The Duke criteria for diagnosing infective endocarditis are specific: analysis of 100 patients with acute fever or fever of unknown origin

Evaluation of the specificity of the 2023 European Society of Cardiology classification for infective endocarditis

BACKGROUND

The 2023 Duke-ISCVID and 2023 ESC classifications have recently issued independent diagnostic criteria for infective endocarditis (IE), updating the 2015 ESC criteria.

OBJECTIVES

The specificity of the 2023 ESC criteria should be evaluated and compared to the two other classifications in IE suspected patients.

METHODS

We retrospectively collected the characteristics of patients hospitalised in Bichat University Hospital, in 2021, who had been evaluated for suspicion of IE, and in whom IE diagnosis was finally rejected. All were classified by 2015 ESC, 2023 Duke-ISCVID, and 2023 ESC.

RESULTS

In total 130 patients were analysed. Mean age was 62 years, 64.6% were male, 30.0% had prosthetic cardiac valve or valve repair, 16.2% had cardiac implanted electronic device, and 23.1% other cardiac conditions. Overall, 2, 5 and 5 patients were falsely classified as definite IE with the 2015 ESC, 2023 Duke-ISCVID and 2023 ESC criteria, respectively. The corresponding specificities were 99% (95% CI [94%; 100%], 96% (95% CI [91%; 99%]), and 96% (95% CI [91%; 99%]).

CONCLUSION

The 2023 ESC and the 2023 Duke-ISCVID criteria are highly specific, although slightly less than the 2015 ESC criteria, for ruling out the diagnosis of definite IE.HIGHLIGHTS2023 Duke-ISCVID and 2023 ESC criteria are recently issued diagnostic classifications2023 ESC criteria have an excellent specificity, equivalent to the 2023 Duke-ISCVID one2023 ESC criteria and the 2023 Duke-ISCVID are less specific than the 2015 ESC criteriaSpecificities were quite similar according to the nature of the cardiac valve (native or prosthetic valve) or the duration of antibiotic therapy.

Uncommon pathogens causing infective endocarditis

Infective endocarditis is caused by a wide range of aetiological agents. The microbiology, epidemiology, and treatment of this disease have changed considerably in the last two decades. Staphylococci and streptococci are known to be the classical causative agents; however, blood culture-negative endocarditis caused by fastidious and slow-growing organisms is now common. The list of uncommon pathogens causing endocarditis has expanded in recent years. This is a narrative literature review of the aetiological agents of endocarditis that are rarely encountered in clinical practice, their epidemiology, the characteristics of these pathogens, the clinical presentations of the cases, and their management.

Compared Performance of the 2023 Duke-International Society for Cardiovascular Infectious Diseases, 2000 Modified Duke, and 2015 European Society of Cardiology Criteria for the Diagnosis of Infective Endocarditis in a French Multicenter Prospective Cohort

BACKGROUND

The 2023 Duke-International Society for Cardiovascular Diseases (ISCVID) criteria for infective endocarditis (IE) were proposed as an updated diagnostic classification of IE. Using an open prospective multicenter cohort of patients treated for IE, we compared the performance of these new criteria to that of the 2000 Modified Duke and 2015 European Society of Cardiology (ESC) criteria.

METHODS

Cases of patients treated for IE between January 2017 and October 2022 were adjudicated as certain IE or not. Each case was also categorized as either definite or possible/rejected within each classification. Sensitivity, specificity, and accuracy were estimated with 95% confidence intervals.

RESULTS

Of the 1194 patients analyzed (mean age, 66.1 years; 71.2% males), 414 (34.7%) had a prosthetic valve and 284 (23.8%) had a cardiac implanted electronic device (CIED); 946 (79.2%) were adjudicated as certain IE; 978 (81.9%), 997 (83.5%), and 1057 (88.5%) were classified as definite IE in the 2000 modified Duke, 2015 ESC, and 2023 Duke-ISCVID criteria, respectively. The sensitivity of each set of criteria was 93.2% (95% confidence interval [CI], 91.6-94.8), 95.0% (95% CI, 93.7-96.4), and 97.6% (95% CI, 96.6-98.6), respectively (P < .001 for all 2-by-2 comparisons). Corresponding specificity rates were 61.3% (95% CI, 55.2-67.4), 60.5% (95% CI, 54.4-66.6), and 46.0% (95% CI, 39.8-52.2), respectively. In patients without CIED, sensitivity rates were 94.8% (95% CI, 93.2-96.4), 96.5% (95% CI, 95.1-97.8), and 97.7% (95% CI, 96.6-98.8); specificity rates were 59.0% (95% CI, 51.6-66.3), 56.6% (95% CI, 49.3-64.0), and 53.8% (95% CI, 46.3-61.2), respectively.

CONCLUSIONS

Overall, the 2023 Duke-ISCVID criteria had a significantly higher sensitivity but a significantly lower specificity compared with older criteria. This decreased specificity was mainly attributable to patients with CIED.

Evaluation of the Specificity of the 2023 Duke-International Society of Cardiovascular Infectious Diseases Classification for Infective Endocarditis

BACKGROUND

The 2023 Duke-ISCVID (International Society of Cardiovascular Infectious Diseases) classification is a new diagnostic tool for infective endocarditis, updating the 2000 modified Duke and the 2015 European Society for Cardiology (ESC) classifications. In comparison, its sensitivity is higher; however, its specificity remains to be evaluated and compared to that of the 2 other classifications in endocarditis suspected patients.

METHODS

We retrospectively collected the characteristics of patients hospitalized in Bichat University's Hospital, Paris, in 2021, who had been evaluated for clinical suspicion of endocarditis, have had at least a transthoracic echocardiography, 2 pairs of blood cultures, 3-month follow-up and in whom endocarditis diagnosis was finally rejected. All patients were classified by 2000 modified Duke, 2015 ESC and 2023 Duke-ISCVID, as though the endocarditis diagnosis had not been rejected.

RESULTS

In total, 130 patients' charts were analyzed. Mean age was 62 years, 84 (64.6%) were male, 39 (30.0%) had prosthetic cardiac valve or valve repair, 21 (16.2%) cardiac implanted electronic device, and 30 (23.1%) other cardiac conditions. Overall, 5, 2, and 5 patients were falsely classified as definite endocarditis with the 2000 modified Duke, 2015 ESC, and 2023 Duke-ISCVID classifications, respectively. The corresponding specificities were 96.2% (95% confidence interval [CI] [90.8%, 98.6%]), 98.5% (95% CI [93.9%, 99.7%]), and 96.2% (95% CI [90.8%, 98.6%]). The rates of possible endocarditis were of 38%, 35%, and 35% in the 3 classifications, respectively.

