Infective endocarditis and echocardiography

Diagnostic accuracy of transthoracic echocardiography to identify native valve infective endocarditis: a systematic review and meta-analysis

Infective endocarditis (IE) is a serious and potentially life-threatening disease, and accurate diagnosis is essential. We performed a systematic review and meta-analysis to assess the diagnostic accuracy of transthoracic echocardiography (TTE), with transesophageal echocardiography (TEE) as the reference standard, in patients with suspected IE of the native valves. We performed a systematic search in MEDLINE, EMBASE and Cochrane Library searching for studies that enrolled adult patients with suspected native valves IE where data about both TTE and TEE could be extracted. We included 11 studies, for a total of 2209 patients. The overall sensitivity, specificity, negative and positive likelihood ratios (LR) of TTE are 0.71 (95% CI 0.56-0.82), 0.80 (95% CI 0.58-0.92), 0.37 (95% CI 0.20-0.68) and 3.56 (95% CI 1.3-9.72), respectively. The subgroup analyses of the studies considering different cut-off levels show that the strict negative criteria (i.e., managing indeterminate results as positive) have the highest sensitivity and the lowest LR-. On the contrary, when managing indeterminate results as negative (standard criteria), the specificity and LR+ are the highest. We observed no differences between the studies performed with older and more recent technologies. In conclusion, our study results support the use of a negative TTE as a single rule-out test in patients with a low pre-test probability. In selected cases, the use of strict negative criteria might exclude IE in intermediate-risk patients, and a positive TTE might be considered as a single rule-in test with no need for TEE if TEE results would not change the patient's management.

Guidelines for the Use of Echocardiography in the Evaluation of a Cardiac Source of Embolism

Embolism from the heart or the thoracic aorta often leads to clinically significant morbidity and mortality due to transient ischemic attack, stroke or occlusion of peripheral arteries. Transthoracic and transesophageal echocardiography are the key diagnostic modalities for evaluation, diagnosis, and management of stroke, systemic and pulmonary embolism. This document provides comprehensive American Society of Echocardiography guidelines on the use of echocardiography for evaluation of cardiac sources of embolism. It describes general mechanisms of stroke and systemic embolism; the specific role of cardiac and aortic sources in stroke, and systemic and pulmonary embolism; the role of echocardiography in evaluation, diagnosis, and management of cardiac and aortic sources of emboli including the incremental value of contrast and 3D echocardiography; and a brief description of alternative imaging techniques and their role in the evaluation of cardiac sources of emboli. Specific guidelines are provided for each category of embolic sources including the left atrium and left atrial appendage, left ventricle, heart valves, cardiac tumors, and thoracic aorta. In addition, there are recommendation regarding pulmonary embolism, and embolism related to cardiovascular surgery and percutaneous procedures. The guidelines also include a dedicated section on cardiac sources of embolism in pediatric populations.

Avoiding transthoracic echocardiography and transesophageal echocardiography for patients with variable body mass indexes in infective endocarditis

Background

Echocardiography has been a popular modality used to aid in the diagnosis of infective endocarditis (IE) with the modified Duke criteria. We evaluated the necessity between the uses of either a transthoracic echocardiography (TTE) or transesophageal echocardiography (TEE) in patients with a body mass index (BMI) greater than or equal to 25 kg/m² and less than 25 kg/m².

Methods

A single-centered, retrospective study of 198 patients between 2005 and 2012 diagnosed with IE based on modified Duke criteria. Patients, required to be above age 18, had undergone an echocardiogram study and had blood cultures to be included in the study.

Results

Among 198 patients, two echocardiographic groups were evaluated as 158 patients obtained a TTE, 143 obtained a TEE, and 103 overlapped with TEE and TTE. Out of these patients, 167 patients were included in the study as 109 (65%) were discovered to have native valve vegetations on TEE and 58 (35%) with TTE. TTE findings were compared with TEE results for true negatives and positives to isolate valvular vegetations. Overall sensitivity of TTE was calculated to be 67% with a specificity of 93%. Patients were further divided into two groups with the first group having a BMI ≥25 kg/m² and the subsequent group with a BMI <25 kg/m². Patients with a BMI ≥25 kg/m² who underwent a TTE study had a sensitivity and specificity of 54 and 92%, respectively. On the contrary, patients with a BMI < 25 kg/m² had a TTE sensitivity and specificity of 78 and 95%, respectively.

Conclusions

Patients with a BMI <25 kg/m² and a negative TTE should refrain from further diagnostic studies, with TEE strong clinical judgment is warranted. Patients with a BMI ≥ 25 kg/m² may proceed directly to TEE as the initial study, possibly avoiding an additional study with a TTE.

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.

