From the Guidelines
The prototypic lesion of infective endocarditis is a vegetation, which is a mass of platelets, fibrin, microorganisms, and inflammatory cells that adheres to the heart valves or endocardial surface. This is based on the most recent and highest quality study available, which highlights the importance of vegetations in the diagnosis and management of infective endocarditis 1. According to this study, the presence of vegetations is the hallmark for a definitive diagnosis of infective endocarditis, and transesophageal echocardiography (TEE) is the most sensitive imaging technique for identifying them.
Some key characteristics of vegetations include:
- They are oscillating masses attached to valvular structures, with a motion independent of that of the valve 2
- They can also present as non-oscillating masses with atypical features 2
- Their size and other characteristics on echocardiography can be useful in predicting complications such as peripheral embolization 1
It's worth noting that other manifestations of infective endocarditis, such as Janeway lesions, Osler's nodes, and Roth's spots, are immunological phenomena that may occur as a result of the infection, but they are not the defining lesions of the disease itself. The primary pathological finding at the site of infection is the vegetation, which is why it is considered the prototypic lesion of infective endocarditis. The use of TEE to identify vegetations has been shown to have a high sensitivity and specificity, with a negative predictive value of up to 98.6% in suspected infective endocarditis 1.
From the Research
Definition of Prototypic Lesion
The prototypic lesion of infective endocarditis is characterized as a mass of:
- Platelets
- Fibrin
- Microcolonies of microorganisms
- Scant inflammatory cells, referred to as a vegetation 3, 4
Composition and Formation
The vegetation is composed of various elements, including:
- Platelets
- Fibrin
- Microorganisms
- Inflammatory cells The formation of the vegetation is associated with endothelial injury, deposition of non-infective sterile thrombotic vegetations, and transient bacteremia with microorganism adhesion 4
Clinical Significance
The presence of vegetations is a key diagnostic feature of infective endocarditis, and their size and morphology can be used to predict the risk of embolic events and mortality 5 Echocardiography, including transthoracic (TTE) and transesophageal (TEE) echocardiography, plays a crucial role in detecting vegetations and assessing their size, shape, location, and mobility 3, 5, 6