Nosocomial endocarditis in the intensive care unit: an analysis of 22 cases

Healthcare-Associated Infective Endocarditis—Surgical Perspectives

Health-care-associated infective endocarditis (HCA-IE), a disease with a poor prognosis, has become increasingly important. As surgical treatment is frequently required, this review aims to outline surgical perspectives on HCA-IE. We searched PubMed to identify publications from January 1980 to March 2022. Reports were evaluated by the authors against a priori inclusion/exclusion criteria. Studies reporting on surgical treatment of HCA-IE including outcome were selected. Currently, HCA-IE accounts for up to 47% of IE cases. Advanced age, cardiac implants, and comorbidity are important predispositions, and intravascular catheters or frequent vascular access are significant sources of infection. Staphylococci and enterococci are the leading causative microorganisms. Surgery, although frequently indicated, is rejected in 24–69% because of prohibitive risk. In-hospital mortality is significant after surgery (29–50%) but highest in patients rejected for operation (52–83%). Furthermore, the length of hospital stay is prolonged. With aging populations, age-dependent morbidity, increasing use of cardiac implants, and growing healthcare utilization, HCA-IE is anticipated to gain further importance. A better understanding of pathogenesis, clinical profile, and outcomes is paramount. Further research on surgical treatment is needed to provide more comprehensive information for defining the most suitable treatment option, finding the optimal time for surgery, and reducing morbidity and mortality.

Infective endocarditis of a native aortic valve due to Pseudomonas aeruginosa complicated by progressive multi-drug resistance

BACKGROUND

Treatment of infective endocarditis secondary to Pseudomonas aeruginosa can be challenging because of this organism's ability to acquire antimicrobial resistance over time.

METHODS

We describe a patient with native aortic valve infective endocarditis due to P. aeruginosa who developed progressive multi-drug resistance while on therapy. The resistance mechanisms were characterized using whole-genome sequencing.

RESULTS

We identified two mutations in subsequent isolates (dacB and OprD) that conferred resistance to anti-pseudomonal penicillins, cephalosporins, and carbapenems. The patient was treated with combination high-dose continuous infusion meropenem and ciprofloxacin therapy, in addition to bioprosthetic aortic valve replacement and repair of ventricular septal wall defect. Antibiotics were continued for 6 weeks post-cardiac surgery and the patient remains infection free 18 months post-completion of antibiotic therapy.

CONCLUSION

Clinicians should be aware of the ability of P. aeruginosa to acquire resistance mechanisms in response to selective antibiotic pressures in high-inoculum infections such as infective endocarditis. The mutations identified in this case report correlated well with the evolving antimicrobial resistance profile observed.

Acinetobacter Baumannii Native Valve Infective Endocarditis: A Case Report

Infective endocarditis caused by Acinetobacter (A.) baumannii is a rare but severe complication that affects seriously ill, hospitalized patients undergoing invasive procedures. It is associated with an increased mortality rate than that of endocarditis due to the HACEK group (Haemophilus species, Aggregatibacter actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, Kingella kingae) gram-negative bacteria. We report a case of a 54-year-old woman who was diagnosed with infective endocarditis caused by A. baumannii three days following her admission to the intensive unit care (ICU). The diagnosis was made on the basis of repeated blood cultures and transthoracic echocardiography, which revealed mobile vegetation attached to the mitral valve. In spite of aggressive therapeutic regimens, outcomes were poor and the patient died. This report underlines the severe nature of A. baumannii infections, which are still associated with a prolonged hospital stay, and increased morbidity, mortality, and medical costs.

Risk factors for poor prognosis in nosocomial infective endocarditis

BACKGROUND/AIMS

The aim of our study was to compare the characteristics of nosocomial infective endocarditis (NIE) with community-acquired infective endocarditis (CIE) and to determine independent risk factors for in-hospital death.

METHODS

We retrospectively reviewed the medical records of 560 patients diagnosed with infective endocarditis. NIE was defined by a diagnosis made > 72 hours after hospital admission or within 2 months of hospital discharge.