Antithrombotic Therapy in Valvular Heart Disease—Native and Prosthetic

This chapter about antithrombotic therapy in native and prosthetic valvular heart disease is part of the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy: Evidence Based Guidelines. Grade 1 recommendations are strong and indicate that the benefits do, or do not, outweigh risks, burden, and costs. Grade 2 suggests that individual patients' values may lead to different choices (for a full understanding of the grading see Guyatt et al, CHEST 2004; 126:179S-187S). Among the key recommendations in this chapter are the following: For patients with rheumatic mitral valve disease and atrial fibrillation (AF), or a history of previous systemic embolism, we recommend long-term oral anticoagulant (OAC) therapy (target international normalized ratio [INR], 2.5; range, 2.0 to 3.0) [Grade 1C+]. For patients with rheumatic mitral valve disease with AF or a history of systemic embolism who suffer systemic embolism while receiving OACs at a therapeutic INR, we recommend adding aspirin, 75 to 100 mg/d (Grade 1C). For those patients unable to take aspirin, we recommend adding dipyridamole, 400 mg/d, or clopidogrel (Grade 1C). In people with mitral valve prolapse (MVP) without history of systemic embolism, unexplained transient ischemic attacks (TIAs), or AF, we recommended against any antithrombotic therapy (Grade 1C). In patients with MVP and documented but unexplained TIAs, we recommend long-term aspirin therapy, 50 to 162 mg/d (Grade 1A). For all patients with mechanical prosthetic heart valves, we recommend vitamin K antagonists (Grade 1C+). For patients with a St. Jude Medical (St. Paul, MN) bileaflet valve in the aortic position, we recommend a target INR of 2.5 (range, 2.0 to 3.0) [Grade 1A]. For patients with tilting disk valves and bileaflet mechanical valves in the mitral position, we recommend a target INR of 3.0 (range, 2.5 to 3.5) [Grade 1C+]. For patients with caged ball or caged disk valves, we suggest a target INR of 3.0 (range, 2.5 to 3.5) in combination with aspirin, 75 to 100 mg/d (Grade 2A). For patients with bioprosthetic valves, we recommend vitamin K antagonists with a target INR of 2.5 (range, 2.0 to 3.0) for the first 3 months after valve insertion in the mitral position (Grade 1C+) and in the aortic position (Grade 2C). For patients with bioprosthetic valves who are in sinus rhythm and do not have AF, we recommend long-term (> 3 months) therapy with aspirin, 75 to 100 mg/d (Grade 1C+).

Early surgical intervention for infective endocarditis

Infective endocarditis remains a serious and complex disease with significant morbidity and mortality. Sixty cases of infective endocarditis were retrospectively reviewed, consisting of 41 males and 19 females aged 7 to 50 years (mean, 30 years). Congenital heart disease was diagnosed in 19 of the patients and rheumatic heart disease in 41. Congestive heart failure occurred in 36 and systemic embolism in 8 cases. Blood cultures were positive in only 21.7% of the cases, while vegetations were detected by 2-dimensional echocardiography in 70%. Elective surgery was performed in 57 patients and emergent operation for systemic arterial embolization and/or intractable congestive heart failure in 3 patients. Two patients required reoperation for postoperative bleeding. All but 2 patients had been followed up for 6 to 160 months with no evidence of reinfection. Three patients with mechanical valve implantation later died of intracranial bleeding due to over-anticoagulation. The remaining 55 resumed normal activity. The encouraging outcomes were the result of an aggressive diagnostic approach and early surgical intervention.

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.

Value of echocardiographic findings in predicting cardiovascular complications in infective endocarditis

Echocardiography allows the detection of vegetations and estimation of valvular dysfunction in patients with infective endocarditis. The value of echocardiographic findings in predicting cardiac and other vascular complications in infective endocarditis is not well understood. Identification of high-risk patients and early surgery may improve their prognosis. The authors reviewed echocardiographic findings and related them to the development of congestive heart failure, systemic embolism, and the need for surgery or the risk of death without surgery in patients with infective endocarditis. There were 125 episodes of endocarditis in 114 patients (84 episodes [67%] in men) with a mean age +/- standard deviation of 37 +/- 7 years. Vegetations were detected by echocardiography on at least 1 valve in 87 episodes (70%); on the mitral valve in 36 episodes (29%); on the aortic valve in 21 episodes (17%); and on the tricuspid valve in 45 episodes (36%). Severe aortic regurgitation was present in 9 episodes (7%) and severe mitral regurgitation in 4 instances (3%). In 12 of 21 episodes (57%) of vegetations on the aortic valve compared with 15 of 104 patients (14%) without vegetations on the aortic valve (p < 0.001), and in 8 of 9 instances (89%) of severe aortic regurgitation compared with 19 of 116 episodes (16%) without severe aortic regurgitation (p<0.00001), the patients developed congestive heart failure. In 18 of 55 episodes (33%) of vegetations on the aortic/mitral valve compared with 17 of 70 episodes (25%) without vegetations on the aortic valve/mitral valve (p = NS), the patients developed systemic embolism. In 13 of 21 episodes (62%) of vegetations on the aortic valve compared with 19 of 104 episodes (19%) without vegetations on the aortic valve (p < 0.001), and in 8 of 9 episodes (89%) of severe aortic regurgitation compared with 24 of 116 episodes (21%) without severe aortic regurgitation (p < 0.00001), the patients either had surgery or died without surgery. Echocardiographic findings do not reliably predict the risk of systemic embolism in patients with infective endocarditis. Vegetations on the aortic valve and severe aortic regurgitation detected by echocardiography predict a high risk of developing congestive heart failure, and for the combined outcome of requiring surgery, or dying without surgery in infective endocarditis. Early surgery may improve the outlook for survival of these patients.

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.

Surgical treatment of endocarditis

Since early investigators first suggested that the treatment of endocarditis should include valve replacement for infections not readily controlled with medical therapy alone, the role of surgery has become expanded, yet refined, to improve the outcome of patients with this potentially fatal disease. Innovative surgical techniques have also been developed in an effort to improve the results of surgical treatment for complex sequelae of invasive infections. This article examines the current indications for surgical intervention, compares the various surgical options, and assesses the expected short-and long-term outcome after valve replacement for patients with native valve or prosthetic valve 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.

