Hein J Verberne

Academisch Medisch Centrum Universiteit van Amsterdam, Amsterdamo, North Holland, Netherlands

Are you Hein J Verberne?

Claim your profile

Publications (100)369.52 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: The I-metaiodobenzylguanidine (I-MIBG) late heart-to-mediastinum ratio (H/M) is a well-established prognostic parameter in patients with chronic heart failure (CHF). However, I presents imaging problems owing to high-energy photon emission leading to penetration of collimator septa and subsequent reduction in image quality. Most likely this affects the H/M ratio and may subsequently lead to incorrect patient risk classification. In this prospective study we assessed the intrapatient variation in late H/M ratio between low-energy high-resolution (LEHR) and medium-energy (ME) collimators in patients with CHF. Fifty-three patients with CHF (87% male, age 63±8.3 years, left ventricular ejection fraction 29±7.8) referred for I-MIBG scintigraphy were enrolled in the study. In each patient, after the administration of 185 MBq I-MIBG, early (15 min after injection) and late (4 h after injection) planar anterior thoracic images were acquired with both LEHR and ME collimators. Early and late H/M ratios were calculated on the basis of the mean count densities from the manually drawn regions of interest (ROIs) over the left ventricle and a predefined fixed ROI placed in the upper mediastinum. Additional ROIs were drawn over the liver and lungs. Liver/lung to myocardium and liver/lung to mediastinal ratios were calculated to estimate the effect of collimator septa penetration from liver and lung activity on the myocardial and mediastinal ROIs. The mean LEHR collimator-derived parameters were lower compared with those from the ME collimator (late H/M 1.41±0.18 vs. 1.80±0.41, P<0.001). Moreover, Bland-Altman analysis showed that with increasing late H/M ratios the difference between the ratios from the two collimator types increased (R=0.73, P=0.001). Multivariate regression analysis showed that almost 90% of the variation in the difference between ME and LEHR late H/M ratios could be explained by scatter from the liver in both the mediastinal and myocardial ROIs (R=0.90, P=0.001). Independent predictors for the difference in the late H/M between ME and LEHR were the liver-to-heart ratio and the liver-to-mediastinum ratio assessed by ME (standardized coefficient of -1.69 and 1.16, respectively) and LEHR (standardized coefficient of 1.24 and -0.90, respectively) (P<0.001 for all). Intrapatient comparison in H/M between the ME and LEHR collimators in patients with CHF showed that with increasing H/M the difference between the ratios increased in favour of the ME collimator. These differences could be explained by septal penetration of high-energy photons from both the liver and the lung in the mediastinum and myocardium, being lowest when using the ME collimator. These results strengthen the importance of the recommendation to use ME collimators in semiquantitative I-MIBG studies.
    Nuclear Medicine Communications 11/2014; · 1.38 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Patients with familial hypercholesterolemia (FH) are characterized by elevated atherogenic lipoprotein particles, predominantly low-density lipoprotein cholesterol (LDL-C), which is associated with accelerated atherogenesis and increased cardiovascular risk.
    Journal of the American College of Cardiology 10/2014; 64(14):1418-26. · 14.09 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background Understanding how leukocytes impact atherogenesis contributes critically to our concept of atherosclerosis development and the identification of potential therapeutic targets. Objectives The study evaluates an in vivo imaging approach to visualize peripheral blood mononuclear cell (PBMC) accumulation in atherosclerotic lesions of cardiovascular (CV) patients using hybrid single-photon emission computed tomography/computed tomography (SPECT/CT). Methods At baseline, CV patients and healthy controls underwent 18fluorodeoxyglucose positron emission tomography-computed tomography and magnetic resonance imaging to assess arterial wall inflammation and dimensions, respectively. For in vivo trafficking, autologous PBMCs were isolated, labeled with technetium-99m, and visualized 3, 4.5, and 6 h post-infusion with SPECT/CT. Results Ten CV patients and 5 healthy controls were included. Patients had an increased arterial wall inflammation (target-to-background ratio [TBR] right carotid 2.00 ± 0.26 in patients vs. 1.51 ± 0.12 in controls; p = 0.022) and atherosclerotic burden (normalized wall index 0.52 ± 0.09 in patients vs. 0.33 ± 0.02 in controls; p = 0.026). Elevated PBMC accumulation in the arterial wall was observed in patients; for the right carotid, the arterial-wall-to-blood ratio (ABR) 4.5 h post-infusion was 2.13 ± 0.35 in patients versus 1.49 ± 0.40 in controls (p = 0.038). In patients, the ABR correlated with the TBR of the corresponding vessel (for the right carotid: r = 0.88; p < 0.001). Conclusions PBMC accumulation is markedly enhanced in patients with advanced atherosclerotic lesions and correlates with disease severity. This study provides a noninvasive imaging tool to validate the development and implementation of interventions targeting leukocytes in atherosclerosis.
