgical intervention on multivariate analysis were: age ≤60 years [Odds ratio (OR) 5.30; 95% CI (2.46-11.41), P < 0.01], heart failure [OR 3.27; 95% CI (1.03-10.35), P = 0.04], cardiogenic shock [OR 3.31; 95% CI (1.47-7.46), P = 0.004], septic shock [OR 0.25; 95% CI (0.11-0.59), P = 0.002], immunosuppression [OR 0.15; 95% CI (0.04-0.55), P = 0.004], and diagnosis before or within 24 h of ICU admission [OR 2.81; 95% CI (1.14-6.95), P = 0.025]. SOFA score calculated the day of surgery was the only independently associated factor with long-term mortality [HR (95% CI) 1.59 (0.77-3.28) for SOFA 5-9; 3.56 (1.71-7.38) for SOFA 10-14; 11.58 (4.02-33.35) for SOFA 15-20; reference category SOFA 0-4; P < 0.0001]. Surgical timing was not associated with post-operative outcomes. Of the 158 patients with a theoretical indication for surgery, the 58 deemed not fit had a 95% mortality rate.

CONCLUSION

Mortality in patients with critical IE remains unacceptably high. Factors associated with long-term outcomes are the severity of multiorgan failure, prosthetic mechanical valve IE, vegetation size ≥15 mm, and surgical treatment. Up to one-third of potential candidates do not undergo surgery and these patients experience extremely high mortality rates. The strongest independent predictor of post-operative mortality is the pre-operative multiorgan failure score while surgical timing does not seem to impact on outcomes.

Role of echocardiography in guiding the optimal timing of surgery in infective endocarditis

Infective endocarditis (IE) is a complex cardiovascular infection with the potential for multiorgan complications. While early surgery can be life saving in IE patients with acute heart failure and acute valve regurgitation, the appropriate timing of surgery for embolic complications is less certain. The ongoing debate concerns the ideal timing of surgical therapy and stems primarily from a scarcity of therapeutic randomized controlled trials in this population. Based largely on the evidence from observational studies and expert consensus, the European Society of Cardiology has issued guidelines on the optimal surgical timing in IE. Nonetheless, selection bias in published studies and the clinical complexity of this disease entity continue to pose management challenges in the individual patient. In this review, we focus on the cardinal role of echocardiography as a diagnostic tool in patients with complicated IE and discuss the available evidence pertaining to the ideal timing of surgical intervention.

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.

[Central nervous system embolism in the course of infective endocarditis]

Despite the progress made in diagnosis and treatment of heart valve diseases, the incidence of infective endocarditis (IE) remains constant. It is still associated with high mortality and high rate of embolic complications, including most dangerous one, i.e. stroke. It has a significant impact on further treatment and qualifications for cardiac surgery. In this paper, the authors discuss the epidemiology, mechanisms of stroke and its impact on the qualifications for cardiac surgery. The authors discuss the problem of clinically silent central nervous system embolism in the course of IE and the usefulness of neuroimaging and markers of central nervous system damage in diagnosis of cerebral embolism.

Acute ischemic brain lesions in infective endocarditis: incidence, related factors, and postoperative outcome

BACKGROUND

Acute brain infarction affects the timing and regimen of cardiac surgery in patients with infective endocarditis (IE). We aimed to identify preoperative brain MRI characteristics, incidence, and related factors for acute ischemic lesions in left-sided IE patients undergoing cardiac surgery. Furthermore, we investigated whether preoperative acute ischemic lesions are associated with postoperative neurological complications in IE patients.

METHODS

We retrospectively reviewed consecutive patients with a definite left-sided IE who underwent cardiac surgery in 6 university-affiliated hospitals from January 2004 to November 2011. Preoperative brain MRI evaluations were systematically performed on all patients without contraindications, regardless of neurological complications, with the aim of preventing perioperative complications. Patients were included if diffusion-weighted imaging and fluid-attenuated inversion recovery sequences were performed within 14 days after diagnosis. Associations between acute ischemic lesions and related factors were analyzed. Neurological complications within 30 days after surgery were evaluated for postoperative outcome analyses.

RESULTS

Of 139 consecutive patients with left-sided IE who underwent cardiac surgery, 85 patients were evaluated in this study. The mean age was 58 ± 16 years, and 22 patients (26%) were women. Preoperative MRI revealed acute ischemic lesions in 47 patients (55%), and 19 of these patients developed neurological symptoms. Among the patients with ischemic lesions, 24 (60%) had small lesions (<10 mm), 36 (77%) had multiple lesions, and 30 (64%) had lesions in multiple vascular territories. Compared to patients without ischemic lesions, patients with acute ischemic lesions were older and had significantly higher white blood cell counts and plasma C-reactive protein (CRP) levels, but lower hemoglobin levels. Logistic regression analyses showed that the white blood cell count and plasma CRP level were independently associated with acute ischemic lesions [adjusted OR per 1-SD increase were 2.21 (95% CI: 1.23-4.35) and 2.33 (95% CI: 1.27-4.96), respectively]. Three patients developed postoperative neurological complications, but preoperative acute ischemic lesions and postoperative complications were not associated.

