Early Diagnosis of Abscess in Aortic Bioprosthetic Valve by 18F-Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography

Abstract

A 69-year-old woman, with an aortic bioprosthetic valve implanted 2 years before, was referred to our department because of a suspicion of endocarditis. She had experienced fever for 1 week, and Haemophilus parainfluenza was identified in 1 blood culture. The total white blood count (WBC) was 12ϫ10 9 /L, and the erythrocyte sedimentation rate (ESR) was 60 mm. The first transthoracic and transesophageal echocardiographic (TEE) studies were considered as normal. However, the 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET-CT), performed the day after, revealed an intense fixation at the level of the bioprosthetic valve. Then, a treatment with ceftriaxone and gentamicin was started. Six days later, although fever persisted and ESR remained elevated, a second TEE showed the emergence of a periprosthetic abscess without any dehiscence (Figure 1 and Movies I and II). The lesions were confirmed during surgery performed thereafter. Case 2A 68-year-old man, with a history of aortic bioprosthetic valve implanted 4 years before and a malignant lymphoma of the skin, was referred to our department because of a suspicion of endocarditis. He had experienced recurrent fever for 1 month associated with many methicillin sensible Staphylococcus aureus-positive blood cultures. The WBC was 3.2ϫ10 9 /L, and the ESR was 105 mm. A treatment with vancomycin (allergy to penicillin) and gentamicin was started, and the first transthoracic echocardiographic study and TEE (day 1) were considered as normal. However, the 18F-FDG PET-CT, performed at day 4, revealed an intense fixation at the level of the bioprosthetic valve. Another TEE was normal at day 7. At the end of the treatment (1 month), although the WBC increased at 6.1ϫ10 9 /L and the ESR remained high, a large periprosthetic abscess with dehiscence was identified by a new TEE (Figure 2 and Movies III and IV). These lesions were confirmed during surgery. Unfortunately, the patient died 48 hours after the operation because of septic complications. Case 3A 68-year-old woman, with a history of aortic bioprosthetic valve implanted 3 years before, was referred to our department because of a suspicion of endocarditis. She had experienced recurrent fever for 4 months associated with negative blood cultures and negative serologies for Coxiella burnetii, Bartonella sp, Mycoplasma sp, Legionella sp, Aspergillus sp, and Brucella sp. The WBC was 8.3ϫ109 /L and the ESR was 61 mm. Several TEE and transthoracic echocardiographic studies remained doubtful, with a thickening of the periprosthetic tissue. Under amoxicillin plus gentamicin, and 2 days after the last TEE, the 18F-FDG PET-CT revealed an intense fixation at the level of the bioprosthetic valve. Four days after (day 6), although the WBC and ESR did not change, the patient experienced a transient ischemic attack, and a periprosthetic abscess without dehiscence was identified by a new TEE (Figure 3 and Movies V and VI). The patient underwent an urgent valve surgery, which confirmed the lesions. No microor...

Diagnostic value of imaging in infective endocarditis: a systematic review

“…Echocardiography remains the most important tool for detection of endocardial lesions (vegetations, abscesses, and perforations) and should be done rapidly and repeatedly if infective endocarditis is suspected. 93 Concomitant use of imaging techniques providing high-resolution anatomic and metabolic imaging of the heart next to clinical and microbiological data has the potential to increase sensitivity of diagnosis of infective endocarditis to almost 100%-while simultaneously optimising specifi city. This improved accuracy is particularly important in patients with intracardiac prosthetic material because the modifi ed Duke criteria are even less sensitive in this group than they are in patients with native valve endocarditis.…”

Incremental value of PET and MRI in the evaluation of cardiovascular abnormalities

“…Information obtained from hybrid PET/MR can also achieve better differentiation of valve abscess from infective valve vegetations. Although there are some case series on the diagnostic value of PET-CT [ 36 ], there is no published report on the additional value of PET/MR in identification and management of cardiac valve abscesses [ 36 ]. MR or PET/MRI in patients with prosthetic valves can be challenging due to susceptibility artefacts.…”

Contemporary imaging of infective endocarditis. Infective endocarditis on prosthetic valves, implantable devices and right-sided location. Expert consensus statement of the Polish Clinical Forum for Cardiovascular Imaging

“…Jest to powód, dla którego wykorzystuje się możliwości tej metody w diagnostyce PVE. Obecnie wyniki badań wskazują na potencjalną wartość 18F-FDG-PET-CT w diagnostyce IZW na elektrodach i sztucznych zastawkach [17][18][19].…”

“…Istnie-Rycina 6. Proponowany algorytm postępowania diagnostycznego u chorego z podejrzeniem infekcyjnego zapalenia wsierdzia na protezach zastawkowych (PVE); CT -tomografia komputerowa; PET -pozytonowa tomografia emisyjna; zaadaptowano z [19] ją przesłanki o skuteczności profilaktycznej antybiotykoterapii przed zabiegiem i w jego trakcie [23].…”