Eduard M Laufer

University Medical Center Utrecht, Utrecht, Utrecht, Netherlands

Are you Eduard M Laufer?

Claim your profile

Publications (11)49.09 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: To assess the maximally achievable computed tomography (CT) dose reduction for coronary artery calcium (CAC) scoring with iterative reconstruction (IR) by using phantom-experiments and a systematical within-patient study. Our local institutional review-board approved this study and informed consent was obtained from all participants. A phantom and patient study were conducted with 30 patients (23 men, median age 55.0 (52.0-56.0) years) who underwent 256-slice electrocardiogram-triggered CAC-scoring at four dose levels (routine, 60%, 40%, and 20%-dose) in a single session. Tube-voltage was 120 kVp, tube-current was lowered to achieve stated dose levels. Data were reconstructed with filtered back-projection (FBP) and three IR levels. Agatston, volume and mass scores were determined with validated software and compared using Wilcoxon signed ranks-tests. Subsequently, patient reclassification was analyzed. The phantom study showed that Agatston scores remained nearly stable with FBP between routine-dose and 40%-dose and increased substantially at lower dose. Twenty-three patients (77%) had coronary calcifications. For Agatston scoring, one 40%-dose and six 20%-dose FBP reconstructions were not interpretable due to noise. In contrast, with IR all reconstructions were interpretable. Median Agatston scores increased with FBP from 26.1 (5.2-192.2) at routine-dose to 60.5 (11.6-251.7) at 20% dose. However, IR lowered Agatston scores to 22.9 (5.9-195.5) at 20%-dose and strong IR (level 7) with Agatston reclassifications in 15%. IR allows for CAC-scoring radiation dose reductions of up to 80% resulting in effective doses between 0.15 and 0.18 mSv. At these dose-levels, reclassification-rates remain within 15% if the highest IR-level is applied. Copyright © 2015 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.
    No preview · Article · Aug 2015 · Journal of cardiovascular computed tomography
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Both end-stage and milder stages of chronic kidney disease (CKD) are associated with an increased risk of adverse cardiovascular events. Several studies found an association between decreasing renal function and increasing coronary artery calcification, but it remains unclear if this association is independent from traditional cardiovascular risk factors. Therefore, the aim of this study was to investigate whether mild to moderate CKD is independently associated with coronary plaque burden beyond traditional cardiovascular risk factors.
    Full-text · Article · Oct 2012 · PLoS ONE
  • Source

    Full-text · Dataset · Sep 2012
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Vitamin K-antagonists (VKA) are treatment of choice and standard care for patients with venous thrombosis and thromboembolic risk. In experimental animal models as well as humans, VKA have been shown to promote medial elastocalcinosis. As vascular calcification is considered an independent risk factor for plaque instability, we here investigated the effect of VKA on coronary calcification in patients and on calcification of atherosclerotic plaques in the ApoE(-/-) model of atherosclerosis. A total of 266 patients (133 VKA users and 133 gender and Framingham Risk Score matched non-VKA users) underwent 64-slice MDCT to assess the degree of coronary artery disease (CAD). VKA-users developed significantly more calcified coronary plaques as compared to non-VKA users. ApoE(-/-) mice (10 weeks) received a Western type diet (WTD) for 12 weeks, after which mice were fed a WTD supplemented with vitamin K(1) (VK(1), 1.5 mg/g) or vitamin K(1) and warfarin (VK(1)&W; 1.5 mg/g & 3.0 mg/g) for 1 or 4 weeks, after which mice were sacrificed. Warfarin significantly increased frequency and extent of vascular calcification. Also, plaque calcification comprised microcalcification of the intimal layer. Furthermore, warfarin treatment decreased plaque expression of calcification regulatory protein carboxylated matrix Gla-protein, increased apoptosis and, surprisingly outward plaque remodeling, without affecting overall plaque burden. VKA use is associated with coronary artery plaque calcification in patients with suspected CAD and causes changes in plaque morphology with features of plaque vulnerability in ApoE(-/-) mice. Our findings underscore the need for alternative anticoagulants that do not interfere with the vitamin K cycle.
    Full-text · Article · Aug 2012 · PLoS ONE
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Recent studies have demonstrated the association between increased concentrations of high-sensitivity cardiac troponin T (hs-cTnT) and the incidence of myocardial infarction, heart failure, and mortality. However, most prognostic studies to date focus on the value of hs-cTnT in the elderly or general population. The value of hs-cTnT in symptomatic patients visiting the outpatient department remains unclear. The aim of this study was to investigate the prognostic value of hs-cTnT as a biomarker in patients with symptoms of chest discomfort suspected for coronary artery disease and to assess its additional value in combination with other risk stratification tools in predicting cardiac events.
    Full-text · Article · Apr 2012 · PLoS ONE
  • [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND: The usual diagnostic work-up of chest pain patients includes clinical risk profiling and exercise-ECG, possibly followed by additional tests. Recently cardiac computed tomographic angiography (CCTA) has been employed. We evaluated the prognostic value of the combined use of exercise-ECG and CCTA for the development of cardiovascular endpoints. METHODS: In 283 patients (143 male, mean age 54±10years) with intermediate pre-test probability for coronary artery disease presenting with stable chest pain, exercise-ECG, CCTA and calcium score were performed. Patients were followed-up for combined endpoint of acute coronary syndrome (ACS) and revascularization. RESULTS: After a median follow-up of 769days (interquartile range 644-1007), 6 ACS and 9 revascularizations were recorded. A positive exercise-ECG predicted for the combined endpoint, [hazard ratio (HR) 5.14 (95% confidence interval (CI) 1.64-16.13), p=0.005], as well as a positive calcium score [HR 4.59 (95% CI 1.30-16.28), p=0.02] and a ≥50% stenosis on CCTA [HR 45.82 (95% CI 6.02-348.54), p<0.001]. ROC-analysis showed an area under the curve (AUC) of 0.79 (95% CI 0.67-0.90) for exercise-ECG, which increased significantly when CCTA was added: 0.91 (95% CI; 0.86-0.97; p=0.006). Multivariable Cox regression showed exercise-ECG predicted independently [HR 3.6, (95% CI 1.1-11.2), p=0.03], as well as CCTA [HR 31.4 (95% CI 4.0-246.6), p=0.001], but not calcium score [HR 0.6 (95% CI 0.2-2.3), p=0.5]. CONCLUSIONS: The combined subsequent use of exercise-ECG for functional information and CCTA for anatomical information provides a high diagnostic yield in stable chest pain patients with an intermediate pre-test probability for coronary artery disease.
    No preview · Article · Jan 2012 · International journal of cardiology

