Early-onset prosthetic valve endocarditis definition revisited: Prospective study and literature review

Advancements and Challenges in the Management of Prosthetic Valve Endocarditis: A Review

Prosthetic valve endocarditis (PVE) is the medical term used to describe a focus of infection involving a valvular substitute within the heart. It is a significant concern in the field of cardiology, and the epidemiology of PVE has seen notable developments over the last five decades. The disease currently affects an older demographic and is becoming increasingly prevalent in patients with transcatheter-implanted valves. It is imperative that we urgently address the significant challenges posed by PVE. It is a disease that has a wide range of potential aetiologies, clinical presentations, and courses. In developed countries, Staphylococcus aureus is now the predominant causative organism, resulting in an aggressive form of disease that frequently afflicts vulnerable or elderly populations. However, it is clear that Enterococcus species present a significant challenge in the context of PVE following TAVR procedures, given their elevated prevalence. The 2023 Duke/International Society for Cardiovascular Infectious Diseases infective endocarditis diagnostic criteria now include significant developments in microbiological and image-based techniques for diagnostic purposes, specifically the incorporation of fluorine-18 fluorodeoxyglucose positron emission tomography and computed tomography. These developments unequivocally enhance the diagnostic sensitivity for PVE, while maintaining the specificity. They do so in accordance with the results of studies conducted specifically for the purpose of validation. The lack of rigorous scientific studies and a shortage of funding and resources for research have led to a significant gap in our understanding. Randomized controlled trials could provide invaluable insight and guidance for clinical practice, but they are missing, which represents a major gap. It is clear that there is an urgent need for more research. PVE is a life-threatening condition that must be handled by a multidisciplinary endocarditis team at a cardiac centre in order to improve outcomes. The emergence of innovative surgical techniques has empowered clinicians to steer more patients away from surgical procedures, despite the presence of clear indications for them. A select group of patients can now complete parenteral or oral antimicrobial treatment at home. Additionally, antibiotic prophylaxis is the best option for individuals with prosthetic valves who are going to have invasive dental procedures. These individuals should be given antibiotics beforehand.

The Clinical Challenge of Prosthetic Valve Endocarditis: JACC Focus Seminar 3/4

During the past 6 decades, there have been numerous changes in prosthetic valve endocarditis (PVE), currently affecting an older population and increasing in incidence in patients with transcatheter-implanted valves. Significant microbiologic (molecular biology) and imaging diagnostic (fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography) advances have been incorporated into the 2023 Duke-International Society for Cardiovascular Infectious Diseases infective endocarditis diagnostic criteria, thus increasing the diagnostic sensitivity for PVE without sacrificing specificity in validation studies. PVE is a life-threatening disease requiring management by multidisciplinary endocarditis teams in cardiac centers to improve outcomes. Novel surgical options are now available, and an increasing set of patients may avoid surgical intervention despite indication. Selected patients may complete parenteral or oral antimicrobial treatment at home. Finally, patients with prosthetic valves implanted surgically or by the transcatheter approach are candidates for antibiotic prophylaxis before invasive dental procedures.

Epidemiological differences, clinical aspects, and short-term prognosis of patients with healthcare-associated and community-acquired infective endocarditis

Background

The prevalence of healthcare-associated infective endocarditis in Brazil is poorly known.

Aim

To analyze the epidemiological, clinical and microbiological characteristics, and the prognosis of healthcare-associated infective endocarditis (HAIE) compared with community-acquired infective endocarditis (CIE) and identify the associated factors with hospital mortality.

Method

A historical cohort study was carried out, with a data collection period from January 2009 to December 2019 at the Federal University of São Paulo. Data were collected from medical records of patients with infective endocarditis (IE) hospitalized during the study period. Patients were classified into three groups: CIE, non-nosocomial HAIE (NN-HAIE) and nosocomial HAIE (NHAIE).

Results

A total of 204 patients with IE were included; of these, 127 (62.3%) were cases of HAIE, of which 83 (40.7%) were NN-HAIE and 44 (21.6%) were NHAIE. Staphylococcus spp. Were the main causative agents, especially in HAIE groups (P<0.001). Streptococcus spp. were more prevalent in the CIE group (P<0.001). In-hospital mortality was 44.6%, with no differences between groups. Independent risk factors for in-hospital mortality were age ≥ 60 years (odds ratio (OR): 6.742), septic shock (OR 5.264), stroke (OR 3.576), heart failure (OR 7.296), and Intensive Care Unit admission (OR 7.768).