RESULTS

Among the 560 cases reviewed, 121 were classified as NIE. Compared with patients with CIE, patients with NIE were older (mean ± SD, 51.30±18.01 vs. 59.76±14.87, p < 0.001). The in-hospital death rate of the NIE group was much higher than that of the CIE group (27.3% vs. 5.9%, p < 0.001). More patients with NIE had central intravenous catheters, and were undergoing hemodialysis (p < 0.001). Methicillin-resistant Staphylococcus aureus (MRSA) was the most common causal microorganism of NIE, and MRSA (p < 0.001) and fungus (p = 0.002) were more common in NIE compared with CIE. On multiple analysis, age, liver cirrhosis, cancer chemotherapy, central intravenous catheter, hemodialysis, and genitourinary tract manipulation were independent clinical risk factors for NIE. Among the patients with NIE, 33 died during their hospital admission. The independent risk factors for in-hospital death were older age (adjusted odds ratio [OR], 1.04; 95% confidence interval [CI], 1.01 to 1.07; p = 0.037) and chemotherapy for malignancy (adjusted OR, 3.89; 95% CI, 1.18 to 12.87; p = 0.026).

CONCLUSIONS

Because of the considerable incidence of NIE and its poor prognosis, we should pay attention to early diagnosis and active management of NIE, especially for older patients and patients receiving chemotherapy.

Infective and non-infective endocarditis in critically ill patients: a clinical-pathological study

The aims of this study are to estimate the incidence, the outcome and the associated risk factors of infective and non-infective endocarditis (IE and NIE, respectively) in intensive care unit (ICU) patients. We studied the post-mortem findings and the clinical data of the patients who died in our ICU between 1996 and 2010. Of the 765 reviewed autopsies, 21 patients (2.7%) presented cardiac vegetations. These cases consisted of 12 IEs and 9 NIEs. Three patients with IE had a mechanical prosthetic valve, and in 11 cases invasive devices had been used. Multiple peripheral embolisms were discovered at autopsy. In particular, the brain appeared to be more affected in patients with IE, while pulmonary embolisms were commonly associated with NIE. Blood cultures were positive in nine patients with IE. The imaging diagnostics (transthoracic and transesophageal echocardiography) which were seldom performed in both groups, proved to be of little help. As a consequence, an IE was correctly diagnosed before death in three patients (25%) and suspected in two other cases (17%), while a NIE was diagnosed before death in one patient alone. In conclusions, critically ill patients admitted to general ICUs, multiple factors related both to the underlying conditions and to performed procedures can facilitate the occurrence of IE and NIE making, at the same time, their diagnosis challenging. Many cases, in fact, are diagnosed only at autopsy. Yet again, post-mortem examination proves to be an invaluable tool for the evaluation of diagnostic accuracy in critical care.

[Associated factors and descriptive analysis of healthcare-related infective endocarditis in a tertiary reference hospital]

INTRODUCTION AND OBJECTIVES

The primary aim of this study was to evaluate associated factors, clinical features and prognosis of healthcare-related infective endocarditis cases compared with community-acquired and intravenous drug user-related episodes. Changes in the distribution of healthcare-related infective endocarditis were also analysed over time in our setting.

METHODS

A prospective, observational, comparative study was performed. We included all the cases of infective endocarditis from January 2003 to June 2010, which were then classified into 2 groups: group 1: community-acquired and intravenous drug user origin, and group 2: nosocomial and non-nosocomial healthcare-related cases. The episodes were classified into 2 periods: period I: January/2003-June/2006 and period II: July/2006-June 2010. Univariate and multivariate analyses were performed.

RESULTS

A total of 212 cases were included (group 1: 138, group 2: 74). The variables of age (risk ratio 1.026; 95%CI, 1.003 to 1.049), Charlson index (risk radio 1.242; 95%CI, 1.067 to 1.445), and previous heart surgery (risk ratio 2.522; 95%CI, 1.353 to 4.701) were independently associated with healthcare-related infective endocarditis on multivariate analysis. A non-significant increase was observed in healthcare-related cases of infective endocarditis in period II (40/104; 38.4% vs. 34/108; 31.4%).