Neurologic manifestations in Staphylococcus aureus endocarditis: a review of 260 bacteremic cases in nondrug addicts

PURPOSE

To investigate the neurologic manifestations of infective endocarditis caused by Staphylococcus aureus in a population of nondrug addicts with special emphasis on the clinical presentation, epidemiology, and mortality.

PATIENTS AND METHODS

During the period from 1982 to 1991 a total of 8,514 cases of bacteremia with S aureus were reported to the Staphylococcus Laboratory, Copenhagen, Denmark. The medical records of cases of suspected infective endocarditis were retrospectively reviewed and classified according to the new diagnostic criteria for endocarditis proposed by Durack.

RESULTS

A total of 260 cases from 63 hospitals fulfilled the diagnostic criteria. Overall, 91 patients (35%) experienced neurologic manifestations. Sixty-one presented with neurologic symptoms, whereas 30 patients developed neurologic complications at various intervals (median: 10 days) after the debut of the disease. The most frequent neurologic manifestation was unilateral hemiparesis, which occurred in 41 patients (45%). Forty-two percent of the females had neurologic manifestations compared to only 30% of the males (P = 0.06). Cases with native mitral valve infection had a significantly higher frequency of neurologic manifestations compared with all other valvular involvement (44% versus 29%, P = 0.02) but the frequency of neurologic complications was only nonsignificantly higher in those patients with native mitral valve infection than in those patients with native aortic valve infection (44% versus 31%, P = 0.10). Only two of the patients with tricuspid valve infection and none of those with congenital heart disorder experienced neurologic manifestations. A neurologic manifestation occurred in 22 (35%) of the 63 episodes in which vegetations were detected on the echocardiograms, compared with 17 (26%) of the 65 episodes without vegetations (P = 0.38). The mortality was 74% in patients with major neurologic manifestations and 56% in patients without neurologic manifestations (P = 0.008). In patients with neurologic complications the mortality was significantly higher among those treated with antibiotics alone as compared with those treated surgically (65 of 81, 80% versus 2 of 10, 20%; P = 0.0003).

CONCLUSIONS

In a population of nondrug addicts with infective endocarditis caused by S aureus the following main conclusions can be drawn: neurologic manifestations occur with a higher frequency in patients with native mitral valve infection. The presence of vegetations on echocardiograms is not a risk factor for developing neurologic complications but this conclusion is based on the results of transthoracic echocardiograms performed in only one half of the patients. The majority of the neurologic manifestations occur on presentation or shortly thereafter and the risk of recurrent embolism is low. Mortality is increased in patients with neurologic manifestations. A neurologic event per se may constitute an indication for surgical treatment.

Neurologic complications of infective endocarditis observed in a south Indian referral hospital

We retrospectively reviewed the records of 110 patients with infective endocarditis (IE) who were hospitalized between 1977 and 1994 at a tertiary referral center in Southern India to assess the occurrence of neurologic complications and the factors that contribute to their development, and to compare our experience from a developing country with the reported data from developed countries. There were 62 males and 48 females, aged 0.6-59 (mean 24.0) years. Rheumatic heart disease (RHD) was the most frequent underlying cardiac lesion accounting for 65 (59.1%) patients. Neurologic complications were observed in 58 (52.7%) patients: cerebral embolism was the most frequent (23 patients). Thirty-five (31.8%) patients died. Mortality in the group with neurologic complications (41.4%) was significantly higher than in the group without (21.2%) (p = 0.04). The duration of symptoms prior to the diagnosis was longer in the group with neurologic complications, mean 174.9 versus 95.6 days (p = 0.03). We conclude that (1) IE occurs at younger ages in the Third World and RHD still constitute the major underlying heart disease; (2) in spite of the differences in the general aspects of IE between developed and developing nations, the frequency and gravity of neurologic complications are similar, (3) mortality is significantly increased in patients with neurologic complications; and (4) delay in the diagnosis of IE contributes to the development of neurologic complications.

Infective endocarditis in infants and children

Due to changing characteristics of infective endocarditis in the past two decades, we, retrospectively analysed 28 cases of infective endocarditis in children of age less than 15 years at Sher-i-Kashmir Institute of Medical Sciences, Soura, Srinagar from December, 1983 to November, 1993. The incidence of disease was observed as 1.5 cases/1000 children admitted with a M:F ratio of 2:1. Three patients were of age less than 2 years (group I) as 25 were above 2 years of age (group II). The two groups had significant difference in portal of entry of infection, infective microorganisms, echocardiography and prognosis. Congenital heart disease was the commonest underlying cardiac lesion in 24 (85.71%) patients. Portal of entry of infection was apparent in 35.71% only; dental route being more frequent in group II. Streptococcus viridans (in 9 cases) followed by staphylococcus aureus (in 4 cases) were the two common organisms isolated. Patients were treated, for a period of 4-6 weeks with a over all mortality rate of 25%. Factors associated with poor prognosis were age < 2 years, staphylococcal infection ad negative blood cultures. Heart failure resistant to medical therapy was a leading cause of death.