    Journal of the American College of Cardiology 09/2014; 64(10):1019–1029. · 14.09 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Aims: We sought to compare the diagnostic accuracy of basal stenosis resistance index (BSR), instantaneous wave-free ratio (iFR) and fractional flow reserve (FFR) for stenosis-specific myocardial ischaemia identified by means of a combined reference standard of myocardial perfusion scintigraphy and the hyperaemic stenosis resistance index. Methods and results: BSR and FFR were determined for 299 coronary stenoses, iFR was determined for 85 coronary stenoses (iFR cohort). The discriminative value for stenosis-specific myocardial ischaemia was compared by means of the area under the receiver operating characteristic (ROC) curves (AUC). Classification agreement with the reference standard was determined according to ROC curve-derived ischaemic cut-off values, as well as according to clinical cut-off values, equivalent to the 0.80 FFR cut-off. Across all stenoses, the discriminative value of BSR and FFR was equivalent (AUC: 0.90 and 0.91, respectively, p=0.46). In the iFR cohort, the discriminative value was equivalent for BSR, iFR, and FFR (AUC: 0.88, 0.84, and 0.88, respectively; p≥0.20 for all). At both ischaemic as well as clinical cut-off values, classification agreement with the reference standard was equivalent for BSR and FFR across all stenoses, as well as for BSR, iFR, and FFR in the iFR cohort. Conclusions: BSR, iFR, and FFR have equivalent diagnostic accuracy for the detection of ischaemia-generating coronary stenoses.
    08/2014;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Cellular imaging modalities are important for revealing the behavior and role of monocytes in response to neovascularization progression in coronary artery disease. In this study we aimed to develop methods for high-resolution three-dimensional (3D) imaging and quantification of monocytes relative to the entire coronary artery network using a novel episcopic imaging modality. In a series of ex vivo experiments, human umbilical vein endothelial cells and CD14 + monocytes were labeled with fluorescent live cell tracker probes and infused into the coronary artery network of excised rat hearts by a Langendorff perfusion method. Coronary arteries were subsequently infused with fluorescent vascular cast material and processed with an imaging cryomicrotome, whereby each heart was consecutively cut (5 μm slice thickness) and block face imaged at appropriate excitation and emission wavelengths. The resulting image stacks yielded 3D reconstructions of the vascular network and the location of cells administered. Successful detection and quantification of single cells and cell clusters were achieved relative to the coronary network using customized particle detection software. These methods were then applied to an in vivo rabbit model of chronic myocardial ischemia in which autologous monocytes were isolated from peripheral blood, labeled with a fluorescent live cell tracker probe and re-infused into the host animal. The processed 3D image stacks revealed homing of monocytes to the ischemic myocardial tissue. Monocytes detected in the ischemic tissue were predominantly concentrated in the mid-myocardium. Vessel segmentation identified coronary collateral connections relative to monocyte localization. This study established a novel imaging platform to efficiently determine the localization of monocytes in relation to the coronary microvascular network. These techniques are invaluable for investigating the role of monocyte populations in the progression of coronary neovascularization in animal models of chronic and sub-acute myocardial ischemia.