Conclusion

HAIE accounted for most cases in this cohort, with a higher prevalence of non-nosocomial infections. Staphylococcus spp. were the main causative agents. Hospital mortality was high, 44.6%, with no difference between groups.

The Assessment of Antimicrobial Resistance in Gram-Negative and Gram-Positive Infective Endocarditis: A Multicentric Retrospective Analysis

Background and Objectives: Multidrug-resistant microorganisms have made treating bacterial infections challenging. Resistance to antibiotics is expected to overcome efforts to produce new, effective antibacterial medication that is lifesaving in many situations. Infective endocarditis (IE) is a life-threatening infection that affects 5–15 per 100,000 patients annually and requires rapid antibiotic therapy to prevent morbidity and mortality. Materials and Methods: The present research assessed IE cases over five years, from a multicentric database, with the main objective of determining the degree of antibiotic resistance in these patients, stratified by Gram-positive and Gram-negative bacteria. Results: Bad oral hygiene was present in 58.6% of patients from the Gram-negative group (vs. 38.7% in the Gram-positive group). Non-valvular heart disease was identified in approximately 40% of all patients, and valvopathies in approximately 20%. It was observed that 37.9% of Gram-negative IE bacteria were resistant to three or more antibiotics, whereas 20.7% were susceptible. Among Gram-positive infections, S. aureus was the most commonly involved pathogen, with a multidrug-resistant pattern in 11.2% of patients, while Acinetobacter baumannii had the highest resistance pattern of all Gram-negative pathogens, with 27.4% of all samples resistant to three or more antibiotics. Patients with Gram-negative IE were 4.2 times more likely to die. The mortality risk was 4 times higher when bacteria resistant to two or more antibiotics was involved and 5.7 times higher with resistance patterns to three or more antibiotics than the reference group with no antibiotic resistance. Peripheral catheters were the most common cause of multi-resistant IE, followed by heart surgery, dental procedures, and ENT interventions. Conclusions: Even though Gram-positive infections were the most frequent (83.0% of all cases), Gram-negative IE infections are substantially more deadly than Gram-positive IE infections. However, it was also observed that patients with Gram-negative infections were more likely to have underlying comorbidities, be institutionalized, and be underweight. Although the Gram-negative infections were more severe, their resistance patterns were similar to Gram-positive bacteria. As resistance patterns increase, more efforts should be made to prevent a healthcare catastrophe. At the same time, careful prophylaxis should be considered in patients at risk, including those with central catheters, undergoing dental procedures, and with poor oral hygiene.

Readmission with infective endocarditis within 90 days following transcatheter aortic valve implantation

INTRODUCTION

Transcatheter aortic valve implantation (TAVI) continues to be the most common modality of treating aortic stenosis in the United States. While infective endocarditis (IE) and its outcomes have been well documented after surgical aortic valve replacement, the incidence and outcomes of early IE after TAVI have not been well described.

METHODS

All patients who underwent TAVI from 2012 through 2018 were identified using the National Readmission Database. Among them, patients who underwent TAVI at the index admission and readmitted within 90 days were included. Patients who died or had IE during the index admission were excluded. Clinical outcomes were compared between patients readmitted with IE (IE group) and those without (non-IE group).

RESULTS

A total of 168,283 patients were readmitted to a hospital within 90 days after TAVI. The median age of the IE group and non-IE group were 81 and 82 years old, respectively (p = 0.21). Of those, 525 (0.3%) were readmitted with IE. The median time from TAVI to readmission was 20 days. During readmissions, 11.6% of the IE group died while only 3.15% of the non-IE group experienced death (p < 0.001). The most common causative organism of IE was enterococcus (22.1%). Multivariable analysis revealed that congestive heart failure, cerebrovascular disease, dialysis, concomitant valve disease, Medicaid, and discharge to a facility were independently associated with readmission with IE within 90 days.

CONCLUSION

The incidence of readmission with IE is low after TAVI. However, the mortality was markedly high during readmissions. Surgical intervention was rarely performed for IE during the first admission. Enterococcus was the most common organism observed in IE after TAVI.

DISCLOSURE

IS receives institutional research support from Abbott, Atricure, cryolife, and Medtronic. None related to this manuscript.

CLINICAL TRIAL REGISTRATION

Not applicable.