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

Early identification of a high risk patient subgroup with infective endocarditis which develops a major complication (emboli, congestive heart failure, surgery for valve replacement, or death) during hospitalization would reduce morbidity, mortality and cost. Thus, for 74 patients with native valve infective endocarditis with documented vegetation by transthoracic two-dimensional echocardiogram, we reviewed 67 variables: history (15), physical examination (9), hematology/miscellaneous (7), chest X-ray (2), electrocardiogram (4), transthoracic two-dimensional echocardiograms (15) and hospital course (15). There were 48 men and 26 women, ages 45 +/- 19 years: 35 intravenous drug abusers and 39 non-users. There were 32 mitral, 21 tricuspid, 20 aortic, and 1 pulmonic valve vegetations; mean vegetation size was 1.4 +/- 0.9 cm2. Over the course of their hospitalization, 14 patients died (19%), 27 developed congestive heart failure (36%), 27 had systemic emboli (36%), and 22 required surgery (30%). The incidence of complications (death, heart failure or embolic events) did not differ between the drug abusers and non-users. Initial complaint of dyspnea on admission predicted the subsequent development of heart failure (P < 0.001), and a pre-admission embolus predicted a second in-hospital embolus (P < 0.001). Left atrial size, ventricular systolic or diastolic dimension did not effect prognosis. Importantly, a vegetation > 1.8 cm2 was 100% specific but only 30% sensitive for predicting the development of a complication. Vegetation mobility, shape, and number of cusps involved were not predictive. However, aortic valve vegetations had significantly more complications than those on the mitral valve (P < 0.03). By discriminant function analysis, 87% of major complications were predicted with the patient profile of having aortic valve vegetation, dyspnea on admission, prolonged preadmission fever, and no history of drug abuse; 75% of patients who developed heart failure were predicted by their having aortic valve vegetation, dyspnea, hypotension (systolic < 90 mm Hg), and no history of drug abuse; and 77% of patients requiring surgery were predicted by their having larger vegetation size, rales, and leftward shift of white blood cells. Thus, in native valve bacterial endocarditis with transthoracic echocardiographic documented vegetations, non-drug abusers with aortic vegetations, preadmission prolonged fevers, dyspnea, emboli and larger sized vegetations are at high risk for developing a major complication during their hospitalization.

Criteria for the diagnosis of endocarditis and the role of echocardiography

When infective endocarditis is a diagnostic possibility, echocardiography permits noninvasive imaging of cardiac structures. As involvement of the endocardium is a sine qua non of endocarditis, echocardiography may assist in its diagnosis by demonstrating such involvement. The ability of echocardiography to detect the intracardiac manifestations of infective endocarditis has continued to improve, especially with the introduction of transesophageal imaging. This article will discuss some of the echocardiographic findings in endocarditis and elucidate the incorporation of these findings in the new Duke criteria for the diagnosis of endocarditis.

Outpatient treatment of endocarditis in a clinic-based program in Argentina

The major cost in the treatment of infective endocarditis (IE) is the length of hospitalization required for the administration of intravenous antibiotics. This can be reduced by substituting shorter regimens and by the introduction of outpatient parenteral antibiotic therapy (OPAT). Careful selection of patients is vital for the success of OPAT in IE. The patients should be hemodynamically stable and without clinical complications. The delivery of OPAT for IE followed a clinical and home-based program involving an endocarditis team whose members included an infectious diseases physician, a microbiologist, a cardiologist and a nurse trained in intravenous techniques. Among the antimicrobial agents used in OPAT of IE, single-agent ceftriaxone for four weeks followed by a short course of amoxicillin or ceftriaxone in combination with an aminoglycoside for two weeks (short course) are effective modes of treatment for streptococcal endocarditis, the most common cause of IE. This treatment is also effective for carefully selected patients with other types of endocarditis, such as those due to the HACEK group (Haemophilus aphrophilus/paraphrophilis, Actinobacillus actinomycetem comitans, Caradiobacterium hominis, Eikenella corrodens and Kingella kingae). Staphylococcus aureus, enterococci and late prosthetic valve endocarditis associated with a streptococcus may also be treated on an outpatient basis after stabilization (approximately 2 weeks). As a result of their need for prolonged treatment periods, these patients are also very good candidates for OPAT. In conclusion, new regimens utilizing ceftriaxone once daily and short-term therapy on a clinical or home basis offer the potential benefits of cheaper safer and more convenient treatment for patients with IE.

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

The purpose of this study was twofold: (1) to determine interobserver variability of echocardiographic characteristics of vegetations in patients with infective endocarditis, and (2) to assess the value of these vegetation characteristics in predicting embolic events. Although echocardiography contributes to the diagnosis of patients with infective endocarditis, its prognostic role in predicting embolic events is controversial. The echocardiograms of 41 patients with infective endocarditis were independently reviewed by 4 echocardiographers blinded to the clinical data. If a vegetation was present, the following characteristics were analyzed: involved site, size, mobility, shape, and pedunculated or sessile attachment. Each echocardiographer also made a "gestalt" estimate of embolic risk based on these vegetation characteristics. Interobserver agreement on vegetation characteristics and their relation to embolic events was then determined using kappa statistics and logistic regression analysis. Interobserver agreement was 98% with regard to echocardiographic vegetation presence and 97% with regard to the involved site. Of the 30 patients in whom vegetations were observed, complete observer agreement was achieved with regard to size in 22 (73%), mobility in 17 (57%), shape in 11 (37%), and attachment in 12 (40%). Vegetations with a maximal diameter of > 10 mm were associated with a 50% incidence of embolic events, compared with a 42% incidence of emboli in patients with vegetations measuring < or = 10 mm. Interobserver variability was great with respect to vegetation shape, mobility, and attachment characteristics. Echocardiographic vegetation characteristics were not helpful in defining the risk of embolic complications in patients with endocarditis.