CONCLUSIONS

The recent increase in healthcare-related infective endocarditis seems to be associated with the use of invasive procedures in elderly patients with prosthetic cardiac valve, and those with a greater number of underlying diseases, especially patients with chronic renal failure on haemodialysis.

Infective endocarditis

Infective endocarditis (IE) is lethal if not aggressively treated with antibiotics alone or in combination with surgery. The epidemiology of this condition has substantially changed over the past four decades, especially in industrialized countries. Once a disease that predominantly affected young adults with previously well-identified valve disease--mostly chronic rheumatic heart disease--IE now tends to affect older patients and new at-risk groups, including intravenous-drug users, patients with intracardiac devices, and patients exposed to healthcare-associated bacteremia. As a result, skin organisms (for example, Staphylococcus spp.) are now reported as the pathogen in these populations more often than oral streptococci, which still prevail in the community and in native-valve IE. Moreover, progress in molecular diagnostics has helped to improve the diagnosis of poorly cultivable pathogens, such as Bartonella spp. and Tropheryma whipplei, which are responsible for blood-culture-negative IE more often than expected. Epidemiological data indicate that IE mostly occurs independently of medico-surgical procedures, and that circumstantial antibiotic prophylaxis is likely to protect only a minute proportion of individuals at risk. Therefore, new strategies to prevent IE--including improvement of dental hygiene, decontamination of carriers of Staphylococcus aureus, vaccination, and, possibly, antiplatelet therapy--must be explored.

Infective endocarditis of the Dacron patch-a report of 13 cases at autopsy

AIMS

One of the complications of using a synthetic material as a patch in correction of left-to-right shunts is the development of infection. This is an autopsy report of 13 patients who developed infective endocarditis of the Dacron patch as a postoperative complication.

METHODS

We retrospectively reviewed the autopsy records of patients with infective endocarditis over a 15-year period (1994-2008) and selected cases with Dacron-patch infective endocarditis. The patch infective endocarditis was classified into early-onset and late-onset infective endocarditis.

RESULTS

Patch infective endocarditis was seen in 13 patients affecting the patches covering an atrial septal defect and 12 ventricular septal defects. There were nine males and four females, with a mean age of 13.1 years. The episodes occurred 2 to 118 days (mean of 30) after operation, with early-onset infective endocarditis in 10 and late-onset infective endocarditis in three patients. Postoperative wound infection had been present in eight. The organisms isolated or demonstrated on microscopy included Staphylococcus aureus (5), gram-positive cocci (4), Pseudomonas (2), Aspergillus species (1), and Candida species (1). Death was related to embolization and/or accompanying septicemia.

CONCLUSIONS

Correction of simple or complex congenital cardiac defects offers new substrates for organisms to colonize resulting in infective endocarditis, which are often difficult to treat.

Endocarditis complicating central venous catheter bloodstream infections: a unique form of health care associated endocarditis

BACKGROUND

Endocarditis complicating central venous catheter blood stream infection (CVC-BSI) is a serious complication and is being seen with increasing frequency.

METHODS

All patients discharged from our institution with International Classification of Disease (ICD-9) codes of endocarditis and CVC-BSI were identified. The medical records of those meeting our inclusion criteria were reviewed.

RESULTS

From October 1, 1998 until December 31, 2006, 24 patients were identified with inpatient mortality of 20.8%. Nine cases were nosocomial and 15 were non-nosocomial. The most common comorbidities were diabetes mellitus (45.8%), chronic kidney disease (58.4%), prior valvular abnormalities (37.5%), and multiple prior hospitalizations (65.2%). There were 13 external lines, 9 tunneled lines, and 2 implantable ports. Responsible microorganisms included Staphylococcus aureus in 54.6%, coagulase-negative staphylococci in 37.5%, Candida species (spp.) in 16.6%, and enterococci in 12.5%. Five cases were polymicrobial. The line tip was within the right atrium (RA) in 37.5%, the superior vena cava (SVC)-RA junction in 20.8%, the SVC in 33.3%, and the pulmonary artery in 4.2% of patients. Sites of endocardial involvement were the aortic valve in 6 patients, mitral valve in 7 patients, tricuspid valve in 6 patients, right atrial wall in 11 patients, and pacemaker wire in 2 patients. Isolated right-sided involvement occurred in 50% of cases, isolated left-sided in 33.4%, and bilateral involvement in 16.6%. Transesophageal echocardiography (TEE) was necessary for diagnosis in 10 cases (41.6%).

