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

Prevalence and prognostic impact of stroke in a national cohort of infective endocarditis

BACKGROUND

Stroke is a common complication of infective endocarditis (IE). Our aim was to describe the prevalence and prognostic impact of stroke in a national cohort of IE.

METHODS

Consecutive inclusion at 46 Spanish hospitals between 2008 and 2021.

RESULTS

Out of 5667 IE cases, 1125 had acute stroke (19.8%): 818 ischemic strokes (811 cardioembolic strokes (193 with hemorrhagic transformation), 4 transient ischemic attacks, 3 lacunar infarctions), 127 intracranial hemorrhages, and 27 other neurological complications (cerebral abscesses, encephalitis, and meningitis). Compared to patients without stroke, those with stroke had a similar mean age (69 years) but were more frequently female (68.2% vs 63.7%, p = 0.04) and had a higher incidence of intracardiac complications (35% vs 30%, p = 0.01), surgical indication (69.9% vs 65.9%, p = 0.001), in-hospital mortality (40.9% vs 22.0%, p < 0.001), and 1-year mortality (46.2% vs 27.9%, p < 0.001). The following variables were independently associated with stroke: mitral location (odds ratio (OR) = 1.5, 95% confidence interval (CI) = 1.34-1.8, p < 0.001), vascular phenomenon (OR = 2.9, 95% CI = 2.4-3.6, p = 0.0001), acute renal failure (OR = 1.2, 95% CI = 1.0-1.4, p = 0.021), septic shock (OR = 1.3, 95% CI = 1.1-1.6, p = 0.007), sepsis (OR = 1.3, 95% CI = 1.1-1.6, p = 0.005), surgery indicated but not performed (OR = 1.4, 95% CI = 1.2-1.7, p < 0.001), community-acquired IE (OR = 1.2, 95% CI = 1-1.4, p = 0.017), and peripheral embolization (OR = 1.6, 95% CI = 1.4-1.9, p < 0.001). Stroke was an independent predictor of in-hospital (OR = 2.1, 95% CI = 1.78-2.51, p < 0.001) and 1-year mortality (hazard ratio = 1.9, 95% CI = 1.6-2.5).

CONCLUSION

One-fifth of patients with IE have concomitant stroke. Stroke is associated with mortality.

Early Surgery for Infective Endocarditis Complicated With Neurologic Injury

OBJECTIVES

To estimate the association between early surgery and the risk of mortality in patients with left-sided infective endocarditis in the context of stroke.

DESIGN

Retrospective cohort study.

SETTING

This study was a multiinstitution study based on the Chang Gung Research Database, which contains electronic medical records from 7 hospitals in northern and southern Taiwan; these include 2 medical centers, 2 regional hospitals, and 3 district hospitals.

PARTICIPANTS

Patients with active left-sided infective endocarditis who underwent valve surgery between September 2002 and December 2018.

INTERVENTIONS

The authors divided patients into 2 groups, with versus without preoperative neurologic complications, had undergone early (within 7 d) or later surgery, and with brain ischemia or hemorrhage.

MEASUREMENTS AND MAIN RESULTS

Three hundred ninety-two patients with a median time from diagnosis to surgery of 6 days were included. No significant differences in postoperative stroke, in-hospital mortality, or follow-up outcomes were observed between the patients with and without neurologic complications. Among the patients with preoperative neurologic complications, patients who underwent early surgery had a lower 30-day postoperative mortality rate (13.1% v 25.8%; hazard ratio, 0.21; 95% CI 0.07-0.67). In the subgroup analysis of the comparison between brain ischemia and hemorrhage groups, there was no significant between-group difference in the in-hospital outcomes or outcomes after discharge.

CONCLUSIONS

Early cardiac surgery may be associated with more favorable clinical outcomes in patients with preoperative neurologic complications. Thus, preoperative neurologic complications should not delay surgical interventions.

Staphylococcal endocarditis with meningitis and basal ganglia infarcts mimicking meningococcemia

Staphylococcus aureus is one of the common causes of infective endocarditis (IE). IE can present with various neurological complications such as stroke, brain abscess, and meningitis, the mortality rate can be very high in such cases.

Anti-biofilm Approach in Infective Endocarditis Exposes New Treatment Strategies for Improved Outcome

Infective endocarditis (IE) is a life-threatening infective disease with increasing incidence worldwide. From early on, in the antibiotic era, it was recognized that high-dose and long-term antibiotic therapy was correlated to improved outcome. In addition, for several of the common microbial IE etiologies, the use of combination antibiotic therapy further improves outcome. IE vegetations on affected heart valves from patients and experimental animal models resemble biofilm infections. Besides the recalcitrant nature of IE, the microorganisms often present in an aggregated form, and gradients of bacterial activity in the vegetations can be observed. Even after appropriate antibiotic therapy, such microbial formations can often be identified in surgically removed, infected heart valves. Therefore, persistent or recurrent cases of IE, after apparent initial infection control, can be related to biofilm formation in the heart valve vegetations. On this background, the present review will describe potentially novel non-antibiotic, antimicrobial approaches in IE, with special focus on anti-thrombotic strategies and hyperbaric oxygen therapy targeting the biofilm formation of the infected heart valves caused by Staphylococcus aureus. The format is translational from preclinical models to actual clinical treatment strategies.

