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 (PV) and implantable cardiac electronic devices (ICED). The primary aim of this study was to evaluate the diagnostic accuracy of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in patients with suspected IE an 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 years old) between June 2013 and May 2015 was performed in our hospital. The inclusion criteria was 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-body 18F-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 microbiological 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 (PPV) and negative predictive value (NPV) for 18F-FDG PET/CT was 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 63/70 (90%) patients initially classified as possible IE by modified Duke criteria. In 18/70 cases 18F-FDG PET/CT changed possible to definite IE (26%) and in 45/70 cases changed possible to rejected IE (64%). Additionally, 18F-FDG PET/CT identified 8 cases of septic embolism and 3 colorectal cancer in patients with final diagnosis of IE. CONCLUSION: 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

Utilidad de la PET/TC con 18F-Fluorodesoxiglucosa en la detección de infecciones cardiovasculares y embolias sépticas hematógenas

[spa] Las infecciones cardiovasculares (ICV) son entidades de difícil manejo que presentan un alto riesgo de mortalidad y de complicaciones severas. Dentro de estas complicaciones, el diagnóstico temprano de posibles embolias sépticas hematógenas (ESH) es un reto en la práctica clínica diaria y resulta crucial para el correcto manejo de estos pacientes, principalmente aquellas con clínica silente como es el caso de las espondilodiscitis. Los hemocultivos y los hallazgos del ecocardiograma continúan siendo los pilares en la sospecha y en el diagnóstico inicial. Sin embargo, el rendimiento de las pruebas diagnósticas actuales no es óptimo, persistiendo un alto porcentaje de pacientes sin un diagnóstico de confirmación. Las dificultades radican en la interpretación de los estudios microbiológicos y ecocardiográficos, principalmente en los pacientes portadores de válvulas protésicas (VP) y dispositivos de electroestimulación cardiaca (DEC). Publicamos estudios prospectivos observacionales de dos grupos de pacientes: En el primer artículo se estudiaron 80 pacientes consecutivos con sospecha de endocarditis infecciosa (EI) y/o infección de DEC (EI-DEC). Se les realizó PET/TC con inhibición miocárdica, de acuerdo a las siguientes indicaciones: sospecha de EI sobre válvulas nativas (VN) (n:21), EI-VP (n:29) o infección de DEC (n= 30). El diagnóstico final de infección se estableció en 31/80 pacientes: EI-VN (n:6), EI-VP (n:12), EI-DEC (n:8) e infección de DEC (n= 5). Los valores de sensibilidad, especificidad, VPP y VPN de la PET/TC fueron 82%, 96%, 94% y 87%, si se excluyeran las VN estos valores fueran 96%, 94%, 93% y 97%, respectivamente. La PET/TC identificó 8 casos de embolismos sépticos en los pacientes con infección (4 embolias pulmonares, 2 esplénicas y 2 vertebrales) y 3 casos de cáncer colo-rectal en estadios iniciales . La PET/TC fue capaz de reclasificar 63/70 casos (90%) inicialmente clasificados como posibles EI por los criterios de Duke modificados. En el segundo artículo se estudiaron a 26 pacientes con sospecha clínica de espondilodiscitis. Se realizaron estudios PET/TC y RM de columna a todos los pacientes, y se compararon sus resultados. El diagnóstico de espondilodiscitis se confirmo en 18/26 pacientes. Los valores de sensibilidad, especificidad, VPP, y VPN para la PET/TC fueron de 83%, 88%, 94% y 70 %. La RM obtuvo valores del 94%, 38%, 77% y 75%, respectivamente. Se encontraron diferencias estadísticamente significativas en lo valores de media del SUVmax entre los pacientes infectados y no infectados (6,52 y 3,67, respectivamente; p= 0,0013). La combinación de la PET/TC y la RM identificó correctamente la infección en el 100% de los pacientes con espondilodiscitis. La baja especificidad de la RM en el estudio (38%), se debió al numero de falsos positivos (5/8), dado principalmente a la dificultad que presenta la RM de diferenciar infección en aquellos pacientes con antecedentes de fracturas vertebrales previas y enfermedades degenerativas severas de la columna. De acuerdo a la experiencia y a los resultados de nuestras series, consideramos que la PET/TC debe incluirse en el algoritmo diagnóstico de EI, tanto en la sospecha de infección de las VP como de los DEC, reduciendo la tasa de pacientes mal diagnosticados. También consideramos que la técnica debe ser de elección en la detección de complicaciones sistémicas, tales como ESH y neoplasias insospechadas, influenciando de forma sustancial el manejo y el pronóstico de los pacientes. Pese a que la técnica no demuestra ser útil en el diagnóstico de EI-VN, en este grupo de pacientes mejora significativamente la detección del origen de la infección. Los resultados de nuestra serie indican que la PET/TC es una técnica complementaria a la RM en el diagnóstico de espondilodiscitis infecciosa.[eng] Cardiovascular infections are devastating diseases with high risk of mortality. Moreover, early diagnosis and detection of posible complications such as hematogenous septic embolism (HSE) remain a challenge in clinical practice. Diagnosis 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 (PV) and implantable cardiac electronic devices (ICED) We conducted propective studies on two groups of patients: In the first article we included 80 patients with suspected native valve (NV) infective endocarditis (IE) (n:21), PV-IE (n:29), and ICED-related infection (n:30). For the total group, sensitivity, specificity, PPV, and NPV of 82%, 96%, 94%, and 87%, respectively, were reported. In the subgroup of patients with intracardiac prosthetic material, these numbers were 96%, 94%, 93%, and 97%, respectively. PET/CT was able to reclassify 90% of the patients initially classified as possible IE according to the modified Duke criteria (63/70). Aditionally, PET/CT identified 26% of (HSE) and 10% of malignant foci. In the second article we included 26 patients with suspicion of spondylodiscitis. Whole- body PET/CT and an MRI scan of the spine were performed in all patients. Spondylodiscitis was confirmed in 18/26 patients. The sensitivity, specificity,PPV and NPV were 83 %, 88 %, 94 % and 70 % for PET/CT, and 94 %, 38 %, 77 % and 75 % for MRI, respectively. The combination of 18F-FDG PET/CT and MRI detected the infection in 100 % of the patients. According to our results, we consider that PET/CT should be included in the diagnostic workup of patients suspected of having IE or ICED-related infection. Aditionally, PET/CT must be of choice in the detection of HSE, mainly in spondylodiscitis