CONCLUSIONS

Preoperative MRI detected a high incidence of asymptomatic ischemic lesions in IE patients. Acute ischemic lesions were often small, multiple, and located in multiple vascular territories. Inflammatory reactions may play an important role in the development of ischemic lesions in IE patients.

Aortic valve and ascending aorta guidelines for management and quality measures: executive summary

The Society of Thoracic Surgeons Clinical Practice Guidelines are intended to assist physicians and other health care providers in clinical decision making by describing a range of generally acceptable approaches for the diagnosis, management, or prevention of specific diseases or conditions. These guidelines should not be considered inclusive of all proper methods of care or exclusive of other methods of care reasonably directed at obtaining the same results. Moreover, these guidelines are subject to change over time, without notice. The ultimate judgment regarding the care of a particular patient must be made by the physician in light of the individual circumstances presented by the patient.

Heart valve disease

Heart valve disease is often characterized by a prolonged asymptomatic period that lasts for years and presents primary care physicians with an opportunity to detect disease before irreversible heart failure or other cardiac complications develop. Acute valvular disease can masquerade as respiratory illness or present with nonspecific systemic symptoms, and an astute examination by a primary care physician can direct appropriate care. Therefore, an understanding of the common pathologies and presentations of valvular heart disease is critical. This review focuses on the 2 most common valve lesions, aortic stenosis and mitral regurgitation, and provides an overview of other valve disease topics.

Evaluating treatment options for patients with infective endocarditis: when is it the right time for surgery?

Infective endocarditis remains a life-threatening condition with an unchanging incidence and mortality of nearly 30% at 1 year. Surgery is required in 25–50% of acute infections and 20–40% of patients during convalescence. Operative procedures are often technically challenging and high-risk, often due to coexistent multisystem disease. However, international guidelines provide clear indications for surgical intervention, which are applicable for the majority of patients. These are not, however, supported by particularly robust clinical evidence and decision-making often needs to be tailored to the advancing age of the overall patient cohort, the presence of multisystem disease, comorbidities, prior antibiotic therapy of varying duration and the availability of surgical expertise. Native valve endocarditis will be the initial focus of this article, along with subgroups including prosthetic valve endocarditis. We present the treatment options for patients with infective endocarditis, evaluate the evidence-base that supports current clinical practice and attempt to provide an insight and subsequent recommendations for the timing of surgery.

Update on echocardiography in the management of infective endocarditis

Echocardiography is the major imaging modality used for the diagnosis of infective endocarditis (IE). It is also useful in detecting the complications of IE which often necessitate surgical intervention and strongly influence patient outcomes. Transesophageal echocardiography (TEE), with proven superiority over transthoracic echocardiography (TTE) for the detection of vegetations and complications such as abscess, should be performed in the vast majority of cases especially when TTE image quality is poor or implanted devices are present. Three-dimensional (3D) TEE provides enhanced display of anatomic-spatial relationships allowing more precise delineation of complex pathology, particularly of the mitral valve and annulus. Importantly, echocardiographic findings can be non-specific and should always be interpreted in the context of the pre-test probability of IE based on careful clinical assessment. IE remains a challenging disease associated with variable clinical presentations, and high mortality. Whenever IE is suspected, echocardiography should be utilized early for both diagnosis and detection of complications.

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.

Cardiac device-related endocarditis: Epidemiology, pathogenesis, diagnosis and treatment - a review

Cardiac device-related endocarditis (CDE) is a phenomenon for which incidence is on the rise; it presents difficult management problems to the clinician. On one hand, there is the patient who needs the implanted device, and the potential morbidity and mortality associated with its removal. On the other hand, there is the problem of a persistent infection - usually acquired during insertion of an electrical device - that is resistant to many antibiotics, has a high recurrence rate, and necessitates an extensive operation to remove the device if removal is delayed. Most studies recommend device and metal lead replacement if CDE occurs. The aim of the present review is to raise awareness of CDE among clinicians, and to provide an appropriate approach to its management.

Surgical treatment of infective valve endocarditis in children with congenital heart disease

OBJECTIVE

This study assesses surgical procedures, operative outcome, and early and intermediate-term results of infective valve endocarditis in children with congenital heart disease.