Optimal Timing of Surgery for Patients with Active Infective Endocarditis

Infective endocarditis (IE) is a rare but serious condition with a dismal prognosis. One of the keys to improving outcomes is the prompt identification of high-risk patients who have intracardiac and extracardiac (systemic and neurologic) complications. However, as cardiac and extracardiac complications indicating surgery add to the surgical risk for active IE, controversies surround the optimal indication and timing for surgery, especially in patients presenting neurologic complications. This article reviews the necessary evaluation for patients with suspected IE and proposes a state-of-the-art patient flow chart for evaluation of suspected IE.

Blood culture negative infective endocarditis in adult congenital heart disease patients with prosthetic grafts: a case series

Background

Blood culture negative infective endocarditis (BCNIE) is often a diagnostic challenge in adult congenital heart disease patients leading to misdiagnosis, treatment delay and associated high mortality. Studies of BCNIE in adult congenital heart disease patients repaired with prosthetic cardiovascular grafts are limited.

Case summary

We report two cases of BCNIE where serology testing, multiple polymerase chain reaction testing of explanted valve material and multi-modality imaging including ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) were utilized not only to confirm the diagnosis but also to guide management strategy and inform prognosis. Both patients were treated successfully with cardiac surgery and prolonged anti-microbial therapy.

Discussion

Clinical presentation of BCNIE in repaired CHD patients is highly variable. The symptoms are often non-specific with subacute or chronic presentation. This may mislead initial diagnosis and subsequent management. Multi-modality imaging including PET/CT should be considered to support the diagnosis, define the extent of infection, decide the management strategy and inform prognosis in patients. A thorough history of animal exposure, and consideration of serology and multiple molecular testing to identify the causative organism, is critical in the management of BCNIE.

Infective Endocarditis Leading to Intracranial Abscess: A Case Report and Literature Review

Neurologic complications are a hallmark of infective endocarditis (IE). IE leading to intracranial abscess has an unfavorable prognosis. A 17-year-old boy with a past medical history of aortic valve replacement presented with fever and seizure. On examination, he had tachycardia, systolic murmur, slurred speech, meningeal signs, and right homonymous hemianopia. His laboratory analysis revealed an elevated erythrocyte sedimentation rate and C-reactive protein. The brain's magnetic resonance imaging revealed multiple ring-enhancing lesions in the frontal, occipital lobe, and occipitotemporal lobe, consistent with intracranial abscess. Transthoracic echocardiogram revealed a mobile mass adjacent to aortic value, consistent with possible infective vegetation. He was diagnosed with multiple cerebral septic emboli leading to intracranial abscess due to IE. Blood and cerebrospinal fluid culture revealed methicillin-sensitive Staphylococcus aureus growth. He was started on intravenous nafcillin and gentamycin. His condition improved gradually, and he became afebrile on hospital day four. On his recent follow-up, he was doing well.

Stroke Risk Following Infection in Patients with Continuous-Flow Left Ventricular Assist Device

BACKGROUND

Infection has been associated with stroke in patients with left ventricular assist devices (LVAD); however, little data exist on the timing, type and mortality impact of infection-related stroke.

METHODS

Prospectively collected data of HeartMate II (N = 332) and HeartWare (N = 70) LVAD patients from a single center were reviewed. Only strokes (ischemic or hemorrhagic) that occurred within 6 weeks following a LVAD infection were considered in analyses. The association between LVAD infections (wound, pump pocket, driveline and/or bloodstream infection [BSI]), specific pathogens and ischemic and hemorrhagic strokes was evaluated using multivariable logistic regression analysis. The impact of infection-related stroke on cumulative survival was assessed using Kaplan-Meier analysis.

RESULTS

Of 402 patients, LVAD infection occurred in 158 (39%) including BSI in 107 (27%), driveline infection in 67 (17%), wound infection in 31 (8%) and pump pocket infection in 24 (6%). LVAD infection-related stroke occurred in 20/158 (13%) patients in a median of 4 days (0-36 days) from documented infection. In multivariable analysis, ischemic stroke was associated with wound infection (aOR 9.0, 95% CI 2.4-34.0, P = 0.001) and BSI (aOR 7.7, 95% CI 0.9-66.0, P = 0.064), and hemorrhagic stroke was associated with BSI in 100% of cases (P = 0.01). There was no association with driveline or pump pocket infection. The cumulative survival rate among patients with infection-related stroke was significantly lower compared to those with LVAD infection but no stroke (log-rank P < 0.001). There was a trend toward shorter stroke-free survival among patients with LVAD infection.

CONCLUSIONS

LVAD infections, particularly BSI, are significantly associated with stroke, and infection-related stroke conferred significantly lower cumulative survival.