CONCLUSIONS

The 2023 Duke-ISCVID classification is highly specific for ruling out the diagnosis of definite infective endocarditis in patients who had been evaluated for IE.

External Validation of the 2023 Duke-International Society for Cardiovascular Infectious Diseases Diagnostic Criteria for Infective Endocarditis

BACKGROUND

The 2023 Duke-International Society of Cardiovascular Infectious Diseases (ISCVID) criteria for infective endocarditis (IE) were introduced to improve classification of IE for research and clinical purposes. External validation studies are required.

METHODS

We studied consecutive patients with suspected IE referred to the IE team of Amsterdam University Medical Center (from October 2016 to March 2021). An international expert panel independently reviewed case summaries and assigned a final diagnosis of "IE" or "not IE," which served as the reference standard, to which the "definite" Duke-ISCVID classifications were compared. We also evaluated accuracy when excluding cardiac surgical and pathologic data ("clinical" criteria). Finally, we compared the 2023 Duke-ISCVID with the 2000 modified Duke criteria and the 2015 and 2023 European Society of Cardiology (ESC) criteria.

RESULTS

A total of 595 consecutive patients with suspected IE were included: 399 (67%) were adjudicated as having IE; 111 (19%) had prosthetic valve IE, and 48 (8%) had a cardiac implantable electronic device IE. The 2023 Duke-ISCVID criteria were more sensitive than either the modified Duke or 2015 ESC criteria (84.2% vs 74.9% and 80%, respectively; P < .001) without significant loss of specificity. The 2023 Duke-ISCVID criteria were similarly sensitive but more specific than the 2023 ESC criteria (94% vs 82%; P < .001). The same pattern was seen for the clinical criteria (excluding surgical/pathologic results). New modifications in the 2023 Duke-ISCVID criteria related to "major microbiological" and "imaging" criteria had the most impact.

CONCLUSIONS

The 2023 Duke-ISCVID criteria represent a significant advance in the diagnostic classification of patients with suspected IE.

Diurnal temperature variation and the implications for diagnosis and infectious disease screening: a population-based study

OBJECTIVES

Fevers have been used as a marker of disease for hundreds of years and are frequently used for disease screening. However, body temperature varies over the course of a day and across individual characteristics; such variation may limit the detection of febrile episodes complicating the diagnostic process. Our objective was to describe individual variation in diurnal temperature patterns during episodes of febrile activity using millions of recorded temperatures and evaluate the probability of recording a fever by sex and for different age groups.

METHODS

We use timestamped deidentified temperature readings from thermometers across the US to construct illness episodes where continuous periods of activity in a single user included a febrile reading. We model the mean temperature recorded and probability of registering a fever across the course of a day using sinusoidal regression models while accounting for user age and sex. We then estimate the probability of recording a fever by time of day for children, working-age adults, and older adults.

RESULTS

We find wide variation in body temperatures over the course of a day and across individual characteristics. The diurnal temperature pattern differed between men and women, and average temperatures declined for older age groups. The likelihood of detecting a fever varied widely by the time of day and by an individual's age or sex.

CONCLUSIONS

Time of day and demographics should be considered when using body temperatures for diagnostic or screening purposes. Our results demonstrate the importance of follow-up thermometry readings if infectious diseases are suspected.

Candida endocarditis: Update on management considerations

The rise in incidence rates of invasive candidiasis warrants an increase in attention and efforts toward preventing and treating this virulent infection. Cardiac involvement is one of the most feared sequelae and has a poor prognosis. Despite the introduction of several novel antifungal agents over the past quarter century, complications and mortality rates due to Candida endocarditis have remained high. Although fungal endocarditis has a mechanism similar to bacterial endocarditis, no specific diagnostic criteria or algorithm exists to help guide its management. Furthermore, recent data has questioned the current guidelines recommending a combined approach of antifungal agents with surgical valve or indwelling prostheses removal. With the emergence of multidrug-resistant Candida auris, a focus on improved prophylactic measures and management strategies is necessary.

The 2023 Duke-International Society for Cardiovascular Infectious Diseases Criteria for Infective Endocarditis: Updating the Modified Duke Criteria

The microbiology, epidemiology, diagnostics, and treatment of infective endocarditis (IE) have changed significantly since the Duke Criteria were published in 1994 and modified in 2000. The International Society for Cardiovascular Infectious Diseases (ISCVID) convened a multidisciplinary Working Group to update the diagnostic criteria for IE. The resulting 2023 Duke-ISCVID IE Criteria propose significant changes, including new microbiology diagnostics (enzyme immunoassay for Bartonella species, polymerase chain reaction, amplicon/metagenomic sequencing, in situ hybridization), imaging (positron emission computed tomography with 18F-fluorodeoxyglucose, cardiac computed tomography), and inclusion of intraoperative inspection as a new Major Clinical Criterion. The list of "typical" microorganisms causing IE was expanded and includes pathogens to be considered as typical only in the presence of intracardiac prostheses. The requirements for timing and separate venipunctures for blood cultures were removed. Last, additional predisposing conditions (transcatheter valve implants, endovascular cardiac implantable electronic devices, prior IE) were clarified. These diagnostic criteria should be updated periodically by making the Duke-ISCVID Criteria available online as a "Living Document."

Expanding utility of cardiac computed tomography in infective endocarditis: A contemporary review

There is increasing evidence on the utility of cardiac computed tomography (CCT) in infective endocarditis (IE) to investigate the valvular pathology, the extra-cardiac manifestations of IE and pre-operative planning. CCT can assist in the diagnosis of perivalvular complications, such as pseudoaneurysms and abscesses, and can help identify embolic events to the lungs or systemic vasculature. CCT has also been shown to be beneficial in the pre-operative planning of patients by delineating the coronary artery anatomy and the major cardiovascular structures in relation to the sternum. Finally, hybrid nuclear/computed tomography techniques have been shown to increase the diagnostic accuracy in prosthetic valve endocarditis. This manuscript aims to provide a contemporary update of the existing evidence base for the use of CCT in IE.

Diagnostic accuracy of splinter haemorrhages in patients referred for suspected infective endocarditis

OBJECTIVE

Splinter haemorrhages are an examination finding that has classically been associated with infective endocarditis (IE), but are not included in current diagnostic algorithms. Splinter haemorrhages have not been evaluated as a diagnostic tool using modern definitions of IE. We determined their sensitivity and specificity in patients with suspected IE and investigated their inclusion in the Duke criteria.

METHODS

This is a retrospective diagnostic accuracy study using data from 1119 patients with suspected IE referred to the IE service. Patients were categorised according to the Duke criteria, the current diagnostic gold standard, into Duke 'rejected', 'possible' or 'definite' groups. Definite cases (n=451) served as the true positives and rejected cases (n=486) as the true negatives against which splinter haemorrhages were compared. Duke possible cases (n=182) were used the assess the clinical impact of adding splinter haemorrhages to the Duke criteria.

