Periannular complications in infective endocarditis involving prosthetic aortic valves

Atrioventricular conduction disorders in aortic valve infective endocarditis

BACKGROUND

Aortic valve infective endocarditis may be complicated by high-degree atrioventricular block in up to 10-20% of cases.

AIM

To assess high-degree atrioventricular block occurrence, contributing factors, prognosis and evolution in patients referred for aortic infective endocarditis.

METHODS

Two hundred and five patients referred for aortic valve infective endocarditis between January 2018 and March 2021 were included in this study. A comprehensive assessment of clinical, electrocardiographic, biological, microbiological and imaging data was conducted, with a follow-up carried out over 1 year.

RESULTS

High-degree atrioventricular block occurred in 22 (11%) patients. In univariate analysis, high-degree atrioventricular block was associated with first-degree heart block at admission (odds ratio 3.1; P=0.015), periannular complication on echocardiography (odds ratio 6.9; P<0.001) and severe biological inflammatory syndrome, notably C-reactive protein (127 vs 90mg/L; P=0.011). In-hospital mortality (12.7%) was higher in patients with high-degree atrioventricular block (odds ratio 4.0; P=0.011) in univariate analysis. Of the 16 patients implanted with a permanent pacemaker for high-degree atrioventricular block and interrogated, only four (25%) were dependent on the pacing function at 1-year follow-up.

CONCLUSIONS

High-degree atrioventricular block is associated with high inflammation markers and periannular complications, especially if first-degree heart block is identified at admission. High-degree atrioventricular block is a marker of infectious severity, and tends to raise the in-hospital mortality rate. Systematic assessment of patients admitted for infective endocarditis suspicion, considering these contributing factors, could indicate intensive care unit monitoring or even temporary pacemaker implantation in those at highest risk.

Multimodality Imaging of Infective Endocarditis

Infective endocarditis (IE) is a complex multisystemic disease resulting from infection of the endocardium, the prosthetic valves, or an implantable cardiac electronic device. The clinical presentation of patients with IE varies, ranging from acute and rapidly progressive symptoms to a more chronic disease onset. Because of its severe morbidity and mortality rates, it is necessary for radiologists to maintain a high degree of suspicion in evaluation of patients for IE. Modified Duke criteria are used to classify cases as "definite IE," "possible IE," or "rejected IE." However, these criteria are limited in characterizing definite IE in clinical practice. The use of advanced imaging techniques such as cardiac CT and nuclear imaging has increased the accuracy of these criteria and has allowed possible IE to be reclassified as definite IE in up to 90% of cases. Cardiac CT may be the best choice when there is high clinical suspicion for IE that has not been confirmed with other imaging techniques, in cases of IE and perivalvular involvement, and for preoperative treatment planning or excluding concomitant coronary artery disease. Nuclear imaging may have a complementary role in prosthetic IE. The main imaging findings in IE are classified according to the site of involvement as valvular (eg, abnormal growths [ie, "vegetations"], leaflet perforations, or pseudoaneurysms), perivalvular (eg, pseudoaneurysms, abscesses, fistulas, or prosthetic dehiscence), or extracardiac embolic phenomena. The differential diagnosis of IE includes evaluation for thrombus, pannus, nonbacterial thrombotic endocarditis, Lambl excrescences, papillary fibroelastoma, and caseous necrosis of the mitral valve. The location of the lesion relative to the surface of the valve, the presence of a stalk, and calcification or enhancement at contrast-enhanced imaging may offer useful clues for their differentiation. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Bivalvular infective endocarditis complicated by perivalvular abscess and aorto-right atrium fistula

Infective endocarditis caused by Pseudomonas aeruginosa in patients without a history of intravenous drug abuse and endovascular procedures is rare. We present a middle-aged man with fever, chills, night sweats and dyspnoea for 2 weeks. Physical examination and blood cultures were drawn, and the patient was empirically started on antibiotics. Unfortunately, the patient experienced progressive clinical deterioration requiring endotracheal intubation and vasopressor support. Transthoracic echocardiogram followed by transesophageal echocardiogram was performed that showed bicuspid aortic valve, severe aortic regurgitation, membranous ventricular septal defect, vegetations on aortic and tricuspid valves, dilated aortic root, and a fistula between the aorta and right atrium. The patient underwent emergent aortic valve and aortic root replacement along with tricuspid commissuroplasty and ventricular septal defect (VSD) closure. Later, intraoperative tissue cultures grew P. aeruginosa, and antipseudomonal antibiotic coverage was added. This case highlights that P. aeruginosa endocarditis can occur without risk factors and can lead to fatal cardiovascular complications.

Case report: Aorto-left atrial fistula-A rare complication of native aortic valve endocarditis

BACKGROUND

Aorto-cavitary fistula is a rare complication of infective endocarditis. Multimodal imaging is commonly required to assess the severity and extent of infection because of the complex pathology of the valvular and paravalvular apparatus in endocarditis.

CASE PRESENTATION

We present an unusual case of a middle-aged man with recent history of meningoencephalitis who developed infective endocarditis complicated by ruptured abscess in inter-valvular fibrosa between aortic and mitral valve resulting in free communication or fistula formation between aorta and left atrium. Patient underwent double valve replacement (aortic and mitral) along with repair of the aorta.

CONCLUSIONS

Our case highlights recognition of this rare clinical presentation of aorto-left atrial fistula in infective endocarditis and the diagnostic role of transesophageal echocardiography in good clinical outcome with aggressive and timely management.

