The diagnostic ability of echocardiography for infective endocarditis and its associated complications

Valvulitis: a new echocardiographic criterion for the diagnosis of bioprosthetic aortic valve infective endocarditis

INTRODUCTION AND OBJECTIVES

Diffuse homogeneous hypoechoic leaflet thickening, with a wavy leaflet motion documented by transesophageal echocardiography (TEE), has been described in some cases of prosthetic valve endocarditis (PVE) involving aortic bioprosthesis (AoBio-PVE). This echocardiographic finding has been termed valvulitis. We aimed to estimate the prevalence of valvulitis, precisely describe its echocardiographic characteristics, and determine their clinical significance in patients with AoBio-PVE.

METHODS

From 2011 to 2022, 388 consecutive patients with infective endocarditis (IE) admitted to a tertiary care hospital were prospectively included in a multipurpose database. For this study, all patients with AoBio-PVE (n=86) were selected, and their TEE images were thoroughly evaluated by 3 independent cardiologists to identify all cases of valvulitis.

RESULTS

The prevalence of isolated valvulitis was 12.8%, and 20.9% of patients had valvulitis accompanied by other classic echocardiographic findings of IE. A total of 9 out of 11 patients with isolated valvulitis had significant valve stenosis, whereas significant aortic valve regurgitation was documented in only 1 patient. Compared with the other patients with AoBio-PVE, cardiac surgery was less frequently performed in patients with isolated valvulitis (27.3% vs 62.7%, P=.017). In 4 out of 5 patients with valve stenosis who did not undergo surgery but underwent follow-up TEE, valve gradients significantly improved with appropriate antibiotic therapy.

CONCLUSIONS

Valvulitis can be the only echocardiographic finding in infected AoBio and needs to be identified by imaging specialists for early diagnosis. However, this entity is a diagnostic challenge and additional imaging techniques might be required to confirm the diagnosis. Larger series are needed.

Embolic phenomena to the limbs are an independent predictor of in-hospital mortality from infective endocarditis

BACKGROUND

Infective endocarditis (IE) is a morbid condition with high mortality. We investigated predictors of in-hospital mortality and embolic phenomena in a contemporary Australasian cohort.

METHODS

We identified all patients with IE admitted between January 2017 and 30th April 2020 (40 months). Patient characteristics, risk factors and clinical outcomes were retrospectively collected and analysed.

RESULTS

One hundred and seventy-two consecutive patients (mean age: 56.8 ± 17.9 years, male: 63%, 114/172) were included. Causative organisms were Staphylococcus aureus (44%, 75/172), Enterococcus faecalis (15%, 26/172), Streptococcus mitis (6%, 10/172) and Staphylococcus epidermidis (3%, 6/172). In-hospital mortality was 15% (25/172). Embolic complications were found among 57% (98/172) of patients, the most common being stroke (23%, 40/172), septic pulmonary emboli (17%, 29/172), splenic and/or renal emboli (17%, 26/172) and peripheral limb emboli (15%, 25/172). Sixty (35%, 60/172) patients underwent cardiac surgery. On multivariable analysis, independent predictors of in-hospital mortality were: increased age (odds ratio: 1.064, per year older, P = 0.001), ICU admission independent of cardiac surgery (OR 9.81, P < 0.001), moderate or severe LV impairment (OR 5.19, P = 0.012) and any sign of embolic phenomena to limbs (OR 5.02, P = 0.006). Multivariable predictors of embolic complications were S. aureus bacteraemia (OR 3.22, P = 0.001) and large vegetation >10 mm (OR 3.04, P = 0.002).

CONCLUSION

We demonstrate predictors of in-hospital mortality and embolic phenomena in our cohort. Though age remains a consistent predictor of mortality, surprisingly, signs of embolic phenomena to the limbs was established as an independent predictor of mortality. The mechanism of this is unclear and warrants further evaluation.

