Prognosis and follow-up of patients with prosthetic valve endocarditis treated conservatively in relation to WBC-SPECT imaging.

BACKGROUND: Our objective was to evaluate in patients with prosthetic valve endocarditis (PVE) treated conservatively, the prognostic value of white blood cell (WBC) signal intensity on SPECT and to describe the evolution of the WBC signal under antibiotics. METHODS: Patients with PVE treated conservatively and positive WBC-SPECT imaging were identified retrospectively. Signal intensity was classified as intense if equal to or higher, or mild if lower, than the liver signal. Clinical, biological, imaging and follow-up information were collected from medical files. RESULTS: Among 47 patients, WBC signal was classified as intense in 10 patients and as mild, in 37. The incidence of the primary composite endpoint (death, late cardiac surgery, or relapse) was significantly higher in patients with intense vs. mild signal (90% vs. 11%). Twenty-five patients underwent a second WBC-SPECT imaging during follow-up. The prevalence of WBC signal decreased progressively from 89% between 3 and 6 weeks to 42% between 6 and 9 weeks and 8% more than 9 weeks after initiation of antibiotics. CONCLUSIONS: In patients with PVE treated conservatively, intense WBC signal was associated with poor outcome. WBC-SPECT imaging appears as an interesting tool for risk stratification and to monitor locally the efficacy of antibiotic treatment.

Hot spot imaging in cardiovascular diseases: an information statement from SNMMI, ASNC, and EANM.

This information statement from the Society of Nuclear Medicine and Molecular Imaging, American Society of Nuclear Cardiology, and European Association of Nuclear Medicine describes the performance, interpretation, and reporting of hot spot imaging in nuclear cardiology. The field of nuclear cardiology has historically focused on cold spot imaging for the interpretation of myocardial ischemia and infarction. Hot spot imaging has been an important part of nuclear medicine, particularly for oncology or infection indications, and the use of hot spot imaging in nuclear cardiology continues to expand. This document focuses on image acquisition and processing, methods of quantification, indications, protocols, and reporting of hot spot imaging. Indications discussed include myocardial viability, myocardial inflammation, device or valve infection, large vessel vasculitis, valve calcification and vulnerable plaques, and cardiac amyloidosis. This document contextualizes the foundations of image quantification and highlights reporting in each indication for the cardiac nuclear imager.

Nuclear medicine in the assessment and prevention of cancer therapy-related cardiotoxicity: prospects and proposal of use by the European Association of Nuclear Medicine (EANM).

Cardiotoxicity may present as (pulmonary) hypertension, acute and chronic coronary syndromes, venous thromboembolism, cardiomyopathies/heart failure, arrhythmia, valvular heart disease, peripheral arterial disease, and myocarditis. Many of these disease entities can be diagnosed by established cardiovascular diagnostic pathways. Nuclear medicine, however, has proven promising in the diagnosis of cardiomyopathies/heart failure, and peri- and myocarditis as well as arterial inflammation. This article first outlines the spectrum of cardiotoxic cancer therapies and the potential side effects. This will be complemented by the definition of cardiotoxicity using non-nuclear cardiovascular imaging (echocardiography, CMR) and biomarkers. Available nuclear imaging techniques are then presented and specific suggestions are made for their application and potential role in the diagnosis of cardiotoxicity.

Diagnosis and staging of cardiac masses: additional value of CMR with 18F-FDG-PET compared to CMR with CECT.