From Cardiac Mystery to Dental Discovery: Resolving Recurrent Infection in a Prosthetic Heart Valve Patient

We present the case of a 71-year-old female with a history of surgical bioprosthetic aortic valve replacement who developed a liquefactive abscess near the mitral valve trigone following Streptococcus gallolyticus bacteremia. The patient initially presented with dyspnea and symptoms of an upper respiratory tract infection. A trans-esophageal echocardiogram revealed mitral valve vegetation and a possible source of sepsis near the prosthetic aortic valve. However, it was the identification of multiple silent dental abscesses during a routine dental check-up that led to the resolution of the patient's symptoms and the eradication of the infectious process. This case highlights the importance of considering dental infections as a potential cause of recurrent bacteremia and infectious complications in patients with prosthetic heart valves.

Surgical Techniques and Outcomes in Patients With Intra-Cardiac Abscesses Complicating Infective Endocarditis

Background

An intra-cardiac abscess is a serious complication of both native (NV-IE) and prosthetic valve infective endocarditis (PV-IE). Despite being an accepted indication for surgery, controversies remain regarding the optimal timing and type of operation. We aimed to report the outcomes of patients managed for intra-cardiac abscesses over more than a decade.

Methods

Patients aged ≥18 years managed for intra-cardiac abscess between 1 January 2005 and 31 December 2017 were identified from a prospectively collected IE database. The primary outcome was 30-day mortality in operated patients and secondary outcomes were freedom from re-infection, re-operation and long-term mortality comparing those patients with aortic root abscess who underwent aortic valve replacement (AVR) and those who received aortic root replacement (ARR).

Results

Fifty-nine patients developed an intra-cardiac abscess, and their median age was 55 (43-71) years; among them, 44 (75%) were men, and 10 (17%) were persons who injected drugs. Infection with beta-haemolytic streptococci was associated with NV-IE (p = 0.009) and coagulase-negative staphylococci with PV-IE (p = 0.005). Forty-four (75%) underwent an operation, and among those with aortic root abscess, 27 underwent AVR and 12 ARR. Thirty-day mortality was associated with infection with S. aureus (p = 0.006) but not the type or timing of the operation. Survival in operated patients was 66% at 1 year and 59% at 5 years. In operated patients, none had a relapse, although six developed late recurrence. Freedom from infection, re-operation and long-term mortality were similar in patients undergoing AVR compared to ARR.

Conclusion

Patients diagnosed with intra-cardiac abscess who were not operated on had very poor survival. In those who underwent an operation, either by AVR or ARR based upon patient factors, imaging and intra-operative findings outcomes were similar.

Cardiac Imaging for Diagnosis and Management of Infective Endocarditis

Imaging is central to the care of patients with infective endocarditis. While transthoracic and transesophageal echocardiography are the principle imaging techniques, additional modalities including positron emission tomography and cardiac computed tomography, and to a lesser extent intracardiac echocardiography, play an increasing role. This review discusses the role of cardiac imaging in establishing the diagnosis of endocarditis, in predicting its embolic risk and in making decisions regarding the need for and timing of surgery.

OUP accepted manuscript

Enterobacter cloacae are a rare cause of infective endocarditis (IE). We present an interesting case of a 51-year-old intravenous drug user with E. cloacae IE of a prosthetic aortic valve and a fistula into the right ventricle. He underwent surgical repair and 6 weeks of intravenous meropenem.

ACR Appropriateness Criteria® Infective Endocarditis

Infective endocarditis can involve a normal, abnormal, or prosthetic cardiac valve. The diagnosis is typically made clinically with persistently positive blood cultures, characteristic signs and symptoms, and echocardiographic evidence of valvular vegetations or valvular complications such as abscess, dehiscence, or new regurgitation. Imaging plays an important role in the initial diagnosis of infective endocarditis, identifying complications, prognostication, and informing the next steps in therapy. This document outlines the initial imaging appropriateness of a patient with suspected infective endocarditis and for additional imaging in a patient with known or suspected infective endocarditis. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Aorto-Left Atrial Fistula as Sequela of Endocarditis

Aortoatrial fistula formation is a rare complication of bacterial endocarditis. Fistulous tracts may form between the aorta and either atrium. Clinical presentation varies from an insignificant murmur to refractory congestive heart failure. Most clinically relevant fistula manifests with acute and severe symptoms. Transesophageal echocardiography (TEE) is more sensitive than transthoracic echocardiography (TTE) in diagnosing intracardiac shunts, and invaluable in guiding intraoperative surgical repair. Definitive therapy involves closure of the fistula either through an open surgical approach or percutaneously with an occluder device.

Case report: Concomitant MitraClip implantation for severe mitral regurgitation and plug closure of endocarditis induced fistula between aortic root and left atrium after transcatheter aortic valve implantation

Background

Infective endocarditis (IE) after transcatheter aortic valve implantation (TAVI) occurs in up to 1.5% of patients within the first year. The development of an aorto-atrial fistula (AAF) is a rare but problematic complication of IE, which can be confirmed with transoesophageal echocardiography (TOE). We present an exceptional case of occluding an aorto-left atrial fistula only diagnosed with intraprocedural TOE during a subsequent procedure of MitraClip implantation.

Case summary

A 79-year-old symptomatic male patient with multiple comorbidities was referred due to severe mitral regurgitation (MR). He has had prior TAVI which was complicated with streptococcal IE for which he had received prolonged antibacterial therapy. Transthoracic echocardiography (TTE) revealed severe MR. The patient was accepted for a MitraClip procedure by the heart team. Intra-procedural TOE revealed also a significant continuous shunt through an AAF which was likely caused by the endocarditis. The strategy was therefore defined as to occlude the fistula with an Amplatzer Vascular Plug II 12 mm. The plug was released in the fistula leaving an insignificant residual shunt. After the transseptal puncture one MitraClip XTR was implanted, reducing the MR to mild. After the procedure, the patient’s general clinical condition improved without signs of haemolysis. The pre-discharge TTE confirmed trace residual shunt, mild residual MR and mild paravalvular leakage.