CONCLUSIONS

Endocarditis complicating CVC-BSI more often involves right-sided structures, with catheter tips in or near the right atrium, frequently requires TEE for diagnosis, and has significant inpatient mortality.

Outcome of patients with injection drug use-associated endocarditis admitted to an intensive care unit

PURPOSE

The purpose of this study was to study the outcome of patients with injection drug use-associated infective endocarditis (IDU-IE) admitted to an intensive care unit (ICU).

MATERIAL AND METHODS

A retrospective review of medical records of 33 consecutive patients with IDU-IE admitted to ICU was conducted.

RESULTS

Main indications for admission to ICU were as follows: severe sepsis or septic shock (36%), respiratory failure (33%), and neurologic deterioration (18%). Staphylococcus aureus was found in 94% of patients, and 15% had polymicrobial infection. Fifteen (45%) patients had septic emboli to 1 or more organs, including 12 (36%) to lungs and 7 (21%) to central nervous system. In-hospital mortality was 27%, and in univariate analysis, previous history of endocarditis (odds ratio [OR], 11.2; P = .03), respiratory failure (OR, 7; P = .03), neurologic failure (OR, 6.25; P = .03), and high Acute Physiology and Chronic Health Evaluation II (OR, 1.21; P = .016) and Sequential Organ Failure Assessment scores (OR, 1.25; P = .01) increased risk of death. By multivariate logistic regression analysis, previous history of endocarditis and high Acute Physiology and Chronic Health Evaluation II score were independently associated with poor survival.

CONCLUSIONS

Complicated IDU-IE necessitating admission to ICU is associated with high mortality. In addition to consequences of sepsis, septic embolization to central nervous system and lungs contributes to development of organ failure. Increased severity of illness and prior history of endocarditis are associated with poor outcome.

Acute infective endocarditis

Acute infective endocarditis is a complex disease with changing epidemiology and a rapidly evolving knowledge base. To consistently achieve optimal outcomes in the management of infective endocarditis, the clinical team must have an understanding of the epidemiology, microbiology, and natural history of infective endocarditis, as well as a grasp of guiding principles of diagnosis and medical and surgical management. The focus of this review is acute infective endocarditis, though many studies of diagnosis and treatment do not differentiate between acute and subacute disease, and indeed many principles of diagnosis and management of infective endocarditis for acute and subacute disease are identical.

Empiric therapy for intravenous central line infections and nosocomially-acquired acute bacterial endocarditis

Intravascular catheters are essential devices in the intensive care unit, yet catheter-related bloodstream infections (CR-BSI) are associated with increased morbidity and mortality, prolonged hospitalization, and increased medical costs. Management of a CR-BSI requires antibiotics, with or without catheter removal, depending on patient and etiologic factors. Because of the high frequency of staphylococcal infections, it is wise to use a glycopeptide empirically. Extra coverage for Gram-negative bacilli should be administered in severely ill or immunocompromised patients. Once culture and sensitivity results are known, antibiotic therapy can be more selective.

Predictors of death and impact of surgery in Staphylococcus aureus infective endocarditis

BACKGROUND

We studied a large cohort of adults with Staphylococcus aureus infective endocarditis to evaluate the predictors of outcome and to establish whether early surgery is associated with reduced mortality.

METHODS

The study prospectively enrolled 116 consecutive patients with definite S. aureus infective endocarditis, according to Duke criteria and examined by transthoracic and transesophageal echocardiography.