METHODS

Seven consecutive children (five females, two males; mean age, 10.8 years) who underwent surgery for infective valve endocarditis between 2006 and 2010 were included in the study. The aortic and mitral valves were affected in two and tricuspid in five patients. Indications for operation included cardiac failure due to atrioventricular septal rupture, severe tricuspid valve insufficiency, and septic embolization in one, moderate valvular dysfunction with vegetations in three (two tricuspid, one mitral), and severe valvular dysfunction with vegetations in the other three patients (two tricuspid, one mitral). The pathological microorganism was identified in five patients. Tricuspid valve repair was performed with ventricular septal defect (VSD) closure in five patients. Two patients required mitral valve repair including one with additional aortic valve replacement.

RESULTS

There were no operative deaths. Actuarial freedom from recurrent infection at one and three years was 100%. Early echocardiographic follow-up showed four patients to have mild atrioventricular valve regurgitation (three tricuspid and one mitral) and three had no valvular regurgitation. No leakage from the VSD closure or any valvular stenosis was detected postoperatively.

CONCLUSIONS

Mitral and tricuspid valve repairs can be performed with low morbidity/mortality rates and satisfactory intermediate-term results in children with infective valve endocarditis.

Successful treatment of ST elevation myocardial infarction caused by septic embolus with the use of a thrombectomy catheter in infective endocarditis

A 71-year-old patient suffered a transmural (ST elevation) myocardial infarction (MI) as a result of a septic embolus from an infected tissue aortic valve replacement. Following failed fibrinolysis, his MI was successfully treated with thrombectomy using an export catheter. He suffered bleeding complications following the administration of tenectaplase and required aortic valve and root replacement due to ongoing systemic embolisation.

Recommendations for the practice of echocardiography in infective endocarditis

Echocardiography plays a key role in the assessment of infective endocarditis (IE). It is useful for the diagnosis of endocarditis, the assessment of the severity of the disease, the prediction of short- and long-term prognosis, the prediction of embolic events, and the follow-up of patients under specific antibiotic therapy. Echocardiography is also useful for the diagnosis and management of the complications of IE, helping the physician in decision-making, particularly when a surgical therapy is considered. Finally, intraoperative echocardiography must be performed in IE to help the surgeon in the assessment and management of patients with IE during surgery. The current 'recommendations for the practice of echocardiography in infective endocarditis' aims to provide both an updated summary concerning the value and limitations of echocardiography in IE, and clear and simple recommendations for the optimal use of both transthoracic and transoesophageal echocardiography in IE.

Evolution of vegetation size in left-sided endocarditis. Is it a prognostic factor during hospitalization?

The objective was to describe the vegetation changes in patients with endocarditis and evaluate their prognostic importance during hospitalization. We selected patients with left-sided endocarditis and two transesophageal echocardiograms separated by at least 8 days. Patients who required surgery or died during the first week after diagnosis of the disease were excluded. Patients were classified into three groups: I, patients whose vegetation increased in size (n=34); II, patients with vegetations that did not vary in size (n=62); and III, patients whose vegetation decreased in size (n=59). Patients whose vegetation increased in size more frequently required surgery. Multivariate analysis showed that the increase in the vegetation is independently associated with increased mortality: adjusted odds ratio, 4.12 (95% confidence interval, 1.14-14.9; P=.031).

Role of echocardiogram in decision making for surgery in endocarditis

Infective endocarditis is a serious disease that carries significant morbidity and mortality. Adequate treatment is based on a high degree of clinical suspicion, accurate microbiologic diagnosis, and high-quality imaging. Echocardiography has been shown to be a fundamental tool for diagnosis and management. Currently accepted Duke criteria include blood cultures and echocardiography. Transthoracic and transesophageal echocardiography play a critical role in the decision-making process, especially when surgical treatment is contemplated. Because infective endocarditis is considered a medical and surgical disease, and considering that the current rate of surgery is about 50%, echocardiography has definite value in preoperative diagnosis and surgical planning, intraoperative confirmation of lesions and quality of repair or replacement before and after cardiopulmonary bypass, and postoperative assessment.

Prosthetic valve endocarditis

Prosthetic valve endocarditis (PVE) is associated with a high mortality during the early and midterm follow-up despite diagnostic and therapeutic improvements; its incidence is increasing and reaches 20-30% of all infective endocarditis episodes. In this review, changes in epidemiology, microbiology, diagnosis and therapy that have evolved in the past few years are analyzed. Staphylococci (both Staphylococcus aureus and coagulase-negative Staphylococcus) have emerged as the most common cause of PVE and are associated with a severe prognosis. Moreover, diagnosis may often be difficult because of its complications and extracardiac manifestations; thus, a comprehensive assessment of the clinical, echocardiographic and laboratory data must be performed. Early PVE, comorbidity, severe heart failure and new prosthetic dehiscence are predictors of mortality. Therapy is not indicated by evidence-based recommendations but mostly on identification of the high-risk conditions. A PVE is a common indication for surgery, whereas medical treatment alone may be achieved in a few instances. Systematic prophylaxis should be used to prevent this severe complication of cardiac valve replacement.

