Advantages of 18F-FDG PET/CT Imaging over Modified Duke Criteria and Clinical Presumption in Patients with Challenging Suspicion of Infective Endocarditis.

Valentin Pretet,Alessio Imperiale,Olivier Morel,Cyrille Blondet,Matias Martinez,Thomas Schindler,Yvon Ruch,Soraya El Ghannudi,Yves Hansmann

doi:10.3390/diagnostics11040720

Abstract

According to European Society of Cardiology guidelines (ESC2015) for infective endocarditis (IE) management, modified Duke criteria (mDC) are implemented with a degree of clinical suspicion degree, leading to grades such as “possible” or “rejected” IE despite a persisting high level of clinical suspicion. Herein, we evaluate the 18F-FDG PET/CT diagnostic and therapeutic impact in IE suspicion, with emphasis on possible/rejected IE with a high clinical suspicion. Excluding cases of definite IE diagnosis, 53 patients who underwent 18F-FDG PET/CT for IE suspicion were selected and afterwards classified according to both mDC (possible IE/Duke 1, rejected IE/Duke 0) and clinical suspicion degree (high and low IE suspicion). The final status regarding IE diagnosis (gold standard) was based on the multidisciplinary decision of the Endocarditis Team, including the ‘imaging specialist’. PET/CT images of the cardiac area were qualitatively interpreted and the intensity of each focus of extra-physiologic 18F-FDG uptake was evaluated by a maximum standardized uptake value (SUVmax) measurement. Extra-cardiac 18F-FDG PET/CT pathological findings were considered to be a possible embolic event, a possible source of IE, or even a concomitant infection. Based on the Endocarditis Team consensus, final diagnosis of IE was retained in 19 (36%) patients and excluded in 34 (64%). With a sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and global accuracy of 79%, 100%, 100%, 89%, and 92%, respectively, PET/CT performed significantly better than mDC (p = 0.003), clinical suspicion degree (p = 0.001), and a combination of both (p = 0.001) for IE diagnosis. In 41 patients with possible/rejected IE but high clinical suspicion, sensitivity, specificity, PPV, NPV, and global accuracies were 78%, 100%, 100%, 85%, and 90%, respectively. Moreover, PET/CT contributed to patient management in 24 out of 53 (45%) cases. 18F-FDG PET/CT represents a valuable diagnostic tool that could be proposed for challenging IE cases with significant differences between mDC and clinical suspicion degree. 18F-FDG PET/CT allows a binary diagnosis (definite or rejected IE) by removing uncertain diagnostic situations, thus improving patient therapeutic management.

Highlights

Infective endocarditis (IE) is an uncommon and challenging infectious disease associated with severe complications and high mortality despite major advances in diagnostic and therapeutic strategies [1,2]
At present, diagnosis of IE is usually based on clinical probability in combination with modified Duke criteria (mDC), which are dependent on the diagnostic accuracy of either transthoracic (TTE) or transesophageal echocardiography (TEE)
This is a non-interventional, monocentric, retrospective study involving patients addressed to the Nuclear Medicine Department of the Strasbourg University Hospitals (France) for 18 F-FDG positron emission tomography/computed tomography (PET/CT) between May 2013 to November 2019 for suspected IE

Summary

Introduction

Infective endocarditis (IE) is an uncommon and challenging infectious disease associated with severe complications and high mortality despite major advances in diagnostic and therapeutic strategies [1,2]. MDC show inadequate accuracy for IE diagnosis, in patients with prosthetic valve endocarditis (PVE) and pacemaker or defibrillator lead IE, for which echocardiography is inconclusive in up to one-third of patients [5]. This is true in early stages of the infectious process when the physician could have high clinical suspicion without a corresponding adequate mDC score for making the IE diagnosis. At present, diagnosis of IE is usually based on clinical probability in combination with mDC (definite, possible, or rejected IE), which are dependent on the diagnostic accuracy of either transthoracic (TTE) or transesophageal echocardiography (TEE). It is possible to grade patients as having “possible” or even “rejected” IE despite a persisting high level of clinical suspicion [3,4]

Methods

Results

Discussion

Conclusion