Discussion

Our case illustrates a complex transcatheter structural heart intervention with improvised procedural strategies based on the intra-procedural TOE findings. We conclude that the pre-procedural TOE needs to be comprehensive rather than exclusive, particularly in the context of bioprosthesis-related endocarditis.

Aorto-cavitary fistula to the left ventricle with severe aortic regurgitation as a complication of prosthetic valve infective endocarditis: a novel report

Infective endocarditis can present in different clinical forms and lead to a variety of complications depending on the affected valvular and perivalvular structures. We describe a case of a 74-year-old male who developed an aortic-cavitary fistulous tract as a complication of prosthetic aortic valve infective endocarditis. Transesophageal echocardiography (TEE) revealed an aorto-cavitary fistula (ACF) connecting the aortic root with the left ventricle, creating an intracardiac shunt, which resulted in severe aortic regurgitation physiology. The patient underwent surgery with successful exclusion of the ACF. ACF is an unusual complication of infective endocarditis that creates an abnormal communication between the aortic root and the heart chambers, establishing an intracardiac shunt. This case highlights that physicians should be aware of the possibility of rare cardiac complications in infective endocarditis. TEE is a valid diagnostic test for ACF.

Prevalence and predictors of aortic root abscess among patients with left-sided infective endocarditis: a cross-sectional comparative study

BACKGROUND

Aortic root abscess (ARA) is a major complication of infective endocarditis that is associated with increased morbidity and mortality. Limited data are present about patient characteristics and outcomes in this lethal disease. We aimed to study the clinical and echocardiographic characteristics of patients with ARA compared to patients with left-sided infective endocarditis without ARA. We included patients with a definite diagnosis of left-sided infective endocarditis according to modified Duke's criteria. The patients were classified into two groups according to the presence of ARA (ARA and NO-ARA groups). All the patients were studied regarding their demographic data, clinical characteristics, laboratory and imaging data, and complications.

RESULTS

We included 285 patients with left-sided infective endocarditis. The incidence of ARA was 21.4% (61 patients). Underlying heart disease, mechanical prosthesis, bicuspid aortic valve, and prior IE were significantly higher in ARA. The level of CRP was higher in ARA (p = 0.03). ARA group showed more aortic valve vegetations (73.8% vs. 37.1%, p < 0.001), more aortic paravalvular leakage (26.7% vs. 4.5%, p < 0.001), and less mitral valve vegetations (21.3% vs. 68.8%, p < 0.001). Logistic regression analysis showed that the odds of ARA increased in the following conditions: aortic paravalvular leak (OR 3.9, 95% CI 1.2-13, p = 0.03), mechanical prosthesis (OR 3.6, 95% CI 1.5-8.7, p = 0.005), aortic valve vegetations (OR 3.0, 95% CI 1.2-8.0, p = 0.02), and undetected organism (OR 2.3, 95% CI 1.1-4.6, p = 0.02), while the odds of ARA decreased with mitral valve vegetations (OR 0.2, 95% CI 0.08-0.5, p = 0.001). We did not find a difference between both groups regarding the incidence of major complications, including in-hospital mortality.

CONCLUSION

In our study, ARA occurred in one fifth of patients with left-sided IE. Patients with mechanical prosthesis, aortic paravalvular leakage, aortic vegetations, and undetected organisms had higher odds of ARA, while patients with mitral vegetations had lower odds of ARA.

How to repair an acquired Gerbode defect using an aortic root xenograft

A 74-year old female patient presented with a 3-week history of fever, general weakness, and later developed complete heart block. On admission, the patient was febrile (temperature of 39°C) and tachypnoeic (respiratory rate of 29/min) with oxygen saturation of 95% on 2 L of oxygen. Her heart rate was 60 beats/min (VVI pacing), arterial blood pressure was 135/60 mm Hg and the Glasgow Coma Scale was 15. On chest auscultation, she had a harsh systolic murmur over her left precordium and bilateral rales. Blood tests demonstrated moderate anemia (hemoglobin of 95 g/L), leucocytosis (white blood cell count of 13.13 x 10^9/L), hypoalbuminemia (albumin concentration of 18 g/L), normal liver function tests and creatinine clearance of 45 ml/min. Computed tomography aortography demonstrated an irregular mass arising from the aortic root that extended into the right atrium (RA) and a fistulous tract (the Gerbode defect) between the left ventricular outflow tract (LVOT) and the right ventricle (RV). Transoesophageal echocardiography showed large vegetation in the RA and left to right cardiac shunt through the Gerbode defect from the LVOT to the RA and the RV. Using cardiopulmonary bypass, the patient underwent resection of the aortic cusps, debridement of the aortic root, septal and anterior leaflets of the tricuspid valve, and the membranous septum. The Gerbode defect was closed with an autologous pericardial patch, then a sliding annuloplasty of the septal leaflet of the tricuspid valve was performed. Finally, the aortic root was replaced with a 23 mm Freestyle xenograft.

Surgical Options for Aortic Root Replacement in Destructive Endocarditis

Objective

To analyze patients’ preoperative characteristics, surgical data, postoperative courses, and short- and long-term outcomes after implantation of different full-root prostheses for destructive aortic valve endocarditis.

Methods

Between 1999 and 2018, 80 patients underwent aortic root replacement due to infective endocarditis in our institution. We analyzed the abovementioned data with standard statistical methods.

