From the Guidelines
Clinical Cases of Infective Endocarditis
Infective endocarditis can manifest in various clinical cases, with two notable examples being prosthetic valve endocarditis and native valve endocarditis in intravenous drug users.
- Prosthetic valve endocarditis is a serious condition that occurs when a prosthetic heart valve becomes infected, often with microorganisms such as coagulase-negative staphylococci, Staphylococcus aureus, or Enterococcus sp. 1.
- Native valve endocarditis in intravenous drug users is another clinical case, where the infection typically occurs on the tricuspid valve and is often caused by Staphylococcus aureus 1.
Diagnosis and Management
The diagnosis of infective endocarditis involves a combination of clinical presentation, blood cultures, and imaging studies such as transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) 1.
- Blood cultures are essential for identifying the causative microorganism, but may be negative in up to 20% of cases, making empirical antibiotic therapy challenging 1.
- The management of infective endocarditis requires a multidisciplinary approach, with consideration of antimicrobial therapy, surgical intervention, and supportive care 1.
Empirical Antibiotic Therapy
Empirical antibiotic therapy for infective endocarditis should be guided by the clinical presentation, epidemiological features, and the results of blood cultures, if available 1.
- For native valve endocarditis, empirical therapy may include coverage for Staphylococcus aureus, viridans group streptococci, and enterococci, while for prosthetic valve endocarditis, coverage for oxacillin-resistant staphylococci and aerobic Gram-negative bacilli may be necessary 1.
From the Research
Clinical Cases of Infective Endocarditis
- Two clinical cases of infective endocarditis are presented in the study 2, which involved complicated infective endocarditis with various systemic complications.
- The first case involved a patient with prosthetic valve endocarditis complicated by intracerebral hemorrhage caused by mycotic aneurysm rupture, while the second case involved a patient with right-sided valve endocarditis associated with a central catheter and complicated by an abdominal aortic mycotic aneurysm.
Characteristics of the Cases
- The cases presented in the study 2 highlight the complexity and variability of infective endocarditis, with different causal agents and clinical presentations.
- The study 3 also presents a case series involving three different clinical presentations of subacute endocarditis with fastidious microorganisms, which required extensive medical management and surgical valve repair with favorable and unfavorable outcomes.
Microbiological Aspects
- The microbiology of infective endocarditis has changed over time, with staphylococci becoming the most common cause of the disease, as reported in the study 4.
- The study 5 notes that infective endocarditis can involve almost any organ system in the body and that the diagnosis may be difficult to establish, requiring a combination of clinical, microbiological, and echocardiography results.