    Journal of Molecular and Cellular Cardiology 08/2014; 76:196–204. · 5.15 Impact Factor
  • Source
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Cardiac imaging now provides a range of anatomical and functional information with some overlap in the ability of individual techniques to guide diagnosis and management. This report summarizes the conclusions of a panel of cardiac imagers who assembled to discuss the current state of the field. It focuses principally on options for nuclear cardiology, the choice between individual techniques, and areas where further advances would benefit patient management.
    European heart journal cardiovascular Imaging. 05/2014;
  • [Show abstract] [Hide abstract]
    ABSTRACT: Aims: It has been argued that hyperaemic microvascular resistance (HMR), defined as the ratio of mean distal coronary pressure to flow velocity, is overestimated in the presence of a coronary stenosis compared to actual microvascular resistance (MR), due to neglecting collateral flow. We aimed to test the hypothesis that HMR allows accurate identification of microvascular functional abnormalities by evaluating the association between high or low HMR and the presence of myocardial ischaemia on non-invasive stress testing. Methods and results: Myocardial perfusion scintigraphy was performed in 228 patients, with 299 lesions to identify reversible myocardial ischaemia. Intracoronary distal pressure and flow velocity were assessed during adenosine-induced hyperaemia (20-40 µg, intracoronary) to determine hyperaemic stenosis resistance (HSR) and HMR. HMR >1.9 mmHg/cm/s was defined as high. The diagnostic odds ratio (OR) for myocardial ischaemia for lesions associated with high compared to low HMR was 2.6 (95% confidence interval [CI]: 1.5-4.4; p<0.001) overall, 3.3 (95% CI: 1.2-9.0; p=0.02) for lesions with HSR >0.8 mmHg/cm/s, and 1.3 (95% CI: 0.6-2.9; p=0.52) for lesions with HSR ≤0.8 mmHg/cm/s. Conclusions: The increased risk of myocardial ischaemia in the presence of high HMR, uncorrected for collateral flow, demonstrates that HMR is reflective of an increase in actual MR, identifying pertinent pathophysiological alterations in the microvasculature.
    EuroIntervention: journal of EuroPCR in collaboration with the Working Group on Interventional Cardiology of the European Society of Cardiology 04/2014; 9(12):1423-31. · 3.17 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Fractional flow reserve (FFR) aims to identify the extent of epicardial disease, but may be obscured by involvement of the coronary microvasculature. We documented the impact of hyperaemic stenosis resistance (HSR) and hyperaemic microvascular resistance (HMR) on FFR, and its relationship with myocardial ischaemia in patients with stable coronary artery disease. We evaluated 255 coronary arteries with stenoses of intermediate severity by means of intracoronary pressure and flow measurements to determine FFR, HSR and HMR. Myocardial perfusion scintigraphy (MPS) was performed to identify inducible myocardial ischaemia. In 178 patients, HMR was additionally determined in a reference coronary artery. Target vessel HMR was stratified according to reference vessel HMR tertiles. The diagnostic OR for inducible ischaemia on MPS of a positive compared with a negative FFR was significantly higher only in the presence of a high HMR (at the 0.75 and 0.80 FFR cut-off). Among stenoses with a positive FFR, the prevalence of ischaemia was significantly higher when HMR was high despite equivalent FFR across the HMR groups. This was paralleled by a concomitant significant increase in HSR with increasing HMR across groups. The relation between FFR and HSR (r(2)=0.54, p<0.001) was modulated by the magnitude of HMR, and improved substantially after adjustment for HMR (adjusted-r(2)=0.73, p<0.001), where, for epicardial disease of equivalent severity, FFR increased with increasing HMR. Identification of epicardial disease severity by FFR is partly obscured by the microvascular resistance, which illustrates the necessity of combined pressure and flow measurements in daily practice.