  • No preview · Article · Dec 2011
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This study explored the relationship between coronary atherosclerotic plaque burden and quantifiable circulating levels of troponin measured with a recently introduced high sensitive cardiac troponin T (hs-cTnT) assay. Cardiac patients suspected of having coronary artery disease (CAD) but without acute coronary syndrome were studied. Cardiac troponin T levels were assessed using the fifth-generation hs-cTnT assay. All patients (n=615) underwent cardiac computed tomographic angiography (CCTA). On the basis of CCTA, patients were classified as having no CAD or mild (<50% lesion), moderate (50% to 70% lesion), severe (>70% lesion), or multivessel CAD (multiple >70% lesions). As a comparison, high-sensitivity C-reactive protein levels were measured. Progressively increasing hs-cTnT levels were found in patients with mild (median, 4.5 ng/L), moderate (median, 5.5 ng/L), severe (median, 5.7 ng/L), and multivessel (median, 8.6 ng/L) CAD compared with patients without CAD (median, 3.7 ng/L) (all P<0.01). For high-sensitivity C-reactive protein and N-terminal pro-B-type natriuretic peptide, no such relationship was observed. In patients without CAD, 11% showed hs-cTnT levels in the highest quartile, compared with 62% in the multivessel disease group (P<0.05). Multivariance analysis identified hs-cTnT as an independent risk factor for the presence of CAD. In patients without acute coronary syndrome, even mild CAD is associated with quantifiable circulating levels of hs-cTnT.
    Full-text · Article · Mar 2010 · Arteriosclerosis Thrombosis and Vascular Biology
  • [Show abstract] [Hide abstract]
    ABSTRACT: Endurance exercise is frequently associated with cardiac troponin (cTn) concentrations, otherwise corresponding to minor myocardial infarction. However, research on the underlying mechanisms has been limited because of assay restraints in the low concentration range. Using the pre-commercial, highly sensitive hs-cTnT assay, cTnT concentrations were measured in samples from recreational runners obtained before and after running 5 km (trained, n = 43/untrained, n = 122), 15 km (n = 38), 21 km (n = 10), and 42 km (n = 85) (all trained). The percentage of runners with elevated cTnT concentrations after the run increased with running distance (0, 11, 13, 40, and 86%), in contrast to NT-proBNP (2, 7, 0, 0, 5). Median (IQR) cTnT post-run concentrations were 0.004 microg/L (0.003), 0.006 microg/L (0.008), 0.010 microg/L (0.006), 0.014 microg/L (0.019), and 0.030 microg/L (0.029), respectively. We found, using a novel hs-cTnT assay, the distance of recreational competitive running to be positively related to asymptomatic increases in cTnT post-run concentrations. In contrast, NT-proBNP showed no increase. In addition, the data indicated that a relatively short running distance of 5 km resulted in cTnT release of untrained participants, in contrast to trained participants, which underlines the necessity of sufficient training. Further effort is needed to clarify the significance of exercise-induced cardiac biomarker elevations.
    No preview · Article · Mar 2010 · Clinical Research in Cardiology
  • Source
    Eduard M Laufer · Mark H M Winkens · Jagat Narula · Leonard Hofstra
    [Show abstract] [Hide abstract]
    ABSTRACT: The ability to identify atherosclerotic plaques that are prone to rupture, also called vulnerable plaques, may provide a major step forward in the recognition of patients that have a high risk of developing acute myocardial infarction. Current clinical risk profiling algorithms, such as the Framingham and Procam risk scores, have reasonable predictive value in the assessment of the 10 year risk. These clinical risk profiling scores typically classify patients into low risk (10-year risk, less than 5%), intermediate risk (5% to 20% risk), and high risk (greater than 20%). The challenge to imagers is to identify the risk that is beyond 2% yearly risk. Molecular imaging may help identify plaque inflammation and apoptosis of inflammatory cells, which are obligatory components of the plaque instability. These processes offer specific biological targets that can potentially be exploited to obtain biological information on atherosclerosis development in the individual patient.
    Full-text · Article · Jun 2009 · Arteriosclerosis Thrombosis and Vascular Biology
  • Source

    Full-text · Article · Apr 2009 · Journal of the American College of Cardiology

Publication Stats

177 Citations
49.09 Total Impact Points

Institutions

  • 2015
    • University Medical Center Utrecht
      • Department of Cardiology
      Utrecht, Utrecht, Netherlands
  • 2009-2012
    • Maastricht University
      • Department of Cardiology
      Maestricht, Limburg, Netherlands
  • 2011
    • Icahn School of Medicine at Mount Sinai
      Borough of Manhattan, New York, United States
  • 2009-2010
    • Maastricht Universitair Medisch Centrum
      • Central Diagnostic Laboratory
      Maestricht, Limburg, Netherlands