PURPOSE: Characterization of malignant cardiac masses is usually performed with cardiac magnetic resonance (CMR) and staging with whole-body contrast-enhanced computed tomography (CECT). In this study, our objective was to evaluate the role of 18Fluor-fluorodeoxyglucose positron emission tomography (18F-FDG-PET) with CMR for both characterization and staging of cardiac masses. METHODS: Patients with cardiac masses who underwent CMR, CECT, and 18F-FDG-PET were retrospectively identified. For the characterization of cardiac masses, we calculated the respective performances of CMR alone, 18F-FDG-PET alone, and the combination of 18F-FDG-PET and CMR. For staging, we compared head-to-head the respective performances of 18F-FDG-PET and CECT. Histology served as gold standard for malignancy, and response to anticoagulation for thrombus. RESULTS: In a total of 28 patients (median age 60.5 years, 60.7% women), CMR accurately distinguished malignant from benign masses with sensitivity (Se) of 86.7%, specificity (Sp) of 100%, positive predictive value (PPV) of 100%, negative predictive value (NPV) of 86.7%, and accuracy of 92.9%. 18F-FDG-PET demonstrated 93.3% Se, 84.6% Sp, 87.5% PPV, 91.7% NPV, and 89.3% accuracy. Combining CMR with 18F-FDG-PET allowed to benefit from the high sensitivity of 18F-FDG-PET (92.9%) and the excellent specificity of CMR (100%) for malignant diseases. For staging, 18F-FDG-PET outperformed CECT on per-patient (66.7% vs 55.6% correct diagnosis, respectively), per-organ (10 vs 7 organs, respectively), and per-lesion basis (> 29 vs > 25 lesions, respectively). CONCLUSION: Combining 18F-FDG-PET with CMR improved the characterization of cardiac masses compared to each modality alone. Additionally, the diagnostic performance of 18F-FDG-PET was better than CECT for staging. This study suggests that the combination of CMR and 18F-FDG-PET is the most effective for the characterization of cardiac masses and the staging of these lesions.

Diagnostic performance of White Blood Cell SPECT imaging against intra-operative findings in patients with a suspicion of prosthetic valve endocarditis.

AIM: The objective of this study was to evaluate the diagnostic performance of white blood cells (WBC)-SPECT imaging in patients with suspicion of prosthetic valve endocarditis (PVE) against intra-operative findings. METHODS: 36 consecutive patients who underwent cardiac surgery 30 days after WBC-SPECT imaging were identified retrospectively. Clinical, imaging, and biological results were collected from reports. WBC-SPECT results were classified as positive or negative and, if positive, the intensity of signal graded as intense or mild. Lesions observed during cardiac surgery were collected from surgeons' reports. RESULTS: The 20 patients with positive WBC-SPECT study had confirmed PVE intra-operatively. Patients with intense signal on WBC-SPECT had high prevalence of abscesses (83%) compared to patients with only mild signal (12%). The three patients with negative WBC-SPECT but confirmed PVE had longer duration of antibiotic treatment before imaging and had no perivalvular abscess. Sensitivity, specificity, positive predictive and negative values, and accuracy of WBC-SPECT were measured at 87%, 100%, 100%, 81%, and 92%, respectively. Addition of WBC-SPECT results to the modified Duke score helped re-classify correctly 25% of patients from possible to definite PVE. CONCLUSION: In patients with suspicion of PVE, WBC-SPECT imaging provides excellent diagnostic performance against intra-operative findings.

Feasibility of Quantitative Flow Ratio in Adult Patients With Anomalous Aortic Origin of the Coronary Artery With 5 Years of Clinical Follow-up.

OBJECTIVES: Anomalous origin of the right coronary artery (ARCA) represents the most common form of abnormal coronary origin and may potentially increase the risk for sudden cardiac death. Morphological and functional evaluation of ARCA in adult patients referred for invasive coronary angiogram (ICA) is challenging. Quantitative flow ratio (QFR) is an available method able to virtually calculate fractional flow reserve using 3-dimensional quantitative coronary angiography (3D-QCA) based on ICA. We aimed to evaluate the feasibility of QFR analysis in patients with ARCA and its clinical impact. METHODS: Using the registry of proximal anomalous connections of coronary arteries (ANOCOR registry), a multicenter observational registry including 472 adult patients with ANOCOR between 2010 and 2013, we retrospectively performed QFR analysis from ICA and evaluated the rate of death, myocardial infarction, and unplanned revascularization at 5 years. RESULTS: Among 128 patients with ARCA, 41 (32%) could have QFR analysis with median clinical follow-up of 8.3 years. The mean QFR value was 0.90 ± 0.10, and 3D-QCA analysis showed preserved lumen area despite the elliptical shape of the proximal part of the ARCA, which in the worst cases appeared on ICA as a significant narrowing. The event rate was 12.2% (n = 5), including 3 deaths (1 due to cancer, 1 due to stroke, and 1 cause unknown) and 2 unplanned revascularizations at 5 years. No myocardial infarctions were reported. CONCLUSIONS: When QFR analysis of ARCA is feasible, non-significant QFR values are associated with good clinical outcome at 5 years.

Epicardial adipose tissue volume is associated with left ventricular remodelling in calcific aortic valve stenosis.