    Heart (British Cardiac Society) 04/2014; · 5.01 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Nitric oxide (NO) is essential for the optimal perfusion of the heart and its vasculature. NO may be insufficient in surgical patients because its precursor arginine is decreased, and the inhibitor of NO synthesis asymmetric dimethylarginine (ADMA) is increased. Besides arginine, the presence of other amino acids essential for the proper metabolism of cardiac cells may be decreased too. Supplementation of these amino acids with enteral and parenteral nutrition before, during, and after surgery may augment the myocardial and plasma arginine:ADMA ratio and availability of amino acids. Myocardial glucose metabolism and nutritional conditioning may result in a reduction of cardiac injury and support rapid recovery after major surgery. We investigated the effect of nutrition before, during, and after surgery on amino acids and the myocardial arginine:ADMA ratio and its relation to myocardial glucose metabolism. In this trial, 33 patients who were undergoing off-pump coronary artery bypass grafting (CABG) were randomly assigned between enteral, parenteral, or no nutrition (control) from 2 d before, during, and until 2 d after surgery. Both enteral and parenteral solutions were prepared with commercial available products and included proteins or amino acids, glucose, vitamins, and minerals. Concentrations of amino acids including ADMA were analyzed in myocardial tissue and plasma samples. (18)F-fluorodeoxyglucose positron emission tomography was performed before and after surgery to assess myocardial glucose metabolism. The myocardial arginine:ADMA ratio increased during surgery and was significantly higher in the enteral and parenteral groups than in the control group [median (IQR): 115.0 (98.0-142.2) (P = 0.012), 116.9 (100.3-135.3) (P = 0.004), and 93.3 (82.7-101.1), respectively]. Furthermore, the change in the preoperative to postoperative plasma arginine:ADMA ratio correlated with the change in myocardial glucose metabolism in positron emission tomography (r = 0.427, P = 0.033). Enteral or parenteral nutrition before, during, and after CABG may positively influence myocardial glucose metabolism by increasing the plasma and myocardial arginine:ADMA ratio. This trial was registered at http://www.trialregister.nl as NTR2183.
    American Journal of Clinical Nutrition 04/2014; · 6.50 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The purpose of this study was to determine the most appropriate prognostic endpoint for myocardial (123)I-metaiodobenzylguanidine (MIBG) scintigraphy in patients with chronic heart failure (CHF) based on aggregate results from multiple studies published in the past decade. Original individual late (3-5 h) heart/mediastinum (H/M) ratio data of 636 CHF patients were retrieved from six studies from Europe and the USA. All-cause mortality, cardiac mortality, arrhythmic events, and heart transplantation were investigated to determine which provided the strongest prognostic significance for the MIBG imaging data. The majority of patients was male (78%), had a decreased left ventricular ejection fraction (31.1 ± 12.5%), and a mean late H/M of 1.67 ± 0.47. During follow-up (mean 36.9 ± 20.1 months), there were 83 deaths, 67 cardiac deaths, 33 arrhythmic events, and 56 heart transplants. In univariate regression analysis, late H/M was a significant predictor of all event categories, but lowest hazard ratios (HRs) were for the composite endpoint of any event (HR = 0.30, 95% CI 0.19-0.46), all-cause (HR = 0.29, 95% CI 0.16-0.53), and cardiac mortality (HR = 0.28, 95% CI 0.14-0.55). In multivariate analysis, late H/M was an independent predictor for all event categories, except for arrhythmias. This pooled individual patient data meta-analysis showed that, in CHF patients, the late H/M ratio is not only useful as a dichotomous predictor of events (high vs. low risk), but also has prognostic implication over the full range of the outcome value for all event categories except arrhythmias.