When Zoonotic Organisms Cross Over-Trueperella pyogenes Endocarditis Presenting as a Septic Embolic Stroke

Infective endocarditis (IE) remains a significant cause of morbidity and mortality worldwide, with numerous pathogens as culprits. We present a case of IE that evolved to a septic embolic stroke caused by an extremely rare bacteria Trueperella (T.) pyogenes that primarily infects non-humans. In contrast to most cases occurring outside the United States (US), this is the second case of T. pyogenes-associated endocarditis and the first to present as a stroke in the US. T. pyogenes has undergone numerous taxonomic revisions over the years since first being reported and characterized as Bacillus pyogenes in the 1800s. T. pyogenes is a zoonotic infection, and despite advancements in chemotaxonomic detection methods, Trueperella is often misidentified and under-diagnosed. Although epidemiological data is scarce, T. pyogenes infections have the propensity to cause endocarditis, and we aim to summarize all isolated reports of T. pyogenes infections that have been reported in the literature thus far.

MRI Presentation of Infectious Intracranial Aneurysms in Infective Endocarditis

BACKGROUND

The radiographic appearance of infectious intracranial aneurysms (IIAs) of infective endocarditis (IE) on magnetic resonance imaging (MRI) of brain is varied. We aimed to describe the IIA-specific MRI features in a series of patients with IIAs.

METHODS

Records of patients with active IE who had digital subtraction angiography (DSA) at a tertiary medical center from January 2011 to December 2016 were reviewed. MRIs performed prior to IIA treatment were reviewed for findings on susceptibility-weighted imaging (SWI), diffusion-weighted imaging, and T1 with and without contrast.

RESULTS

Of the 732 patients with IE, 53 (7%) had IIAs. Of these, 28 patients had an evaluable pre-treatment MRI, in whom 33 IIAs were imaged. MRI to DSA median time was 1 day (interquartile range = 1-5). On MRI, 12 (36%) IIAs had SWI lesion with contrast enhancement, 7 (21%) had cerebral microbleeds, 3 (11%) had sulcal SWI lesion, 2 (6%) IIAs had abscesses, 3 (9%) had intraparenchymal hemorrhage, 3 (9%) had subarachnoid hemorrhage, and 6 (18%) had ischemic stroke at the anatomical locations of IIAs. Four IIAs (12%) had no correlating MRI findings, though those patients had MRI without contrast.

CONCLUSION

The MRI features such as SWI lesion and contrast enhancement were the commonest MRI presentations associated with the presence of IIA.

Methicillin-Resistant Staphylococcus aureus Prosthetic Valve Endocarditis: Pathophysiology, Epidemiology, Clinical Presentation, Diagnosis, and Management

Staphylococcus aureus prosthetic valve endocarditis (PVE) remains among the most morbid bacterial infections, with mortality estimates ranging from 40% to 80%. The proportion of PVE cases due to methicillin-resistant Staphylococcus aureus (MRSA) has grown in recent decades, to account for more than 15% of cases of S. aureus PVE and 6% of all cases of PVE. Because no large studies or clinical trials for PVE have been published, most guidelines on the diagnosis and management of MRSA PVE rely upon expert opinion and data from animal models or related conditions (e.g., coagulase-negative Staphylococcus infection). We performed a review of the literature on MRSA PVE to summarize data on pathogenic mechanisms and updates in epidemiology and therapeutic management and to inform diagnostic strategies and priority areas where additional clinical and laboratory data will be particularly useful to guide therapy. Major updates discussed in this review include novel diagnostics, indications for surgical management, the utility of aminoglycosides in medical therapy, and a review of newer antistaphylococcal agents used for the management of MRSA PVE.

Pre-operative stroke and neurological disability do not independently affect short- and long-term mortality in infective endocarditis patients

BACKGROUND

Infective endocarditis (IE) is still associated with high morbidity and mortality. The impact of pre-operative stroke on mortality and long-term survival is controversial. In addition, data on the severity of neurological disability due to pre-operative stroke are scarce. We analysed the impact of pre-operative stroke and the severity of its related neurological disability on short- and long-term outcome.

METHODS

We retrospectively reviewed our data from patients operated for left-sided IE between 01/2007 and 04/2013. We performed univariate (Chi-Square and independent samples t test) and multivariate analyses.

RESULTS

Among 308 consecutive patients who underwent cardiac surgery for left-sided IE, pre-operative stroke was present in 87 (28.2 %) patients. Patients with pre-operative stroke had a higher pre-operative risk profile than patient without it: higher Charlson comorbidity index (8.1 ± 2.6 vs. 6.6 ± 3.3) and higher incidence of Staphylococcus aureus infection (43 vs. 17 %) and septic shock (37 vs. 19 %). In-hospital mortality was equal but 5-year survival was significantly worse with pre-operative stroke (33.1 % vs. 45 %, p = 0.006). 5-year survival was worst in patients with severe neurological disability compared to mild disability (19.0 vs. 0.58 %, p = 0.002). However, neither pre-operative stroke nor the degree of neurological disability appeared as an independent risk factor for short or long-term mortality by multivariate analysis.

CONCLUSIONS

Pre-operative stroke and the severity of neurological disability do not independently affect short- and long-term mortality in patients with infective endocarditis. It appears that patients with pre-operative stroke present with a generally higher risk profile. This information may substantially affect decision-making.

[Infective endocarditis in adult patients with congenital heart disease. Experience from a reference centre]

INTRODUCTION

A growing number of patients with congenital heart disease (CHD) will reach adulthood. Infective endocarditis (IE) is a major complication in this population. The aim of this study was to describe the features of IE in adults with CHD treated in a reference centre.