Results

The Freestyle stentless porcine prostheses were implanted in 53 (66.25%) patients, biological valve conduits in 13 (16.25%), aortic root homografts in nine (11.25%), and mechanical valve conduits in five (6.25%). There were no significant preoperative differences between the groups. The incidence of postoperative complications and intensive care unit length of stay did not differ significantly between the groups. The 30-day mortality rate was low among Freestyle patients (n=8, 15.1%) and high in the mechanical conduit cohort (n=3, 60%), though with borderline statistical significance (P=0.055). The best mean survival rates were observed after homograft (13.7 years) and stentless prosthesis (8.1 years) implantation, followed by biological (2.8 years) and mechanical (1.4 years) conduits (P=0.014). The incidence of reoperations was low in the mechanical conduit group (0) and stentless bioroot group (n=1, 1.9%), but two (15.4%) patients with biological conduits and three (33.3%) patients with homografts required reoperations in the investigated follow-up period (P=0.005).

Conclusion

In patients with the destructive form of aortic valve endocarditis, homografts and stentless porcine xenografts offer better survival rates than stented valve conduits; however, the reoperation rate among patients who received homograft valves is high.

A Shortcut to Death: Aorto–Left Atrial Fistula in the Setting of MRSA Infective Endocarditis

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AAFs convey very high mortality and require prompt diagnosis and management.

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Echocardiography, especially TEE, plays a critical role in timely assessment.

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Poor prognostic risk factors include shock, paravalvular leakage, and CHF.

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Surgery remains the primary option; transcatheter closure options are on the rise.

Root abscess in the setting of infectious endocarditis: Short- and long-term outcomes

OBJECTIVES

To evaluate the influence of an aortic root abscess on perioperative outcomes and long-term survival in patients with active infectious endocarditis that was treated surgically.

METHODS

From 1996 to 2017, 336 consecutive patients were treated with aortic valve or root replacement for infective endocarditis, including patients with (n = 179) or without (n = 157) a root abscess. Data were obtained from the Society of Thoracic Surgeons data warehouse, through chart review, patient surveys, and National Death Index data.

RESULTS

Demographic characteristics were similar between groups except the root abscess group had a significantly lower prevalence of congestive heart failure and higher rates of prosthetic valve endocarditis. The abscess group had significantly more aortic root replacements as well as longer cardiopulmonary bypass and crossclamp times. Operative mortality was 8.4% and 3.8% (P = .11) for the abscess and no abscess groups, respectively. Nevertheless, the root-abscess group had prolonged ventilation and longer intensive care unit stays. Kaplan-Meier survival was similar between root abscess and no abscess groups (10-year survival 41% vs 43%; P = .35). Significant risk factors for all-time mortality included age greater than 70 (hazard ratio [HR], 2.85; 95% confidence interval [CI], 1.55, 5.24), the presence of a root abscess (HR, 1.42; 95% CI, 1.02, 1.96), intravenous drug use (HR, 1.81; 95% CI, 1.13, 2.89), congestive heart failure (HR, 1.72; 95% CI, 1.22, 2.42), renal failure requiring dialysis (HR, 3.26; 95% CI, 2.30, 4.64), liver disease (HR, 3.04; 95% CI, 1.65, 5.60), and postoperative sepsis (HR, 3.00; 95% CI, 1.30, 6.93). The 10-year rate of reoperation was also similar between groups (5.9% vs 7.9%).

CONCLUSIONS

Thorough and extensive debridement is critical for successful treatment of active endocarditis with root abscess. Bioprosthetic stented and stentless valves are valid conduits to treat endocarditis with root abscess.

Transcatheter Closure of Aorta to Left Atrium Fistula during Active Prosthetic Valve Endocarditis as a Bridge for Surgery: A Case Report

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Early diagnosis of ALAFs and immediate management are mandatory to reduce mortality.

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Transcatheter closure of ALAF is an option to stabilize the patient as a bridge for surgery.

Three dimensional transesophageal echocardiography: a missing link in infective endocarditis imaging?

The role of two dimensional (2D) echocardiography (ECHO) for the diagnosis and clinical decision making in infective endocarditis (IE) has been extensively studied and described in the medical literature. Some reports have demonstrated the incremental value of three dimensional (3D) transesophageal (TE) ECHO in the setting of IE. However, a systematic review focusing on the role of 3D imaging is lacking. In this manuscript, we examine the role of 3D TE ECHO in the diagnosis of IE. IE is a challenging disease in which 2D transthoracic (TT) and TE ECHO have complementary roles and are unequivocally the mainstay of diagnostic imaging. Still, 2D imaging has important limitations. Technological advances in 3D imaging allow for the reconstruction of real-time anatomical images of cardiac structure and function. 3D imaging has emerged as a diagnostic technique that overcame some of the limitations of 2D ECHO. Currently, both transthoracic and transesophageal echocardiography transducers are able to generate 3D images. However, 3D TE ECHO provides images of a higher quality in comparison to 3D TT ECHO, and is the best echocardiographic modality able to allow for a detailed anatomical imaging. 3D TE ECHO may represent the key adjunctive echocardiographic technique being able to positively impact on IE-related surgical planning and intervention and to facilitate the interaction between the surgeon and the imaging specialist. Importantly, 3D TE ECHO is not the recommended initial modality of choice for the diagnosis of IE; however, in highly specialized centers, it has become an important complementary technique when advanced surgical planning is required. Furthermore, anatomical imaging has become the link between the different techniques that play a role in IE imaging. In fact, both computed tomography and magnetic resonance allow three dimensional reconstruction. An important future goal should allow for the fusion among various imaging modalities. Our review highlights the role of 3D TE ECHO in IE imaging and emphasize where it offers incremental value.

