Neurologic Complications of Infective Endocarditis: A Joint Model for a Septic Thromboembolism and Inflammatory Small Vessel Disease

Prevalence of neurological complications in infective endocarditis

INTRODUCTION

Neurological complications are the most frequent type of extracardiac complications of infective endocarditis (IE), and can be the initial manifestation. The objectives of this study were to determine the prevalence of neurological complications in patients with IE and to evaluate whether initial presentation with neurological symptoms causes a diagnostic delay.

MATERIAL AND METHODS

We conducted a retrospective observational study of patients with IE admitted to a tertiary hospital between 2003 and 2020.

RESULTS

The study included 222 patients with IE (67% men; mean [SD] age, 66.4 [14.2] years). Neurological complications occurred in 21.2% of patients, with ischaemic stroke (74.5%) and intracerebral haemorrhage (23.4%) being the most frequent. No differences in diagnostic delay were found between the group of patients in whom the disease manifested with neurological complications and the rest of the patients (4.4 vs 4.5; P = .76).

CONCLUSIONS

A total of 21.2% of patients with IE presented neurological complications, with ischaemic stroke being the most frequent. Neurological symptoms as the initial manifestation of IE did not lead to a delay in diagnosis.

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.

Leclercia adecarboxylata infective endocarditis in a man with mitral stenosis: A case report and review of the literature

BACKGROUND

Infective endocarditis (IE) is a rare disease with a high mortality rate. Leclercia adecarboxylata (L. adecarboxylata) is a movable Gram-negative bacillus of enterobacteriaceae, and it can rarely be a pathogen which often affects immunodeficient patients. There are about three cases of immunocompetent patients with monomicrobial L. adecarboxylata infection. There are only three reported cases of IE caused by L. adecarboxylata in the world. The mitral valve is often affected in IE, and the prognosis for IE with mitral valve lesions is often poor.

CASE SUMMARY

A 51-year-old man was found to have moderate to severe mitral stenosis on echocardiography. He came to our Cardiothoracic Surgery Department for surgical management. A diastolic murmur was heard on auscultation of the heart in the mitral region. On the second day of hospitalisation, he presented with slurred speech, reduced muscle strength in the left limb, and acute cerebral infarction on cranial computed tomography. Surgical treatment was decided to postpone. On the ninth day of admission, the patient developed a sudden high fever and shock and was transferred to the Cardiac Intensive Care Unit, where echocardiogram revealed an anterior mitral valve leaflet vegetation. After empirical anti-infective treatment with vancomycin (1g q12h), an emergency valve replacement was performed. Bacterial culture identified L. adecarboxylata. Anti-infective treatment with piperacillin-tazobactam (4.5g q8h) was added for 4 wk. Follow-up echocardiography showed normal bioprosthetic valve function after mitral valve replacement.

CONCLUSION

We report the first case of L. adecarboxylata IE in China, and clinicians should pay attention to this pathogen.

Microglia activated by microbial neuraminidase contributes to ependymal cell death

The administration of microbial neuraminidase into the brain ventricular cavities of rodents represents a model of acute aseptic neuroinflammation. Ependymal cell death and hydrocephalus are unique features of this model. Here we demonstrate that activated microglia participates in ependymal cell death. Co-cultures of pure microglia with ependymal cells (both obtained from rats) were performed, and neuraminidase or lipopolysaccharide were used to activate microglia. Ependymal cell viability was unaltered in the absence of microglia or inflammatory stimulus (neuraminidase or lipopolysaccharide). The constitutive expression by ependymal cells of receptors for cytokines released by activated microglia, such as IL-1β, was demonstrated by qPCR. Besides, neuraminidase induced the overexpression of both receptors in ventricular wall explants. Finally, ependymal viability was evaluated in the presence of functional blocking antibodies against IL-1β and TNFα. In the co-culture setting, an IL-1β blocking antibody prevented ependymal cell death, while TNFα antibody did not. These results suggest that activated microglia are involved in the ependymal damage that occurs after the administration of neuraminidase in the ventricular cavities, and points to IL-1β as possible mediator of such effect. The relevance of these results lies in the fact that brain infections caused by neuraminidase-bearing pathogens are frequently associated to ependymal death and hydrocephalus.