METHODS

A retrospective review was performed on a cohort of patients over 16 years of age with CHD who presented with IE (defined by the modified Duke criteria) between 1996 and 2014. Only the first episode from each patient was considered for the descriptive analysis.

RESULTS

IE was observed in 27 patients. The median age at diagnosis of IE was 27.7 years, and 63% were male. Comorbidity was low (median Charlson index was 0). IE was mostly community-acquired (78%). The most frequent CHD were ventricular septal defect (33%). A repair was performed in 48% of patients, and 19% received palliative treatment. Forty-one percent of patients had some type of prosthesis. A residual defect was observed in 81%. The IE was detected in the right side of 44% of the patients. The most frequent aetiological agents were viridans group streptococci (41%) and Staphylococcus epidermidis (30%). Surgery was required to treat IE in 37% of patients. There were five re-infections and three relapses. Two patients died, both as a result of recurrence.

CONCLUSIONS

IE in adults with CHD occurred in young patients, and almost all of them carried some prosthetic material or a residual defect. The IE is frequently right-sided. Although surgical treatment was required in many cases, mortality was low, except in the case of relapses.

Methicillin Resistance and Risk Factors for Embolism inStaphylococcus aureusInfective Endocarditis

Objective.

Infective endocarditis caused byStaphylococcus aureusis an ominous prognosis associated with a high prevalence of embolic episodes and neurological involvement. Whether methicillin resistance decreases the risk of embolism in infective endocarditis is unclear. We sought to assess the association between methicillin resistance and risk factors for embolism in S.aureusinfective endocarditis.

Design.

Retrospective chart review. Data from patients with infective endocarditis due to methicillin-resistantS. aureus werecompared with data from patients with endocarditis due to methicillin-susceptibleS. aureus.Logistic regression was used to identify independent risk factors for embolism.

Setting.

A 2,000-bed, university-affiliated tertiary care hospital.

Patients.

Between 1995 and 2005, 123 patients withS. aureusinfective endocarditis were included in the study. There were 74 male patients and 49 female patients, with a median age of 54 years (range, 0-89 years).

Results.

Of 123 infections, 30 (24%) were nosocomial infections, and 14 (11%) were prosthetic valve infections. Of 123S. aureusisolates, 48 (39%) were methicillin resistant. In total, embolism occurred in 45 (37%) of these patients: pulmonary embolism in 22 (18%), cerebral embolism in 21 (17%), and peripheral embolism in 6 (5%). The independent risk factors for an embolism were injection drug use, presence of a cardiac vegetation with a size of 10 mm or greater, and absence of nosocomial infection. For 83 patients with aortic or mitral infective endocarditis, independent risk factors for an embolism were the presence of a cardiac vegetation with a size of 10 mm or greater and endocarditis due to methicillin-susceptibleS. aureus.Overall, in-hospital death occurred for 32 (26%) of 123 Patients. Methicillin-resistant infection was not an independent risk factor for death.

Conclusions.

Methicillin-resistant S.aureusinfection was associated with decreased risk of embolism in left-side endocarditis, but was not associated with in-hospital death.

Changing profile of infective endocarditis: a clinicopathologic study of 220 patients in a single medical center from 1998 through 2009

The epidemiologic profile of infective endocarditis has changed substantially over the past few years, especially in industrialized countries. Our study evaluates the clinical and pathologic characteristics of infective endocarditis patients treated by cardiac surgery in China during a 12-year period. We retrospectively evaluated 220 surgically treated infective endocarditis patients and analyzed their changes from the beginning of 1998 through 2009. The mean age of the patients increased from 36.9 to 42.7 years during those 12 years (P=0.036). The chief predisposing disease was congenital heart disease (32.8%), rather than rheumatic heart disease (13.2%); this rate did not change significantly during the 12 years. The prevalent congenital lesion was bicuspid aortic valve, the rate of which (55.6%) increased significantly over the 3 time intervals studied (P=0.016). The frequency of infective endocarditis after non-dental surgical and nonsurgical intervention was significantly greater (23.3%) during 1998 through 2001, compared with the 2 intervals that followed (9%; P=0.019). Streptococcus viridans was the most frequent causative agent overall (25.6%). Forty-seven of the 220 patients (21.4%) carried the clinical diagnosis of some other form of heart disease before surgery, but at surgery they were found to have infective endocarditis as the fundamental disease process. Of 47 patients, 33 (70.2%) had either very small or no vegetations but had focal necrosis and inflammation of valve tissue that supported the diagnosis of infective endocarditis.

My paper 10 years later: infective endocarditis in the intensive care unit

INTRODUCTION

Although the recent literature contains plenty of studies concerning all aspects of infective endocarditis (IE), very few focus on severe IE requiring admission to the ICU.

