The Role of Nuclear Cardiac Imaging in Infective Endocarditis

Purpose of Review

Infective endocarditis (IE) remains a deadly disease despite improvements in its management. Echocardiography is crucial for the diagnosis of IE; however, its value is operator-dependent and its sensitivity can decrease in the presence of valvular prosthesis. This review aims to provide an overview on the role of nuclear cardiac imaging in the diagnosis of IE.

Recent Findings

Among all nuclear cardiac imaging modalities, both radiolabeled leukocyte scintigraphy and 2-deoxy-2-[fluorine-18]fluoro-D-glucose positron emission tomography/computed tomography ([¹⁸F]FDG-PET/CT) have been recently introduced in the guidelines of European Society of Cardiology (ESC) for the management of IE. The ESC guidelines included some minor criteria (mainly clinical), and two different sets of major criteria based on blood culture and imaging, respectively. The positivity of either radiolabeled leukocyte scintigraphy or [¹⁸F]FDG-PET/CT images is considered itself a major criterion to diagnose IE. However, nuclear cardiac imaging analysis may be tricky and methodological and technical aspects should be carefully considered.

Summary

Available evidence supports the role of nuclear cardiac imaging in the diagnosis and management of IE. However, all practitioners who act within the “Endocarditis Team” should present a very high level of expertise.

     

超声心动图诊断感染性心内膜炎的意义

目的　探讨感染性心内膜炎 (IE)患者的超声心动图的特征性改变及诊断意义。方法　 17例IE患者进行了经胸超声心动图检查 ,探测赘生物的位置 ,大小 ,活动度及瓣膜功能。结果　男 11例 ,女 6例。平均年龄 3 4岁 (年龄范围 2～76岁 )。超声心动图检查发现 16例自身瓣膜和 1例人工瓣膜有赘生物形成 ,其中 7个二尖瓣 ,9个主动脉瓣和 1个三尖瓣上有赘生物。平均赘生物大小 0 .8cm (范围 0 .3～ 1.6cm)。血培养葡萄球菌 4例 ,链球菌 4例 ,类酵母菌 1例 ,血培养阳性率 5 3 %。住院期间 4例死亡 (2 3 % ) ,11例充血性心衰 (64 % ) ,6例体循环栓塞 (3 5 % ) ,4例接受了瓣膜置换术 (2 3 % )。结论　超声心动图检测IE声像图观察比较直观 ,尤其在血培养阴性的IE患者尤为有用。超声心动图能探测到瓣膜的赘生物 ,提示严重心衰 ,对于需要早期外科手术的IE患者提供重要依据     

感染性心内膜炎的流行病学和病原学研究——附118例病例分析

目的:为了探讨感染性心内膜炎的流行病学及病原学特点。方法:本文对1978年4月至1997年1月在我院心外科行瓣膜替换术的118例感染性心内膜炎患者的流行病学及病原学特点进行分析。结果:在118例患者中,男性90例,女性28例,平均年龄为34.4a。血培养阳性率为35.6％,瓣膜培养阳性率为41.6％。同时,检测结果显示,瓣膜肠道病毒阳性检出率为41.2％,在血培养阴性者中更高达70.6％。结论:①感染性心内膜炎发病人数有逐年递增趋势,男性患者明显多于女性;②致病微生物以革兰氏阳性菌为主;③肠道病毒亦可能是血培养阴性的感染性心内膜炎的致病因素之一。     

Infective endocarditis: the features of its clinical course and the prognosis

The paper covers an investigation of 150 patients with infective endocarditis (IE), including 100 patients (aged 18 to 30 years old) with intravenous drug abuse as the main risk factor. This subgroup is characterized by an acute clinical course of IE, with tricuspid valve disorder in most cases and septic pulmonary embolism relapse in 72% of cases. Heart failure, multiple cardiac valvular disorder and focal lung destruction were found to be the main factors of unfavorable outcome. A relation between the size of vegetation on the heart valves and the mortality rate was established. At the same time, secondary immunodeficiency due to HIV-infection had no significant effect on the mortality rate in the group of drug addicts. More frequent cases of heart failure with systemic circulation embolism lead to higher hospital mortality in the group of patients with a subacute clinical course of IE. In elderly patients other concomitant pathology resulted in late IE detection and a high mortality rate.     

Echocardiography in infective endocarditis.

