1. Introduction

Infective endocarditis is a broad topic that encompasses various types of infections of the heart and is typically used to describe abscess cavities, infectious or inflammatory vegetations on cardiac structures such as valves or implanted prosthetic devices, fistulae, or areas of localized infectious tissue destruction. Without a doubt, infectious problems involving the heart or cardiac structures represent a formidable diagnostic and therapeutic clinical problem. Furthermore, despite advances in medical and surgical therapies—some of which are highlighted in this text there are concerns that there are significant increases in the number of cases reported. Even more concerning are some of the issues that have resulted in the increased incidence of endocarditis case and what impact these issues might have on how individual patients are managed and how society approaches this complex (and expensive) medical, surgical, and—now—social problem.

It is also becoming more apparent that even relatively minor procedures are associated with a risk of infecting both native and prosthetic cardiac structures [1]. Historically, it was assumed that procedures, such as dental work, had a significant role in the development of endocarditis and other procedures, such as endoscopic evaluations, had a minimal role, and therefore prophylactic antibiotics before all such "minor" procedures were not necessary. However, recent evidence suggests that there is a much greater risk for post-procedure endocarditis than initially thought—especially those with inherently abnormal cardiac structures, such as mitral valve prolapse or bicuspid aortic valves [2].

The epidemiology of infections reflects not only the dark side of the progresses in medical therapy but also some of the social problems that plague modern society. The changing microbiology also reflects how this complex disease has also paralleled the advances in medicine. Diagnostic tools continue to evolve with not only improvements in imaging technologies but also our understandings on how to appropriately use them to better understand the overall clinical picture. In addition, the role of therapies—especially early surgical intervention—has

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and eproduction in any medium, provided the original work is properly cited. © 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

been demonstrated to have a significant impact on the management and outcomes of infected patients. The goal of this text is to highlight some of the current concepts in the clinical characteristics, the presentation, the diagnosis, and the management options.

spectrum of clinical presentation, medical and surgical teams are becoming better at individu-

Introductory Chapter: Introduction to Advanced Concepts in Endocarditis

http://dx.doi.org/10.5772/intechopen.79883

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A growing challenge has also been the "war" between evolving resistant bacteria, multidrugresistant organisms, polymicrobial infections, and opportunistic fungi and the drug therapies that are available to safely and appropriately treat these infections. Such infections clearly have been shown to be predictors of poor outcomes and are often primary indications for urgent surgical intervention [11]. While advances in techniques used for testing of genetic techniques and cellular markers have improved the ability to define a causative agent, this does not inherently imply that such infectious are any easier to treat [12]. In addition, the growing recognition of "sepsis" and aggressiveness toward early treatment and diagnostic evaluations might have a secondary effect on the earlier recognition and overall incidence of diagnosing endocarditis. Nevertheless, without a doubt, the growing and routine use of immune modulating medications for common diseases such as rheumatoid arthritis, inflammatory bowel disease, and psoriasis (just to name a few) has also increased the incidence of unusual bacterial and fungal infections—of which progressing to endocarditis is common [13]. Another growing population is those adults with congenital heart disease. Many of these patients have had multiple previous surgical procedures involving prosthetic material and are, in general, living longer—both are risk factors for developing endocarditis [14, 15]. In addition, while the overall focus tends to be on infectious causes, there is clearly much to learn about noninfectious causes

While it is often believed that positive blood cultures are the sine qua non in the diagnosis of endocarditis, it must be recognized that patients can often present with extensive destruction, and involvement of their cardiac structures has negative cultures. The original Duke Criteria has for many years provided the foundation for the diagnostic criteria of endocarditis [17]. However, advances in imaging technology and broader application of such technology have also proven to be extremely useful in the management of infected patients and guiding therapy [18]. Historically, transthoracic and transesophageal imaging were considered and still are first-line diagnostic tests to evaluate patients with suspected endocarditis—and current guidelines and appropriateness criteria continue to support their liberal use [2, 12]. The role of other imaging modalities, such as 3D echocardiography, computed tomography (CT), magnetic resonance imaging, and positron-emission tomography (PET) is expanding [19, 20]. Furthermore, not only is early use of advanced imaging well established in the diagnosis and management of endocarditis; it is clear that there should be a low threshold for repeat imaging to follow the response to medical therapies or, more specifically, help identify those patients who

of endocarditis such as marantic or Libman-Sacks endocarditis [16].

are failing medical therapy and might benefit from surgical intervention.

alizing care plans.

3. Microbiology

4. Diagnosis