RESULTS

In clinically suspected cases of IE and using the Duke criteria as the gold standard comparator, splinter haemorrhages had a sensitivity of 26% (95% CI 22 to 31) (119 out of 451) and a specificity of 83% (95% CI 79 to 86) (403 out of 486). Inclusion of splinter haemorrhages as a minor vascular phenomenon in the Duke criteria would result in a reclassification of 12% of cases from Duke rejected to possible and 13% from Duke possible to definite.

CONCLUSION

Splinter haemorrhages are an insensitive tool in the diagnosis of IE, but their high specificity indicates they do have clinical value in patients with suspected infection. Their inclusion in the Duke criteria as a minor vascular criterion reduces diagnostic uncertainty for some Duke possible cases, while increasing it for a similar proportion of Duke rejected cases.

Contemporary demographics, diagnostics and outcomes in non-bacterial thrombotic endocarditis

OBJECTIVE

Non-bacterial thrombotic endocarditis (NBTE) is a syndrome characterised by cardiac valve vegetations and/or thickening due to non-infective mechanisms. Nowadays, a premortem diagnosis of NBTE is possible based on echocardiographic findings. Therefore, to better characterise this disease, we performed a contemporary review of the epidemiology, demographics, diagnosis and clinical outcomes of these patients.

METHODS

Adults with a diagnosis of NBTE seen within the Mayo Clinic Enterprise from December 2014 to December 2021 were included. NBTE diagnosis was identified by clinicians representing at least two specialties including cardiology, infectious diseases, rheumatology and oncology. Patients with positive blood cultures, infective endocarditis, culture-negative endocarditis and denial of research authorisation were excluded. All patients had a 1-year follow-up.

RESULTS

Forty-eight cases were identified; mean age was 60.0±13.8 years, 75% were female. The most prevalent comorbidities were malignancy (52.1%) and connective tissue disease (37.5%). Valvular abnormalities included 41 (85.4%) patients with vegetations, 43 (89.6%) patients with thickening and 26 (54.2%) with moderate to severe regurgitation. Thirty-eight (79.2%) patients had an embolic event (stroke in 26 (54.2%) patients) within 1 month of NBTE diagnosis and 16 (33.3%) patients died within 1 year of NBTE diagnosis. Metastatic tumours and lung cancer were associated with 1-year all-cause mortality (p=0.0017 and p=0.0004, respectively).

CONCLUSIONS

NBTE was more prevalent in females and embolic complications were the most frequent clinical finding. Overall, patients with NBTE had a poor prognosis, particularly in those with lung cancer or metastatic tumours. Further studies in patients with NBTE are needed given its morbidity and mortality.

Modified Duke/European Society of Cardiology 2015 clinical criteria for infective endocarditis: time for an update?

BACKGROUND

The diagnosis of infective endocarditis (IE) is based on the modified Duke/European Society of Cardiology (ESC) 2015 clinical criteria. The sensitivity of the criteria is unknown in South Africa, but high rates of blood culture negative endocarditis (BCNIE), coupled with a change in the clinical features of IE, may limit the sensitivity.

METHODS

The Tygerberg Endocarditis Cohort study prospectively enrolled patients with IE between November 2019 and June 2021. A standardised protocol for organism detection, with management of patients by an Endocarditis Team, was employed. Patients with definite IE by pathological criteria were analysed to determine the sensitivity of the current clinical criteria.

RESULTS

Eighty consecutive patients with IE were included of which 45 (56.3%) had definite IE by pathological criteria. In patients with definite IE by pathological criteria, 26/45 (57.8%) of patients were classified as definite IE by clinical criteria. BCNIE was present in 25/45 (55.6%) of patients and less than three minor clinical criteria were present in 32/45 (75.6%) of patients. The elevation of Bartonella serology to a major microbiological criterion of the modified Duke/ESC 2015 clinical criteria would increase the sensitivity (57.8% vs 77.8%; p=0.07).

CONCLUSION

The sensitivity of the modified Duke/ESC 2015 clinical criteria is lower than expected in patients with IE in South Africa, primarily due to the high rates of Bartonella-associated BCNIE. The elevation of Bartonella serology to a major microbiological criterion, similar to the status of Coxiella burnetii in the current criteria, would increase the sensitivity. The majority of patients with definite IE by pathological criteria had less than three minor criteria present.

Critical evaluation of YouTube videos on colostomy and ileostomy: Can these videos be used as learning resources?

OBJECTIVES

We aimed at identifying and analyzing the accuracy of YouTube videos on colostomy and ileostomy.

METHODS

YouTube website was searched independently by researchers for videos on colostomy and ileostomy posted before the 18th of May, 2019. Based on predetermined inclusion and exclusion criteria, the videos matching the research objective were identified. Data related to each video were collected, and the videos were categorized using standardized criteria.

RESULTS

A total of 357 videos were identified. Finally, 149 videos were included in the study. Of these, 52 (35%) were educationally useful, and 97 (65%) were not useful. None of the video parameters, including the number of viewers, duration, number of likes or dislikes, days on YouTube or number of comments, was able to differentiate between useful or not useful videos. The score of videos was 14.7 ± 0.6 for valuable videos and 11.0 ± 2.0 for not useful videos (p < 0.001).

CONCLUSIONS

While there were a reasonably number of colostomy and ileostomy videos, there was a smaller number on the surgical procedure. Most non-educational videos were not consistent with clinical guidelines.

PRACTICAL IMPLICATIONS

YouTube videos on colostomy/ileostomy care can be an important educational resource to patients. However, a collaboration between patients, nurse educators and universities/hospitals is needed to produce high-quality videos.

Development of a Clinical Prediction Model for Infective Endocarditis Among Patients with Undiagnosed Fever: A Pilot Case-Control Study

Purpose

Infective endocarditis (IE) may be diagnosed as fever of unknown origin due to its delusively non-descriptive clinical features, especially in outpatient clinics. Our objective is to develop a prediction model to discriminate patients to be diagnosed as “definite” IE from “non-definite” by modified Duke criteria among patients with undiagnosed fever, using only history and results of physical examinations and common laboratory examinations.

Patients and Methods

The study was a single-center case–control study. Inpatients at Saga University Hospital diagnosed with IE from 2007 to 2017 and patients with undiagnosed fever from 2015 to 2017 were enrolled. Patients diagnosed with definite IE according to the modified Duke criteria, except those definitely diagnosed with other disorders responsible for fever, were allocated to the IE group. Patients without IE among those defined as non-definite according to the modified Duke criteria were allocated to the undiagnosed fever group. We developed a prediction model to pick up patients who would be “definite” by modified Duke criteria, which was subsequently assessed by area under the curve (AUC).