BACKGROUND: Echocardiographic demonstration of valvular infection now ranks with positive blood cultures as one of the two major clinical criteria for diagnosis of infective endocarditis (IE), according to new, more accurate guidelines for diagnosis. Because early detection of IE and its complications is essential for determining whether to pursue medical therapy or to intervene surgically, transthoracic echocardiography (TTE) is an essential part of the initial examination of patients with suspected IE. METHODS: Using MEDLINE, we searched and reviewed all articles with the key words infective endocarditis and transesophageal echocardiography. RESULTS: With its superior imaging, transesophageal echocardiography (TEE) has proven to be more sensitive than TTE for the diagnosis of IE as well as in the detection of IE-associated complications. CONCLUSIONS: While superior in predicting which patients with IE have perivalvular abscess or prosthetic valve dysfunction and which are most susceptible to systemic embolism, TEE is more invasive and must be used selectively.     

Results of observation of infective endocarditis patients during 1965-2005

AIM: To clarify the trends in infective endocarditis by our experience for 40 years. MATERIAL AND METHODS: During the last 40 years (1965-2005) we observed 620 patients with infective endocarditis (IE). There were 615 patients with subacute IE (99.2%) and only 5 patients with acute IE (0.8%). There were 402 males (66.8%) and 218 females (35.2%). The age was 16-84 years (mean age 53 +/- 17). We studied the finding of hemoculture, echocardiography, immunological investigations, the levels of C-reactive protein. RESULTS: Streptococcal endocarditis runs a standard course, but more often we encountered staphylococcal, enterococcal endocarditis with a severe course. Predisposing cardiac disorders in 264 IE patients were rheumatic heart disease, congenital heart disease, mitral prolapse, involutive valve disease, hypertrophic cardiomyopathy, prosthetic valve. CONCLUSION: Conventional and unconventional IE cases, recurrent IE, current criteria of IE are described.     

Radionuclide Imaging of Infective Endocarditis: State of Art and Future Perspective

Purpose of Review

Infectious endocarditis is a serious disease requiring rapid diagnosis and accurate risk stratification to offer the best therapeutic strategy. Infection of prosthetic valve (PV) and cardiovascular implantable electronic device (CIED) is increasing due to the ageing of the population and the growing number of implants. Foreign material infection remains clinically challenging given the limitation of ultrasound techniques in this context whereas the diagnosis must be precocious.

Recent Findings

¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography ([¹⁸F]FDG PET/CT) and radiolabelled leukocytes single-photon emission computed tomography/computed tomography (SPECT/CT) are commonly used for this purpose.

Summary

In the present article, we summarized the available evidence for the use of nuclear imaging for the evaluation of infectious endocarditis.

     

An unusual etiology of infective endocarditis: Enterobacter cloacae

Gram-negative microorganisms are rarely implicated in causing infective endocarditis (IE). Although the traditionally identified risk factor for Gram-negative endocarditis has been intravenous drug abuse, recent studies have revealed that healthcare contact and the presence of prosthetic cardiac devices are primary risk factors for IE secondary to non-HACEK Gram-negative bacteria. We present a case of Enterobacter endocarditis in a patient with no prior history of valvular heart disease, implanted endovascular device, or intravenous drug abuse. The patient was treated successfully with carbapenem monotherapy. We have reviewed 43 cases of Enterobacter endocarditis reported in the literature to date. Clinical summary and management of IE secondary to Enterobacter based on all the published cases is outlined.     

Infective endocarditis in the intensive care unit: clinical spectrum and prognostic factors in 228 consecutive patients

Objective To identify factors associated with in-hospital outcome of adult patients admitted to the ICU with infective endocarditis (IE). Design and setting Retrospective study performed in the two medical ICUs of a teaching hospital. Patients and participants The charts of all 228 consecutive patients aged 18 years or older admitted with infective IE between January 1993 and December 2000 were reviewed. All patients satisfied the modified Duke’s criteria for definite IE. Measurements and results There were 146 episodes of native valve endocarditis and 82 of prosthetic valve endocarditis. Staphylococcus aureus was the predominant causative micro-organism. Most complications occurred early during the course of IE. One-half of the patients underwent cardiac surgery during the same hospitalization and had a better outcome than nonoperated patients. The overall in-hospital mortality rate was 45% (102/228). Multivariate analysis revealed the following clinical factors in patients with native valve IE as independently associated with outcome: septic shock (odds ratio 4.81), cerebral emboli (3.00), immunocompromised state (2.88), and cardiac surgery (0.475); in patients with prosthetic valve IE the factors were: septic shock (4.07), neurological complications (3.1), and immunocompromised state (3.46). Conclusions IE still carries high morbidity and mortality rates for the subset of patients requiring ICU admission. Most complications occur early making the decision process for optimal medical and surgical management more difficult. Surgical treatment appears to improve in-hospital outcome. Electronic Supplementary Material Supplementary material is available for this article if you access the article at . A link in the frame on the left on that page takes you directly to the supplementary material.     