BACKGROUND: The severity of left ventricular (LV) remodelling is only partially related to the severity of aortic valve stenosis; additional factors, including diabetes, insulin resistance, obesity and metabolic syndrome, may play important roles. Epicardial adipose tissue (EAT), now considered as a metabolically active organ, is also linked to these factors. AIM: To analyse the association between EAT volume measured using computed tomography and LV remodelling in a prospective cohort of patients with aortic stenosis. METHODS: Consecutive asymptomatic patients with at least mild degenerative aortic stenosis enrolled in a prospective cohort that aimed to assess the determinants of aortic stenosis occurrence and progression constituted our population. RESULTS: We enrolled 143 patients (78±5 years; 65% men). Mean LV mass and EAT volume were 219±64g and 134±56mL, respectively. LV hypertrophy was diagnosed in 86 patients (60%), and concentric hypertrophy (32%) was the main remodelling pattern. EAT was associated with body mass index (P<0.001) and body surface area (P<0.001), but not with age (P=0.33) or aortic stenosis severity (all P>0.10). EAT was correlated with LV mass (r=0.41; P<0.0001), and after adjustment for age, sex, body mass index/body surface area, hypertension, waist circumference, low-density lipoprotein cholesterol and aortic stenosis severity, EAT was independently associated with LV mass (P=0.01/P=0.02). Similar results were found when EAT and LV mass index (adjusted for body surface area) were considered instead of absolute values (P=0.04). CONCLUSIONS: In this prospective cohort of patients with aortic stenosis, EAT volume was independently associated with LV mass. Further studies are warranted to elucidate the underlying mechanisms of this link.

Could FDG-PET imaging play a role in the detection of progressing atherosclerosis in HIV-infected patients?

Important progresses in the management of patients with human immunodeficiency virus, in particular the advent of new anti-retroviral therapies (ART), have turned this rapidly fatal condition into a controllable chronic disease with a life expectancy that approaches the one from the general population. Cardiovascular diseases have now become one of the leading causes of non-HIV-related mortality in this population. Several factors including the presence of HIV in the vascular wall and the development of dyslipidemia and alteration in body fat distribution under ART might play a role the progression of atherosclerosis in HIV-infected patients. The use of imaging biomarkers may help to identify the factors associated with an increased risk of cardiovascular events and select high-risk patients who will benefit the most from the early implementation of preventive treatments.

Imaging inflammation in atherosclerotic plaques: Just make it easy!

The presence of inflammatory cells is a hallmark of unstable atherosclerotic plaques. Several imaging approaches have been developed for the noninvasive detection of inflammatory activities in atherosclerotic plaques. Positron emission tomography (PET) imaging with the injection of 18F-fluorodeoxyglucose (FDG) is currently the most widely used imaging technique to evaluate the density of activated macrophages in atherosclerotic plaques. Nevertheless, FDG-PET imaging has logistical and technical constraints that represent an important obstacle to the wider use of this approach for the evaluation of patients with atherosclerosis. In a similar way as in the oncological field, the balance between the benefits and costs of new drugs need to be improved in patients with cardiovascular diseases. PET imaging of plaque inflammation might represent a very useful tool to identify patients who could benefit the most from anti-inflammatory treatments and to exclude patients with other causes of inflammation who are the most likely to develop severe side effects under these drugs. The availability of radiotracers targeting more specifically inflammation in atherosclerotic plaques would greatly facilitate the logistic organization of this imaging and help to expand the use of PET for the evaluation of atherosclerotic patients.

18F-FDG-PET/CT Imaging to Diagnose Septic Emboli and Mycotic Aneurysms in Patients with Endocarditis and Cardiac Device Infections.

PURPOSE OF REVIEW: This review analyzes recent studies evaluating the diagnostic value of 18F-FDG-PET/CT for the detection of peripheral emboli and secondary infectious foci in patients with infective endocarditis and cardiac device infections. RECENT FINDINGS: Detection of extracardiac septic localizations in patients with infective endocarditis and cardiac device infections is crucial, as it may impact the diagnosis, prognosis, and therapeutic management. Recent literature substantiated the clinical usefulness of 18F-FDG-PET/CT in this setting. 18F-FDG-PET/CT has proven its high diagnostic value for the detection of peripheral emboli in patients with infective endocarditis and cardiac device infections, substantially affecting patients' outcome and treatment. A multimodal approach, combining the high sensitivity of 18F-FDG-PET/CT with morphological imaging seems promising.