    European heart journal cardiovascular Imaging. 03/2014;
  • [Show abstract] [Hide abstract]
    ABSTRACT: The goal of this multicenter retrospective study was to evaluate the contribution of F-FDG PET/CT in the diagnosis of patients with inflammation of unknown origin (IUO). In addition, C-reactive protein (CRP) level and erythrocyte sedimentation rate were assessed as possible predictors for the outcome of F-FDG PET/CT. Inflammation of unknown origin was defined as prolonged and perplexing inflammation, with repeated CRP levels more than 20 mg/L or erythrocyte sedimentation rate more than 20 mm/h, body temperature of less than 38.3°C, and without a diagnosis after a variety of conventional diagnostic procedures.A total of 140 patients with IUO (67 men, 73 women; mean age, 64.2 years; age range, 18-87 years) underwent F-FDG PET/CT. F-FDG PET/CT was considered helpful when the imaging findings led to a diagnosis, either confirmed by histopathology, microbiological assays, clinical and imaging follow-up, or response to treatment. In 104 patients (73%), a final diagnosis could be established as follows: infection in 35 patients, malignancy in 18 patients, noninfectious inflammatory disease in 44 patients, and a variety of uncommon conditions in 7 patients. F-FDG PET/CT was true positive in 95 patients, true negative in 30 patients (ie, self-limiting conditions), false positive in 6 patients, and false negative in 9 patients (predominantly systemic diseases). In this population, the positive predictive value, negative predictive value, and diagnostic accuracy of F-FDG PET/CT were 94%, 77%, and 89%, respectively. In a multivariate analysis, CRP was the only independent predictor for the outcome of F-FDG PET/CT. F-FDG PET/CT correctly identified or excluded a causal explanation in approximately 90% of patients with IUO. However, a negative F-FDG PET/CT is indicative for a self-limiting condition only after systemic diseases are excluded by other diagnostic tests.
    Clinical nuclear medicine 03/2014; · 3.92 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: High intensity systematic physical training leads to myocardial morphophysiological adaptations. The goal of this study was to investigate if differences in training were correlated with differences in cardiac sympathetic activity. 58 males (19-47 years), were divided into three groups: strength group (SG), (20 bodybuilders), endurance group (EG), (20 endurance athletes), and a control group (CG) comprising 18 healthy non-athletes. Cardiac sympathetic innervation was assessed by planar myocardial (123)I-metaiodobenzylguanidine scintigraphy using the early and late heart to mediastinal (H/M) ratio, and washout rate (WR). Left ventricular mass index was significantly higher both in SG (P < .001) and EG (P = .001) compared to CG without a statistical significant difference between SG and EG (P = .417). The relative wall thickness was significantly higher in SG compared to CG (P < .001). Both left ventricular ejection fraction and the peak filling rate showed no significant difference between the groups. Resting heart rate was significantly lower in EG compared to CG (P = .006) and SG (P = .002). The late H/M ratio in CG was significantly higher compared to the late H/M for SG (P = .003) and EG (P = .004). However, WR showed no difference between the groups. There was no significant correlation between the parameters of myocardial sympathetic innervation and parameters of left ventricular function. Strength training resulted in a significant increase in cardiac dimensions. Both strength and endurance training seem to cause a reduction in myocardial sympathetic drive. However, myocardial morphological and functional adaptations to training were not correlated with myocardial sympathetic activity.
