Coronary Artery Disease: Oudkerk M

Oudkerk M, Stillman AE, Halliburton SS, Kalender WA, Möhlenkamp S, McCollough CH, Vliegenthart R, Shaw LJ, Stanford W, Taylor AJ, van Ooijen PM, Wexler L, Raggi P, Anonymous00008, Anonymous00009. · Department of Radiology, Groningen University Hospital, Hanzeplein 1, 9700 RB, Groningen, The Netherlands. · Eur Radiol. · Pubmed #18651153 No free full text.

Abstract: Current guidelines and literature on screening for coronary artery calcium for cardiac risk assessment are reviewed for both general and special populations. It is shown that for both general and special populations a zero score excludes most clinically relevant coronary artery disease. The importance of standardization of coronary artery calcium measurements by multidetector CT is discussed.

Oudkerk M, Stillman AE, Halliburton SS, Kalender WA, Möhlenkamp S, McCollough CH, Vliegenthart R, Shaw LJ, Stanford W, Taylor AJ, van Ooijen PM, Wexler L, Raggi P. · Department of Radiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands. · Int J Cardiovasc Imaging. · Pubmed #18504647 links to  free full text

Abstract: Current guidelines and literature on screening for coronary artery calcium for cardiac risk assessment are reviewed for both general and special populations. It is shown that for both general and special populations a zero score excludes most clinically relevant coronary artery disease. The importance of standardization of coronary artery calcium measurements by multi-detector CT is discussed.

Dorgelo J, Willemsen HM, Van Ooijen PM, Zijlstra F, Oudkerk M. · Academisch Ziekenhuis, Afd. Radiologie, Postbus 30.001, 9700 RB Groningen. · Ned Tijdschr Geneeskd. · Pubmed #15283023 No free full text.

Abstract: In the past decade, improvements in CT techniques have enabled non-invasive visualization of the coronary arteries. Multidetector CT (MDCT) is currently the generally accepted technique for the follow-up of coronary stents and by-pass grafts, and for the evaluation of anomalous coronary arteries and coronary artery disease. Both the degree of stenosis, as well as plaque composition can be determined by MDCT. Plaque composition has proven to be a more important predictor for acute coronary syndromes than the degree of stenosis. In addition, MDCT has less risks of complication and lower costs. Limitations of MDCT are: sensitivity to rhythm- and breathing artefacts, a lower spatial and time resolution than coronary angiography (CAG), and difficulties in coronary evaluation close to high density structures such as calcifications and stents. Coronary angiography is still indicated when functional information has to be obtained about coronary flow. MDCT should be considered in all cases in which diagnostic CAG is performed.

de Feyter PJ, Nieman K, van Ooijen P, Oudkerk M. · University Hospital Rotterdam, Rotterdam, The Netherlands. · Heart. · Pubmed #10995423 links to  free full text

This publication has no abstract.

van Geuns RJ, Wielopolski PA, de Bruin HG, Hulshoff MD, Oudkerk M, de Feyter PJ. · Department of Cardiology, University Hospital Rotterdam, The Netherlands. · Coron Artery Dis. · Pubmed #10562922 No free full text.

Abstract: Magnetic-resonance imaging techniques use different imaging planes than does conventional coronary angiography to acquire longer segments of a coronary artery in a single tomographic slice. At first sight, these planes appear rather puzzling, because the coronary arteries are displayed in unfamiliar orientations. In this article we will review the existing methodology for obtaining the orientations for the proximal coronary arteries and describe the associated anatomical landmarks that can be seen. Additional orientations for the middle segment of the circumflex and distal right coronary artery are introduced. These orientations are used both in various acquisition techniques and for evaluation of three-dimensional data when using multiplanar reformatting.

van Geuns RJ, Wielopolski PA, de Bruin HG, Rensing BJ, van Ooijen PM, Hulshoff M, Oudkerk M, de Feyter PJ. · Department of Cardiology, Thoraxcenter, Dr Daniel den Hoedkliniek, University Hospital Rotterdam, The Netherlands. · Prog Cardiovasc Dis. · Pubmed #10555116 No free full text.