Results

A total of 144 adult patients were included. Of these, 59 patients comprised the IE group. We developed the prediction model using five indicators, including transfer by ambulance, cardiac murmur, pleural effusion, neutrophil count, and platelet count, with a sensitivity 84.7%, a specificity 84.7%, an AUC 0.893 (95% confidence interval 0.828–0.959), a shrinkage coefficient 0.635, and a stratum-specific likelihood ratio 0.2–50.4.

Conclusion

Our prediction model, which uses only indicators easy to gain, facilitates prediction of patients with IE. These indicators can be acquired even at common hospitals and clinics, without requiring advanced medical equipment or invasive examinations.

Trial Registration Number

UMIN000041344.

Editor's Choice - Validation of the Management of Aortic Graft Infection Collaboration (MAGIC) Criteria for the Diagnosis of Vascular Graft/Endograft Infection: Results from the Prospective Vascular Graft Cohort Study

OBJECTIVE

The timely management of vascular graft/endograft infection (VGEI) is crucial to a favourable outcome, yet can be challenging as there is no validated gold standard diagnostic test. Recently, a new case definition has been proposed by the Management of Aortic Graft Infection Collaboration (MAGIC) to close the diagnostic gap. The aim of this study was to validate the MAGIC criteria as a suggested diagnostic standard for the diagnosis of suspected VGEI in the prospective Vascular Graft Cohort study (VASGRA).

METHODS

VASGRA is an open, prospective, observational cohort study. Prospective participants in VASGRA between 2013 and 2019 were included (257 patients; 137 with VGEI). The accuracy of the MAGIC criteria for a diagnosis of VGEI was evaluated retrospectively by calculating the sensitivity and specificity vs. the consensually adjudicated VASGRA infection status.

RESULTS

The VASGRA cohort categorised 137 (53.3%) patients as "diseased" and 120 patients as "not diseased"; using the MAGIC criteria, 183/257 (71.2%) patients were considered to be "diseased". Thus, for the MAGIC criteria, a sensitivity of 99% (95% confidence interval [CI] 96-100) and a specificity of 61% (95% CI 52-70) were calculated. Considering suspected VGEI according to the MAGIC criteria as "not diseased" achieved congruent assessments of the VASGRA team and the MAGIC criteria, with a sensitivity of 93% and a specificity of 93%. The accuracy of the MAGIC criteria for the different graft locations were also compared. If the suspected VGEIs were assigned to the "not diseased" group, VGEIs of the thoracic aorta seemed to have a poorer sensitivity (86%; 95% CI 73-95) than the other graft locations.

CONCLUSION

The current MAGIC criteria offer good sensitivity and specificity in the context of true infections but a reduced specificity for a possible VGEI.

An assessment of transesophageal echocardiography studies rated as rarely appropriate tests for infective endocarditis at an academic medical center

PURPOSE

Endocardial involvement documented by echocardiography is a major criterion of the modified Duke criteria (MDC) for infective endocarditis (IE). Though transesophageal echocardiography (TEE) is sensitive in the diagnosis of IE, it can be inappropriately used.

METHODS

This retrospective study included all patients who underwent TEE due to bacteremia, fever, and/or endocarditis in a single, tertiary academic medical center in 2013. Data collected from electronic medical charts were as follows: demographics, history, physical examination, blood cultures, and transthoracic (TTE) and TEE findings. Cases were categorized based on appropriate use criteria (AUC) and MDC. An infectious disease (ID) specialist reviewed cases with rarely appropriate TEE use.

RESULTS

In the 194 patients included, 147 (75.8%) were rated as appropriate, 36 (18.6%) rarely appropriate, and 11 (5.6%) uncertain. Of the 36 with rarely appropriate TEEs, using MDC 31 (86%) were rejected and 5 (14%) were possible for IE. Retrospective chart review by an ID specialist determined that 10 of these patients warranted TEE due to compelling issues, including immunosuppression or complicated infection.

CONCLUSIONS

In this retrospective cohort, almost one fifth of cases were rated as rarely appropriate. However, a review of these cases showed that TEE was often pursued when the clinical situation involved immunosuppression or complex infectious process. There remains room for improvement to our screening process for TEE and a need to implement a nuanced educational plan to better precisely identify appropriate cases for TEE usage.

Meta-analysis of 18F-FDG PET/CT in the diagnosis of infective endocarditis

BACKGROUND

The current diagnosis of infective endocarditis (IE) is based on the modified Duke criteria, which has approximately 80% sensitivity for the diagnosis of native valve endocarditis (NVE), with lower sensitivity for the diagnosis of prosthetic valve endocarditis (PVE) and culture-negative endocarditis. There is preliminary evidence that 18F-FDG PET/CT is an adjunctive diagnostic test with high accuracy reported in small studies to date. We therefore performed a meta-analysis of studies evaluating the use of PET/CT in the diagnosis of IE to establish a more precise estimate of accuracy.

METHODS

PubMed, Embase, Cochrane library, CINAHL, Web of Knowledge, and www.clinicaltrials.gov were searched from January 1990 to April 2017 for studies evaluating the accuracy of PET/CT for the evaluation of possible IE.

RESULTS

We identified 13 studies involving 537 patients that were included in the meta-analysis. The pooled sensitivity of PET/CT for diagnosis of IE was 76.8% (95% CI 71.8-81.4%; Q = 39.9, P < 0.01; I2 = 69.9%) and the pooled specificity was 77.9% (95% CI 71.9-83.2%; Q = 44.42, P < 0.01; I2 = 73.0%). Diagnostic accuracy was improved for PVE with sensitivity of 80.5% (95% CI 74.1-86.0%; Q = 25.5, P < 0.01; I2 = 72.5%) and specificity of 73.1% (95% CI 63.8-81.2%; Q = 32.1, P < 0.01; I2 = 78.2%). Additional extracardiac foci of infection were found on 17% of patients on whole body PET/CT.

CONCLUSION

PET/CT is a useful adjunctive diagnostic tool in the evaluation of diagnostically challenging cases of IE, particularly in prosthetic valve endocarditis. It also has the potential to detect clinically relevant extracardiac foci of infection, malignancy, and other sources of inflammation leading to more appropriate treatment regimens and surgical intervention.

Pericardial effusion in prosthetic and native valve infective endocarditis

BACKGROUND

Pericardial effusion (PE) is widely believed to signify more advanced infective endocarditis (IE) and a generally worse outcome.

PURPOSE

To determine the prevalence and clinical significance of PE in a series of patients with confirmed native and prosthetic valve infections.