    Journal of Nuclear Cardiology 03/2014; · 2.85 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Individuals of south Asian origin have a very high risk of developing type 2 diabetes compared with white Caucasians. We aimed to assess volume and activity of brown adipose tissue (BAT), which is thought to have a role in energy metabolism by combusting fatty acids and glucose to produce heat and might contribute to the difference in incidence of type 2 diabetes between ethnic groups. We enrolled Dutch nationals with south Asian ancestry and matched Caucasian participants at The Rijnland Hospital (Leiderdorp, Netherlands). Eligible participants were healthy lean men aged 18-28 years, and we matched groups for BMI. We measured BAT volume and activity with cold-induced (18)F-fluorodeoxyglucose ((18)F-FDG) PET CT scans, and assessed resting energy expenditure, non-shivering thermogenesis, and serum parameters. This study is registered with the Netherlands Trial Register, number 2473. Between March 1, 2013, and June 1, 2013, we enrolled 12 participants in each group; one Caucasian participant developed hyperventilation after (18)F-FDG administration, and was excluded from all cold-induced and BAT measurements. Compared with Caucasian participants, south Asian participants did not differ in age (mean 23·6 years [SD 2·8] for south Asians vs 24·6 years [2·8] for Caucasians) or BMI (21·5 kg/m(2) [2·0] vs 22·0 kg/m(2) [1·6]), but were shorter (1·74 m [0·06] vs 1·85 m [0·04]) and lighter (65·0 kg [8·5] vs 75·1 kg [7·2]). Thermoneutral resting energy expenditure was 1297 kcal per day (SD 123) in south Asian participants compared with 1689 kcal per day (193) in white Caucasian participants (difference -32%, p=0·0008). On cold exposure, shiver temperature of south Asians was 2·0°C higher than Caucasians (p=0·0067) and non-shivering thermogenesis was increased by 20% in white Caucasians (p<0·0001) but was not increased in south Asians. Although the maximum and mean standardised uptake values of (18)F-FDG in BAT did not differ between groups, total BAT volume was lower in south Asians (188 mL [SD 81]) than it was in Caucasians (287 mL [169]; difference -34%, p=0·04). Overall, BAT volume correlated positively with basal resting energy expenditure in all assessable individuals (β=0·44, p=0·04). Lower resting energy expenditure, non-shivering thermogenesis, and BAT volumes in south Asian populations might underlie their high susceptibility to metabolic disturbances, such as obesity and type 2 diabetes. Development of strategies to increase BAT volume and activity might help prevent and treat such disorders, particularly in south Asian individuals. Dutch Heart Foundation (2009T038) and Dutch Diabetes Research Foundation (2012.11.1500).
    The lancet. Diabetes & endocrinology. 03/2014; 2(3):210-7.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Purpose of this study was to assess the impact of mediastinal region of interest (ROI) definition on intra- and inter-observer variability in relation to collimator type. Thirty-five subjects with CHF (80% men, mean age 66 ± 9 years, NYHA 2.4 ± 0.5, LVEF 29 ± 8.4%) were enrolled. 15 minutes and 4 hours post-injection (p.i.) of (123)I-MIBG, planar images were sequentially acquired with low energy high energy (LEHR) and medium energy (ME) collimators. In the first analysis, observer-defined mediastinal ROI was used. In the second analysis, a predefined mediastinal ROI was used. Intra- and inter-observer variability of late H/M was assessed using Lin's concordance coefficient (LCC). There was substantial agreement between all three observers using predefined mediastinum ROI. LCCs for LEHR were 0.98, 0.96, and 0.95, for ME 0.98, 0.97, and 0.97. However, observer-defined mediastinal ROI resulted in poor-moderate agreement. LCCs for LEHR were 0.82, 0.94, and 0.70, for ME 0.77, 0.91, and 0.80. Intra-observer analysis using predefined mediastinal ROI showed substantial agreement. LCC was 0.97 for LEHR and 0.96 for ME. Predefined mediastinal ROI results in low intra- and inter-observer variability of late H/M and is, therefore, to be preferred over observer-defined mediastinal ROI. Intra- and inter-observer variability of late H/M is not influenced by collimator choice.