Cardiac Positron Emission Tomography: a Clinical Perspective

Cardiac positron emission tomography is a powerful, quantitative, non-invasive imaging modality, which adds valuable diagnostic and prognostic information to the clinical work-up. Myocardial perfusion and viability imaging are, as a result of continuously growing evidence, established clinical indications that may be cost-effective, due to the high diagnostic accuracy of cardiac positron emission tomography, despite high single-test costs. In the field of inflammation imaging, new indications are entering the clinical arena, which may contribute to a better diagnosis and overall patient care, as for instance in patients with cardiac sarcoidosis, prosthetic valve endocarditis and cardiac device infections. This review will discuss the individual strengths and weaknesses of cardiac positron emission tomography and, hence, the resulting clinical usefulness based on the current evidence for an individualized, patient-centered imaging approach.     

Corynebacterium jeikeium-induced infective endocarditis and perivalvular abscess diagnosed by 16S ribosomal RNA sequence analysis: A case report

IntroductionCorynebacterium jeikeium normally presents on human skin, and it is often judged as contamination when it is cultured from blood. C. jeikeium can cause infective endocarditis, especially, that associated with cardiac surgery and prosthetic valvular endocarditis.Case reportA 66-year-old Japanese male patient was diagnosed with C. jeikeium-induced infective endocarditis (IE) and perivalvular abscess after a coronary artery bypass grafting and aortic valve replacement with bioprosthesis; pyogenic spondylodiscitis was also observed. Patch repair for aortic valve annulus and re-Bentall procedure with bioprosthesis was performed for IE and perivalvular abscess. The causative bacterium was confirmed as C. jeikeium on 16S ribosomal RNA sequencing of surgical sample and positive blood culture. The patient underwent six weeks of intravenous antibacterial treatment with vancomycin and an additional two weeks of oral treatment with linezolid, following which, his condition improved. Corynebacterium jeikeium can cause infective endocarditis and perivalvular abscess, which is a more severe condition than IE.Conclusion16S ribosomal RNA sequencing is useful in diagnosing bacterial species that can cause contamination, such as Corynebacterium spp.     

感染性心内膜炎38例临床分析

目的 探讨感染性心内膜炎（IE）的临床特点,诊断,治疗方法及转归.方法 回顾分析近17年38例感染性心内膜炎患者的临床特征及诊断.结果 ①38例患者中36例为自体心脏瓣膜心内膜炎,2例为人工瓣膜心内膜炎.36例自体瓣膜心内膜炎中,基础心脏病占72.22%（26/36）,其中风湿性心脏病占36.11%（13/36）,先天性心脏病占22.22%（8/36）,原发性二尖瓣脱垂占8.33%（3/36）,高血压性心脏病占2.78%（1/36）.心肌病占2.78%（1/36）.②38例患者临床表现包括发热100%（38/38）,寒颤57.89%（22/38）.贫血55.26%（21/38）.脾肿大50%（19/38）.脏器栓寒15.79%（6/38）.③血培养阳性率为31.58%（12/38）.其中8例为链球菌属,4例为葡萄球菌属.④38例患者中30例（78.94%）患者经单纯抗感染治疗后治愈,4例（11.1l%）患者经手术联合药物抗感染治疗后治愈,有4例（11.11%）合并心衰而死亡.⑤38例感染性心内膜炎患者中,无基础心脏病患者10例,有基础心脏病患者26例.10例无基础心脏病患者中有明确感染途径的占6例,26例有基础心脏病患者中有明确感染途径的占7例,两者感染途径阳性率比较差异有统计学意义（P=0.006）.结论 感染性心内膜炎最常见的基础心脏病是风湿性瓣膜病、先天性心脏病、二尖瓣脱垂;对于长期不明原因发热,应考虑有感染性心内膜炎的可能,有明确感染途径而长期发热者应高度怀疑感染性心内膜炎.超声心动图有助于感染性心内膜炎的诊断,血培养阳性率并不高.合并心力哀竭者则预后不良.     