METHODS

Data were collected from 338 consecutive patients with definite or possible IE who visited a single referral center; these patients were examined for the presence of PE as detected by transthoracic echocardiography. Clinical characteristics, the incidence of complications, and outcomes were compared between patients with IE with and without PE. IE patients with PE were then divided into two subgroups: those with and those without cardiac prostheses.

RESULTS

Eighty-eight patients out of the total 338 (26%) were found to have PE. Compared with patients who did not have PE, patients who did were significantly younger (32.9 ± 13.4 vs 29.0 ± 9.2, p = 0.003), had more left-sided vegetation (55.6% vs 77.3%, p < 0.001), more root abscesses (9.2% vs 25.0%, p < 0.001), needed surgery more frequently (68.0% vs 84.1%, p = 0.001), and had a higher mortality rate (22.0% vs 32.9%, p = 0.03). PE was not found to be a predictor of mortality. No significant difference was found between IE patients with PE with (n = 13) and without (n = 75) prostheses with regard to causative organisms, clinical characteristics, or clinical outcomes.

CONCLUSION

Regardless of whether the IE was in native or prosthetic valves, compared with patients without PE, patients with PE had more severe infections and a worse prognosis, but PE was not an independent predictor of mortality.

Experience of parents of children with autism on YouTube: are there educationally useful videos?

The aims of this study were to determine the following: first, are there educationally useful videos of parents of children with autism sharing their experiences? Second, do any of the data related to videos help in identifying useful videos? And third, what do posted comments tell us? YouTube was searched for videos of parents sharing their experiences. The following parameters were collected: title, creator, URL, duration, number of viewers, likes, dislikes, comments, days on YouTube, and country. Based on agreed-upon criteria, videos were divided independently into educationally useful and non-useful categories. A critical thematic analysis of comments was conducted. A total of 180 videos were finally identified, of which 106 (59%) provided useful information, scoring 15.3 ± 0.7 (mean ± SD); 74 (41%) were determined to be not educationally useful, scoring 8.6 ± 2.1. The differences in scores were significant (p < 0.001), but there were no significant differences between the useful and non-useful groups in terms of video parameters. No correlation was found between scores and any of the videos' parameters. In conclusion, there are videos that can be used as educational resources. The videos' parameters did not differentiate between useful and non useful. Useful videos were mostly created by professional societies and by parents. The study reflects the emerging role of YouTube in sharing experiences.

Complete Resolution of a Large Bicuspid Aortic Valve Thrombus with Anticoagulation in Primary Antiphospholipid Syndrome

Native aortic valve thrombosis in primary antiphospholipid syndrome (APLS) is a rare entity. We describe a 38-year-old man who presented with neurological symptoms and a cardiac murmur. Transthoracic echocardiography detected a large bicuspid aortic valve thrombus. Laboratory evaluation showed the presence of antiphospholipid antibodies. Anticoagulation was started, and serial echocardiographic studies showed complete resolution of the aortic valve vegetation after 4 months. The patient improved clinically and had no residual symptoms. This report and review of the literature suggests that vegetations in APLS can be treated successfully with conservative treatment, regardless of their size.

Use of Dithiothreitol to Dislodge Bacteria From the Biofilm on an Aortic Valve in the Operating Theatre: A Case of Infective Endocarditis Caused by Staphylococcus aureus and Proteus mirabilis

This is the first reported case of 2 biofilm-producing bacteria, Staphylococcus aureus and Proteus mirabilis, identified from an aortic valve using an innovative device with dithiothreitol solution, able to dislodge bacterial biofilm. The method is usable in the operating theatre and recommended in infective endocarditis nonresponders to empiric therapy.

Infective endocarditis

Infective endocarditis (IE) is a rare, life-threatening disease that has long-lasting effects even among patients who survive and are cured. IE disproportionately affects those with underlying structural heart disease and is increasingly associated with health care contact, particularly in patients who have intravascular prosthetic material. In the setting of bacteraemia with a pathogenic organism, an infected vegetation may form as the end result of complex interactions between invading microorganisms and the host immune system. Once established, IE can involve almost any organ system in the body. The diagnosis of IE may be difficult to establish and a strategy that combines clinical, microbiological and echocardiography results has been codified in the modified Duke criteria. In cases of blood culture-negative IE, the diagnosis may be especially challenging, and novel microbiological and imaging techniques have been developed to establish its presence. Once diagnosed, IE is best managed by a multidisciplinary team with expertise in infectious diseases, cardiology and cardiac surgery. Antibiotic prophylaxis for the prevention of IE remains controversial. Efforts to develop a vaccine that targets common bacterial causes of IE are ongoing, but have not yet yielded a commercially available product.

Infective Endocarditis in Adults: Diagnosis, Antimicrobial Therapy, and Management of Complications: A Scientific Statement for Healthcare Professionals From the American Heart Association

BACKGROUND

Infective endocarditis is a potentially lethal disease that has undergone major changes in both host and pathogen. The epidemiology of infective endocarditis has become more complex with today's myriad healthcare-associated factors that predispose to infection. Moreover, changes in pathogen prevalence, in particular a more common staphylococcal origin, have affected outcomes, which have not improved despite medical and surgical advances.

METHODS AND RESULTS

This statement updates the 2005 iteration, both of which were developed by the American Heart Association under the auspices of the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease, Council on Cardiovascular Disease of the Young. It includes an evidence-based system for diagnostic and treatment recommendations used by the American College of Cardiology and the American Heart Association for treatment recommendations.

CONCLUSIONS

Infective endocarditis is a complex disease, and patients with this disease generally require management by a team of physicians and allied health providers with a variety of areas of expertise. The recommendations provided in this document are intended to assist in the management of this uncommon but potentially deadly infection. The clinical variability and complexity in infective endocarditis, however, dictate that these recommendations be used to support and not supplant decisions in individual patient management.

Assesment of the Duke criteria for the diagnosis of infective endocarditis after twenty-years. An analysis of 241 cases

BACKGROUND AND AIMS

In the absence of classical features (fever, cardiac murmur, and peripheral vascular stigmata) the diagnosis of infective endocarditis (IE) may be difficult. Current clinical guidelines for the diagnosis and management of IE recommend the use of modified Duke criteria. Correct and prompt diagnosis of IE is crucial for the treatment and outcome of the patients. The aim of this study was to evaluate the presence and the individual value of each criterion of the modified Duke criteria in our patients with infective endocarditis.