    Journal of Nuclear Cardiology 02/2014; · 2.85 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Tako-tsubo cardiomyopathy (TCM) is an increasingly recognized clinical syndrome characterized by acute reversible apical ventricular dysfunction, commonly preceded by exposure to severe physical or emotional stress. In this review, we give a short overview on clinical presentation and treatment of TCM and discuss the possible pathophysiological mechanisms of TCM and the role of various non-invasive imaging modalities in TCM with a focus on the potential role of (123)I-meta-iodobenzylguanidine (MIBG) scintigraphy. Currently, the dominating hypothesis on the pathophysiology of TCM postulates that high levels of the neurotransmitter epinephrine may trigger a change in intracellular signaling in ventricular myocytes. More specific, epinephrine stimulates G-protein coupled β2 adenoreceptors (β2AR) which are located on ventricular myocytes. Normal levels of this neurotransmitter predominantly stimulate the intracellular G-protein, and induce a positive inotropic effect. However, with significant increasing levels of epinephrine, the predominance of stimulation is shifted from G-stimulating to the G-inhibitor protein coupling, which leads to a negative inotropic effect. Interestingly, this negative inotropic effect is the largest in the apical myocardium where the β2AR:β1AR ratio is the highest within the heart. Echocardiography and ventriculography are essential to diagnose TCM, but new imaging tools are promising to diagnose TCM and to evaluate therapeutic efficacy. Cardiovascular magnetic resonance can be used to differentiate TCM from other myocardial diseases, such as myocarditis. (123)I-meta-iodobenzylguanidine ((123)I-MIBG) scintigraphy can be used to assess ventricular adrenergic activity and may guide optimization of individual (pharmacological) therapy. These new insights into the possible pathophysiological mechanisms and novel diagnostic imaging modalities can be used as starting point for the development of international guidelines of TCM which may increase the awareness, and optimize the treatment of TCM.
    Journal of Nuclear Cardiology 01/2014; · 2.85 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Brown adipose tissue (BAT) has emerged as a novel player in energy homeostasis in humans and is considered a potential new target for combating obesity and related diseases. The current 'gold standard' for quantification of BAT volume and activity is cold-induced 18F-FDG uptake in BAT. However, use of this technique is limited by cost and radiation exposure. Given the fact that BAT is a thermogenic tissue, mainly located in the supraclavicular region, the aim of the current study was to investigate whether cold-induced supraclavicular skin temperature and core body temperature may be alternative markers of BAT activation in humans.
    PLoS ONE 01/2014; 9(6):e98822. · 3.53 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective Hypoglycemia is associated with increased heat production and, despite of this, hypothermia. Heat production is likely to be mediated by sympathetic innervation. Brown adipose tissue is activated by cold exposure and stimulated by the sympathetic nervous system. We therefore examined the effect of hypoglycemia on uptake of the labeled glucose analogue 18 F-fluorodeoxyglucose in brown adipose tissue using positron emission tomography and computer tomography. Methods In nine healthy adults 18 F-fluorodeoxyglucose uptake as measure of brown adipose tissue activity was assessed in a cold environment (17 °C) during euglycemia (blood glucose 4.5 mmol/L) and hypoglycemia (2.5 mmol/L) using a hyperinsulinemic glucose clamp. Results Brown adipose tissue activity was observed in all participants. No difference was observed in the median (range) maximal standardized uptake values of 18 F-fluorodeoxyglucose in brown adipose tissue between euglycemia and hypoglycemia: 4.2 (1.0-7.7) versus 3.1 (2.2-12.5) g/mL (p = 0.7). Similarly there were no differences in mean standardized 18 F-fluorodeoxyglucose uptake values or total brown adipose tissue volume between euglycemia and hypoglycemia. Body temperature dropped by 0.6 °C from baseline during the hypoglycemic condition and remained unchanged during the euglycemic condition. There was no correlation between the maximal standardized uptake values of 18 F-fluorodeoxyglucose in brown adipose tissue and levels of counterregulatory hormones. Conclusions This study shows that there is a similar amount of 18 F-fluorodeoxyglucose uptake in brown adipose tissue during hypoglycemia when compared to euglycemia, which makes a role for systemic catecholamines in brown adipose tissue activation and a role for brown adipose tissue thermogenesis in hypoglycemia associated hypothermia unlikely. Future studies in humans should determine whether hypoglycemia indeed increases energy expenditure, and if so which alternative source can explain this increase.