Aortic valve endocarditis complicated by proximal false aneurysm

Background

Aortic valve endocarditis remains a life-threatening condition, especially in cases of periannular complications. Aorto-ventricular discontinuity associated with proximal false aneurysm represents a severe picture caused by extensive tissue disruption and is usually associated with prosthetic valve infection. Complex surgical repair is required in these cases and continues to be associated with high mortality and morbidity rates.

Methods

We retrieved information for 32 patients undergoing operation for infective aortic valve/prosthetic valve endocarditis complicated by pseudoaneurysm arising from aorto-ventricular discontinuity. Patients were relatively young, mostly male and most of them had a prior cardiac operation. Aortic root replacement with valve graft conduit was performed in all cases; it was associated with other procedures in seven patients: CABG (n=2), MV surgery (n=3), MV surgery + CABG (n=1) and pulmonary valve replacement (n=1). We reported and analysed patient outcomes at early and mid-term follow-up.

Results

Pre-discharge mortality was 22% (n=7). The postoperative course was complicated in 24 (75%) cases. Eighteen patients (56%) sustained low cardiac output resulting in multiple organ failure syndrome and death in five cases. One patient (3%) experienced a major neurologic deficit with a permanent cerebral stroke. Acute kidney injury complicated the course in 12 cases (37%), continuous renal replacement therapy was necessary in four patients (12%). Overall survival and freedom from endocarditis and reoperation at 5-year was 59% and 89%, respectively.

Conclusions

Patients with complicated aortic valve endocarditis presented generally in a poor preoperative state. Surgical treatment poses a non-negligible risk of postoperative mortality and morbidity but provides an acceptable survival rate and a satisfactory recovery at mid-term.

[Complications and prognosis of infective endocarditis]

Clinical manifestations of infective endocarditis may involve almost all body organs. They are usually classified as either cardiac or extra-cardiac complications. The first stage of infection is the development of intra-cardiac vegetation, which may further spread with an increase in size and number of vegetations, destructive valve lesions, and perivalvular extension of the infection. These anatomical lesions are responsible for hemodynamic disorders, mostly valvular regurgitation, and often lead to heart failure, which is the most frequent complication of IE. Embolic events may affect various vascular territories, the most frequent sites being brain, spleen and kidney for left-sided IE, and lung for right-sided IE. Cerebral complications may be of ischemic, hemorrhagic and/or infectious origin, are often the revealing symptoms of IE, and are well-recognized factors of poor prognosis. IE remains a dreadful disease with an in hospital mortality of 20%, a 5 year mortality of 40% and a significant morbidity.

Normal Values of the Mitral-Aortic Intervalvular Fibrosa Thickness: A Multimodality Study

Background:

The avascular region of the fibrous body between the mitral and aortic valves, named mitral-aortic intervalvular fibrosa (MAIVF), is often involved in the periaortic diffusion of infective endocarditis (IE), resulting in abscess or pseudoaneurysm formation. The early recognition of these life-threatening complications is of crucial importance, as urgent surgical correction is necessary. In the first stages of the abscess formation, the only sign is an increased thickness of the MAIVF. To the best of our knowledge, normal transesophageal echocardiography (TEE) examination reference values for MAIVF thickness has not yet been established. The aim of the study was to define the normal ranges of MAIVF thickness in a population of healthy adults who underwent a TEE examination.

Materials and Methods:

A population of consecutive adult patients who underwent a TEE examination was enrolled in the study. Measurement was performed in short-axis (SAX) and long-axis (LAX) views. Mean-2 standard deviations (mean-2SDs) and 5%, 10%, 90%, and 95% confidence intervals were evaluated. A comparison with MAIVF thickness in patients affected by aortic IE complicated by abscess formation was performed, and receiver operating characteristic (ROC) curves were constructed to achieve the optimal cutoff value of normality.

Results:

A total of 477 consecutive Caucasian adult patients were enrolled (mean age: 69 years, range: 27–93 years). Mean-2SD MAIVF measurement in SAX view was 0.325 cm (95% confidence interval [CI]: 0.319–0.330 cm) and in LAX view was 0.340 cm (95% CI: 0.334–0.346 cm). Computed tomography–MAIVF mean measurement (±2SD) was 0.237 cm (95% CI: 0.110–0.340 cm). ROC curves showed that a cutoff SAX value measurement of 0.552 (area under the curve [AUC]: 95.2%) had a sensibility of 88.2% and a specificity of 92.4%; a LAX measurement value of 0.623 (AUC: 93.3%) had a sensibility of 82.7% and a specificity of 85.7%. The multivariate analysis showed no significant correlation between MAIVF thickness, age, and sex.

Conclusion:

In healthy patients, MAIVF thickness should not exceed 0.600 cm. Above these values, the suspicion of a periaortic abscess formation should be raised. MAIVF increased thickness may be an early sign of perivalvular diffusion requiring an urgent endocarditis team evaluation.

Prosthetic valve endocarditis: predictors of early outcome of surgical therapy. A multicentric study

OBJECTIVES

Prosthetic valve endocarditis (PVE) is an uncommon yet dreadful complication in patients with prosthetic valves that requires a distinct analysis from native valve endocarditis. The present study aims to investigate independent risk factors for early surgical outcomes in patients with PVE.

METHODS

A retrospective cohort study was conducted in 8 Italian Cardiac Surgery Units from January 2000 to December 2013 by enrolling all PVE patients undergoing surgical treatment.