METHODS

We performed a prospective observational study between January 2008 - June 2014, in which we enrolled consecutive adult patients admitted for suspicion of IE to the Hospital of Infectious Diseases and at the Heart Institute . We used and extensive database in order to collect demographic data, laboratory and echocardiography results, evolution and outcome of the patients. Using the modified Duke criteria we identified 3 categories of IE: definite, possible and rejected. In order to evaluate the importance of each criterion in the diagnosis of IE we tested two hypotheses. First, we excluded each criterion from the final diagnosis and we counted how many cases felt into a lower category. Second, after adding each major and minor criterion, we tested how many cases would have been classifiable as definite IE.

RESULTS

The study included 241 adult patients with a mean age 58.16 years and sex ratio male/female 1.94. According to the modified Duke criteria 137 patients had definite IE, 79 patients had possible IE and 25 cases had rejected IE We had blood cultures positive IE in 109 cases and blood culture negative IE (BCNE) in 132 (71.21%) cases. Antibiotic treatment prior to blood culture was recorded in 152 (63.07%) patients. In the absence of the echocardiography major criterion, 43% of cases would become possible. After extraction of major microbiological criterion, only one third of definite cases would become possible. Minor criteria such as fever and predisposition contributed to the diagnosis only in 10% of cases. In the presence of vascular or immunological phenomena, or in the presence of minor microbiological criterion, half of the possible IE cases could become possible.

CONCLUSION

Twenty-years after their launch, the Duke criteria for the diagnosis of IE continue to be important tools. Low index of suspicion of IE and inappropriate use of antibiotics may have a great negative impact on the diagnosis of IE. Nowadays, the scarcity of classical Osler manifestations - bacteremia, fever and peripheral stigmata - makes the diagnosis of IE a challenge.

Current diagnosis and treatment of infective endocarditis

The incidence of infective endocarditis continues to rise with a yearly incidence of around 15,000 to 20,000 new cases in the USA. As a result, rapid diagnosis, effective treatment and prompt recognition of complications are essential to desirable clinical outcomes. Recent guidelines such as the Duke criteria have incorporated echocardiography for diagnosis of infective endocarditis, making this diagnostic test mandatory for patients with suspected infective endocarditis. The diversity of pathogens that can cause infective endocarditis, some of which cannot be cultured easily, makes diagnosis even more difficult. Coagulase-negative staphylococci and viridans streptococci groups continue to be the major causative microorganisms of infective endocarditis. In the case of culture-negative endocarditis or infective endocarditis caused by fastidious microorganisms, the polymerase chain reaction and probe-based diagnostic methods are available to clinical reference laboratories.

A roadmap for fever of unknown origin in children

Fever of unknown origin (FUO) in adults is conventionally defined by the occurrence of body temperatures above 38.3 degrees C (101 degrees F) for a period of 3 weeks without any identified etiology after a period of 1-week hospitalization. The issue of FUO in pediatrics is rather hazy and still represents a challenging diagnostic dilemma. Most of the available data are limited to nationwide cohorts of patients of any age. The major difficulty in establishing a diagnosis is that the characteristic features rendering specific disorders clinically recognizable are absent or subtle, hence only a painstaking questioning on family background may elicit the correct investigative path. No diagnostic algorithms are actually available and clinicians must rely on a very careful step-by-step evaluation of the single patient. The need for invasive diagnostic techniques should be closely taken into consideration when laboratory tests or simple imaging procedures fail to discern the origin of FUO. Fevers with no reasonable explanation and no localizing signs often conceal different common diseases in children, which tend to display an unusual or atypical pattern. The principal causes behind FUO in pediatric age remain infections, followed by collagen vascular diseases and neoplastic disorders, although most children with malignancies present other systemic signs or suggestive laboratory abnormalities. The possibility of autoinflammatory syndromes, drug fever, and factitious fever should also be taken into account.

Etiology and Risk Factors of 339 Cases of Infective Endocarditis: Report from a 10-year National Prospective Survey in the Slovak Republic

The authors studied the etiology, outcome and risk factors of 339 cases of infective endocarditis (IE) in Slovakia over the last 10 years. Aortic valve was infected in 59.9%, mitral in 38.1% and tricuspidal/pulmonary in 5.0% of cases. The majority of IE were caused by staphylococci (29.2%), 15.0% were due to viridans streptococci, 7.4% due to Enterococcus faecalis, 3.9% due to the HACEK group (Haemophilus spp., Actinobacillus spp., Corynebacterium spp., Eikenella spp., Kingella spp.) and 39.2% were culture negative. The following risk factors were the most frequently identified: rheumatic fever in 24.2%, dental surgery in 13.3%, previous cardiosurgery in 7.1% and neoplasia in 7.1%. All patients were treated with antimicrobials and 42.5% of patients also with surgery (valvular prosthesis replacement): 61 (18.0%) died, and 278 (82.0%) survived at day 60 after the diagnosis of endocarditis was made. Univariate analysis did not show significant differences in most of the recorded risk factors between patients who died and those who survived: apart from staphylococcal etiology (44.3% vs. 26.6%, P < 0.01), persistent bacteremia (with three or more positive blood cultures 24.6% vs. 9.7% P < 0.002) which were significantly associated with higher attributable mortality, as was absence of surgery (55.7% vs. 6.1% P < 0.001), whereas antibiotic therapy in combination with surgery significantly predicted better outcome (P < 0.001). We compared risk factors, etiology, therapeutic strategies and outcome of IE in two periods: from 1991-1997 (180 cases) and from 1998-2001 (159 cases). Rheumatic fever was less commonly observed in second period (1998-2001) P < 0.01 since its prevalence in Slovakia is rapidly decreasing. Dental surgery was less frequent as well (20.5% vs. 5.0% P < 0.001). There was a significant shift in etiology within the second study period: negative-culture endocarditis (despite better bacteriological techniques) (P < 0.001) was more frequently observed in the 1st period and represented 53.3% of all cases in 1998-2001 in comparison to 26.7% in 1991-1997. Enterococci (P < 0.0002) were also more frequent in the 2nd period. Persistent bacteremia (3 or more positive blood cultures 20.5% vs. 3.1%, P < 0.001 was less commonly observed within the 2nd period (1998-2001) in comparison to 1991-1997. More patients in the second period (1998-2001) had complications of IE (P < 0.001) than in the 1st period. However mortality was lower (22.2% vs. 13.2%, P < 0.044) because of more surgical intervention in the 2nd period (52.8% vs. 33.3%, P < 0.001).