Four decades of experience of prosthetic valve endocarditis reflect a high variety of diverse pathogens

Prosthetic valve endocarditis (PVE) remains a serious condition with a high mortality rate. Precise identification of the PVE-associated pathogen/s and their virulence is essential for successful therapy, and patient survival. The commonly described PVE-associated pathogens are staphylococci, streptococci and enterococci, with Staphylococcus aureus being the most frequently diagnosed species. Furthermore, multi-drug resistance pathogens are increasing in prevalence, and continue to pose new challenges mandating a personalized approach. Blood cultures in combination with echocardiography are the most common methods to diagnose PVE, often being the only indication, it exists. In many cases, the diagnostic strategy recommended in the clinical guidelines does not identify the precise microbial agent and to frequently, false negative blood cultures are reported. Despite the fact that blood culture findings are not always a good indicator of the actual PVE agent in the valve tissue, only a minority of re-operated prostheses are subjected to microbiological diagnostic evaluation. In this review, we focus on the diversity and the complete spectrum of PVE-associated bacterial, fungal and viral pathogens in blood, and prosthetic heart valve, their possible virulence potential, and their challenges in making a microbial diagnosis. We are curious to understand if the unacceptable high mortality of PVE is associated with the high number of negative microbial findings in connection with a possible PVE. Herein, we discuss the possibilities and limits of the diagnostic methods conventionally used and make recommendations for enhanced pathogen identification. We also show possible virulence factors of the most common PVE-associated pathogens and their clinical effects. Based on blood culture, molecular biological diagnostics, and specific valve examination, better derivations for the antibiotic therapy as well as possible preventive intervention can be established in the future.

Very early infective endocarditis after transcatheter aortic valve replacement

BACKGROUND

Scarce data exist about early infective endocarditis (IE) after trans-catheter aortic valve replacement (TAVR).

OBJECTIVE

The objective was to evaluate the characteristics, management, and outcomes of very early (VE) IE (≤ 30 days) after TAVR.

METHODS

This multicenter study included a total of 579 patients from the Infectious Endocarditis after TAVR International Registry who had the diagnosis of definite IE following TAVR.

RESULTS

Ninety-one patients (15.7%) had VE-IE. Factors associated with VE-IE (vs. delayed IE (D-IE)) were female gender (p = 0.047), the use of self-expanding valves (p < 0.001), stroke (p = 0.019), and sepsis (p < 0.001) after TAVR. Staphylococcus aureus was the main pathogen among VE-IE patients (35.2% vs. 22.7% in the D-IE group, p = 0.012), and 31.2% of Staphylococcus aureus infections in the VE-IE group were methicillin-resistant (vs. 14.3% in the D-IE group, p = 0.001). The second-most common germ was enterococci (34.1% vs. 24.4% in D-IE cases, p = 0.05). VE-IE was associated with very high in-hospital (44%) and 1-year (54%) mortality rates. Acute renal failure following TAVR (p = 0.001) and the presence of a non-enterococci pathogen (p < 0.001) were associated with an increased risk of death.

CONCLUSION

A significant proportion of IE episodes following TAVR occurs within a few weeks following the procedure and are associated with dismal outcomes. Some baseline and TAVR procedural factors were associated with VE-IE, and Staphylococcus aureus and enterococci were the main causative pathogens. These results may help to select the more appropriate antibiotic prophylaxis in TAVR procedures and guide the initial antibiotic therapy in those cases with a clinical suspicion of IE. Very early infective endocarditis after trans-catheter aortic valve replacement. VE-IE indicates very early infective endocarditis (≤30 days post TAVR). D-IE indicates delayed infective endocarditis.

Recurrent Staphylococcus capitis Prosthetic Valve Endocarditis Presenting With ST-Segment Elevation Myocardial Infarction: A Case Report

We report a case of ST-elevation myocardial infarction (STEMI) due to septic emboli secondary to Staphylococcus capitis endocarditis in a 32-year-old male patient with a past medical history of infectious endocarditis requiring mechanical aortic, mitral and tricuspid valve replacement presented with sharp chest pain and shortness of breath. Electrocardiogram demonstrated an acute inferior STEMI.

Coronary angiography revealed occlusion of the terminal left anterior descending (LAD) artery associated with a large apical wrap-around segment exhibiting TIMI 0 flow. Primary angioplasty was not performed given the distal location of the embolus. Clinical suspicion for septic or thrombotic coronary artery embolism was high given the patient’s history of mechanical valve prosthesis and in the setting of sub-therapeutic INR. Transesophageal echocardiography revealed a new mobile echodensity on the mitral prosthesis consistent with vegetation. S. capitis was isolated from blood cultures, confirming the diagnosis of endocarditis.

