Diagnostic Accuracy of 18F-FDG PET/CT in Infective Endocarditis and Implantable Cardiac Electronic Device Infection: A Cross-Sectional Study.
Early diagnosis of infective endocarditis (IE) is based on the yielding of blood cultures and echocardiographic findings. However, they have limitations and sometimes the diagnosis is inconclusive, particularly in patients with prosthetic valves (PVs) and implantable cardiac electronic devices (ICEDs). The primary aim of this study was to evaluate the diagnostic accuracy of18F-FDG PET/CT in patients with suspected IE and ICED infection.


METHODS
A prospective study with 80 consecutive patients with suspected IE and ICED infection (65 men and 15 women with a mean age of 68 ± 13 y) between June 2013 and May 2015 was performed in our hospital. The inclusion criteria were clinically suspected IE and ICED infection at the following locations: native valve (NV) (n = 21), PV (n = 29), or ICED (n = 30) (automatic implantable defibrillator [n = 11] or pacemaker [n = 19]). Whole-body18F-FDG PET/CT with a myocardial uptake suppression protocol with unfractionated heparin was performed in all patients. The final diagnosis of infection was established by the IE Study Group according to the clinical, echocardiographic, and microbiologic findings.


RESULTS
A final diagnosis of infection was confirmed in 31 patients: NV (n = 6), PV (n = 12), and ICED (n = 13). Sensitivity, specificity, positive predictive value, and negative predictive value for18F-FDG PET/CT were 82%, 96%, 94%, and 87%, respectively.18F-FDG PET/CT was false-negative in all cases with infected NV.18F-FDG PET/CT was able to reclassify 63 of 70 (90%) patients initially classified as possible IE by modified Duke criteria. In 18 of 70 cases,18F-FDG PET/CT changed possible to definite IE (26%) and in 45 of 70 cases changed possible to rejected IE (64%). Additionally,18F-FDG PET/CT identified 8 cases of septic embolism and 3 of colorectal cancer in patients with a final diagnosis of IE.


CONCLUSIONS
18F-FDG PET/CT proved to be a useful diagnostic tool in suspected IE and ICED infection and should be included in the diagnostic algorithm for early diagnosis.18F-FDG PET/CT is not useful in the diagnosis of IE in NV but should be also considered in the initial assessment of this complex scenario to rule out extracardiac complications and possible neoplasms.
Nuclear Medicine Department, Hospital Clinic, Barcelona, Spain.
Ulises
U
Granados
Nuclear Medicine Department, Hospital Clinic, Barcelona, Spain dfuster@clinic.ub.es.|Institut d'Investigacions Biomèdiques Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain.
David
D
Fuster
Institut d'Investigacions Biomèdiques Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain.|Infectious Diseases Department, Hospital Clinic, Barcelona, Spain.
Juan M
JM
Pericas
Statistics Department, Faculty of Biology, University of Barcelona, Barcelona, Spain.
Jaime L
JL
Llopis
Institut d'Investigacions Biomèdiques Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain.|Cardiovascular Surgery Department, Hospital Clinic, Barcelona, Spain.
Salvador
S
Ninot
Institut d'Investigacions Biomèdiques Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain.|Cardiovascular Surgery Department, Hospital Clinic, Barcelona, Spain.
Eduard
E
Quintana
Clinical Microbiology Department, Hospital Clinic, Barcelona, Spain; and.
Manel
M
Almela
Institut d'Investigacions Biomèdiques Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain.|Cardiology Department, Hospital Clinic, Barcelona, Spain.
Carlos
C
Paré
Institut d'Investigacions Biomèdiques Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain.|Cardiovascular Surgery Department, Hospital Clinic, Barcelona, Spain.
José M
JM
Tolosana
Institut d'Investigacions Biomèdiques Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain.|Cardiology Department, Hospital Clinic, Barcelona, Spain.
Carlos
C
Falces
Institut d'Investigacions Biomèdiques Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain.|Infectious Diseases Department, Hospital Clinic, Barcelona, Spain.
Asuncion
A
Moreno
Nuclear Medicine Department, Hospital Clinic, Barcelona, Spain.|Institut d'Investigacions Biomèdiques Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain.
Francesca
F
Pons
Nuclear Medicine Department, Hospital Clinic, Barcelona, Spain.|Institut d'Investigacions Biomèdiques Pi i Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain.
Francisco
F
Lomeña
Jose M
JM
Miro
D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D017147:Defibrillators, Implantable / Q000009:adverse effects*; D004696:Endocarditis / Q000000981:diagnostic imaging* / Q000209:etiology*; D019317:Evidence-Based Medicine; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010138:Pacemaker, Artificial / Q000009:adverse effects*; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
18F-FDG-PET/CT; implantable cardiac electronic devices; infective endocarditis; prosthetic valve; septic embolisms