RESULTS

In 2004, we published a report on the clinical spectrum and prognostic factors in 228 consecutive critically ill patients with IE. Septic shock, neurological complications and immunocompromised state were independently associated with in-hospital mortality. Cardiac surgery during the acute phase of EI was associated with better survival. A lot of information has been accumulated during the past 10 years on management of IE. Although three sets of blood cultures allow the identification of about 90% of cases, culture-negative IE still remains a diagnostic challenge. Blood-polymerase chain reaction in valve tissue may yield a microbiologic diagnosis. New imaging techniques such as positron emission tomography computed tomography (PET-CT) have shown additive value in patients with an intracardiac device or valvular prosthesis. Systematic cerebral magnetic resonance imaging can lead to modification of therapeutic plans. The decision to operate and the timing of cardiac surgery should take into account the presence of congestive heart failure, neurological complications, renal failure and multiorgan dysfunction syndrome. In 2011 and 2013, we published the results of a multicentre prospective observational study of 198 ICU patients with left-sided IE and confirmed that cardiac surgery was associated with better outcome. The strongest independent predictor of post-operative mortality was the pre-operative multiorgan failure score. Neurological failure also represented a major determinant of mortality, regardless of the mechanism of neurological complication.

CONCLUSION

In the present paper, we propose algorithms to optimize the medico-surgical approach.

Infective endocarditis

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

Neurologic complications of valvular heart disease

Valvular heart disease (VHD) is frequently associated with neurologic complications; cerebral embolism is the most common of these since thrombus formation results from the abnormalities in the valvular surfaces or from the anatomic and physiologic changes associated with valve dysfunction, such as atrial or ventricular enlargement, intracardiac thrombi, and cardiac dysrhythmias. Prosthetic heart valves, particularly mechanical valves, are very thrombogenic, which explains the high risk of thromboembolism and the need for anticoagulation for the prevention of embolism. Infective endocarditis is a disease process with protean manifestations that include not only cerebral embolism but also intracranial hemorrhage, mycotic aneurysms, and systemic manifestations such as fever and encephalopathy. Other neurologic complications include nonbacterial thrombotic endocarditis, a process associated with systemic diseases such as cancer and systemic lupus erythematosus. For many of these conditions, anticoagulation is the mainstay of treatment to prevent cerebral embolism, therefore it is the potential complications of anticoagulation that can explain other neurologic complications in patients with VHD. The prevention and management of these complications requires an understanding of their natural history in order to balance the risks posed by valvular disease itself against the risks and benefits associated with treatment.

Neurological complications of infective endocarditis: new breakthroughs in diagnosis and management

Neurological complications are frequent in infective endocarditis (IE) and increase morbidity and mortality rates. A wide spectrum of neurological disorders may be observed, including stroke or transient ischemic attack, cerebral hemorrhage, mycotic aneurysm, meningitis, cerebral abscess, or encephalopathy. Most complications occur early during the course of IE and are a hallmark of left-sided abnormalities of native or prosthetic valves. Ischemic lesions account for 40% to 50% of IE central nervous system complications. Systematic brain MRI may reveal cerebral abnormalities in up to 80% of patients, including cerebral embolism in 50%, mostly asymptomatic. Neurological complications affect both medical and surgical treatment and should be managed by an experimented multidisciplinary team including cardiologists, neurologists, intensive care specialists, and cardiac surgeons. Oral anticoagulant therapy given to patients presenting with cerebral ischemic lesions should be replaced by unfractionated heparin for at least 2 weeks, with a close monitoring of coagulation tests. Recently published data suggest that after an ischemic stroke, surgery indicated for heart failure, uncontrolled infection, abscess, or persisting high emboli risk should not be delayed, provided that the patient is not comatose or has no severe deficit. Surgery should be postponed for 2 to 3 weeks for patients with intracranial hemorrhage. Endovascular treatment is recommended for cerebral mycotic aneurysms, if there is no severe mass effect. Recent data suggests that neurological failure, which is associated with the location and extension of brain injury, is a major determinant for short-term prognosis.

Prediction of hemorrhagic transformation following embolic stroke in patients with prosthetic valve endocarditis

Background

Hemorrhagic transformation (HT) of stroke is a disastrous complication in patients with infective endocarditis (IE). In patients with mechanical heart valves complicated by IE, physicians struggle with the appropriateness of anticoagulation administration given the risk of thromboembolism and HT of stroke. In this study, we aimed to define predictive parameters of HT of stroke in patients with prosthetic valve endocarditis (PVE).

Methods

This study was a multicenter, retrospective design. We recruited from 7 institutions a total of 111 patients diagnosed with PVE during May, 2011 to April, 2012.

Results

Complication of stroke was seen in 26/111 patients (23%), and HT of stroke was seen in 11/111 patients (10%). Most patients with HT (9/11, 82%) had supratherapeutic prothrombin times. However, there were no significant differences in clinical and laboratory values between PVE patients without stroke and those patients who had a stroke and with or without concurrent HT. Furthermore, echocardiographic parameters also did not show significant between-group differences.

Conclusion

Even though this was a multicenter study, a limited number of patients was identified and may explain the negative results seen here. However, a large number of PVE patients with stroke also developed HT. Therefore, further studies to define predictive parameters of HT should be implemented in a larger population.