Application of transthoracic and transesophageal echocardiography in the diagnosis and management of infective endocarditis

Infective endocarditis continues to be a cause of significant cardiac morbidity and mortality. To improve the prognosis of patients with this disorder, early diagnosis is crucial but difficult to establish on the basis of clinical parameters alone. Echocardiography, both transthoracic and transesophageal techniques, has a major role in the detection of vegetations that are the hallmark of endocarditis. Valvular and perivalvular complications can also be well assessed by echocardiography. With the improved resolution provided by recent technologic advances in echocardiography, vegetations can be reliably detected in most patients with endocarditis. We propose that present diagnostic criteria for endocarditis be revised to include echocardiographic findings as a major parameter in the diagnosis. Finally, a diagnostic approach incorporating transthoracic and transesophageal echocardiography in these patients will be discussed taking into consideration the different degrees of clinical suspicion for the existence of the disease.

Right-sided endocarditis in the non-drug addict

Fifteen patients with right-sided infective endocarditis during a 5 year period (1985-1990) were retrospectively reviewed. Isolated tricuspid valve involvement occurred in nine patients. Staphylococcus aureus was the causative organism in seven cases; four were culture negative. The diagnosis was established by two-dimensional echocardiography in 11 patients and at postmortem in the remaining four patients who succumbed shortly after admission. Fever, tachypnoea and pneumonia were universal features. A successful outcome ensued in eight patients with medical therapy alone and in two patients who were submitted to valve replacement. Five patients died, two from uncontrolled infection with repeated pulmonary emboli. Right-sided infective endocarditis should be suspected in any pneumonic illness that complicates post-abortal infection or other inadequately treated sepsis. Two-dimensional echocardiography is important in diagnosis since cardiac signs are minimal at presentation.

Heart disease in patients with stroke: incidence, impact, and implications for rehabilitation. Part 1: Classification and prevalence

Heart disease is found in about 75% of patients who have suffered a stroke. Cardiovascular diseases can be risk factors, etiologic mechanisms, associated conditions, or direct consequences of stroke. Cardiac comorbidity may delay initiation of rehabilitation, complicate the course and care of the patient with stroke, inhibit participation in a therapeutic exercise program, limit functional outcomes, and contribute to early mortality in the individual with cerebrovascular disease. Part 1 of this two-part article describes the various forms of heart disease that may be seen in stroke patients, and reviews the incidence figures for each type of associated cardiac condition.

Transesophageal echocardiography in right-sided endocarditis

OBJECTIVES

Our aim was to determine the diagnostic value of transesophageal echocardiography in right-sided endocarditis.

BACKGROUND

Recent studies have demonstrated that transesophageal echocardiography is superior to transthoracic echocardiography in the detection of vegetations associated with left-sided endocarditis. Its diagnostic value in right-sided endocarditis has not been established.

METHODS

Transthoracic and transesophageal echocardiography were prospectively performed in 48 patients who met specific criteria for the suspicion of right-sided endocarditis. All were intravenous drug abusers.

RESULTS

Vegetations were found in 22 of 48 patients by both transthoracic and transesophageal echocardiography. The vegetations were more precisely characterized by transesophageal echocardiography in 14 (63%) of 22 patients. In the remaining 26 patients, no vegetations were found by either transthoracic or transesophageal echocardiography. No statistically significant differences were found between the two techniques in the assessment of tricuspid regurgitation, which was detected in 21 (44%) of 48 patients.

CONCLUSIONS

We conclude that transesophageal echocardiography does not improve the diagnostic accuracy of transthoracic echocardiography in the detection of vegetations associated with right-sided endocarditis in intravenous drug abusers. Transesophageal echocardiography may not be indicated as a routine procedure in patients suspected of having right-sided endocarditis.

The febrile parenteral drug user: a prospective study in 121 patients

OBJECTIVE

To determine the most efficient approach to the diagnosis of infective endocarditis (IE) in febrile parenteral drug users (PDUs) and evaluate possible effects of human immunodeficiency virus (HIV) infections or acquired immunodeficiency syndrome (AIDS) on susceptibility to IE and final outcome.

DESIGN

A prospective study of appropriate patients admitted on 149 random sampling days during a 14-month period and review of past experience with IE, HIV, and AIDS admissions to hospital.

SETTING

An urban university hospital.

PATIENTS

Prospectively, 121 febrile PDUs plus an additional 16 found to have IE on nonsampling days during the study period. Retrospectively, all PDUs with IE from 1985 to 1991 and all patients with HIV infections with or without AIDS from July 1990 through December 1991.

MEASUREMENTS

Physical examination, hemograms, urinalysis, blood cultures (plus other body fluids when indicated), echocardiography, laboratory testing for HIV status.

MAIN RESULTS

Five categories of patients were identified: I. Infective endocarditis (n = 16); II. Other infections with bacteremia (n = 21); III. Bacteremia with unidentified source of infection (n = 14); IV. Infections without bacteremia (n = 52); V. Fever of unknown origin (n = 18). Physical findings and standard laboratory testing did not differentiate Group I from any of the other diagnostic categories. Adding additional IE cases from nonstudy days brought the total to 32. Vegetations were found on echocardiography in 94%; blood cultures, available in 30 of 32 instances, were all positive. HIV or AIDS status was not found to alter susceptibility to IE or influence mortality. While hospital admissions for HIV and especially AIDS have continued to increase among PDUs, the number of cases of IE has decreased since 1988 to 1989.