Abstract: Recently a new noninvasive imaging technique, magnetic resonance imaging (MRI) has been developed that has the potential to assess the coronary arteries. MRI of the coronary arteries is a challenging task because of the motion of the vessels during cardiac contraction and the motion of the heart with respiration. Several two-dimensional and three-dimensional acquisition techniques have been developed to overcome these problems. In this article we will describe different conventional MR techniques such as spin-echo and gradient-echo imaging. Also, we will describe new developments in MRI as ultrafast breathhold techniques using echo planar imaging or targeted volume scanning. Other new developments are respiratory gating techniques with or without respiratory motion correction. Finally, we will review the results of these techniques in the detection of coronary artery bypass graft patency, coronary artery stenosis, and the evaluation of coronary artery anomalies.

van Geuns RJ, Wielopolski PA, Rensing BJ, van Ooijen PM, Oudkerk M, de Feyter PJ. · Department of Cardiology, University Hospital Rotterdam, The Netherlands. · Coron Artery Dis. · Pubmed #10376205 No free full text.

Abstract: Magnetic resonance imaging of coronary arteries will visualize, besides the arteries, the myocardium, blood in the cavities and cardiac veins. This will hamper the application of projectional visualization techniques such as those used in conventional coronary angiography. Volume rendering, a different visualization technique, can be used to create a three-dimensional impression of a magnetic resonance data set on a two-dimensional surface. In this article, we will review the volume-rendering technique and anatomy of the coronary arteries and veins in the obtained images. Also we will discuss the relation between arteries and veins and the possible sites of confusion.

Slart RH, Bax JJ, de Boer J, Willemsen AT, Mook PH, Oudkerk M, van der Wall EE, van Veldhuisen DJ, Jager PL. · Department of Nuclear Medicine and Molecular Imaging, Groningen University Medical Center, Hanzeplein 1, P.O. Box 30001, 9700 RB, Groningen, The Netherlands. · Eur J Nucl Med Mol Imaging. · Pubmed #15824927 No free full text.

Abstract: PURPOSE: Dual-isotope simultaneous acquisition (DISA) single-photon emission computed tomography (SPECT) is an attractive technique as it permits assessment of both myocardial glucose metabolism and perfusion within a single session, but few data on its accuracy for the assessment of viability are available as yet. In the present study, DISA SPECT was compared with positron emission tomography (PET) for the detection of myocardial viability in normal and dysfunctional left ventricular (LV) myocardium. METHODS: Fifty-eight patients with chronic coronary artery disease and LV dysfunction (LV ejection fraction 33+/-12%) were studied. Patients underwent a 1-day dipyridamole stress 99mTc-sestamibi/18F-fluorodeoxyglucose (18FDG) DISA SPECT and 13N-ammonia/18FDG PET protocol. Within 1 week, resting MRI was performed to assess contractile function. Comparison of PET and SPECT data was performed using both visual and quantitative analysis. RESULTS: The correlation of normalised activities of the flow tracers 99mTc-sestamibi and 13N-ammonia was good (r = 0.82; p < 0.001). The correlation between the two 18FDG studies was also good (r = 0.83; p < 0.001). The agreement for the assessment of viability for all segments between DISA SPECT and PET was 82%, with a kappa-statistic of 0.59 (95% CI 0.53-0.64), without a significant difference; in dysfunctional segments only, the agreement was 82%, with a kappa-statistic of 0.63 (95% CI 0.56-0.70), without a significant difference. When the DISA SPECT data were analysed visually, the agreement between DISA SPECT and PET was 83%, with a kappa-statistic of 0.58 (95% CI 0.52-0.63), without a significant difference. Moreover, there was no significant difference between visual and quantitative DISA SPECT analysis for the detection of viability. CONCLUSION: This study shows an overall good agreement between 99mTc-sestamibi/18FDG DISA SPECT and PET for the assessment of myocardial viability in patients with severe LV dysfunction. Quantitative or visual analysis of the SPECT data did not influence the agreement with PET, suggesting that visual assessment may be sufficient for clinical purposes.

Kuijpers D, van Dijkman PR, Janssen CH, Vliegenthart R, Zijlstra F, Oudkerk M. · Department of Radiology and Cardiology, State University and Academic Hospital Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands. · Eur Radiol. · Pubmed #15278416 No free full text.

