Diagnostic Impact of 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography and White Blood Cell SPECT/Computed Tomography in Patients With Suspected Cardiac Implantable Electronic Device Chronic Infection.

BACKGROUND: Cardiac implantable electronic devices (CIEDs) chronic infection diagnosis is challenging because the clinical presentation is frequently misleading and echocardiography may be inconclusive. The aim of this study was to evaluate the diagnostic value of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (CT) and radiolabeled white blood cells single photon emission CT/CT in a cohort of patients who underwent both scans for suspicion of CIED infection and inconclusive routine investigations. METHODS: Forty-eight consecutive patients with suspicion of CIED infection who underwent both 18F-fluorodeoxyglucose positron emission tomography/CT and white blood cell single photon emission CT/CT in a time span ≤30 days were retrospectively included. The final diagnosis of CIED infection by the endocarditis expert team was based on the modified Duke-Li classification at the end of follow-up. 18F-Fluorodeoxyglucose positron emission tomography/CT and white blood cell single photon emission CT/CT scans were independently analyzed blinded to the patients' medical record. RESULTS: In the overall study population, the diagnostic sensitivity, specificity, positive predictive value, and negative predictive value were respectively 80%, 91%, 80%, and 91% for 18F-fluorodeoxyglucose positron emission tomography/CT and 60%, 100%, 100%, and 85% for white blood cell single photon emission CT/CT. Addition of a positive nuclear imaging scan as a major criterion markedly improved the Duke-Li classification at admission. Semiquantitative parameters did not allow to discriminate between definite and rejected CIED infection. Prolonged antibiotic therapy before imaging tended to decrease the sensitivity for both techniques. CONCLUSIONS: Nuclear imaging can improve the diagnostic performances of the Duke-Li score at admission in a selected population of patients with suspected CIED infection, particularly when the infection was initially graded as possible. Whenever possible, imaging should be performed before or early after antibiotic initiation.

Early and late outcomes after trans-catheter aortic valve implantation in patients with previous chest radiation.

OBJECTIVE: Surgery for aortic stenosis in patients with thoracic radiation therapy is associated with high morbi-mortality. Trans-catheter aortic valve implantation (TAVI) represents an alternative but has never been studied in this population. We aimed to compare outcomes in radiation and matched control patients undergoing TAVI and to identify predictive factors of survival. METHODS: Between 2006 and 2011, 288 consecutive patients underwent TAVI in our institution, of whom 26 had previous chest radiation. They were matched 1:1 for age, sex and TAVI approach with controls. RESULTS: In both groups, median age was 73 years, 50% of patients were male and 15% had a transapical approach. Procedural success was 88% in the radiation group versus 100% in controls (p<0.001) and 30-day survival was 92% in both groups. Five-year survival was 33%±10% in the radiation group and 42%±11% in controls (p=0.26). In radiation patients, the main cause of death was respiratory insufficiency in 40%. We identified four independent predictive factors of death in the radiation group: extracardiac arteriopathy (p=0.002) and the absence of ß-blocker therapy (p=0.005) as preprocedural variables, and infectious complications (p=0.009) and a higher peak creatinine level (p=0.009) as postprocedural variables. In the radiation group, 89% of survivors were in New York Heart Association class I-II at last follow-up. CONCLUSIONS: Patients in the radiation group displayed high mortality rates although not significantly different from the controls. Respiratory failure was the main cause of death, emphasising the need for a careful pulmonary evaluation. Finally, we show a sustained improvement in functional results after TAVI in this population.

First reported human case of native mitral infective endocarditis caused by Streptococcus canis.

A 65 year-old woman was admitted for acute heart failure and severe sepsis revealing definite mitral infective endocarditis with severe regurgitation, complicated by multiple embolisms. Three blood cultures yielded a group G Streptococcus canis strain. Urgent surgery was performed with bioprosthetic valve replacement. Polymerase chain reaction analysis of the valve found S canis DNA. Amoxicillin and gentamicin were given for 2 weeks followed by 4 weeks of amoxicillin alone. She reported contact with a dog without bite. S canis has been reported to cause zoonotic septicemia but to our knowledge, this is the first human case of native valve infective endocarditis.