Current treatment of active infective endocarditis with brain complications

We describe the optimal timing of surgery in active infective endocarditis patients with brain complications. (1) Non-hemorrhagic infarction: elective surgery has been recommended in patients with non-hemorrhagic infarction. However, the timing is changing to an earlier phase. Recent studies have shown that silent brain embolism and small-size infarction (15-20 mm) without coma can be operated safely without delay. On the other hand, in patients with large non-hemorrhagic infarction with impaired consciousness, early surgery is not recommended. (2) Non-ruptured infectious intracranial aneurysm: treatment strategies for patients with infectious aneurysms without rupture remain controversial. However, the treatments are generally as follows. If the intracranial aneurysm without rupture decreases in size by administration of effective antibiotics, neurosurgery will not be required and cardiac surgery can be prioritized without delay. When the aneurysm without rupture enlarges and changes its morphology, neurosurgery or endovascular surgery should be prioritized to prevent its rupture. (3) Hemorrhagic stroke: this type is classified into primary intra-cerebral hemorrhage due to simple necrotic arteritis, hemorrhagic transformation of ischemic infarcts, and rupture of intracranial infectious aneurysms. Among these, primary intracerebral hemorrhage is the most frequently observed. In patients with the primary intracerebral hemorrhage, surgery must be postponed for at least 4 weeks to prevent exacerbation of bleeding. In patients with ruptured infectious aneurysm, neurosurgery or endovascular surgery is performed initially and cardiac surgery should be postponed at least 2-3 weeks.

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

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

Future challenges and treatment of Staphylococcus aureus bacteremia with emphasis on MRSA

Staphylococcus aureus bacteremia (SAB) is an urgent medical problem due to its growing frequency and its poor associated outcome. As healthcare delivery increasingly involves invasive procedures and implantable devices, the number of patients at risk for SAB and its complications is likely to grow. Compounding this problem is the growing prevalence of methicillin-resistant S. aureus (MRSA) and the dwindling efficacy of vancomycin, long the treatment of choice for this pathogen. Despite the recent availability of several new antibiotics for S. aureus, new strategies for treatment and prevention are required for this serious, common cause of human infection.

Purulent Meningitis as an Unusual Presentation of Staphylococcus aureus Endocarditis: A Case Report and Literature Review

On presentation of Staphylococcus aureus endocarditis, unusual manifestations may represent the main clinical features of the disease. Isolated bacterial meningitis as the first manifestation of endocarditis is considered to be an unusual neurological complication. Here, we describe a case S. aureus endocarditis presenting as isolated meningitis and mimicking meningococcal septicaemia. Because of the high mortality rate of the disease, the prompt recognition of this infectious syndrome is of crucial importance for the correct management of patients.

Management of neurological complications of infective endocarditis in ICU patients

Patients with infective endocarditis (IE) are generally referred to the intensive care unit (ICU) for one or more organ dysfunctions caused by complications of IE. Neurologic events are frequent causes of ICU admission in patients with IE. They can arise through various mechanisms consisting of stroke or transient ischemic attack, cerebral hemorrhage, mycotic aneurysm, meningitis, cerebral abscess, or encephalopathy. Most complications occur early during the course of IE and are a hallmark of left-sided abnormalities of native or prosthetic valves. Occlusion of cerebral arteries, with stroke or transient ischemic attack, accounts for 40% to 50% of the central nervous system complications of IE. CT scan is the most easily feasible neuroimaging in critically unstable patients. However, magnetic resonance imaging is more sensitive and when performed should follow a standardized protocol. In patients with ischemic stroke who are already receiving oral anticoagulant therapy, this treatment should be replaced by unfractionated heparin for at least 2 weeks with a close monitoring of coagulation tests. Mounting evidence shows that, for both complicated left-sided native valve endocarditis and Staphylococcus aureus prosthetic valve endocarditis, valve replacement combined with medical therapy is associated with a better outcome than medical treatment alone. In a recent series, approximately 50% of patients underwent valve replacement during the acute phase of IE before completion of antibiotic treatment. After a neurological event, most patients have at least one indication for cardiac surgery. Recent data from literature suggest that after a stroke, surgery indicated for heart failure, uncontrolled infection, abscess, or persisting high emboli risk should not be delayed, provided that the patient is not comatose or has no severe deficit. Neurologic complications of IE contribute to a severe prognosis in ICU patients. However, patients with only silent or transient stroke had a better prognosis than patients with symptomatic events. In addition, more than neurologic event per se, a better predictor of mortality is neurologic dysfunction, which is associated with location and extension of brain damage. Patients with severe neurological impairment and those with brain hemorrhage have the worse outcome.

[Neurological complications revealing infectious endocarditis: 2 case reports]

Neurological signs are reported in less than 20% of infectious endocarditis (IE) cases. The most frequent complications include cerebral infarction, intracerebral hemorrhage, meningitis, and mycotic aneurysm. We describe two patients, one with congenital heart disease and the other with normal heart, who presented neurological manifestations and fever leading to an IE diagnosis. Neurological complications may be the first symptom of infectious endocarditis and are a major factor associated with increased morbidity and mortality. Early diagnosis and early treatment will minimize cardiac and neurological morbidities.