A comparison of different antibiotic regimens for the treatment of infective endocarditis

BACKGROUND

Infective endocarditis is a microbial infection of the endocardial surface of the heart. Antibiotics are the cornerstone of treatment, but due to the differences in presentation, populations affected, and the wide variety of micro-organisms that can be responsible, their use is not standardised. This is an update of a review previously published in 2016.

OBJECTIVES

To assess the existing evidence about the clinical benefits and harms of different antibiotics regimens used to treat people with infective endocarditis.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase Classic and Embase, LILACS, CINAHL, and the Conference Proceedings Citation Index - Science on 6 January 2020. We also searched three trials registers and handsearched the reference lists of included papers. We applied no language restrictions.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) assessing the effects of antibiotic regimens for treating definitive infective endocarditis diagnosed according to modified Duke's criteria. We considered all-cause mortality, cure rates, and adverse events as the primary outcomes. We excluded people with possible infective endocarditis and pregnant women.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, 'Risk of bias' assessment, and data extraction in duplicate. We constructed 'Summary of findings' tables and used GRADE methodology to assess the quality of the evidence. We described the included studies narratively.

MAIN RESULTS

Six small RCTs involving 1143 allocated/632 analysed participants met the inclusion criteria of this first update. The included trials had a high risk of bias. Three trials were sponsored by drug companies. Due to heterogeneity in outcome definitions and different antibiotics used data could not be pooled. The included trials compared miscellaneous antibiotic schedules having uncertain effects for all of the prespecified outcomes in this review. Evidence was either low or very low quality due to high risk of bias and very low number of events and small sample size. The results for all-cause mortality were as follows: one trial compared quinolone (levofloxacin) plus standard treatment (antistaphylococcal penicillin (cloxacillin or dicloxacillin), aminoglycoside (tobramycin or netilmicin), and rifampicin) versus standard treatment alone and reported 8/31 (26%) with levofloxacin plus standard treatment versus 9/39 (23%) with standard treatment alone; risk ratio (RR) 1.12, 95% confidence interval (CI) 0.49 to 2.56. One trial compared fosfomycin plus imipenem 3/4 (75%) versus vancomycin 0/4 (0%) (RR 7.00, 95% CI 0.47 to 103.27), and one trial compared partial oral treatment 7/201 (3.5%) versus conventional intravenous treatment 13/199 (6.53%) (RR 0.53, 95% CI 0.22 to 1.31). The results for rates of cure with or without surgery were as follows: one trial compared daptomycin versus low-dose gentamicin plus an antistaphylococcal penicillin (nafcillin, oxacillin, or flucloxacillin) or vancomycin and reported 9/28 (32.1%) with daptomycin versus 9/25 (36%) with low-dose gentamicin plus antistaphylococcal penicillin or vancomycin; RR 0.89, 95% CI 0.42 to 1.89. One trial compared glycopeptide (vancomycin or teicoplanin) plus gentamicin with cloxacillin plus gentamicin (13/23 (56%) versus 11/11 (100%); RR 0.59, 95% CI 0.40 to 0.85). One trial compared ceftriaxone plus gentamicin versus ceftriaxone alone (15/34 (44%) versus 21/33 (64%); RR 0.69, 95% CI 0.44 to 1.10), and one trial compared fosfomycin plus imipenem versus vancomycin (1/4 (25%) versus 2/4 (50%); RR 0.50, 95% CI 0.07 to 3.55). The included trials reported adverse events, the need for cardiac surgical interventions, and rates of uncontrolled infection, congestive heart failure, relapse of endocarditis, and septic emboli, and found no conclusive differences between groups (very low-quality evidence). No trials assessed quality of life.

AUTHORS' CONCLUSIONS

This first update confirms the findings of the original version of the review. Limited and low to very low-quality evidence suggests that the comparative effects of different antibiotic regimens in terms of cure rates or other relevant clinical outcomes are uncertain. The conclusions of this updated Cochrane Review were based on few RCTs with a high risk of bias. Accordingly, current evidence does not support or reject any regimen of antibiotic therapy for the treatment of infective endocarditis.