CONCLUSIONS

Based on the high incidence of blood culture positivity and the sensitivity of echocardiography in detecting vegetations in IE, a simple algorithm has been developed for the initial diagnostic management of febrile PDUs admitted with the possible diagnosis of IE. HIV infection, with or without full-blown AIDS, does not appear to affect the incidence or outcome of IE among these patients. Current practices among PDUs may be effecting a decline in IE but not HIV infections.

Implication of negative results on a monoplane transesophageal echocardiographic study in patients with suspected infective endocarditis

OBJECTIVES

This study was conducted to determine the implications of negative findings on a transesophageal echocardiographic study in which neither a vegetation nor an abscess is identified in patients with clinically suspected infective endocarditis.

BACKGROUND

Echocardiography is the procedure of choice for evaluating suspected infective endocarditis in patients. Transesophageal echocardiography has been shown to be superior to transthoracic imaging. Although the importance of positive results or a diagnostic study is known, the significance of negative findings on a transesophageal study is not clear.

METHODS

All transesophageal echocardiographic studies performed over a 2-year period for suspected infective endocarditis were reviewed and the clinical course of patients with an initially negative study result was assessed to determine their final diagnosis.

RESULTS

Of the 105 patients identified, 65 had a negative transesophageal study result. In the majority of this group (56 of 65), an alternate diagnosis was made or there was no infective endocarditis on follow-up examination, or both. Of the remaining nine patients, four were treated for endocarditis without a definite diagnosis and five had infective endocarditis proved by either repeat transesophageal study (n = 3), pathologic findings (n = 1) or a diagnostic clinical course (n = 1). Gram-positive bacteremia and the presence of a prosthetic valve in the aortic position tended to be more common in the latter group.

CONCLUSIONS

A negative transesophageal study result reduces the likelihood that endocarditis is present. Repeat examination, however, should be considered in high risk patients, such as those with prosthetic valves or unexplained bacteremia, to avoid a missed diagnosis.

Active infective endocarditis observed in an Indian hospital 1981-1991

Clinical data from 186 patients (133 males and 53 females) with 190 episodes of infective endocarditis (IE) occurring between January 1981 and July 1991 were studied retrospectively at a large referral hospital in Northern India with the intention of highlighting certain essential differences from those reported in the West. The mean age was much lower (25 +/- SD 12 years, range 2 to 75 years). Rheumatic heart disease was the most frequent underlying heart lesion accounting for 79 patients (42%). This was followed by congenital heart disease in 62 (33%) and normal valve endocarditis in 17 (9%). Twenty-four patients had either aortic regurgitation (n = 15) or mitral regurgitation (n = 9) of uncertain etiology. Prosthetic valve infection and mitral valve prolapse were present in only 2 patients each. A definite predisposing factor could be identified in only 28 patients (15%). Postabortal sepsis and sepsis related to childbirth accounted for 6 and 5 cases, respectively. Only 1 patient had history of intravenous drug abuse. Two-dimensional echocardiography showed vegetations in 121 patients (64%). Blood cultures were positive in only 87 (47%), with a total of 90 microbial isolates. Commonest infecting organisms were staphylococci (37 cases) and streptococci (34 cases). Except for a significantly higher number of patients with neurologic complications in the culture-negative group, there were no differences between patients with culture-positive and culture-negative IE. Of the 190 episodes of IE, the patients had received antibiotics before admission in 110 (58%) instances. A significantly greater number of culture-negative patients had received antibiotics than did culture-positive patients (87 vs 23, p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Echocardiographic assessment of patients with infectious endocarditis: prediction of risk for complications

To enhance the echocardiographic identification of high risk lesions in patients with infectious endocarditis, the medical records and two-dimensional echocardiograms of 204 patients with this condition were analyzed. The occurrence of specific clinical complications was recorded and vegetations were assessed with respect to predetermined morphologic characteristics. The overall complication rates were roughly equivalent for patients with mitral (53%), aortic (62%), tricuspid (77%) and prosthetic valve (61%) vegetations, as well as for those with nonspecific valvular changes but no discrete vegetations (57%), although the distribution of specific complications varied considerably among these groups. There were significantly fewer complications in patients without discernible valvular abnormalities (27%). In native left-sided valve endocarditis, vegetation size, extent, mobility and consistency were all found to be significant univariate predictors of complications. In multivariate analysis, vegetation size, extent and mobility emerged as optimal predictors and an echocardiographic score based on these factors predicted the occurrence of complications with 70% sensitivity and 92% specificity in mitral valve endocarditis and with 76% sensitivity and 62% specificity in aortic valve endocarditis.

