Positron emission tomography/computed tomography for diagnosis of prosthetic valve endocarditis: increased valvular 18F-fluorodeoxyglucose uptake as a novel major criterion

Abstract

Purpose: The diagnosis of Prosthetic Valve Endocarditis (PVE) remains challenging. In PVE cases, initial echocardiography is normal or inconclusive in almost 30% of cases, leading to a decreased diagnostic accuracy for the modified Duke criteria. We sought to determine the value of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) for diagnosing PVE. Methods: We prospectively studied 72 consecutive patients suspected of having PVE. All of the patients were subjected to clinical, microbiological, and echocardiographic evaluation. Cardiac PET/CT was performed at admission. The final diagnosis was defined according to the clinical and/or pathological modified Duke criteria determined during a 3-month follow-up. Results: A total of 36 (50%) patients exhibited abnormal FDG uptake around the site of the prosthetic valve. The sensitivity, specificity, positive predictive value, negative predictive value, and global accuracy were as follows (95% confidence interval): 73% (54%-87%), 80% (56%-93%), 85% (64%-95%), 67% (45%-84%), and 76% (63%-86%), respectively. Adding abnormal FDG uptake around the prosthetic valve as a new major criterion significantly increased the sensitivity of the modified Duke criteria at admission [70% (52%-83%) vs. 97% (83%-99%), p=0.008]. This result was due to a significant reduction (p<0.0001) in the number of possible PVE cases from 40 (56%) to 23 (32%). Conclusions: The use of 18F-FDG PET/CT is helpful for diagnosing PVE. The results of this study support the addition of abnormal FDG uptake as a novel major criterion for PVE.