ABC | Volume 112, Nº2, February 2019

Viewpoint Early Diagnosis and Treatment in Infective Endocarditis: Challenges for a Better Prognosis Daniely Iadocico Sobreiro, 1 Roney Orismar Sampaio, 1 R inaldo Focaccia Siciliano, 2 Calila Vieira Andrade Brazil, 1 Carlos Eduardo de Barros Branco, 1 Antônio Sergio de Santis Andrade Lopes, 1 Flávio Tarasoutchi, 1 Tânia Mara Varejão Strabelli 2 Unidade Clínica de Cardiopatias Valvares do Instituto do Coração do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, 1 São Paulo, SP – Brazil Unidade de Controle de Infecção Hospitalar do Instituto do Coração do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, 2 São Paulo, SP – Brazil Mailing Address: Roney Orismar Sampaio • Rua Comandante Garcia d`Avila, 412. Postal code 05654-040, Morumbi, São Paulo, SP – Brazil E-mail: orismar@cardiol.br, sampaioroney@yahoo.com.br Manuscript received May 15, 2018, revised manuscript August 08, 2018, acepted September 05, 2018 Keywords Endo c a r d i t i s , Ba c t e r i a l /mo r t a l i t y ; P r o s t he s i s Implantation; Catheters; Pacemaker, Artificial; Diagnostic Imaging; Echocardiography. DOI: 10.5935/abc.20180270 Infective endocarditis (IE), a microbial infection of the cardiac or adjacent vascular endothelium, remains a feared disease, although the modern diagnosis systematizations date back to 1885 by Osler. 1 Although relatively uncommon, 2 with approximately 3-10 cases per 100,000 individuals/year, 3 the mortality remains high: more than one-third of patients die in the first year after the diagnosis. 1,4 Only early diagnosis and treatment, whether exclusively clinical or associated with cardiac surgery, may interfere to reduce this high mortality rate. IE used to bemore frequent in young andmiddle-aged adults with rheumatic or congenital heart disease. 3 However, recent studies have shown a significant reduction in the incidence of IE in these groups, especially in more developed countries. 2 IE can be increasingly seen in patients with valve prostheses, vascular catheters, implantable electronic devices such as pacemakers and implantable cardiac defibrillators 5,6 and new surgical devices, such as transcatheter valve implantation. 2 Moreover, due to the population aging, even in Brazil, an increased incidence has been observed in the elderly, especially when associated with comorbidities such as diabetes (20%), chronic kidney disease (14%) and anemia (10%), 5 with a 4.6-fold increase in IE, when compared to the general population. 5,6 At the same time, reflecting the change in the epidemiology, the incidence of endocardial infection by staphylococci has been steadily increasing, even predominating in relation to streptococci in many centers. 3,7 The diagnosis of IE is based on the modified Duke Criteria for Infective Endocarditis: the association of clinical signs (such as fever and presence of murmur in patients with risk of heart disease), positive blood culture for frequent etiological agents and typical echocardiographic findings (vegetation, periannular abscess) 4 show high sensitivity (> 80%), mainly in native valve infections. 4,6 However, the criteria show lower diagnostic accuracy for an early diagnosis in clinical practice, mainly in the previously mentioned group of patients, in which the incidence has been increasing. The diagnosis is challenging, especially if the echocardiography is normal or inconclusive, as it occurs in up to 30% of cases, 8 or when blood cultures are negative. 4,6 In fact, negative blood cultures occur in approximately 2% to 20% of cases of endocarditis. Common causes are: concomitant or prior use of antibiotics and presence of slow-growing or difficult-to-detect microorganisms in routine cultures. The following microorganisms stand out: Coxiella burnetii , Bartonella species and fungi. 4 The incidence of negative blood cultures has been reduced 3 with automated blood culture techniques, specific serologies ( Coxiella sp ) andpolymerase chain reaction (PCR). Thesemethods 2 allow the direct identification of bacterial species, especially in difficult-to-recognize cases, helping to attain an early diagnosis in relation to routine culture methods. 3 (Figure 1) Imaging methods, mainly echocardiography, play a key role in the diagnosis and management of IE. 6 Being the technique of choice for the initial investigation, it should be rapidly performed, and if the clinical suspicion persists in the transthoracic modality, the transesophageal assessment should be carried out, with an evident increase in the method accuracy. Individuals with prostheses and catheters or devices often require assessment by transesophageal echocardiography (TEE), considering that the sensitivity and specificity rates are between 40-70% for transthoracic echocardiography (TTE) and 85% for TEE in prosthetic valves. 8 A negative result in the TEE does not exclude IE in patients with strong clinical suspicion. Therefore, the examination should be repeated within seven days for diagnostic clarification, whenever there is the possibility of IE. The echocardiographic diagnosis may be limited by acoustic shadowing, confusing images, especially in the postoperative period, very small vegetation or absence of vegetation. 1 These limitations led to a growing interest in the use of other imaging modalities that would complement the echocardiography. 9,10 The use of transesophageal three-dimensional echocardiography has improved the evaluation of cardiac volumes and structures, mainly for better identification of paraprosthetic regurgitation. This technique has improved and will certainly be even more useful in the near future. 8 201