RESULTS

The in-hospital mortality rate was 26%, and the 36-month survival rate was 57% +/- 5%. Multivariate analyses identified comorbidity index, congestive heart failure, severe sepsis, prosthetic valve infective endocarditis, and major neurologic events as predictors of in-hospital mortality; severe sepsis and comorbidity index as predictors of overall mortality; and the comorbidity index as a predictor of late mortality. In unadjusted analyses, early surgery performed in 47% of patients was associated with lower in-hospital mortality (16% versus 34%; p = 0.034) and with better 36-month survival (77% +/- 6% versus 39% +/- 7%; p < 0.001). After adjustment of baseline variables related to mortality, early surgery remained associated with reduced overall mortality.

CONCLUSIONS

Prognosis of S. aureus infective endocarditis remains poor, related to the comorbidities, presence of congestive heart failure, severe sepsis, major neurologic events, and prosthetic valve. Early surgery is independently associated with reduced overall mortality and should be considered in selected cases to improve the outcome.

Nosocomial endocarditis in a tertiary hospital: an increasing trend in native valve cases

INTRODUCTION

Changes in the etiology, epidemiology, and outcome of infective endocarditis (IE) have been observed in recent years. Newer invasive therapeutic interventions have increased the risk of bacteremia and nosocomial endocarditis in the population at risk. A retrospective analysis of hospital-acquired IE cases was performed in a tertiary hospital during 1985 to 1999.

MATERIAL AND METHODS

Cases included were those classified as "probable" or "definite" by the IE diagnostic criteria of Durack. Nosocomial acquisition was considered if diagnosis was made > 72 h after hospital admission and there was no evidence that IE was present at the time of admission. Patients receiving a diagnosis within 60 days of a previous hospital admission were also classified as nosocomial, when a risk procedure for bacteremia was performed, or when any predisposing factor for IE was present during hospitalization. Early prosthetic valve endocarditis (PVE) cases (< 1 year) were excluded from the analysis. Clinical characteristics, etiology, predisposing cardiac condition, source of infection, and outcome were analyzed. Results were compared with those obtained in community-acquired cases.

RESULTS

Of 493 cases of IE diagnosed over 15 years, 38 were considered to be hospital acquired. Twenty-eight cases were native valve endocarditis (NVE) in non-IV drug user patients, and 10 cases were late PVE. Overall, the most frequent microorganisms involved were staphylococci (58%). The main sources of infection were intravascular procedures or catheter-related infections (55%). When nosocomial NVE cases were compared with community-acquired cases, mortality was greater (29% vs 9.7%) in hospital-acquired endocarditis. Analysis of time trends showed an increased rate of nosocomial cases in NVE throughout the years of the study.

CONCLUSIONS

In NVE, the number of cases that are hospital acquired has been increasing during the last 15 years. These cases are frequently associated with invasive intravascular procedures or IV catheter-related infections. Most patients have a previous valvulopathy that predisposes to IE. The spectrum of microorganisms involved is different from the community-acquired cases. Also, the outcome of endocarditis is worse in nosocomial NVE patients.

Comparison of clinical and morphological characteristics of Staphylococcus aureus endocarditis with endocarditis caused by other pathogens

OBJECTIVES

To analyse clinical, echocardiographic, and prognostic characteristics of Staphylococcus aureus infective endocarditis (IE) compared with endocarditis caused by other pathogens.

DESIGN

Cohort study.

METHODS

194 consecutive patients with definite IE according to the Duke criteria prospectively examined by transthoracic and transoesophageal echocardiography were enrolled. Patients without identified microorganisms were excluded. The S aureus IE group (n = 61) was compared with the group with IE caused by other pathogens (n = 133).