RESULTS

A total of 209 consecutive patients were included in the study. During the study period, the global rate of surgical procedures for PVE among all operations for isolated or associated valvular disease was 0.45%. Despite its rarity this percentage increased significantly during the second time frame (2007-2013) in comparison with the previous one (2000-2006): 0.58% vs 0.31% (P < 0.001). Intraoperative and in-hospital mortality rates were 4.3% and 21.5%, respectively. Logistic regression analysis identified the following factors associated with in-hospital mortality: female gender [odds ratio (OR) = 4.62; P < 0.001], shock status (OR = 3.29; P = 0.02), previous surgical procedures within 3 months from the treatment (OR = 3.57; P = 0.009), multivalvular involvement (OR = 8.04; P = 0.003), abscess (OR = 2.48; P = 0.03) and urgent surgery (OR = 6.63; P < 0.001).

CONCLUSIONS

Despite its rarity, PVE showed a significant increase over time. Up to now, in-hospital mortality after surgical treatment still remains high (>20%). Critical clinical presentation and extension of anatomical lesions are strong preoperative predictors for poor early outcome.

Aortic root replacement with cryopreserved homograft for infective endocarditis in the modern North American opioid epidemic

OBJECTIVE

To study mid-term survival in patients with infective endocarditis as a result of IV drug use undergoing aortic root replacement with cryopreserved aortic homograft.

METHODS

Patients undergoing aortic root homograft replacement from 2011-2017 were studied retrospectively. Aortic root replacement was performed using a modified Bentall technique. Primary outcomes included both short-term and mid-term survival. Secondary outcomes included immediate postoperative complications.

RESULTS

A total of 138 patients underwent cryopreserved homograft replacement of the aortic root for aortic root abscesses. Eighty-five patients (61.6%) underwent reoperative sternotomy, and 12 patients (8.7%) underwent second or third reoperative sternotomy. Sixty-seven (48.5%) patients had severe aortic insufficiency preoperatively. Operative mortality was 12.3% (17 patients). Five patients (3.6%) sustained a permanent stroke. Twenty-one patients (15.2%) required dialysis for renal failure, and 21 patients (15.2%) had complete heart block necessitating a permanent pacemaker. Estimated 5-year mortality for the cohort was 43%.

CONCLUSIONS

Cryopreserved homograft replacement is a safe and desirable option for high-risk patients with infective endocarditis and aortic root abscess. Homograft accommodation for a widely debrided aortic annular bed provides a reasonable surgical strategy for patients needing aortic root replacement with annular abscess.

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.

Characterization of 18 F-Fluorodeoxyglucose Uptake Pattern in Noninfected Prosthetic Heart Valves

Background—

18 F-Fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) has been recently acknowledged as a diagnostic tool for prosthetic valve endocarditis, but its specificity is limited by uptake on noninfected valves. The objective of this study was to outline the main features of FDG uptake on PET/CT in patients with noninfected prosthetic heart valve (PHV).

Methods and Results—

Our institution’s PET/CT database was reviewed to identify patients with PHV, excluding those suspected of infection or who had received antibiotic treatment. PET indication, valve location, and type (biological/mechanical) and time from implantation were collected for each patient. Images with and without attenuation correction were considered for interpretation. The pattern of FDG uptake (absent, homogeneous, or heterogeneous) was recorded. Fifty-four PHVs (51 patients) were identified, including 32 biological valves. Indications for PET were oncology (n=26), suspicion of prosthetic valve endocarditis subsequently excluded (n=17), and history of vasculitis (n=11). A periprosthetic FDG uptake was present in 47 (87%) and 30 (56%) PHVs with and without attenuation correction, respectively, and the pattern was homogeneous in all but 4 (7%) and 3 (6%) PHVs, respectively. On quantitative analysis, maximum standardized uptake values was greater in mechanical than in biological valves (4.0 [2.4–8.0] versus 3.3 [2.1–6.1]; P =0.01) and in patients with vasculitis than in those referred for other indications. The uptake intensity did not differ before and 3 months after valve replacement.

Conclusions—

Noninfected PHVs frequently display homogeneous FDG uptake, which remains steady over time. Caution is, therefore, needed when interpreting FDG PET/CT in suspected prosthetic valve endocarditis, with specific attention to uptake pattern.

[Which patients with infective endocarditis require emergency surgery?]

Half of patients with infectious endocarditis have surgery during the active phase of infective endocarditis (before the end of antibiotic therapy). The American Heart Association and the European Society of Cardiology, independently from each other, have published guidelines in September 2015. As regards surgical indications, these guidelines are similar. The surgical indication must be a common decision of a multidisciplinary team of experts in cardiology, cardiac surgery, imaging and infectious diseases. The main indications are heart failure, non-infectious process control and prevention of embolisms.

Iatrogenic ventricular septal defect: A rare complication of surgical reconstruction of mitral paravalvular dehiscence

INTRODUCTION

Iatrogenic ventricular septal defect is a rare complication after the surgical replacement of cardiac valves. Small defects may have no hemodynamic significance or remain unremarked at the end of the surgical procedure. Understanding of the valvular anatomy alone is not always enough to avoid such complications, especially in the hands of young surgeons.

PRESENTATION OF CASE

We present a case of iatrogenic ventricular septal defect that developed early after the surgical closure of a hemodynamically significant mitral paravalvular leak. Although the patient's critical state did not allow surgical intervention and he died, we think the lessons drawn from this case could be helpful to avoid such horrible complications in the future.

DISCUSSION

This case documents a rare disastrous complication after imperfect surgical closure of a mitral paravalvular leak. Despite the unfortunate end, in reporting this case we try to direct the light to the possible mechanisms that led to the development of this injury focusing on the embryological and anatomical background.