Endocarditis at a tertiary hospital: reduced acute mortality but poor long term prognosis

The outcome in 132 patients with infective endocarditis diagnosed in accordance with the Duke criteria at a tertiary hospital in Denmark in the period 1998-2000 is reported. The total in-hospital mortality was 15%. Indications are that in-hospital mortality over the last decade has been reduced by around a quarter. Mortality after 3 months was 17% (CI 29%), after 3 years 32% (CI 16-47%) and after 5 years 39% (CI 22-55%). This 5-years mortality was 5 times that of an age and gender matched background population. After follow-up for 5-8 y, mortality was highest for prosthetic valve endocarditis (63% vs. 39%, p = 0.05). Heart surgery was performed in 51% of the cases. Patients who underwent surgery had a lower mortality at follow-up (36% vs. 52%, p = 0.04). The 5-year mortality was 30% (CI 9-52%) for patients treated with surgery and 48% (CI 23-72%) for patients treated without surgery. In multivariable analysis surgery was not an independent predictor for lower long-term mortality. Surgery was however an independent predictor for lower intermediate-term mortality. It is concluded that surgery may be associated with lower short- and intermediate-term mortality, while the effect might decline in the long-term. High age, prosthetic valve endocarditis, and Staphylococcus aureus endocarditis were independent predictors for high mortality. Although improvements have occurred over recent years, infective endocarditis is still a high mortality disease.

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

BACKGROUND

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

METHODS AND RESULTS

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

CONCLUSIONS

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

Evolving trends in infective endocarditis

Infective endocarditis is a microbial infection of the endocardial surface and, despite improvements in diagnostic accuracy, medical therapy and surgical techniques, mortality remains high. This review focuses on changes in epidemiology, microbiology and diagnosis, as well as changes in medical and surgical management of infective endocarditis affecting native and prosthetic valves in adults, that have evolved during the past two decades. Significant changes have included an increasing involvement of prosthetic valves and nosocomially-acquired disease, an increased involvement of staphylococci as the causative agents, and a recognition that elderly individuals with degenerative valvular disease are the most vulnerable population. Topics still requiring study include whether and when valve replacement should be performed, and how to predict perivalvular complications or embolisation based on echocardiography findings. Optimisation of antimicrobial treatment schemes (choice of the antibiotic, dose and duration) also requires further investigation.

Contribution of systematic serological testing in diagnosis of infective endocarditis

Despite progress with diagnostic criteria, the type and timing of laboratory tests used to diagnose infective endocarditis (IE) have not been standardized. This is especially true with serological testing. Patients with suspected IE were evaluated by a standard diagnostic protocol. This protocol mandated an evaluation of the patients according to the modified Duke criteria and used a battery of laboratory investigations, including three sets of blood cultures and systematic serological testing for Coxiella burnetii, Bartonella spp., Aspergillus spp., Legionella pneumophila, and rheumatoid factor. In addition, cardiac valvular materials obtained at surgery were subjected to a comprehensive diagnostic evaluation, including PCR aimed at documenting the presence of fastidious organisms. The study included 1,998 suspected cases of IE seen over a 9-year period from April 1994 to December 2004 in Marseilles, France. They were evaluated prospectively. A total of 427 (21.4%) patients were diagnosed as having definite endocarditis. Possible endocarditis was diagnosed in 261 (13%) cases. The etiologic diagnosis was established in 397 (93%) cases by blood cultures, serological tests, and examination of the materials obtained from cardiac valves, respectively, in 348 (81.5%), 34 (8%), and 15 (3.5%) definite cases of IE. Concomitant infection with streptococci and C. burnetii was seen in two cases. The results of serological and rheumatoid factor evaluation reclassified 38 (8.9%) possible cases of IE as definite cases. Systematic serological testing improved the performance of the modified Duke criteria and was instrumental in establishing the etiologic diagnosis in 8% (34/427) cases of IE.

Staphylococcus aureus native valve infective endocarditis: report of 566 episodes from the International Collaboration on Endocarditis Merged Database

BACKGROUND

Staphylococcus aureus native valve infective endocarditis (SA-NVIE) is not completely understood. The objective of this investigation was to describe the characteristics of a large, international cohort of patients with SA-NVIE.

METHODS

The International Collaboration on Endocarditis Merged Database (ICE-MD) is a combination of 7 existing electronic databases from 5 countries that contains data on 2212 cases of definite infective endocarditis (IE).

RESULTS

Of patients with native valve IE, 566 patients [corrected] had IE due to S. aureus, and 1074 patients had IE due to pathogens other than S. aureus (non-SA-NVIE). Patients with S. aureus IE were more likely to die (20% vs. 12%; P < .001), to experience an embolic event (61% [corrected] vs. 31%; P < .001), or to have a central nervous system event (21% [corrected] vs. 13%; P < .001) and were less likely to undergo surgery (26% vs. 39%; P < .001) than were patients with non-SA-NVIE. Multivariate analysis of prognostic factors of mortality identified age (odds ratio [OR], 1.4; 95% confidence interval [CI], 1.1-1.7), periannular abscess (OR, 2.4; 95% CI, 1.0 [corrected] -5.6), heart failure (OR, 3.9; 95% CI, 2.3-6.7), and absence of surgical therapy (OR, 2.3; 95% CI, 1.3-4.2) as variables that were independently associated with mortality in patients with SA-NVIE. After adjusting for patient-, pathogen-, and treatment-specific characteristics by multivariate analysis, geographical region was also found to be associated with mortality in patients with SA-NVIE (P < .001).

CONCLUSIONS

S. aureus is an important and common cause of IE. The outcome of SA-NVIE is worse than that of non-SA-NVIE. Several clinical parameters are independently associated with mortality for patients with SA-NVIE. The clinical characteristics and outcome of SA-NVIE vary significantly by geographic region, although the reasons for such regional variations in outcomes of SA-NVIE are unknown and are probably multifactorial. A large, prospective, multinational cohort study of patients with IE is now under way to further investigate these observations.

Enterococcal endocarditis: 107 cases from the international collaboration on endocarditis merged database

PURPOSE

To describe clinical features and outcomes of enterococcal left-sided native valve endocarditis and to compare it to endocarditis caused by other pathogens.

SUBJECTS AND METHODS

Patients in the International Collaboration on Endocarditis-Merged Database were included if they had left-sided native valve endocarditis. Demographic characteristics, clinical features, and outcomes were analyzed. Multivariable analysis evaluated enterococcus as a predictor of mortality.

RESULTS

Of 1285 patients with left-sided native valve endocarditis, 107 had enterococcal endocarditis. Enterococcal endocarditis was most frequently seen in elderly men, frequently involved the aortic valve, tended to produce heart failure rather than embolic events, and had relatively low short-term mortality. Compared to patients with non-enterococcal endocarditis, patients with enterococcal endocarditis had similar rates of nosocomial acquisition, heart failure, embolization, surgery, and mortality. Compared to patients with streptococcal endocarditis, patients with enterococcal endocarditis were more likely to be nosocomially acquired (9 of 59 [15%] vs 2 of 400 [1%]; P <.0001) and have heart failure (49 of 107 [46%] vs 234 of 666 [35%]; P = 0.03). Compared to patients with S. aureus endocarditis, patients with enterococcal endocarditis were less likely to embolize (28 of 107 [26%] vs 155 of 314 [49%]; P <.0001) and less likely to die (12 of 107 [11%] vs 83 of 313 [27%]; P = 0.001). Multivariable analysis of all patients with left-sided native valve endocarditis showed that enterococcal endocarditis was associated with lower mortality (odds ratio [OR] 0.49; 95% confidence interval [CI] 0.24 to 0.97).