RESULTS

Compared with IE caused by other pathogens, S aureus IE was characterised by severe co-morbidity, a shorter duration of symptoms before diagnosis, and a higher prevalence of right sided IE, cutaneous portal of entry, and history of renal failure. Severe sepsis, major neurological events, and multiple organ failure were more frequent during the acute phase in S aureus IE. In-hospital mortality (34% v 10%, p < 0.001) was higher in patients with S aureus IE and the 36 month actuarial survival rate was lower in S aureus IE than in IE caused by other pathogens (47% v 68%, p = 0.002). Multivariate analyses identified S aureus infection as a predictive factor for in-hospital mortality and for overall mortality.

CONCLUSIONS

S aureus IE compared with IE caused by other pathogens occurs in a more debilitated clinical setting and is characterised by a higher prevalence of severe sepsis, major neurological events, and multiple organ failure leading to higher mortality.

Infective endocarditis: a review of the best treatment options

Despite significant advances in antimicrobial therapy and an enhanced ability to diagnose and treat complications, infective endocarditis is still associated with substantial morbidity and mortality today, and its incidence has not decreased over the past decades. This apparent paradox may be explained by a progressive change in risk factors, leading to an evolution in its epidemiological and clinical features. In fact, new risk factors for endocarditis have emerged, such as intravenous drug abuse, diffusion of heart surgery procedures and prosthetic valve implantation, atherosclerotic valve disease in elderly patients, and nosocomial disease. Recently identified microorganisms (including Bartonella spp., Abiotrophia defectiva, and the HACEK group of bacteria [including Haemophilus spp., Actinobacillus spp., Cardiobacterium hominis, Eikenella corrodens and Kingella kingae]) are sometimes the cause of culture-negative endocarditis, and emerging resistant bacteria (such as methicillin- or vancomycin-resistant Staphylococci and vancomycin-resistant Enterococci) are becoming a new challenge for conventional antibiotic therapy. New therapeutic approaches need to be developed for the treatment of infective endocarditis caused by drug-resistant Gram-positive cocci, and some antimicrobial compounds recently introduced in clinical practice (such as streptogramins and oxazolidinones) may be an effective alternative, but further clinical studies are needed in order to confirm their effectiveness and safety. This review should help redefine the best therapeutic and preventive strategies against infective endocarditis.

Post mortem examination in the intensive care unit: still useful?

OBJECTIVE

Post mortem examination rates have decreased worldwide and their usefulness has been challenged. The aim of this study was to compare ante- versus post mortem findings in a multidisciplinary ICU.

DESIGN

Retrospective study.

SETTING

Thirty-one-bed, medico-surgical ICU.

PATIENTS

All patients who died on the ICU and underwent an autopsy examination in 1999.

MEASUREMENTS

Records from autopsies were compared with clinical records. A modified Goldman's criteria was used to categorize the post mortem diagnoses. Unexpected findings were evaluated according to the duration of hospitalization prior to death (fewer than or more than 10 days).

RESULTS

Among 2,984 ICU admissions, there were 489 deaths; 222 autopsies were conducted (45.4% autopsy rate). Post mortem examination revealed unexpected findings in 50 patients (22.5%), including malignancy (22 [9.9%]), fungal infections (9 [4%]), pulmonary embolism (7 [3.2%]), nosocomial infections (3 [1.3%]), Hashimoto's disease (3 [1.3%]), mesenteric infarction (2 [0.9%]), Barrett's esophagus (2 [0.9%]), endocarditis (1 [0.5%]) and myocardial infarction (1 [0.5%]). These unexpected findings were considered as major (Class I/II) in 19 (8.5%), and minor (Class III) in 31 (14%) patients. In patients with a short ICU length of stay (<10 days), there were more major unexpected findings than minor, while after a prolonged stay (>10 days), minor unexpected findings were more common.

CONCLUSIONS

After a short ICU stay (<10 days), autopsy revealed discrepancies primarily related to the cause of death associated with diseases whose diagnosis can be difficult. Following more prolonged ICU stays (>10 days), autopsy was more likely to reveal coexisting diseases unrelated to death.