Multisystem organ failure secondary to Haemophilus parainfluenzae infective endocarditis on an ICD lead: A case report

Infection of implanted cardiac devices (ICD) is an unusual but life threatening event, rarely caused by Haemophilus parainfluenzae. While clinical presentation varies widely, infective endocarditis (IE) involving an ICD lead requires aggressive resuscitation and a multidisciplinary approach. We present a case of a 33-year-old intravenous drug user who presented in multisystem organ failure secondary to infective endocarditis on an ICD lead. This patient had a complicated hospital course requiring removal of her ICD, highlighting the dramatic presentation of this clinical state.     

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.     

Cardiovascular Implantable Electronic Device Infection in Patients with Staphylococcus aureus Bacteremia

Background: Staphylococcus aureus bacteremia (SAB) in patients with cardiovascular implantable electronic devices (CIED), including permanent pacemakers (PPMs) and implantable cardioverter‐defibrillators (ICD), can be the sole manifestation of device infection. Methods: To assess clinical factors associated with CIED infection, we retrospectively reviewed all patients with both CIED and SAB seen at Mayo Clinic Rochester between 2001 through 2006. CIED infection was defined using microbiological and clinical criteria. Results: Of the 62 patients with SAB and a CIED, 22 patients (35.5%) had CIED infection. The generator pocket was identified as the source of bacteremia in seven (11%) patients. The majority of CIED infections were device‐related infective endocarditis (12 of 22, 55%). Thirty percent of patients presenting with SAB greater than 1 year after device implantation had CIED infection; all but one had CIED‐related infective endocarditis. Sixty percent of ICD patients (12 of 20) with SAB had CIED infection, compared with 24% of PPM patients (10 of 42, P = 0.01). On univariate analysis factors associated with CIED‐related infective endocarditis included device type [odds ratio (OR) for ICD 13.3, 95% confidence interval [CI] 2.1, 84.9) and presence of a prosthetic heart valve (OR 6.8 95% CI 1.1, 43.4). Conclusions: CIED infection is common in patients with SAB. The presence of an ICD and prosthetic heart valve were associated with CIED‐related infective endocarditis. Subsequent work should focus on prospectively characterizing the subset of patients with CIED infection who present with SAB as the sole manifestation of their device infection. (PACE 2010; 407–413)     

感染性心内膜炎伴心功能不全超声表现北大核心CSCD

目的观察感染性心内膜炎(IE)伴心功能不全超声表现及其诊断价值。方法回顾性收集98例IE伴心功能不全患者,根据纽约心脏协会(NYHA)分级将其分为NYHAⅡ级组(n=30)、NYHAⅢ级组(n=43)及NYHAⅣ级组(n=25);对比3组临床及超声资料,将组间差异有统计学意义的指标纳入logistic回归分析,观察各指标与IE伴心功能不全的关系。结果98例中,45例血培养阳性(45/98,45.92%),其中24例(24/45,53.33%)致病菌为甲型溶血性链球菌;67例(67/98,68.37%)合并心脏基础疾病,其中19例(19/67,28.36%)合并二叶主动脉瓣。经手术治疗后,77例症状减轻,NYHAⅢ级组8例、NYHAⅣ级组13例死亡。3组合并瓣膜反流、赘生物累及多个瓣膜及瓣叶穿孔病例占比差异均有统计学意义(P均<0.05),且重度瓣膜反流、赘生物累及多个瓣膜及瓣叶穿孔是评估IE伴心功能不全分级的独立预测因素(P均<0.05)。结论IE伴心功能不全超声心动图可表现为重度瓣膜反流、赘生物累及多个瓣膜和瓣叶穿孔;根据上述表现可预测其分级。     

感染性心内膜炎194例的临床和病原学特点

目的 分析血培养阳性的感染性心内膜炎(infective endocantitis,IE)患者的临床及病原学特点,为合理使用抗菌药物提供依据.方法 回顾性分析武汉亚洲心脏病医院2014年1月-2018年12月收治的194例血培养阳性的IE患者病历资料,包括年龄、性别、临床表现及病原学检查结果 等.结果 194例血培养阳...     

