Diagnosis of Infective Endocarditis by Subtype Using ¹⁸F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography: A Contemporary Meta-Analysis

Background Infective endocarditis (IE) remains a difficult to diagnose condition associated with high mortality. ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) has recently emerged as another IE imaging modality, although diagnostic accuracy varies across observational studies and types of IE. This meta-analysis assessed the diagnostic performance of ¹⁸F-FDG PET/CT for IE and its subtypes. Methods We searched Pubmed, Cochrane, and Embase from January 1980 to September 2019 for studies reporting both sensitivity and specificity of ¹⁸F-FDG PET/CT for IE. Meta-Disc 1.4 was used to pool data for all cases of IE and its subgroups of native valve IE, prosthetic valve IE, and cardiac implantable electronic devices IE. Results We screened 2566 records from the search, assessed 52 full-text articles, and included 26 studies totaling 1358 patients (509 IE cases). Pooled sensitivity and specificity (95% CI, inconsistency I-square statistic) were 0.74 (0.70-0.77, 71.5%) and 0.88 (0.86-0.91, 78.5%) for all cases of endocarditis. Corresponding parameters for native valve IE were sensitivity 0.31 (0.21-0.41, 29.4%) and specificity 0.98 (0.95-0.99, 34.4%); for prosthetic valve IE: sensitivity 0.86 (0.81-0.89, 60.0%) and specificity 0.84 (0.79-0.88, 75.2%); and for cardiac implantable electronic devices IE: sensitivity 0.72 (0.61-0.81, 76.2%) and specificity 0.83 (0.75-0.89, 83.6%). Pooled sensitivities and specificities were higher for the 17 studies since 2015 than the 9 studies published before 2015. Conclusions ¹⁸F-FDG PET/CT had high specificity for all IE subtypes; however, sensitivity was markedly lower for native valve IE than prosthetic valve IE and cardiac implantable electronic devices IE. It is, therefore, a useful adjunct modality for assessing endocarditis, especially in the challenging scenarios of prosthetic valve IE and cardiac implantable electronic devices IE, with improving performance over time, related to advances in ¹⁸F-FDG PET/CT techniques.