Nosocomial infective endocarditis in critically ill patients: a report of three cases and review of the literature

Nosocomial infective endocarditis (NIE) is a relatively uncommon but nevertheless a serious complication affecting critically ill hospitalized patients who are frequently exposed to life-saving invasive procedures. We report three cases of NIE in a tertiary-care hospital encountered during a period of two years. The first case developed in a 50% burn-injured patient; the second in a liver transplant recipient; and the third in a renal transplant recipient. All patients met indications for cardiac surgical intervention, however, the patient who had received a liver transplant (case 2) was considered a poor candidate and unfit for surgery; she subsequently died. The other two patients underwent open-heart surgery. The burns patient (case 1) survived; conversely, the renal transplant recipient (case 3) died postoperatively. We have reviewed the literature concerning NIE in critically ill patients and describe the epidemiology, microbiology and clinical features of this uncommon infection and comment on its diagnosis and management.

Infective endocarditis in the intensive care unit: clinical spectrum and prognostic factors in 228 consecutive patients

OBJECTIVE

To identify factors associated with in-hospital outcome of adult patients admitted to the ICU with infective endocarditis (IE).

DESIGN AND SETTING

Retrospective study performed in the two medical ICUs of a teaching hospital.

PATIENTS AND PARTICIPANTS

The charts of all 228 consecutive patients aged 18 years or older admitted with infective IE between January 1993 and December 2000 were reviewed. All patients satisfied the modified Duke's criteria for definite IE.

MEASUREMENTS AND RESULTS

There were 146 episodes of native valve endocarditis and 82 of prosthetic valve endocarditis. Staphylococcus aureus was the predominant causative micro-organism. Most complications occurred early during the course of IE. One-half of the patients underwent cardiac surgery during the same hospitalization and had a better outcome than nonoperated patients. The overall in-hospital mortality rate was 45% (102/228). Multivariate analysis revealed the following clinical factors in patients with native valve IE as independently associated with outcome: septic shock (odds ratio 4.81), cerebral emboli (3.00), immunocompromised state (2.88), and cardiac surgery (0.475); in patients with prosthetic valve IE the factors were: septic shock (4.07), neurological complications (3.1), and immunocompromised state (3.46).

CONCLUSIONS

IE still carries high morbidity and mortality rates for the subset of patients requiring ICU admission. Most complications occur early making the decision process for optimal medical and surgical management more difficult. Surgical treatment appears to improve in-hospital outcome.

Hospital‐Acquired Infective Endocarditis: Should the Definition be Broadened?

Hospital-acquired infective endocarditis (IE) is a growing health-care problem. Hospital-acquired IE, according to the commonly used definition, is IE manifesting > or =72 h after admission to the hospital or within several weeks after a hospital-based invasive procedure. To assess the validity of this definition, we evaluated 87 episodes of IE, with special attention to recent hospitalizations. The incidence rate of IE in the 6-month period after discharge from the hospital was 27 cases per 100,000 person-years, compared with 1.1 cases per 100,000 person-years in a population with no recent hospitalizations. Furthermore, episodes of IE manifesting during this 6-month period were notable for a high proportion of typically hospital-acquired pathogens (26% vs. 0%; P=.001) and a low proportion of viridans streptococci (0% vs. 36%; P<.001), compared with community-acquired episodes that did not involve recent hospitalization. We conclude that characteristics of hospital-acquired IE extend to episodes arising within 6 months after discharge from the hospital and suggest that the definition of hospital-acquired IE be broadened to include these episodes.

Infective endocarditis

Despite improvements in health care, the incidence of infective endocarditis has not decreased over the past decades. This apparent paradox is explained by a progressive evolution in risk factors; while classic predisposing conditions such as rheumatic heart disease have been all but eradicated, new risk factors for infective endocarditis have emerged. These include intravenous drug use, sclerotic valve disease in elderly patients, use of prosthetic valves, and nosocomial disease. Newly identified pathogens, which are difficult to cultivate--eg, Bartonella spp and Tropheryma whipplei--are present in selected individuals, and resistant organisms are challenging conventional antimicrobial therapy. Keeping up with these changes depends on a comprehensive approach, allying understanding of the pathogenesis of disease with the development of new drugs for infective endocarditis. Infection by staphylococci and streptococci is being dissected at the molecular level. New ideas for antimicrobial agents are being developed. These novel insights should help redefine preventive and therapeutic strategies against infective endocarditis.