Abstract: The aim of this study was to determine the prognostic value of dobutamine cardiovascular magnetic resonance (CMR) in patients suspected of myocardial ischemia. Clinical data and dobutamine-CMR results were analyzed in 299 consecutive patients. Follow-up data were analyzed in categories of risk levels defined by the history of coronary artery disease and presence of rest wall motion abnormalities (RWMA). Major adverse cardiac events (MACE) as evaluated end points included cardiac death, nonfatal myocardial infarction and clinically indicated coronary revascularization. Follow-up was completed in 214 (99%) patients with a negative dobutamine-CMR study (no signs of inducible myocardial ischemia) with an average of 24 months. The patients with a negative dobutamine-CMR study and RWMA showed a significantly higher annual MACE rate (18%) than the patients without RWMA (0.56%) ( P<0.001). Patients without RWMA showed an annual MACE rate of 2% when they had a history of coronary artery disease and <0.1% without a previous coronary event ( P<0.001). Dobutamine-CMR showed a positive and negative predictive value of 95 and 93%, respectively. The cardiovascular occurrence-free survival rate was 96.2%. In patients suspected of myocardial ischemia, dobutamine-CMR is able to assess risk levels for coronary events with high accuracy.

van Ooijen PM, Nieman K, de Feyter PJ, Oudkerk M. · Department of Radiology, University Hospital Groningen, Groningen, The Netherlands. · Am J Cardiol. · Pubmed #12398971 No free full text.

This publication has no abstract.

Piers LH, Touw HR, Gansevoort R, Franssen CF, Oudkerk M, Zijlstra F, Tio RA. · Department of Cardiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands. · Am J Cardiol. · Pubmed #19427449 No free full text.

Abstract: Patients with chronic renal failure have increased cardiac calcium loads. Previous studies have investigated the prevalence and quantitative extent of aortic valve calcium (AVC) and coronary artery calcium (CAC) in patients with various stages of chronic kidney disease (CKD). However, the impact of preexisting atherosclerosis on the calcification burden has not been clarified. Therefore, this study was conducted to examine the effect of CKD stage as well as the primary cause of renal failure (atherosclerotic vs nonatherosclerotic) on AVC and CAC. Twenty-two, 13, and 28 patients with stage 3, 4, and 5 CKD, respectively, were included, of whom 24 had atherosclerotic CKD. Patients underwent electron-beam computed tomography to assess AVC and CAC. AVC was present in 27% of patients with stage 3 CKD, in 38% of patients with stage 4 CKD, and in 43% of patients with stage 5 CKD. CAC was present in 77% of patients with stage 3 CKD, in 54% of patients with stage 4 CKD, and in 64% of patients with stage 5 CKD. There was no correlation between CKD stage and the quantitative extent of AVC and CAC. AVC was more frequent (58% vs 23%, p <0.01) and more extensive (median score 43 [range 0 to 494] vs 0 [range 0 to 8], p <0.01) in patients with CKD caused by atherosclerotic renal disease than in patients with nonatherosclerotic causes of CKD. CAC was more frequent (83% vs 56%, p <0.05) and more extensive (median score 437 [range 61 to 1,565] vs 31 [range 0 to 155], p <0.001) in patients with atherosclerotic causes of CKD than in patients with CKD caused by nonatherosclerotic renal disease. In conclusion, the prevalence as well as the severity of AVC and CAC did not vary between patients with stage 3, 4, and 5 CKD. Cardiac calcification, both AVC and CAC, were more frequent and more severe in patients with atherosclerotic causes of renal failure. These results suggest that cardiac calcium is related to atherosclerotic burden rather than to the severity of CKD.

Piers LH, Salachova F, Slart RH, Vliegenthart R, Dikkers R, Hospers FA, Bouma HR, Zeebregts CJ, Willems TP, Oudkerk M, Zijlstra F, Tio RA. · Department of Cardiology, University Medical Center Groningen, Groningen, the Netherlands. · BMC Cardiovasc Disord. · Pubmed #19091061 links to  free full text

Abstract: BACKGROUND: Coronary artery calcification (CAC) measured by electron-beam computed tomography (EBCT) has been well studied in the prediction of coronary artery disease (CAD). We sought to evaluate the impact of the CAC score in the diagnostic process immediately after its introduction in a large tertiary referral centre. METHODS: 598 patients with no history of CAD who underwent EBCT for evaluation of CAD were retrospectively included into the study. Ischemia detection test results (exercise stress test, single photon emission computed tomography or ST segment analysis on 24 hours ECG detection), as well as the results of coronary angiography (CAG) were collected. RESULTS: The mean age of the patients was 55 +/- 11 years (57% male). Patients were divided according to CAC scores; group A < 10, B 10 - 99, C 100 - 399 and D >or= 400 (304, 135, 89 and 70 patients respectively). Ischemia detection tests were performed in 531 (89%) patients; negative ischemia results were found in 362 patients (183 in group A, 87 in B, 58 in C, 34 in D). Eighty-eight percent of the patients in group D underwent CAG despite negative ischemia test results, against 6% in group A, 16% in group B and 29% in group C. A positive ischemia test was found in 74 patients (25 in group A, 17 in B, 16 in C, 16 in D). In group D 88% (N = 14) of the patients with a positive ischemia test were referred for CAG, whereas 38 - 47% in group A-C. CONCLUSION: Our study showed that patients with a high CAC score are more often referred for CAG. The CAC scores can be used as an aid in daily cardiology practice to determine further decision making.