beta-Neurexin is a ligand for the Staphylococcus aureus MSCRAMM SdrC

Gram-positive bacteria contain a family of surface proteins that are covalently anchored to the cell wall of the organism. These cell-wall anchored (CWA) proteins appear to play key roles in the interactions between pathogenic organisms and the host. A subfamily of the CWA has a common structural organization with multiple domains adopting characteristic IgG-like folds. The identified microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) belong to this subfamily, as does SdrC from S. aureus. However, an interactive host ligand for the putative MSCRAMM SdrC was not previously identified. We have screened a phage display peptide library and identified a peptide sequence found in beta-neurexin that binds SdrC. A synthetic peptide corresponding to the identified sequence as well as a recombinant form of the beta-neurexin 1 exodomain binds SdrC with high affinity and specificity. Furthermore, expression of SdrC on bacteria greatly enhances microbial adherence to cultured mammalian cells expressing beta-neurexin on their surface. Taken together, our experimental results demonstrate that beta-neurexin is a ligand for SdrC. This interaction involves a specific sequence located in the N-terminal region of the mammalian protein and the N(2)N(3) domain of the MSCRAMM. The fact that these two proteins interact when expressed on the appropriate cells demonstrates the functionality of the interaction. Possible implications of this interaction are discussed.

Heart failure in left-sided native valve infective endocarditis: characteristics, prognosis, and results of surgical treatment

AIMS

Although congestive heart failure (CHF) represents the most common cause of death in native valve infective endocarditis (IE), recent data on the outcome of IE complicated by CHF are lacking. We aimed to analyse the characteristics and prognosis of patients with left-sided native valve IE complicated by CHF and to evaluate the impact of early surgery on 1 year outcome.

METHODS AND RESULTS

Two hundred and fifty-nine consecutive patients with definite left-sided native valve IE according to the Duke criteria were included in this analysis. When compared with patients without CHF (n = 151), new heart murmur, high comorbidity index, aortic valve IE, and severe valve regurgitation were more frequently observed in CHF patients (n = 108, 41.6%). Mitral valve IE, embolic events and neurological events were less frequent in CHF patients. Congestive heart failure was independently predictive of in-hospital [OR 3.8 (1.7-9.0); P = 0.0013] and 1 year mortality [HR 1.8 (1.1-3.0); P = 0.007]. Early surgery was performed in 46% of CHF patients with a peri-operative mortality of 10%. In the CHF group, comorbidity index, Staphylococcus aureus IE, uncontrolled infection, and major neurological events were univariate predictors of 1 year mortality. Early surgery was independently associated with improved 1 year survival [HR 0.45 (0.22-0.93); P = 0.03].

CONCLUSION

Left-sided native valve IE complicated by CHF is more frequent in aortic IE and is associated with severe regurgitation. Congestive heart failure is an independent predictor of in-hospital and 1 year mortality. In CHF patients, early surgery is independently associated with reduced mortality and should be widely considered to improve outcome.

Brain magnetic resonance findings in infective endocarditis with neurological complications

PURPOSE

Diagnosing infective endocarditis and its complications can be difficult because of the nonspecific symptoms. We reviewed findings of intracranial abnormalities on magnetic resonance imaging (MRI) in 14 patients with neurological complications and herein discuss the overall intracranial MRI findings.

MATERIALS AND METHODS

We retrospectively reviewed patients with infective endocarditis from August 2004 to August 2006. Brain MRI, the causative bacteria, and abnormal neurological symptoms were reviewed for 14 patients with neurological complications.

RESULTS

Of the 14 patients, 13 showed intracranial abnormalities on MRI. Embolization was seen in 10 patients, hemorrhage in 3, abscess formation in 3, and encephalitis in 2. Hyperintense lesions with a central hypointense area on T2-weighted and/or T2*-weighted imaging (Bull's-eye-like lesion) were seen in four patients. A combination of these intracranial abnormalities was observed in 6 patients.

CONCLUSION

The MRI findings associated with infective endocarditis are wide-ranging: embolization, hemorrhage, meningitis, cerebritis, abscess, the bull's-eye-like lesion. Clinicians should consider the possibility of infective endocarditis in patients with unknown fever and neurological abnormality. Brain MRI should be promptly performed for those patients, and T2*-weighted imaging is recommended for an early diagnosis of infective endocarditis.

Radiologic manifestations of extra-cardiac complications of infective endocarditis

Infective endocarditis (IE) is a disease with high morbidity and a mortality rate of 9-30%, even with appropriate diagnosis and therapy. Septic emboli, caused by IE, can affect any organ or tissue in the body with an arterial supply and occur in 12-40% of IE cases. The most common extra-cardiac organ system involved in IE is the central nervous system. Other organs frequently involved are the lungs (especially in right-sided IE), spleen, kidneys, liver, and the musculoskeletal system. In addition, the arterial system itself is susceptible to the development of potentially fatal mycotic aneurysms. As extra-cardiac complications often antedate the clinical diagnosis of IE, it is important that the diagnosis is suggested when characteristic findings are encountered during imaging. In addition, imaging is often used to monitor the extent of complications in patients with a known diagnosis of IE.

Long-term outcome of infective endocarditis: a study on patients surviving over one year after the initial episode treated in a Finnish teaching hospital during 25 years

Background

Only a few previous studies have focused on the long-term prognosis of the patients with infective endocarditis (IE). Our purpose was to delineate factors potentially associated with the long-term outcome of IE, recurrences of IE and requirement for late valve surgery.