CONCLUSION

Understanding the anatomical and embryological structure of the cardiac fibrotic skeleton should keep cardiac surgeons more vigilent in detecting iatrogenic ventricle septal defects before the development of a devastating hemodynamic state.

Infective Endocarditis With Paravalvular Extension: 35-Year Experience

BACKGROUND

We investigated our surgical strategy and clinical results in patients from active infective endocarditis (AIE) complicated by paravalvular involvement to determine the risk factors of early and late death and reoperation.

METHODS

From October 1979 to December 2014, 955 patients underwent operations for AIE; among them 207 had AIE with paravalvular extension. The patients were a mean age of 59.9 ± 15.4 years, and 162 (78%) were male. Of these patients, 137 (66%) had isolated aortic valve endocarditis, and 138 (67%) had native valve endocarditis. Follow-up was 99% complete.

RESULTS

The operative mortality of the cohort was 16% (n = 34). Abnormal communication, mechanical valve implantation, and renal failure were independent predictors of 30-day death. Survival at 1, 5, 10, and 15 years was 90.3% ± 2.3%, 62.4% ± 3.7%, 49.3% ± 4.1%, and 37.9% ± 4.4%, respectively. Streptococcus endocarditis (all species), complex annular repair, and preoperative heart failure were independent predictors of long-term death. A reoperation was required in 29 patients (14%). Streptococcus pneumoniae endocarditis was the only independent predictor of early reoperation (within 30 days after the operation or during the same hospitalization). Freedom from reoperation at 1, 5, 10, and 15 years was 91.9% ± 2.2%, 89.6% ± 2.6%, 89.6% ± 2.6%, and 87.0% ± 3.5%, respectively. Independent predictors of late reoperation were urgent/emergency operation, prosthetic valve endocarditis, and complex annular repair.

CONCLUSIONS

AIE complicated by paravalvular involvement remains a surgical challenge. Valve replacement (particularly using bioprosthesis) associated with ad hoc reconstruction seems to be a reliable option and showed very encouraging results in this context.

Resistance to infection of long-term cryopreserved human aortic valve allografts

OBJECTIVE

To analyze the in vitro antimicrobial activity of 3 antibiotic regimens (group A, gentamicin-piperacillin-vancomycin-metronidazole-amphotericin B; group B, gentamicin-piperacillin-flucloxacillin-metronidazole-amphotericin B; and group C, meropenem-vancomycin-tobramycin-colistin-amphotericin B) used in the processing of cryopreserved human ascending aortic tissue and aortic valves against Staphylococcus epidermidis and Staphylococcus aureus. The results were additionally compared with the infection resistance of cryopreserved ascending aortic tissue against Escherichia coli and Pseudomonas aeruginosa.

MATERIALS

Each of 10 cryopreserved human allografts (CHAs) was divided into 25 pieces (separating aortic wall and valve). Eighteen segments were microbiologically tested, and 7 pieces underwent scanning electron microscopy. A bacterial solution (4 mL; optical density, 0.20 ± 0.02) was used for contamination. After incubation, the optical density of the solution was measured. CHAs underwent sonication to release viable adherent bacteria. The number of attached bacteria was quantified by the colony forming units per square centimeter of CHA surface.

RESULTS

Antibiotic regimen groups B and C were more efficient than group A in eradicating gram-positive organisms adherent to the aortic wall (P < .001). Group C showed enhanced resistance against E coli compared with group A or B (P < .001), whereas group B appeared to be more effective against P aeruginosa (P < .001). With reference to each antibiotic regimen, ascending aortic tissue showed significantly less bacterial contamination with staphylococcal bacteria than valve grafts (P ≤ .01).

CONCLUSIONS

CHAs possess antibacterial activity despite long-term storage over 5 years. Antibiotic combinations applied during CHA processing have a significant influence on their infection resistance. Ascending aortic tissue shows a significantly enhanced bacterial resistance against staphylococcal bacteria compared with aortic valves.

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

Echocardiography, transthoracic and transoesophageal, plays a key role in the diagnosis and prognosis assessment of patients with infective endocarditis. It constitutes a major Duke criterion and is pivotal in treatment guiding. Seven echocardiographic findings are major criteria in the diagnosis of infective endocarditis (IE) (vegetation, abscess, pseudoaneurysm, fistulae, new dehiscence of a prosthetic valve, perforation and valve aneurysm). Echocardiography must be performed as soon as endocarditis is suspected. Transoesophageal echocardiography should be done in most cases of left-sided endocarditis to better define the anatomic lesions and to rule out local complications. Transoesophageal echocardiography is not necessary in isolated right-sided native valve IE with good quality transthoracic examination and unequivocal echocardiographic findings. Echocardiography is a very useful tool to assess the prognosis of patients with IE at any time during the course of the disease. Echocardiographic predictors of poor outcome include presence of periannular complications, prosthetic dysfunction, low left ventricular ejection fraction, pulmonary hypertension and very large vegetations.

Aortico-Left Atrial Fistula: A Rare Complication of Bioprosthetic Aortic Valve Endocarditis Secondary to Enterococcus faecalis

Paravalvular aortic root abscess with intracardiac fistula formation is an exceedingly rare complication of infective endocarditis. This condition is even more rarely encountered in patients with bioprosthetic valve endocarditis. We report an unusual case of a 68-year-old Bosnian female with a bioprosthetic aortic valve, who developed an extensive aortic root abscess, complicated by an aortico-left atrial intracardiac fistula. This case illustrates that a high index of suspicion, prompt diagnosis by echocardiography, proper antibiotic therapy, and early surgical intervention are crucial to improving treatment outcomes for this rare condition.