S. capitis is a rare cause of prosthetic valve endocarditis and should remain in the differential of septic coronary artery embolism among patients with features of infectious endocarditis.

Clinical Profile of Prosthetic Valve Endocarditis due to Candida parapsilosis: An 11-year Retrospective Observational Study from a Quaternary Cardiac Referral Institute in India

Background: Recent changes in the diagnostic criteria and the introduction of newer technologies like prosthetic valve replacement require the need to identify the changing epidemiology of prosthetic valve endocarditis (PVE).

Materials and methods: This is a retrospective, cross-sectional, observational study. Patients diagnosed with Candida parapsilosis definite and possible PVE as per modified Duke’s criteria for a period of 11 years from January 2010 to December 2020 were included for the analysis.

Results: Twelve of the 47 PVE cases (25.5%) were caused by C. parapsilosis. The median age of the patients was 52 years. Males were predominantly affected (58%). Based on the modified Duke’s criteria, eight (67%) were definite infective endocarditis (IE) cases. The single valve was affected in 11 cases (92%) with the mitral valve being the commonest (n = 8, 67%). The type of valve commonly involved was mechanical [n = 10, 83%]. The mean size of the vegetation was 13.15 mm. Most cases (n = 7, 58%) were late-onset PVE. The mean C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and procalcitonin (PCT) levels for C. parapsilosis PVE were 70.2 mg/L, 51.08 mm/hour, and 0.3 ng/mL, respectively. The rates of complications and in-hospital mortality were 75% each. The most common observed complication was embolic events (n = 8, 67%). Statistical significance (p ≤ 0.05) was observed for mean vegetation size, overall complications, embolic events, and mortality for C. parapsilosis PVE when compared with bacterial PVE.

Conclusion:C. parapsilosis was the commonest etiological agent causing PVE. Predominant mitral valve involvement, higher rates of late-onset presentation, complications, and mortality were key differential characteristics observed.

Highlights: The manuscript throws light on the changing epidemiology, clinical, and microbiological profile of PVE due to Candida sp., which are scarcely studied and reported in low- and middle-income countries like India.

How to cite this article: Ponnambath DK, Gopalakrishnan A, Pillai VV, Kaviyil JE, Raja K. Clinical Profile of Prosthetic Valve Endocarditis due to Candida parapsilosis: An 11-year Retrospective Observational Study from a Quaternary Cardiac Referral Institute in India. Indian J Crit Care Med 2021;25(8):860–865.

Assessment of patients with a suspected cardioembolic ischemic stroke. A national consensus statement

OBJECTIVES

Several cardiovascular, structural, and functional abnormalities have been considered as potential causes of cardioembolic ischemic strokes. Beyond atrial fibrillation, other sources of embolism clearly exist and may warrant urgent action, but they are only a minor part of the many stroke mechanisms and strokes that seem to be of embolic origin remain without a determined source. The associations between stroke and findings like atrial fibrillation, valve calcification, or heart failure are confounded by co-existing risk factors for atherosclerosis and vascular disease. In addition, a patent foramen ovale which is a common abnormality in the general population is mostly an innocent bystander in patients with ischemic stroke. For these reasons, experts from the national Danish societies of cardiology, neurology, stroke, and neuroradiology sought to develop a consensus document to provide national recommendations on how to manage patients with a suspected cardioembolic stroke. Design: Comprehensive literature search and analyses were done by a panel of experts and presented at a consensus meeting. Evidence supporting each subject was vetted by open discussion and statements were adjusted thereafter. Results: The most common sources of embolic stroke were identified, and the statement provides advise on how neurologist can identify cases that need referral, and what is expected by the cardiologist. Conclusions: A primary neurological and neuroradiological assessment is mandatory and neurovascular specialists should manage the initiation of secondary prophylactic treatment. If a cardioembolic stroke is suspected, a dedicated cardiologist experienced in the management of cardioembolism should provide a tailored clinical and echocardiographic assessment.

A fatal case of early prosthetic valve endocarditis caused by multidrug-resistant (MDR) - Sphingomonas paucimobilis

Sphyngomonas paucimobilis (S. paucimobilis) is a low-pathogenicity, gram-negative bacilli (GNB) that are previously known as an opportunist microorganism. Recent studies have shown that S. paucimobilis is an emerging pathogen causing various infections. Multidrug-resistant GNB has emerged as a major clinical and therapeutic dilemma in various hospital-associated infections. Although rare, S. paucimobilis could be associated with infective endocarditis (IE). Prosthetic valve endocarditis (PVE) is the most severe type of IE, which has high mortality rates despite diagnostic and treatment advances. We report a fatal case of early PVE associated with multidrug-resistant (MDR) - S. paucimobilis complicated with perivalvular abscess, complete heart block, valve detachment, and septic arthritis.