Methods

A total of 326 episodes of IE in 303 patients were treated during 1980–2004 in the Turku University Hospital. We evaluated the long-term outcome and requirement for late valve surgery for 243 of these episodes in 226 patients who survived longer than 1 year after the initial admission. Factors associated with recurrences were analysed both for the 1-year survivors and for all 303 patients.

Results

The mean (SD) follow-up time for the 1-year survivors was 11.5 (7.3) years (range 25 days to 25.5 years). The overall survival was 95%, 82%, 66%, 51% and 45% at 2, 5, 10, 15 and 20 years. In age and sex adjusted multivariate analyses, significant predictors for long-term overall mortality were heart failure within 3 months of admission (HR 1.97, 95% CI 1.27 to 3.06; p = 0.003) and collagen disease (HR 2.54, 95% CI 1.25 to 5.19; p = 0.010) or alcohol abuse (HR 2.39, 95% CI 1.30 to 4.40; p = 0.005) as underlying conditions, while early surgery was significantly associated with lower overall mortality rates (HR 0.31, 95% CI 0.17 to 0.58; p < 0.001). Heart failure was also significantly associated with the long-term cardiac mortality (p = 0.032). Of all 303 patients, 20 had more than 1 disease episode. Chronic dialysis (p = 0.002), intravenous drug use (p = 0.002) and diabetes (p = 0.015) were significant risk factors for recurrent episodes of IE, but when analysed separately for the 1-year survivors, only chronic dialysis remained significant (p = 0.017). Recurrences and late valve surgery did not confer a poor prognosis.

Conclusion

Heart failure during the index episode of IE was the complication, which significantly predicted a poor long-term outcome. Patients who underwent surgery during the initial hospitalisation for IE faired significantly better than those who did not.

The relationship between the initiation of antimicrobial therapy and the incidence of stroke in infective endocarditis: an analysis from the ICE Prospective Cohort Study (ICE-PCS)

BACKGROUND

Embolic events to the central nervous system are a major cause of morbidity and mortality in patients with infective endocarditis (IE). The appropriate role of valvular surgery in reducing such embolic events is unclear. The purpose of this study was to determine the relationship between the initiation of antimicrobial therapy and the temporal incidence of stroke in patients with IE and to determine if this time course differs from that shown for embolic events in previous studies.

METHODS

Prospective incidence cohort study involving 61 tertiary referral centers in 28 countries. Case report forms were analyzed from 1437 consecutive patients with left-sided endocarditis admitted directly to participating centers.

RESULTS

The crude incidence of stroke in patients receiving appropriate antimicrobial therapy was 4.82/1000 patient days in the first week of therapy and fell to 1.71/1000 patient days in the second week. This rate continued to decline with further therapy. Stroke rates fell similarly regardless of the valve or organism involved. After 1 week of antimicrobial therapy, only 3.1% of the cohort experienced a stroke.

CONCLUSIONS

The risk of stroke in IE falls dramatically after the initiation of effective antimicrobial therapy. The falling risk of stroke in patients with IE as a whole precludes stroke prevention as the sole indication for valvular surgery after 1 week of therapy.

Cerebral hemorrhage in infective endocarditis caused by Actinobacillus actinomycetemcomitans

Cerebral hemorrhage occurs rarely in endocarditis caused by Actinobacillus actinomycetemcomitans. A 51-year-old man with a prosthetic mitral valve, who had been prophylactically treated (7 years) with warfarin, presented with intermittent fever. On admission, a Levine grade II/VI systolic cardiac murmur was detected. A transthoracic echocardiogram was negative for valve vegetation. Cefepime (1 g every 8 hours) was administered intravenously. On day 4, culturing of Gram-negative bacilli from blood and a transesophageal echocardiogram revealed a small oscillating filament attached to lateral mitral prosthetic ring on the atrial side. Ceftriaxone (2 g once daily) was started. Gait instability and left-side weakness developed abruptly 2 weeks later; brain magnetic resonance imaging revealed a hematoma over the right parietal-occipital lobe. Ceftriaxone was adjusted to 2 g every 12 hours. Actinobacillus actinomycetemcomitans was identified 3 weeks later. Recovery was achieved, with significant interval improvement and resolution of the cerebral lesions evident on CT.

[Non-aneurysmal subarachnoid haemorrhage]

A subarachnoid haemorrhage (SAH) is frequent after a severe head injury. Traumatic-SAH is associated with a bad outcome and may induce cerebral vasospasm. There is no agreement on the treatment based on the amount of traumatic-SAH. Non-aneurysmal SAH accounts for 15% of all causes of non-traumatic SAH. There is a risk of cerebral vasospasm, although less frequent than after aneurysmal rupture. The improvement in imaging techniques has decreased the frequency of idiopathic SAH.

Fatal brain abscess due to community-associated methicillin-resistant Staphylococcus aureus strain USA300

We report a fatal case of brain abscess caused by infection due to a community-associated methicillin-resistant Staphylococcus aureus strain (USA300) in a 37-year-old incarcerated woman with a history of furunculosis and injection drug use. Community-onset pyogenic brain abscess should be added to the growing list of life-threatening invasive infections caused by epidemic community-acquired methicillin-resistant S. aureus.