Abstract
Introduction
Infective Endocarditis (IE) is an uncommon disease that can lead to serious complications and mortality. It is diagnosed based on modified duke criteria, with relevant findings on clinical examination, echocardiography, microbiological studies, and imaging, and the sensitivity of the same can be improved by new imaging techniques as per the European Society of Cardiology (ESC) 2015, if echocardiography/Microbiological studies are inconclusive, particularly to diagnose Prosthetic Valve Endocarditis (PVE).
Case report
A 79-year-old female presented with confusion and high-grade fever. Electrocardiography showed Atrial Fibrillation (AF). Blood culture resulted positive for Group G Streptococcus, and she was started on Benzylpenicillin. Echocardiography showed old calcified posterior mitral annulus and associated thickening of the underside of the posterior mitral valve with independent motion seen only in some views. It could not exclude valvular endocarditis. Echocardiography was repeated after 1 week, which showed an abnormal posterior mitral valve with thickened echo bright mass and its appearance was larger than that of the previous study. The valvular multi-disciplinary team (MDT) reviewed the case, concluded that the imaging is non-conclusive, and advised further imaging, as the patient cannot be anticoagulated for AF if there is active Endocarditis. 18F-FDG PET CT showed focal intense activity about the heavily calcified mitral valve to support Valvular Endocarditis with no other metabolic evidence identified. The patient was treated for native valve endocarditis and started on anticoagulation after completing the antibiotic treatment.
Discussion
18F-FDG PET CT is widely used to improve the diagnosis of Prosthetic Valve Endocarditis, however, the evidence of its use in patients with native valve endocarditis is limited. Furthermore, it can detect the inflammation before the structural changes occur which is necessary for echocardiographic detection. In this patient, 18F-FDG PET CT supported the diagnosis of Valvular endocarditis after two inconclusive echocardiographic studies.
Reference
Abikhzer G et al., 2022, J Nucl Cardiol., DOI:10.1007/s12350-020-02092-6.
Ten Hove D et al., 2021, Curr Cardiol Rep., DOI:10.1007/s11886-021-01542-y.
Gilbert Habib et al., 2015, Eur Heart J., DOI:10.1093/eurheartj/ehv319.