A Rare Entity-Percutaneous Lead Extraction in a Very Late Onset Pacemaker Endocarditis: Case Report and Review of Literature

The number of infections related to cardiac implantable electronic devices (CIEDs) has increased as the number of devices implanted around the world has grown exponentially in recent years. CIED complications can sometimes be difficult to diagnose and manage, as in the case of lead-related infective endocarditis. We present the case of a 48-year-old male diagnosed with Staphylococcus aureus device-related infective endocarditis, 12 years after the implant of a single chamber pacemaker. A recent history of the patient includes two urinary catheterizations due to obstructive uropathy in the context of a prostatic adenoma, 2 months previously, both without antibiotic prophylaxis; no other possible entry sites were found and no history of other invasive procedures. After initiation of antibiotic therapy according to antibiotic susceptibility testing, we decided to remove the right ventricular passive fixation lead along with the vegetation and pacemaker generator; because of severe lead adhesions in the costoclavicular region, and especially in the right ventricle, we needed mechanical sheaths to remove the abundant fibrous tissue that encompassed the lead. After a difficult, but successful, lead extraction along with a large vegetation and 6 weeks' antibiotic therapy, the clinical and biological evolution was favorable, without reappearance of symptoms. While very late lead endocarditis is a rarity, late lead-related infective endocarditis (more than 12 months elapsed since implant) is not an exception; this is why we find that endocarditis prophylaxis should be reconsidered in certain patient categories, our patient being proof that procedures with neglectable endocarditis risk according to the guidelines can lead to bacterial endocarditis.

Clinical characteristics, microbiology, and outcomes of infective endocarditis in Qatar

Background: Infective endocarditis (IE) is a serious and potentially life-threatening disease. The epidemiology, treatment options, and outcomes have changed considerably over the last two decades. The aim of the study was to describe the epidemiology, clinical characteristics, and outcomes of patients with IE in Qatar.

Methods: Patients were identified from Hamad Medical Corporation hospitals’ electronic records, the national referral center for the State of Qatar. We included those aged ≥ 18 years with Duke Criteria-based diagnosis of IE during the period from January 2015 to September 2017. Demographic and clinical data were retrieved. Descriptive statistics were performed, and logistic regression analysis was used to describe the relationship between patient characteristics and all-cause in-hospital mortality. All potentially relevant variables were included in the univariate analysis, while those with p < 0.1 in the univariate logistic regression model were included in the multivariate analysis. For the final model, we calculated odds ratios (OR) adjusted for each of the variables included, along with their 95% confidence intervals (95% CI). Data were analyzed using STATA software version 15 (StataCorp, College Station, Texas, USA). The study was approved by the Institutional Research Board with a waiver for informed consent.

Results: Fifty-seven cases were included, of which 70% were males. The mean age was 51 years ( ± 16.8 years). Eleven (19%) were associated with prosthetic valves, and 6 (11%) with implantable cardiac devices. Fever (84%), dyspnea (46%), and heart failure (37%) were the most common presentations. Only 58% of patients had known preexisting valvular heart disease or an intracardiac device. Skin infections (10 patients, 18%) were the most prevalent portals of infection, followed by venous catheters, recent valve surgery, and implantable cardiac devices. Staphylococci were implicated in 19 (34%) and Streptococcaceae in 9 (16%) patients, whereas 21 (37%) patients were culture negative. Left-side IE (49 patients, 86%) was predominant. Acute kidney injury (AKI) (17 patients, 30%) and heart failure (11 patients, 19%) were common complications. The majority of patients received targeted antimicrobial therapy with at least two active agents. Only 9 (16%) patients underwent surgical intervention. Fourteen (25%) patients died of any cause before hospital discharge. Logistic regression analysis identified septic shock [OR 57.8, 95% CI 2.6–1360.2; p < 0.01] and AKI OR 33.9, 95% CI 2.9–398.1; p < 0.01) as the only risk factors independently associated with in-hospital mortality.

Conclusion: Staphylococci are the most common microbiological cause of IE in Qatar. Surgical intervention is uncommon, and mortality is relatively high. Our findings suggest that efforts should be directed toward improving IE prevention strategies in high-risk patients, encouraging early microbiological investigations and improving medical and surgical management.