A case for early surgery in native left-sided endocarditis complicated by heart failure: results in 203 patients

From January 1982 to December 1988, 203 consecutive patients were selected for early valve replacement (mean 10 days from time of admission) if they had clinical evidence of native valve endocarditis with 1) vegetations on echocardiography, 2) severe valvular lesions, and 3) heart failure. Surgery was performed within 7 days of admission in 56% of patients and was done urgently because of hemodynamic deterioration in 108 (53%). All vegetations were identified by echocardiography and confirmed macroscopically at surgery. One hundred ten patients had isolated aortic valve infection, 50 had isolated mitral valve infection (p less than 0.05 for aortic vs. mitral) and 43 had double-valve infection. Mean aortic cross-clamp time was 57, 38 and 67 min, respectively. Sixty-four patients (32%) had extensive infection involving the anulus or adjacent tissues, or both; such infection more frequently involved the aortic than the mitral valve (p less than 0.05). Thirty-eight patients (35%) with aortic valve infection had abscess formation compared with 1 patient (2%) with mitral valve infection (p less than 0.05). Only eight patients (4%) died in the hospital. There were seven patients (3%) with a periprosthetic leak and five patients (3%) with early prosthetic valve endocarditis. Long-term follow-up, available in 174 hospital survivors (89%), revealed 10 deaths and two new ring leaks at 38 +/- 22 months. In conclusion, among patients with endocarditis who need surgery for heart failure, aortic valve infection is more prevalent than mitral valve infection and is more often associated with extensive infection, including abscess formation.(ABSTRACT TRUNCATED AT 250 WORDS)

Diagnostic value of transesophageal compared with transthoracic echocardiography in infective endocarditis

To compare the diagnostic value of transesophageal and transthoracic echocardiography in infective endocarditis, paired transesophageal and transthoracic echocardiograms were obtained prospectively for 66 episodes of suspected endocarditis in 62 patients. Echocardiographic results were compared with the presence or absence of endocarditis determined by pathologic or nonechocardiographic data from the subsequent clinical course. All echocardiograms were interpreted by an observer told only that the studies were from patients in whom the diagnosis of endocarditis was suspected. The diagnosis of endocarditis was eventually made in 16 of the 66 episodes of suspected endocarditis (14 by pathologic and 2 by clinical criteria). In 7 of 16 transthoracic and 15 of 16 transesophageal echocardiograms, endocarditis was diagnosed at a probability level of "almost certain," giving a sensitivity of 44% and 94%, respectively (p less than 0.01). For the remaining episodes, 49 of 50 transthoracic and all transesophageal studies yielded normal results, giving a specificity of 98% and 100%, respectively. This study suggests that transesophageal echocardiography is highly sensitive and specific for the diagnosis of infective endocarditis and significantly more sensitive than transthoracic echocardiography. Although echocardiography cannot rule out endocarditis, the high diagnostic sensitivity of transesophageal echocardiography results in a low probability of the disease when the study yields negative results in a patient with an intermediate likelihood of the disease.

The role of two-dimensional echocardiology in the diagnosis of infective endocarditis [corrected]

Two-dimensional echocardiography has had a significant impact on and is considered the technique of choice for the diagnosis and management of infective endocarditis. Over a thirty-six month period, 106 patients were evaluated by echocardiography for the possibility of endocarditis. The diagnosis of endocarditis was determined by strict clinical and laboratory criteria. All clinical histories, blood cultures, echocardiograms, and autopsy results were reviewed. Five echocardiograms were technically inadequate, resulting in a study population of 101 patients. The age of the patients ranged from forty-five days to eighty-eight years (mean fifty-seven years). The clinical manifestations of endocarditis included fever (83%), chills (60%), congestive heart failure (25%), and splenomegaly (18%). Twelve patients had preexisting valvular or congenital heart disease. Gram-positive cocci were the most common microorganisms. Complications included mitral regurgitation, subarachnoid hemorrhage, renal infarction, stroke, and a pulmonary embolus. The patients were divided into two groups: Group I consisted of 36 patients with definite vegetations by echocardiography, and Group II had 65 patients with no vegetations. In Group I, acute infective endocarditis was present in 35 patients, whereas only 4 patients had endocarditis in Group II. The sensitivity of two-dimensional echocardiography for detecting endocarditis was 90%. The specificity was 98%. The predictive accuracy for a positive test was 97%, and the predictive accuracy for a negative test was 94%. Thus, two-dimensional echocardiography appears to have a high sensitivity, specificity, and predictive value in the evaluation of patients with suspected endocarditis.

Improvement in the diagnosis of abscesses associated with endocarditis by transesophageal echocardiography

BACKGROUND

Echocardiography is recognized as the method of choice for the noninvasive detection of valvular vegetations in patients with infective endocarditis, with transesophageal echocardiography being more accurate than transthoracic echocardiography. The diagnosis of associated abscesses by transthoracic echocardiography is difficult or even impossible in many cases, however, and it is not known whether transesophageal echocardiography is any better.

METHODS

To determine the value of transesophageal echocardiography in the detection of abscesses associated with endocarditis, we studied prospectively by two-dimensional transthoracic and transesophageal echocardiography 118 consecutive patients with infective endocarditis of 137 native or prosthetic valves that was documented during surgery or at autopsy.

RESULTS

During surgery or at autopsy, 44 patients (37.3 percent) had a total of 46 definite regions of abscess. Abscesses were more frequent in aortic-valve endocarditis than in infections of other valves, and the infecting organism was more often staphylococcus (52.3 percent of cases) in patients with abscesses than in those without abscesses (16.2 percent). The hospital mortality rate was 22.7 percent in patients with abscesses, as compared with 13.5 percent in patients without abscesses. Whereas transthoracic echocardiography identified only 13 of the 46 areas of abscess, the transesophageal approach allowed the detection of 40 regions (P less than 0.001). Sensitivity and specificity for the detection of abscesses associated with endocarditis were 28.3 and 98.6 percent, respectively, for transthoracic echocardiography and 87.0 and 94.6 percent for transesophageal echocardiography; positive and negative predictive values were 92.9 and 68.9 percent, respectively, for the transthoracic approach and 90.9 and 92.1 percent for the transesophageal approach. Variation between observers was 3.4 percent for transthoracic and 4.2 percent for transesophageal echocardiography.