CONCLUSIONS

Enterococcal native valve endocarditis has a distinctive clinical picture with a good prognosis.

Blood culture-negative endocarditis in a reference center: etiologic diagnosis of 348 cases

To identify the current etiologies of blood culture-negative infective endocarditis and to describe the epidemiologic, clinical, laboratory, and echocardiographic characteristics associated with each etiology, as well as with unexplained cases, we tested samples from 348 patients suspected of having blood culture-negative infective endocarditis in our diagnostic center, the French National Reference Center for Rickettsial Diseases, between 1983 and 2001. Serology tests for Coxiella burnettii, Bartonella species, Chlamydia species, Legionella species, and Aspergillus species; blood culture on shell vial; and, when available, analysis of valve specimens through culture, microscopic examination, and direct PCR amplification were performed. Physicians were asked to complete a questionnaire, which was computerized. Only cases of definite infective endocarditis, as defined by the modified Duke criteria, were included. A total of 348 cases were recorded-to our knowledge, the largest series reported to date. Of those, 167 cases (48%) were associated with C. burnetii, 99 (28%) with Bartonella species, and 5 (1%) with rare, fastidious bacterial agents of endocarditis (Tropheryma whipplei, Abiotrophia elegans, Mycoplasma hominis, Legionella pneumophila). Among 73 cases without etiology, 58 received antibiotic drugs before the blood cultures. Six cases were right-sided endocarditis and 4 occurred in patients who had a permanent pacemaker. Finally, no explanatory factor was found for 5 remaining cases (1%), despite all investigations.Q fever endocarditis affected males in 75% of cases, between 40 and 70 years of age. Ninety-one percent of patients had a previous valvulopathy, 32% were immunocompromised, and 70% had been exposed to animals. Our study confirms the improved clinical presentation and prognosis of the disease observed during the last decades. Such an evolution could be related to earlier diagnosis due to better physician awareness and more sensitive diagnostic techniques. As for Bartonella species, B. quintana was recorded more frequently than B. henselae (53 vs 17 cases). For 18 patients with Bartonella endocarditis, the responsible species was not identified. Species determination was achieved through culture and/or PCR in 49 cases and through Western immunoblotting in 22. Comparison of B. quintana and B. henselae endocarditis revealed distinct epidemiologic patterns. The 2 cases due to T. whipplei reflect the emerging role of this agent as a cause of infective endocarditis. Because identification of the bacterium was possible only through analysis of excised valves by histologic examination, PCR, and culture on shell vial, the prevalence of the disease might be underestimated. Among patients who received antibiotic drugs before blood cultures, 4 cases (7%) were found to be associated with Streptococcus species (2 S. bovis and 2 S. mutans) through 16S rDNA gene amplification directly from the valve, which shows the usefulness of this technique in overcoming the limitations of previous antibiotic treatment. Right-sided endocarditis occurred classically in young patients (mean age, 36 yr), intravenous drug users in 50% of cases, and suffering more often from embolic complications. Finally, 5 cases without etiology or explaining factors were all immunocompetent male patients with previous aortic valvular lesions, and 3 of the 5 presented with an aortic abscess. Further investigations should be focused on this group to identify new agents of infective endocarditis.

A clinical study of culture-negative endocarditis

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

Staphylococcus aureus bacteremia and endocarditis

Staphylococcus aureus is a leading cause of bacteremia and endocarditis. Over the past several years, the frequency of S aureus bacteremia (SAB) has increased dramatically. This increasing frequency, coupled with increasing rates of antibiotic resistance, has renewed interest in this serious, common infection. S aureus is a unique pathogen because of its virulent properties, its protean manifestations, and its ability to cause endocarditis on architecturally normal cardiac valves. Although the possibility of underlying endocarditis arises in virtually every patient with SAB, only a minority of bacteremic patients will actually have cardiac involvement. Distinguishing patients with S aureus infective endocarditis (IE) from those with uncomplicated SAB is essential, but often difficult. In this review, the authors summarize recent changes in the epidemiology of SAB and IE, discuss the challenges in distinguishing SAB from IE, and discuss current trends in the management of patients with SAB and IE.

Clinical presentation of infective endocarditis

Despite the decline in rheumatic heart disease worldwide and the use of antibiotic prophylaxis, there is no evidence that the incidence of infective endocarditis is decreasing. In fact, some data suggest it may be increasing. The classical fever of unknown origin presentation represents a minority of infective endocarditis cases today; thus, clinicians need to be vigilant about keeping infective endocarditis in mind with some of these more unusual presentations. This article focuses on the various presentations of infective endocarditis, which are organized into three groups of presenting symptoms and signs: nonspecific, cardiac, and embolic.

Infective endocarditis in the injection drug user

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

Better prognosis of elderly patients with infectious endocarditis in the era of routine echocardiography and nonrestrictive indications for valve surgery

OBJECTIVE

It has been reported that endocarditis in the elderly may have a poor outcome. Our aim was to assess the different features and prognosis, if any, in the present time.

METHODS

Of 103 patients with proven endocarditis, 31 were 65 years or older and 72 were younger than 65 years. Degenerative heart disease was seen more frequently in the elderly (22.5% vs 2.7%, P =.003). Drug abuse and immunodeficiency virus infection were more common in the younger group, as was tricuspid endocarditis (26.3% vs 0%, P <.001). At clinical presentation cardiac failure (41.9 vs 19.4%, P =.02) and leukocytosis (61.2% vs 40.2%, P =.049) were seen more frequently in the elderly.

RESULTS

Despite other similar clinical features, it took longer to diagnose older patients (7.2 +/- 6.2 vs 3.2 +/- 3.5 days, P <.001). Enterococcus infected the aged more often (32.2% vs 13.1%, P =.001). During hospitalization, heart failure and embolization tended to be more common in the elderly and the younger group, respectively. There were no significant differences in the incidence of anatomic complications, the need for operation, and overall mortality.

CONCLUSION

Although a worse prognosis has been reported in elderly patients with infective endocarditis, the early use of transesophageal echocardiographic examinations and equal therapeutic options provides a similar outcome when compared with younger subjects.