Effectiveness of combined treatment of infective endocarditis

The purpose of the study was to develop and perfect complex therapy of modern infective endocarditis (IE). Ten-year experience in clinical diagnostics of 240 patients with acute, subacute, and lingering IE was summarized; the effectiveness of their treatment was evaluated. The features of modern IE were acute and subacute course of the disease with the involvement of aortal (37.8% of cases), tricuspid (16.8%), mitral (15.2%) valve, and septicemia, caused by highly virulent microflora (staphylococci--51% of cases; gram-negative bacteria--13%; fungi--5%). The clinical manifestations of modern IE included toxic infectious syndrome (24% of cases), heart failure (21%), symptoms of complications (16%), central hemodynamics disturbances (12%), and splenomegaly (8%). The treatment included antibacterial, pathogenetic, and symptomatic therapy, as well as extracorporal hemocorrection and cardiosurgery. Analysis of the results of surgical treatment of 140 IE patients allowed development of indications for valve prosthesis.     

感染性心内膜炎的临床变迁（附116例临床分析）

目的 探讨感染性心内膜炎(IE)的病因、致病微生物的变化、临床变迁及预后等因素，提高IE的诊治水平。方法 对1990年6月-2002年6月住院的116例IE患基础心脏病情况、主要临床表现、血培养、超声心动图检查、治疗结果及预后等进行分析。结果 IE基础心脏病中，先天性心脏病的比例(34．5％)有所升高，而风湿性心脏病的比例(25．9％)有所下降，无器质性心脏病的比例(19．O％)较既往国内外报道的发病率有明显的提高。血培养阳性率为41．4％，草绿色链球菌是IE的主要致病菌(29．2％)；近年来，发现条件致病菌假单胞菌属引起IE(本组4例)。超声心动图探测心内赘生物的比例为65．5％。人工瓣膜性IE发病率(17．2％)有所升高，死亡率为25．O％。本组死亡13例(11．2％)，本病预后严重。结论 IE基础心脏病和致病菌发生较明显变化，超声心动图对IE诊断及治疗有重要价值，本病预后严重，人工瓣膜性IE发病率及死亡率高，应尽早手术治疗。     

Time interval between infective endocarditis first symptoms and diagnosis: relationship to infective endocarditis characteristics,microorganisms and prognosis

Objective: To analyze the characteristics and outcome of infective endocarditis (IE) according to the time interval between IE first symptoms and diagnosis.

Methods: Among the IE cases of a French population-based epidemiological survey, patients having early-diagnosed IE (diagnosis of IE within 1 month of first symptoms) were compared with those having late-diagnosed IE (diagnosis of IE more than 1 month after first symptoms).

Results: Among the 486 definite-IE, 124 (25%) had late-diagnosed IE whereas others had early-diagnosed IE. Early-diagnosed IE were independently associated with female gender (OR?=?1.8; 95% CI [1.0–3.0]), prosthetic valve (OR=?2.6; 95% CI [1.4–5.0]) and staphylococci as causative pathogen (OR?=?3.7; 95% CI [2.2–6.2]). Cardiac surgery theoretical indication rates were not different between early and late-diagnosed IE (56.3% vs 58.9%), whereas valve surgery performance was lower in early-diagnosed IE (41% vs 53%; p?=?.03). In-hospital mortality rates were higher in early-diagnosed IE than in late-diagnosed IE (25.1% vs 16.1%; p?Conclusions: The time interval between IE first symptoms and diagnosis is closely related to the IE clinical presentation, patient characteristics and causative microorganism. Better prognosis reported in late-diagnosed IE may be related to a higher rate of valvular surgery.

• KEY MESSAGES

• Infective endocarditis, which time interval between first symptoms and diagnosis was less than one month, were mainly due to Staphylococcus aureus in France.

• Staphylococcus aureus infective endocarditis were associated with septic shock, transient ischemic attack or stroke and higher mortality rates than infective endocarditis due to other bacteria or infective endocarditis, which time interval between first symptoms and diagnosis was more than one month.

• Infective endocarditis, which time interval between first symptoms and diagnosis was more than one month, were accounting for one quarter of all infective endocarditis in our study and were associated with vertebral osteomyelitis and a higher rate of cardiac surgery performed for hemodynamic indication than other infective endocarditis.