Outcomes of patients with acute prosthetic aortic valve endocarditis

BACKGROUND

Prosthetic valve endocarditis is burdened by high mortality and morbidity. We reviewed our experience in the management of patients with acute prosthetic aortic valve infection and studied the implications and outcomes associated with surgical treatment and medical therapy.

METHODS

Data of 118 consecutive patients admitted during the period 2008-2018 with definite acute prosthetic aortic valve endocarditis, and presenting a surgical indication, were retrieved from the hospital database. Univariate and multivariate analysis were undertaken to study the association of preoperative characteristics with hospital mortality and the probability of undergoing a reoperation. Survival was assessed with Kaplan-Meier analysis.

RESULTS

In the overall population, prosthesis dehiscence was independently associated with the possibility of undergoing surgical reoperation, while presentation with embolic stroke was associated with medical treatment. Hospital mortality was 24%, medical treatment was found to be independently associated with early death. One hundred (85%) patients underwent redo procedures; aortic valve replacement was performed in 53 and full root replacement in 47. Postoperative hospital mortality was 17%. Survival at 1-, 5-, and 8-years was 78%, 74%, and 66%, respectively. Freedom from reoperation and recurrent endocarditis was 95% at 8-year follow-up.Hospital mortality in patients who did not receive a redo operation was 61% with a survival rate of 17% at 1-year follow-up.

CONCLUSIONS

Surgical mortality after reoperation for prosthetic aortic valve endocarditis is still high but mid-term outcomes are satisfactory. Failure to undertake surgery when indicated is an independent risk factor for early death.

Current and emerging pharmacotherapy for the treatment of infections following open-heart surgery

INTRODUCTION

Patients undergoing open-heart surgery may suffer from postoperative complications, including severe infections. Antimicrobials to treat infectious complications in this population should be selected thoughtfully, taking into account three different and fundamental issues: (i) the site of infection; (ii) the suspected or proven causative agent and its susceptibility pattern; and (iii) the risk of suboptimal pharmacokinetic characteristics and potential toxicity of the chosen drug/s.

AREAS COVERED

The present narrative review summarizes the current and future antimicrobial options for the treatment of infections developing after open-heart surgery.

EXPERT OPINION

The pharmacological treatment of infections developing in cardiac surgery patients poses peculiar challenges, including the need for an active empirical therapy for severe events such as bloodstream infections, deep sternal wound infections, or early-onset postoperative prosthetic endocarditis. In addition, the risk for multidrug-resistant pathogens should also be taken into account in endemic areas. A multidisciplinary evaluation on a patient-by-patient basis, deeply involving infectious diseases specialists and cardiothoracic surgeons, remains essential for appropriately balancing both short-term and long-term risks and benefits of any possible surgical reintervention in combination with adequate pharmacotherapy.

Complementary role of cardiac computed tomography angiography in the diagnosis of prosthetic aortic valve endocarditis and septic coronary embolism - a case report

A 73-year old man presented with a posterolateral ST-elevated myocardial infarction 9 months after biological aortic valve replacement for aortic valve stenosis. Invasive coronary angiography showed a filling defect across the left main coronary artery bifurcation extending into the left anterior descending artery and the ramus circumflex. Transthoracic echocardiography revealed a thickened prosthesis leaflet with signs of slight stenosis. Cardiac computed tomography angiography showed a mass on the left coronary cusp of the valve prosthesis, suggestive for vegetation or thrombus. The scan also revealed central luminal filling defects, indicative for thrombus or septic emboli. Blood cultures proved positive for Propionibacterium acnes, therefore the patient was treated for prosthetic valve endocarditis. Computed tomography angiography offers high diagnostic accuracy for detecting infective endocarditis and renders complementary information about valvular anatomy, coronary artery disease and the extension of infections.

Complete Genome Sequences of the Potential Zoonotic Pathogens Staphylococcus felis and Staphylococcus kloosii

Coagulase-negative staphylococci (CoNS) are opportunistic pathogens frequently encountered in nosocomial infections. Animal-associated CoNS pose a zoonotic risk and constitute a potential reservoir for virulence and antimicrobial resistance genes. To improve our knowledge of animal-associated CoNS, we sequenced the complete genomes of Staphylococcus felis (ATCC 49168) and Staphylococcus kloosii (ATCC 43959).