Right-Sided Infective Endocarditis 2020: Challenges and Updates in Diagnosis and Treatment

Compared with the extensive data on left-sided infective endocarditis (IE), there is much less published information on the features and management of right-sided IE. Right-sided IE accounts for 5% to 10% of all IE cases, and compared with left-sided IE, it is more often associated with intravenous drug use, intracardiac devices, and central venous catheters, all of which has become more prevalent over the past 20 years. In this manuscript on right-sided IE we provide an up-to-date overview on the epidemiology, etiology, microbiology, potential locations of infection in the right heart, diagnosis, imaging, common complications, management, and prognosis. We present updated information on the treatment of pacemaker and device infections, infected fibrin sheaths that appear to be an easily missed source of infection after central line as well as pacemaker removal. We review current data on the AngioVac percutaneous aspiration device, which can obviate the need for surgery in patients with infected pacemaker leads and fibrin sheaths. We also focused on advanced diagnostic modalities, such as positron emission tomography/computed tomography. All of these are supported by specific case examples with detailed echocardiographic imaging from our experience.

Calculated initial parenteral treatment of bacterial infections: Bacterial endocarditis

This is the twelfth chapter of the guideline "Calculated initial parenteral treatment of bacterial infections in adults - update 2018" in the 2^nd updated version. The German guideline by the Paul-Ehrlich-Gesellschaft für Chemotherapie e.V. (PEG) has been translated to address an international audience. The bacterial endocarditis is characterised by a constant incidence but a shift in the patient population due to the use of prosthetic heart valves and foreign materials like pacemakers and the increasing application of invasive medical procedures. This is linked to a change in the predominant infecting organisms towards staphylococci. This chapter gives recommendations for the interdisciplinary management of infective endocarditis from the diagnostic workup over prevention to therapy with a focus on antibiotic therapy.

Echocardiography in Infective Endocarditis: State of the Art

PURPOSE OF REVIEW

In this review, we examine the central role of echocardiography in the diagnosis, prognosis, and management of infective endocarditis (IE).

RECENT FINDINGS

2D transthoracic echocardiography (TTE) and transesophageal echocardiography TEE have complementary roles and are unequivocally the mainstay of diagnostic imaging in IE. The advent of 3D and multiplanar imaging have greatly enhanced the ability of the imager to evaluate cardiac structure and function. Technologic advances in 3D imaging allow for the reconstruction of realistic anatomic images that in turn have positively impacted IE-related surgical planning and intervention. CT and metabolic imaging appear to be emerging as promising ancillary diagnostic tools that could be deployed in select scenarios to circumvent some of the limitations of echocardiography. Our review summarizes the indispensable and central role of various echocardiographic modalities in the management of infective endocarditis. The complementary role of 2D TTE and TEE are discussed and areas where 3D TEE offers incremental value highlighted. An algorithm summarizing a contemporary approach to the workup of endocarditis is provided and major societal guidelines for timing of surgery are reviewed.

Echocardiographic agreement in the diagnostic evaluation for infective endocarditis

Echocardiography is essential for the diagnosis and management of infective endocarditis (IE). However, the reproducibility for the echocardiographic assessment of variables relevant to IE is unknown. Objectives of this study were: (1) To define the reproducibility for IE echocardiographic variables and (2) to describe a methodology for assessing quality in an observational cohort containing site-interpreted data. IE reproducibility was assessed on a subset of echocardiograms from subjects enrolled in the International Collaboration on Endocarditis registry. Specific echocardiographic case report forms were used. Intra-observer agreement was assessed from six site readers on ten randomly selected echocardiograms. Inter-observer agreement between sites and an echocardiography core laboratory was assessed on a separate random sample of 110 echocardiograms. Agreement was determined using intraclass correlation (ICC), coverage probability (CP), and limits of agreement for continuous variables and kappa statistics (κweighted) and CP for categorical variables. Intra-observer agreement for LVEF was excellent [ICC = 0.93 ± 0.1 and all pairwise differences for LVEF (CP) were within 10 %]. For IE categorical echocardiographic variables, intra-observer agreement was best for aortic abscess (κweighted = 1.0, CP = 1.0 for all readers). Highest inter-observer agreement for IE categorical echocardiographic variables was obtained for vegetation location (κweighted = 0.95; 95 % CI 0.92-0.99) and lowest agreement was found for vegetation mobility (κweighted = 0.69; 95 % CI 0.62-0.86). Moderate to excellent intra- and inter-observer agreement is observed for echocardiographic variables in the diagnostic assessment of IE. A pragmatic approach for determining echocardiographic data reproducibility in a large, multicentre, site interpreted observational cohort is feasible.