Infective endocarditis (IE) is a very complex condition that can be difficult to diagnose. If left unchecked, it can have severe consequences. While the Duke criteria can help diagnose some cases, it cannot solve all of them. To address this issue, the European Society of Cardiology proposed using positron emission tomography / computer tomography (PET/CT) with 18F-fluorodesoxyglucose as a marker for increased metabolism in their 2015 guidelines. So, what is the impact of these guidelines?
To find out, a search was conducted on PubMed using the terms “endocarditis AND PET” for articles published from 2016 onwards. PET with 18-fluoro-desoxyglucose can help identify inflammation, infection, and malignancies. Out of one hundred search results, only 41 articles were relevant. Among them, only 16 were original series, which had low numbers. The rest of the articles were editorials, comments, reviews, and “image vignettes.”
PET/CT can increase the sensitivity of the Duke criteria in cases of prosthetic valve endocarditis (PVE), but it has a much lesser impact in native valve endocarditis (NVE). Patient preparation is critical to ensure accurate results. This includes following a low carbohydrate – high-fat diet, fasting, and administering unfractionated heparin. Standardizing image acquisition and processing (quantification, correction for attenuation, and accounting for implanted metallic materials) is also essential.
It is important to distinguish between infection and inflammation from other causes, such as postoperative healing and foreign body reaction. Scintigraphic techniques based on radiolabeled WBC can help distinguish between sterile inflammation and infection. Antibiotics and inflammation should also be considered, especially in cases where negative imaging results are obtained before a cure.
PET/CT is a valuable tool for diagnosing IE, particularly PVE. However, early postoperative cases must be interpreted with caution. To confirm the value of PET/CT, major centers should standardize their methods. This will allow for the comparison of results from larger patient groups, which can be collected in the International Collaboration of Endocarditis – Prospective Cohort Study. A standardized method for patient preparation, imaging acquisition, and processing is needed, which can best be undertaken through the International Collaboration on Endocarditis– Prospective Control Study ICE-PCS. Nuclear cardiologists should also be included in endocarditis teams.
Author(s) Details:
Wilhelm P. Mistiaen,
Department of Health and Social Care, Artesis Plantijn University College Antwerp, Belgium and Faculty of Medicine and Health Sciences, University of Antwerp, Belgium.
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