Electronic medical devices: a primer for pathologists

CONTEXT

Electronic medical devices (EMDs) with downloadable memories, such as implantable cardiac pacemakers, defibrillators, drug pumps, insulin pumps, and glucose monitors, are now an integral part of routine medical practice in the United States, and functional organ replacements, such as the artificial heart, pancreas, and retina, will most likely become commonplace in the near future. Often, EMDs end up in the hands of the pathologist as a surgical specimen or at autopsy. No established guidelines for systematic examination and reporting or comprehensive reviews of EMDs currently exist for the pathologist.

OBJECTIVE

To provide pathologists with a general overview of EMDs, including a brief history; epidemiology; essential technical aspects, indications, contraindications, and complications of selected devices; potential applications in pathology; relevant government regulations; and suggested examination and reporting guidelines.

DATA SOURCES

Articles indexed on PubMed of the National Library of Medicine, various medical and history of medicine textbooks, US Food and Drug Administration publications and product information, and specifications provided by device manufacturers.

STUDY SELECTION

Studies were selected on the basis of relevance to the study objectives.

DATA EXTRACTION

Descriptive data were selected by the author.

DATA SYNTHESIS

Suggested examination and reporting guidelines for EMDs received as surgical specimens and retrieved at autopsy.

CONCLUSIONS

Electronic medical devices received as surgical specimens and retrieved at autopsy are increasing in number and level of sophistication. They should be systematically examined and reported, should have electronic memories downloaded when indicated, will help pathologists answer more questions with greater certainty, and should become an integral part of the formal knowledge base, research focus, training, and practice of pathology.

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.

Progress toward a global understanding of infective endocarditis. Lessons from the International Collaboration on Endocarditis

In the century and a quarter since William Osler delivered his famed Gulstonian lectures on endocarditis, continual advancements have been made in understanding and treating this disease. Here we have reviewed some key aspects of current knowledge in the areas of population epidemiology, host factors, microorganisms, and diagnosis. The advent of the ICE investigation provides the opportunity to further expand our understanding of IE by developing a very large, global database of IE patients whose clinical, echocardiographic, and microbiologic findings have been characterized with standard methodology. Further, ICE may serve as a rich source of material for investigators seeking to perform specific studies. Finally, the ICE infrastructure creates the opportunity for performing randomized trials to test therapeutic strategies. Although many obstacles remain to be overcome, ICE has created the opportunity for a quantum leap in our knowledge of IE over the next 25 years.

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

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

Fungal endocarditis, 1995-2000

One hundred fifty-two cases of fungal endocarditis (FE) were identified in the English-language literature between January 1, 1995, and June 30, 2000. Although the median age of patients (44 years) was relatively young, injection drug use was identified as a risk factor in only 4.1% of cases. Other factors, including underlying cardiac abnormalities (47.3%), prosthetic valves (44.6%), and central venous catheters (30.4%), were more commonly identified as predisposing conditions and reflect the changing epidemiology of the syndrome. Unfortunately, mortality remains unacceptably high, particularly for patients with Aspergillus-related FE. Novel therapies are needed to improve patient outcomes.

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

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

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.

Progress toward a global understanding of infective endocarditis. Early lessons from the International Collaboration on Endocarditis investigation

In the century and a quarter since William Osler delivered his framed lectures on endocarditis substantial advancements have occurred in the understanding and treatment of this disease. This article summarizes current understanding of endocarditis in the areas of population epidemiology, host factors, microorganisms, diagnosis, and therapy. In addition, the authors discuss possible directions for investigation in the future, including a new multinational consortium, the International Collaboration on Endocarditis (ICE). This collaboration aims to provide a mechanism to advance the understanding of endocarditis in areas difficult to study without an established network. The multinational nature of the collaboration may also permit a more global view of IE and provide opportunities for studies such as randomized trials of therapeutic treatment strategies.