Piers LH, Dikkers R, Willems TP, de Smet BJ, Oudkerk M, Zijlstra F, Tio RA. · Department of Cardiology, University Medical Centre Groningen, University of Groningen, Hanzeplein 1, PO Box 30001, 9700 RB Groningen, The Netherlands. · Eur Heart J. · Pubmed #18854332 No free full text.

Abstract: AIMS: To evaluate non-invasive angiography using dual-source computed tomography (CT) for the determination of the most appropriate therapeutic strategy in patients with suspected coronary artery disease (CAD). METHODS AND RESULTS: CT angiography (Dual Source CT, Somatom Definition, Siemens Medical Systems, Forchheim, Germany) was performed in 60 consecutive patients [51 men, median age 64 (57-70) years] scheduled for elective coronary angiography. Both techniques were used to evaluate the presence of CAD, significant stenosis, and the need for revascularization therapy. Sensitivity and specificity for the presence of significant stenosis were: per segment (n = 766) 62% (95% CI 50-72) (64/104) and 79% (95% CI 74-84) (526/662), respectively; per patient (n = 60) 100% (95% CI 91-100) (38/38) and 45% (95% CI 24-68) (10/22), respectively. In therapeutic decision-making based on CT angiography, sensitivity, specificity, positive and negative predictive values for intervention were 97% (95% CI 84-100) (36/37), 48% (95% CI 27-69) (11/23), 75% (95% CI 60-86) (36/48), and 92% (95% CI 60-100) (11/12), respectively. If a revascularization procedure was needed, the CT angiographic data indicated the appropriate modality (percutaneous coronary intervention or coronary artery bypass grafting) in 70% (26/36) of patients. CONCLUSION: Although imaging qualities have improved considerably, CT angiography cannot be used for definitive therapeutic decision-making with regard to revascularization procedures in patients with suspected CAD.

de Vos AM, Rutten A, van de Zaag-Loonen HJ, Bots ML, Dikkers R, Buiskool RA, Mali WP, Lubbers DD, Mosterd A, Prokop M, Rensing BJ, Cramer MJ, van Es HW, Moll FL, van de Pavoordt ED, Doevendans PA, Velthuis BK, Mackaay AJ, Zijlstra F, Oudkerk M. · Department of radiology, University medical Center Groningen, Groningen, The Netherlands. · Trials. · Pubmed #18673542 links to  free full text

Abstract: ABSTRACT: BACKGROUND: Peripheral arterial disease (PAD) is a common disease associated with a considerably increased risk of future cardiovascular events and most of these patients will die from coronary artery disease (CAD). Screening for silent CAD has become an option with recent non-invasive developments in CT (computed tomography)-angiography and MR (magnetic resonance) stress testing. Screening in combination with more aggressive treatment may improve prognosis. Therefore we propose to study whether a cardiac imaging algorithm, using non-invasive imaging techniques followed by treatment will reduce the risk of cardiovascular disease in PAD patients free from cardiac symptoms. DESIGN: The GROUND study is designed as a prospective, multi-center, randomized clinical trial. Patients with peripheral arterial disease, but without symptomatic cardiac disease will be asked to participate. All patients receive a proper risk factor management before randomization. Half of the recruited patients will enter the 'control group' and only undergo CT calcium scoring. The other half of the recruited patients (index group) will undergo the non invasive cardiac imaging algorithm followed by evidence-based treatment. First, patients are submitted to CT calcium scoring and CT angiography. Patients with a left main (or equivalent) coronary artery stenosis of > 50% on CT will be referred to a cardiologist without further imaging. All other patients in this group will undergo dobutamine stress magnetic resonance (DSMR) testing. Patients with a DSMR positive for ischemia will also be referred to a cardiologist. These patients are candidates for conventional coronary angiography and cardiac interventions (coronary artery bypass grafting (CABG) or percutaneous cardiac interventions (PCI)), if indicated. All participants of the trial will enter a 5 year follow up period for the occurrence of cardiovascular events. Sequential interim analysis will take place. Based on sample size calculations about 1200 patients are needed to detect a 24% reduction in primary outcome. IMPLICATIONS: The GROUND study will provide insight into the question whether non-invasive cardiac imaging reduces the risk of cardiovascular events in patients with peripheral arterial disease, but without symptoms of coronary artery disease. TRIAL REGISTRATION: Clinicaltrials.gov NCT00189111.