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 (PV) and implantable cardiac electronic devices (ICED). The primary aim of this study was to evaluate the diagnostic accuracy of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in patients with suspected IE an 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 years old) between June 2013 and May 2015 was performed in our hospital. The inclusion criteria was 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-body 18F-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 microbiological 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 (PPV) and negative predictive value (NPV) for 18F-FDG PET/CT was 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 63/70 (90%) patients initially classified as possible IE by modified Duke criteria. In 18/70 cases 18F-FDG PET/CT changed possible to definite IE (26%) and in 45/70 cases changed possible to rejected IE (64%). Additionally, 18F-FDG PET/CT identified 8 cases of septic embolism and 3 colorectal cancer in patients with final diagnosis of IE. CONCLUSION: 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

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 (PV) and implantable cardiac electronic devices (ICED). The primary aim of this study was to evaluate the diagnostic accuracy of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in patients with suspected IE an 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 years old) between June 2013 and May 2015 was performed in our hospital. The inclusion criteria was 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-body 18F-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 microbiological 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 (PPV) and negative predictive value (NPV) for 18F-FDG PET/CT was 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 63/70 (90%) patients initially classified as possible IE by modified Duke criteria. In 18/70 cases 18F-FDG PET/CT changed possible to definite IE (26%) and in 45/70 cases changed possible to rejected IE (64%). Additionally, 18F-FDG PET/CT identified 8 cases of septic embolism and 3 colorectal cancer in patients with final diagnosis of IE. CONCLUSION: 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