Serum Albumin Is a Marker of Myocardial Fibrosis, Adverse Pulsatile Aortic Hemodynamics, and Prognosis in Heart Failure With Preserved Ejection Fraction.

Background Data regarding the phenotypic correlates and prognostic value of albumin in heart failure with preserved ejection fraction (HFpEF) are scarce. The goal of the current study is to determine phenotypic correlates (myocardial hypertrophy, myocardial fibrosis, detailed pulsatile hemodynamics, and skeletal muscle mass) and prognostic implications of serum albumin in HFpEF. Methods and Results We studied 118 adults with HFpEF. All-cause death or heart-failure-related hospitalization was ascertained over a median follow-up of 57.6 months. We measured left ventricular mass, myocardial extracellular volume, and axial muscle areas using magnetic resonance imaging. Pulsatile arterial hemodynamics were assessed with a combination of arterial tonometry and phase-contrast magnetic resonance imaging. Subjects with lower serum albumin exhibited a higher body mass index, and a greater proportion of black ethnicity and diabetes mellitus. A low serum albumin was associated with higher myocardial extracellular volume (52.3 versus 57.4 versus 39.3 mL in lowest to highest albumin tertile, respectively; P=0.0023) and greater N-terminal pro B-type natriuretic peptide levels, but not with a higher myocardial cellular volume (123 versus 114 versus 102 mL; P=0.13). Lower serum albumin was also associated with an increased forward wave amplitude and markedly increased pulsatile power in the aorta. Serum albumin was a strong predictor of death or heart failure hospitalization even after adjustment for N-terminal pro B-type natriuretic peptide levels and the Meta-Analysis Global Group in Chronic Heart Failure (MAGGIC) risk score (adjusted standardized hazard ratio=0.56; 95% CI=0.37-0.83; P<0.0001). Conclusions Serum albumin is associated with myocardial fibrosis, adverse pulsatile aortic hemodynamics, and prognosis in HFpEF. This readily available clinical biomarker can enhance risk stratification in HFpEF and identifies a subgroup with specific pathophysiological abnormalities.

ACR Appropriateness Criteria® Chronic Chest Pain-High Probability of Coronary Artery Disease.

In patients with chronic chest pain in the setting of high probability of coronary artery disease (CAD), imaging has major and diverse roles. First, imaging is valuable in determining and documenting the presence, extent, and severity of myocardial ischemia, hibernation, scarring, and/or the presence, site, and severity of obstructive coronary lesions. Second, imaging findings are important in determining the course of management of patients with suspected chronic myocardial ischemia and better defining those patients best suited for medical therapy, angioplasty/stenting, or surgery. Third, imaging is also necessary to determine the long-term prognosis and likely benefit from various therapeutic options by evaluating ventricular function, diastolic relaxation, and end-systolic volume. Imaging studies are also required to demonstrate other abnormalities, such as congenital/acquired coronary anomalies and severe left ventricular hypertrophy, that can produce angina in the absence of symptomatic coronary obstructive disease due to atherosclerosis. Clinical risk assessment is necessary to determine the pretest probability of CAD. Multiple methods are available to categorize patients as low, medium, or high risk for developing CAD. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Heart Failure, Left Ventricular Remodeling, and Circulating Nitric Oxide Metabolites.

BACKGROUND: Stable plasma nitric oxide (NO) metabolites (NOM), composed predominantly of nitrate and nitrite, are attractive biomarkers of NO bioavailability. NOM levels integrate the influence of NO-synthase-derived NO production/metabolism, dietary intake of inorganic nitrate/nitrite, and clearance of NOM. Furthermore, nitrate and nitrite, the most abundant NOM, can be reduced to NO via the nitrate-nitrite-NO pathway. METHODS AND RESULTS: We compared serum NOM among subjects without heart failure (n=126), subjects with heart failure and preserved ejection fraction (HFpEF; n=43), and subjects with heart failure and reduced ejection fraction (HFrEF; n=32). LV mass and extracellular volume fraction were measured with cardiac MRI. Plasma NOM levels were measured after reduction to NO via reaction with vanadium (III)/hydrochloric acid. Subjects with HFpEF demonstrated significantly lower unadjusted levels of NOM (8.0 µmol/L; 95% CI 6.2-10.4 µmol/L; ANOVA P=0.013) than subjects without HF (12.0 µmol/L; 95% CI 10.4-13.9 µmol/L) or those with HFrEF (13.5 µmol/L; 95% CI 9.7-18.9 µmol/L). There were no significant differences in NOM between subjects with HFrEF and subjects without HF. In a multivariable model that adjusted for age, sex, race, diabetes mellitus, body mass index, current smoking, systolic blood pressure, and glomerular filtration rate, HFpEF remained a predictor of lower NOM (ß=-0.43; P=0.013). NOM did not correlate with LV mass, or LV diffuse fibrosis. CONCLUSIONS: HFpEF, but not HFrEF, is associated with reduced plasma NOM, suggesting greater endothelial dysfunction, enhanced clearance, or deficient dietary ingestion of inorganic nitrate. Our findings may underlie the salutary effects of inorganic nitrate supplementation demonstrated in recent clinical trials in HFpEF.

Differential background clearance of fluorodeoxyglucose activity in normal tissues and its clinical significance.