Infective endocarditis in dogs: diagnosis and therapy

Infective endocarditis (IE) is a bacterial disease that commonly occurs in dogs. Difficulty in diagnosis and underreporting of IE in dogs contribute to the reported low prevalence rate of the disease. The mitral and aortic valves are the worst affected by IE. Common causative microbial agents include Staphylococcus spp, Streptococcus spp, Escherichia coli, and Bartonella spp. Congestive heart failure, immune-mediated disease, and thromboembolism are the major complications of IE. Diagnosis of IE by echocardiography and long-term treatment with broad-spectrum antibiotics may contribute to the timely detection and treatment of the disease.

Use of echocardiography in the diagnosis and management of infective endocarditis

The first use of echocardiography in infective endocarditis (IE) was described in 1973. Since then, echocardiography has emerged as a major tool for the diagnosis and management of this disease. In general, transthoracic echocardiography (TTE) is adequate for diagnosing IE in cases where cardiac structures-of-interest are well visualized. Specific situations where transesophageal echocardiography is preferred over TTE include the presence of a prosthetic device, suspected periannular complications, children with complex congenital cardiac lesions, selected patients with Staphylococcus aureus bacteremia, and certain pre-existing valvular abnormalities that make TTE interpretation problematic (eg, calcific aortic stenosis). Echocardiography is also useful for risk stratification. Evidence suggests that vegetation size can predict embolic complications, although the data are inconsistent. Careful clinical assessment is essential to the proper use of echocardiography in diagnosing IE, visualizing complications related to IE, and evaluating candidacy for surgical intervention.

An introduction to non-invasive cardiac imaging

According to the World Health Organization (2009), an estimated 17.1 million people died from cardiovascular disease in 2005 (29% of global deaths), 7.2 million from coronary heart disease. It is the number one killer globally and with new and more complex ways of investigating the heart non-invasively, it is important to understand what is available and when to use each modality. This article explains how the different forms of non-invasive cardiac imaging work, their advantages and disadvantages (Table 1), when to use each one and finally what developments are likely in the future. Some may not be available in all hospitals, but access and availability to cardiac imaging is likely to change significantly in the future.

Incidence of neurological complications in patients with native-valve infective endocarditis and cerebral microembolism: an open cohort study

The objective of this open cohort study was to assess the association between neurological complications in patients with definite native-valve infective endocarditis (IE) and cerebral microembolism (MES). MES detection was performed with 1-h, bilateral middle cerebral arteries (MCA) insonation using a transcranial Doppler ultrasound (TCD) machine. Thirty patients with definite native-valve IE were stratified into 2 groups based upon the presence of MES. The most striking difference between the 2 groups of patients was the incidence of clinically evident neurological complications. Neurological complications of IE occurred in 10 (83.3%) patients with positive MES and in 6 (33.3%) MES-negative patients (p=0.021). Ischaemic stroke was the most common complication, occurring in 11 of 16 patients, followed by meningitis in 4 patients and cerebritis in 1 patient. There was a trend towards greater in-hospital mortality in patients with recorded MES than in the MES-negative, although this was not statistically significant (33.3% vs 16.6%; p=0.392). Our results reveal a significant association between MES and neurological complications in patients with native-valve IE. TCD is a promising tool in predicting individual patient risk for neurological complications of IE.

Judicious use of transthoracic echocardiography in infective endocarditis screening

BACKGROUND

Patients with a very low probability of infective endocarditis (IE) do not benefit from transthoracic echocardiography (TTE). Because the term 'very low probability' has not yet been defined, the present prospective study sought to identify the population with a 'very low probability'.

METHODS

TTE was performed between July 2005 and October 2006 in consecutive patients clinically suspected of having IE. Clinical parameters suggestive of IE and presence of infectious focus were recorded.

RESULTS

Twenty-four (15.5%) of 155 patients studied had positive findings on TTE. Significant positive predictors were embolic events, intravenous drug use, the presence of a prosthetic valve, positive blood cultures and immunological phenomena. The significant negative predictor was confirmed infection sites other than endocardium. Sixty-three (40.6%) of 155 patients without positive predictors were found to have no vegetation. Thus, the collective absence of these predictors indicated a zero probability of TTE showing evidence of IE. A significant negative predictor was a definite etiology of infection other than IE. Only one in 76 patients was diagnosed with both IE and infection at another site.

CONCLUSIONS

The absence of positive predictors or the presence of a negative predictor indicate a near-zero probability of IE being detected by TTE. Use of clinical parameters may avoid up to 41% of unnecessary TTE examinations, increasing the likelihood that such a diagnosis will be correct.