Infective endocarditis in patients with an implanted transcatheter aortic valve: Clinical characteristics and outcome of a new entity

AIMS

This study reports one case and review the literature on TAVI-associated endocarditis (TAVIE), to describe its clinical picture and to perform an analysis on prognostic factors.

METHODS AND RESULTS

A MEDLINE search from January 2002 to October 2014 revealed 31 cases of TAVIE, including 1 from our hospital. Median age was 81 years (IQR, 78-85), 53% of patients were males and the median age-adjusted Charlson score was 7 (IQR, 5-8). Heart failure was recorded in 42%, embolic events in 19%, and periannular complications in 45%. The most common causative agent was Enterococcus spp (36%). Ten patients (32%) underwent surgery and nine patients died (29%). The prognostic factors for 6-month mortality were heart failure (HR, 9.97 [3.7-24.5]; p = 0.001), periannular complications (HR, 11.82 [3.3-41.3]; p = 0.004), and nonenterococcal/streptococcal etiology (HR, 4.76 [2.1-11.1]; p = 0.03). In patients with heart failure who did not undergo surgery, mortality was 89% (8 out of 9); in those who did undergo surgery, mortality was 0% (p < 0.001).

CONCLUSIONS

TAVIE is an emerging entity with high mortality. Patients with heart failure who did not undergo surgery had a higher probability of dying. Surgical treatment provided better outcomes even in patients in whom surgery had previously been ruled out.

[Infective endocarditis]

Colonization of native cardiac valves or polymer implants, e.g. valves, conduits, rings, electrode leads and polymer-associated endocarditis (PIE), by microorganisms, primarily gram-positive bacteria (infective endocarditis), constitutes a severe, prognostically unfavorable disease. Fever and in the majority of cases development of a valve regurgitant murmur are clinical landmark findings. The white blood cell count, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are regularly elevated. With a normal CRP level, infective endocarditis is extremely unlikely. Irrespective of body temperature, at least three blood cultures (aerobic and anaerobic) should be taken and if initiation of antimicrobial therapy is urgent, 1 h apart before therapy is initiated. Identification of the pathogen to the species level and testing antimicrobial susceptibility to antibiotics by a quantitative hemodilution test, not with agar diffusion tests, are obligatory. A minimum inhibitory concentration should be administered for antibiotics and usual combinations of antibiotics with an expected synergistic potential. Streptococci, staphylococci and enterococci are the most frequent causative organisms. Immediate initiation of transthoracic echocardiography (TTE) is mandatory followed by transesophageal echocardiography if imaging quality is poor, involvement of intracardiac implants is possible or TTE is insufficient to establish the diagnosis. An insufficiently long antimicrobial therapy promotes recurrent infections, thus a 4-week treatment is standard, while in special cases (e.g. PIE) treatment for 6 weeks should be the rule. If typical complications of infective endocarditis, such as uncontrolled local infection, systemic thromboembolism, central nervous involvement, development of a severe valve incompetence or mitral kissing vegetation in primary aortic valve endocarditis occur, urgent surgical intervention should be considered. If cardiac implants are involved, early surgical removal followed by a 6-week antimicrobial treatment is the rule. Adequate and timely diagnosis and treatment are the key to improve the overall prognosis.

Aorto-right atrial fistula: Late complication of tricuspid valve infective endocarditis

Abnormal connections between the ascending aorta and the cardiac chambers are rare, especially in the context of right-sided infective endocarditis (IE). Transthoracic echocardiography (TTE) with color-flow Doppler, transesophageal echocardiography (TEE), or both may be required for diagnosis. We present the case of a woman admitted with right-sided heart failure (HF) symptoms. She had a previous history of tricuspid valve IE 30 years ago. TTE and TEE revealed an aorto-right atrium fistula located just under the non-coronary cusp into the right atrium at the level of the previously affected tricuspid valve. The Patient refused surgery and was discharged home on HF medications. She has been stable for the last 3 years. The peculiarity of this case is the late symptomatic presentation of the aorto-atrial fistula and the unusual association to tricuspid valve IE.

Risk factors for pericardial effusion in native valve infective endocarditis and its influence on outcome

Data on the incidence, associated factors, and prognosis of pericardial effusion (PE) in patients with infective endocarditis (IE) are scarce. Patients with native valve IE were prospectively followed in our center from 1990 to 2007. A logistic regression analysis was performed to identify independent variables associated with PE and mortality. We included 479 episodes of IE from 459 patients (70% men, mean age 51 years). Small-to-moderate PE was observed in 109 episodes (23%) and large-to-very large PE was observed in 9 episodes (2%). Patients with small-to-moderate PE had a greater prevalence of intravenous drug use (38% vs 23%) and more frequent right-sided IE than patients without PE (33% vs 17%). Patients with large-to-very large PE had a higher rate of systemic emboli (22% vs 18%) and periannular abscess (22% vs 6%) than patients without PE. Renal failure was associated with a higher risk of PE (odds ratio [OR] 2.1, 95% confidence interval [CI] 1.3 to 3.3); age was associated with a lower risk of PE (OR 0.98, 95% CI 0.97 to 0.99). One-year mortality of patients with IE with large-to-very large PE was higher than that of patients with small-to-moderate and absence of PE (56%, 18%, and 24%, respectively, p = 0.033). Large-to-very large PE increases the 1-year mortality of IE (OR 3.0, 95% CI 1.2 to 7.9). In conclusion, renal failure and younger age are associated with a higher risk of PE. Large-to-very large PE was associated with an increase in 1-year mortality.