CONCLUSIONS

The data indicate that transesophageal echocardiography leads to a significant improvement in the diagnosis of abscesses associated with endocarditis. The technique facilitates the identification of patients with endocarditis who have an increased risk of death and permits earlier treatment.

Eustachian valve endocarditis

M mode and cross sectional echocardiography showed a highly mobile globular pedunculated mass(3.0 cm long with a maximum diameter of i.5 cm) attached to the eustachian valve in a heroin addict with staphylococcal endocarditis.

Pathogenicity of the enterococcus in surgical infections

The enterococcus has been relegated to a position of unimportance in the pathogenesis of surgical infections. However the increasing prevalence and virulence of these bacteria prompt reconsideration of this view, particularly because the surgical patient has become increasingly vulnerable to infectious morbidity due to debility, immunosuppression, and therapy with increasingly potent antibiotics. The enterococcus is a versatile opportunistic nosocomial pathogen, causing such diverse infections as wound, intra-abdominal, and urinary tract infections; catheter-associated infection; suppurative thrombophlebitis; endocarditis; and pneumonia. Although surgical drainage remains the cornerstone of therapy for enterococcal infections involving a discrete focus, in the circumstances typified by the compromised surgical patient, specific antibacterial therapy directed against the enterococcus is warranted. Recent evidence indicates that parenteral antibiotic therapy for enterococcal bacteremia is mandatory and that appropriate therapy clearly reduces the number of deaths.

Prosthetic valve endocarditis 1976-1987. Antibiotics, anticoagulation, and stroke

We retrospectively reviewed the clinical characteristics and outcomes of 61 patients with 62 episodes of prosthetic valve endocarditis, paying particular attention to neurologic complications (stroke). Atypical features of the group included a benign outcome of early postoperative infection (18% mortality) and a high stroke morbidity and mortality rate with Staphylococcus epidermidis infections. Eleven patients (18%) suffered an embolic stroke, most less than or equal to 3 days after diagnosis and before the initiation of antimicrobial therapy; the rate of embolic stroke recurrence was low (9%). The risk of embolic stroke was lower with bioprosthetic than with mechanical valves. No protective effect of anticoagulation therapy with warfarin was observed. Six patients (8%) suffered brain hemorrhage due to septic arteritis, brain infarction, or undetermined causes; no specific risk of hemorrhagic stroke was evident with anticoagulation therapy. Antibiotic treatment appears to be more important than anticoagulation to prevent neurologic complications in patients with prosthetic valve endocarditis.

Infective endocarditis, 1983-1988: echocardiographic findings and factors influencing morbidity and mortality

The echocardiograms and clinical records of 70 patients with infective endocarditis seen between 1983 and 1988 were examined to evaluate the role of two-dimensional and Doppler echocardiography in the diagnosis of infective endocarditis and identify risk factors for morbidity and mortality. A blinded observer reviewed the echocardiograms for the presence and size of vegetations and the severity of the valvular regurgitation. Vegetations were identified in 54 (78%) of 69 technically satisfactory echocardiograms. In 38 patients whose heart was examined at surgery or autopsy, all vegetations diagnosed by echocardiography were confirmed, but six additional vegetations were found. Abnormal (greater than or equal to 2+) valvular regurgitation was present in 88% of patients. No patient with less than or equal to 1+ regurgitation (n = 8) died or required valve surgery for heart failure, but three of the eight patients did undergo surgery for mycotic aneurysm, recurrent embolism or paravalvular abscess. In patients without embolism before echocardiography, there was a trend toward a greater incidence of subsequent embolism in those with vegetations greater than 10 mm in size (26% [8 of 31] compared with 11% [2 of 18] with vegetations less than or equal to 10 mm) (p = 0.19). By multivariate analysis, risk factors for in-hospital death (n = 7) were an infected prosthetic valve (p less than 0.007), systemic embolism (p less than 0.02) and infection with Staphylococcus aureus (p = 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Stroke in infective endocarditis

We reviewed 212 consecutive episodes of infective endocarditis in 203 patients at six hospitals between 1978 and 1986 and found that 21% were complicated by stroke. Of 133 episodes involving native mitral and/or aortic valves, brain ischemia occurred in 19%, brain hemorrhage in 7%, and non-central nervous system emboli in 11%; vegetations were identified in 56% of 113 adequate echocardiograms and did not correlate with risk of embolism. In native-valve endocarditis, most (74%) ischemic strokes had occurred by the time of presentation and an additional 13% occurred less than or equal to 48 hours after diagnosis; the incidence of brain ischemia was 13% on presentation, 3% during the first 48 hours of hospitalization, and 2%-5% during the remainder of the acute course. Stroke recurred at a rate of 0.5%/day, often heralding relapse/uncontrolled infection. Only 9% of ischemic infarcts were large (all in patients with Staphylococcus aureus infection), while 8% were small and subcortical. Brain hemorrhage occurred primarily at the time of presentation, particularly in intravenous drug abusers, and was associated with uncontrolled S. aureus infection with pyogenic arteritis. Ischemic and hemorrhagic stroke continue to be frequent and important in patients with infective endocarditis and are clustered during uncontrolled infection.(ABSTRACT TRUNCATED AT 250 WORDS)