    Metabolism. 01/2014;
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Patients with clinical suspicion of large-vessel vasculitis (LVV) may present with nonspecific signs and symptoms and increased inflammatory parameters and may remain without diagnosis after routine diagnostic procedures. Both the nonspecificity of the radiopharmaceutical (18)F-FDG and the synergy of integrating functional and anatomical images with PET/CT offer substantial benefit in the diagnostic work-up of patients with clinical suspicion for LVV. A negative temporal artery biopsy, an ultrasonography without an arterial halo, or a MRI without aortic wall thickening or oedema do not exclude the presence of LVV and should therefore not exclude the use of (18)F-FDG PET/CT when LVV is clinically suspected. This overview further discusses the notion that there is substantial underdiagnosis of LVV. Late diagnosis of LVV may lead to surgery or angioplasty in occlusive forms and is often accompanied by serious aortic complications and a fatal outcome. In contrast to the American College of Rheumatology 1990 criteria for vasculitis, based on late LVV effects like arterial stenosis and/or occlusion, (18)F-FDG PET/CT sheds new light on the classification of giant cell arteritis (GCA) and Takayasu arteritis (TA). The combination of these observations makes the role of (18)F-FDG PET/CT in the assessment of patients suspected for having LVV promising.
    BioMed Research International 01/2014; 2014:687608. · 2.71 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Carvedilol, a nonselective β-blocker, may be more effective than the selective β-blocker metoprolol in reducing the risk of thromboembolic events in heart failure. The aim of this study was, first, to assess whether there is a differential response in cardiac sympathetic activity by (123)I-meta-iodobenzylguanidine ((123)I-MIBG) imaging when either β-blocker is used. Second, we assessed whether that response correlates with levels of various serum factors that serve as markers for coagulability. In this prospective, randomized, open-label crossover study with masked outcome assessments, stable heart failure patients (left ventricular ejection fraction < 40%) homozygous for the Arg16/Gln27 (n = 13) or Gly16/Glu27 haplotype (n = 8) of the β2-receptor were randomized to equipotent dosages of carvedilol or metoprolol for two 6-wk periods. Primary outcome was sympathetic activity as measured by (123)I-MIBG myocardial washout. Secondary outcomes included markers of hemostasis. (123)I-MIBG cardiac washout was lower during carvedilol than metoprolol treatment (12.9% ± 3.9% vs. 22.1% ± 2.8%, respectively, P = 0.003), irrespective of β2-adrenergic receptor haplotype. In addition, treatment with carvedilol resulted in a lower von Willebrand factor than did metoprolol (149% ± 13% vs. 157% ± 13%, respectively, P = 0.01), irrespective of β2-adrenergic receptor haplotype. Compared with metoprolol, carvedilol resulted in greater reduction of sympathetic activity after 6 wk of treatment and lower von Willebrand factor concentrations in both Arg16/Gln27 and Gly16/Glu27 individuals. Therefore, carvedilol may reduce the risk of thromboembolic events in patients with heart failure, irrespective of β2-receptor haplotype status.
    Journal of Nuclear Medicine 08/2013; · 5.77 Impact Factor

Publication Stats

878 Citations
369.52 Total Impact Points

Institutions

  • 1999–2014
    • Academisch Medisch Centrum Universiteit van Amsterdam
      • • Department of Nuclear Medicine
      • • Department of Internal Medicine
      • • Department of Cardiology and Cardio-thoracic Surgery
      • • Department of Endocrinology and Metabolism
      Amsterdamo, North Holland, Netherlands
  • 2013
    • University Medical Center Utrecht
      • Department of Cardiology
      Utrecht, Utrecht, Netherlands
  • 2012–2013
    • Medisch Centrum Leeuwarden
      Leewarden, Friesland, Netherlands
    • Onze Lieve Vrouwe Gasthuis
      • Department of Cardiology
      Amsterdam, North Holland, Netherlands
  • 2006–2012
    • University of Amsterdam
      • • Department of Nuclear Medicine
      • • Faculty of Medicine AMC
      Amsterdamo, North Holland, Netherlands
  • 2010
    • Hospital de la Santa Creu i Sant Pau
      Barcino, Catalonia, Spain
  • 2008
    • Centre Hospitalier Universitaire de Caen
      Caen, Lower Normandy, France
  • 2001
    • Academic Medical Center (AMC)
      Amsterdamo, North Holland, Netherlands