The clearance of 2-deoxy-2-[18F]fluoro-D-glucose (FDG) activity in normal tissues varies significantly with extended distribution time. Although most tissues have lower standardized uptake value (SUV) on 2-hour/3-hour delayed images, others may have stable or higher FDG activity with longer distribution times. The continuously decreased SUV on delayed imaging in some tissues, especially in the liver, indicates that longer distribution time will decrease background activity, increase lesion-to-background ratio, and thus improve imaging quality, whereas the continuously increased SUV from 1 to 3 hours in the heart suggest that longer distribution time will improve detection of viable myocardium in a viability study.

Serial changes of FDG uptake and diagnosis of suspected lung malignancy: a lesion-based analysis.

OBJECTIVE: This study prospectively evaluates the serial change of FDG uptake and its diagnostic value in malignant versus benign lung lesions in patients with suspected lung cancer. PATIENTS AND METHODS: Patients with suspected lung malignancy underwent whole-body FDG PET/CT at 1, 2, and 3 hours after an IV injection of F-FDG. The SUVs of FDG in lung nodules and hilar/mediastinal nodes at each time point were correlated with biopsy/surgical pathologic findings. RESULTS: There were a total of 45 malignant lesions and 80 benign lesions from 43 patients with pathologic diagnosis that were included for analysis. The SUVmax had an average of 25.5% increase in all tumor-positive lesions from 1 to 2 hours (vs 1.6% decrease in all tumor-negative lesions, P < 0.0001) and an average of 39.1% increase from 1 to 3 hours (vs 4.5% increase in all tumor-negative lesions, P < 0.0001). The receiver operating characteristic analysis showed that the 2-hour and 3-hour SUVmax had similar area under the curve and outperformed the SUVmax on the 1-hour initial imaging or retention index (RI). The optimal cutoff values to differentiate malignancy from benign lesions were 3.24 for 1-hour SUVmax, 3.67 for 2-hour SUVmax, and 4.21 for 3-hour SUVmax, with 11.6% for 1- to 2-hour RI and 23.9% for 1- to 3-hour RI. The 3-hour delayed SUVmax of 4.21 provided the best overall performance (accuracy of 88.8%). The analysis of the lesion-to-background ratio revealed that delayed imaging improved the image quality significantly, leading to much easier detection of either malignant or benign lesions. CONCLUSIONS: Multiple time point FDG PET/CT imaging moderately improves the diagnostic accuracy of lung cancer and significantly improves the image quality.

Differential washout of FDG activity in two different inflammatory lesions: implications for delayed imaging.

We describe the changes of FDG uptake in different inflammatory lesions on multiple time point FDG PET/CT. FDG uptake in granulomatous lesions was more intense and focal, with higher intensity on delayed images. In contrast, FDG uptake in chronic arthritic joint inflammation was diffuse and mild, without significant change over time, while FDG uptake in nonarthritic joints was at near-background level with decreased activity on delayed images. The retention index was significantly higher in patients with granulomatous lesions than that in other groups. Our finding indicates differential FDG uptake and clearance in active granulomas versus chronic inflammation.

Superscan-like hypermetabolic lesions on delayed FDG PET/CT imaging in a patient with lung cancer.

A 69-year-old man with a lung mass underwent multiple-time-point FDG PET/CT imaging for diagnostic evaluation. The initial PET imaging (performed at 1 hour after tracer injection) revealed equivocal bone marrow uptake in the right iliac bone and proximal femurs in addition to lung and mediastinal lesions. The 3-hour delayed PET imaging, however, demonstrated widespread bone marrow metastases. Biopsies of the right lung mass and right iliac bone marrow were later performed and revealed a poorly differentiated squamous cell carcinoma in both sites. This case indicates the value of delayed FDG PET in detecting superscan-like hypermetabolic bone marrow lesions in patients with lung cancer.

Review of Clinical Applications of Fluorodeoxyglucose-PET/Computed Tomography in Pediatric Patients with Lymphoma.

[(18)F]fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) imaging is routinely used in the initial diagnosis and response assessment during and immediately after therapy, as well as in the follow-up surveillance. FDG PET/CT outperforms diagnostic CT and other conventional imaging modalities in the evaluation of pediatric patients with lymphoma, with higher sensitivity and specificity, leading to more accurate staging/restaging and modifications of therapeutic strategies. Resolution of FDG-avid lesions in the early post-therapy phase often indicates good response to treatment and better prognosis. FDG PET/CT also outperforms bone marrow biopsy in detecting bone marrow infiltration of lymphoma.

Spectrum of pulmonary neuroendocrine cell proliferation: diffuse idiopathic pulmonary neuroendocrine cell hyperplasia, tumorlet, and carcinoids.

OBJECTIVE: The objectives of this article are to review the radiologic, pathologic, and clinical features of diffuse idiopathic pulmonary neuroendocrine cell hyperplasia, tumorlet, and carcinoids and to discuss the possible role of diffuse idiopathic pulmonary neuroendocrine cell hyperplasia and tumorlet in the development of carcinoids. CONCLUSION: Given the potential significant morbidity of diffuse idiopathic pulmonary neuroendocrine cell hyperplasia and its neoplastic counterparts, it is important to understand and recognize these disease entities. A conceptual continuum of these neuroendocrine entities is suggested.