van Woudenbergh GJ, Vliegenthart R, van Rooij FJ, Hofman A, Oudkerk M, Witteman JC, Geleijnse JM. · Division of Human Nutrition, Wageningen University, Wageningen, P.O. Box 8129, 6700 EV Wageningen, The Netherlands. · Arterioscler Thromb Vasc Biol. · Pubmed #18323515 links to  free full text

Abstract: BACKGROUND: The role of coffee in the cardiovascular system is not yet clear. We examined the relation of coffee intake with coronary calcification in a population-based cohort. METHODS AND RESULTS: The study involved 1570 older men and women without coronary heart disease who participated in the Rotterdam Study. Coffee intake was assessed with a semiquantitative food frequency questionnaire. Coronary calcification was detected with electron beam computed tomography. Severe calcification was defined as an Agatson calcium score >400. Sex-specific odds ratios (ORs) with 95% confidence intervals (95% CI) were obtained by logistic regression with adjustment for age, smoking, body mass index, education, and intake of energy and alcohol. In multivariable analysis, coronary calcification in women was significantly reduced for moderate (>3 to 4 cups) and high (>4 cups) coffee intake, compared with a daily intake of 3 cups or less (OR of 0.41 [95% CI: 0.25 to 0.65] and 0.54 [0.33 to 0.87], respectively). The association persisted after additional adjustment for tea and other dietary confounders, and was not modified by smoking. A nonsignificant inverse relationship was also found in men who smoked, whereas in nonsmoking men a direct association was observed. CONCLUSIONS: The present study suggests a beneficial effect of coffee drinking against coronary calcification, particularly in women. More research is needed to confirm these findings and to clarify possible effect modification by gender and smoking.

Groen JM, Greuter MJ, Vliegenthart R, Suess C, Schmidt B, Zijlstra F, Oudkerk M. · Department of Radiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands. · Int J Cardiovasc Imaging. · Pubmed #18038190 links to  free full text

Abstract: PURPOSE: Assessment of calcium scoring (Ca-scoring) on a 64-slice multi-detector computed tomography (MDCT) scanner, a dual-source computed tomography (DSCT) scanner and an electron beam tomography (EBT) scanner with a moving cardiac phantom as a function of heart rate, slice thickness and calcium density. METHODS AND MATERIALS: Three artificial arteries with inserted calcifications of different sizes and densities were scanned at rest (0 beats per minute) and at 50-110 beats per minute (bpm) with an interval of 10 bpm using 64-slice MDCT, DSCT and EBT. Images were reconstructed with a slice thickness of 0.6 and 3.0 mm. Agatston score, volume score and equivalent mass score were determined for each artery. A cardiac motion susceptibility (CMS) index was introduced to assess the susceptibility of Ca-scoring to heart rate. In addition, a difference (Delta) index was introduced to assess the difference of absolute Ca-scoring on MDCT and DSCT with EBT. RESULTS: Ca-score is relatively constant up to 60 bpm and starts to decrease or increase above 70 bpm, depending on scoring method, calcification density and slice thickness. EBT showed the least susceptibility to cardiac motion with the smallest average CMS-index (2.5). The average CMS-index of 64-slice MDCT (9.0) is approximately 2.5 times the average CMS-index of DSCT (3.6). The use of a smaller slice thickness decreases the CMS-index for both CT-modalities. The Delta-index for DSCT at 0.6 mm (53.2) is approximately 30% lower than the Delta-index for 64-slice MDCT at 0.6 mm (72.0). The Delta-indexes at 3.0 mm are approximately equal for both modalities (96.9 and 102.0 for 64-slice MDCT and DSCT respectively). CONCLUSION: Ca-scoring is influenced by heart rate, slice thickness and modality used. Ca-scoring on DSCT is approximately 50% less susceptible to cardiac motion as 64-slice MDCT. DSCT offers a better approximation of absolute calcium score on EBT than 64-slice MDCT when using a smaller slice thickness. A smaller slice thickness reduces the susceptibility to cardiac motion and reduces the difference between CT-data and EBT-data. The best approximation of EBT on CT is found for DSCT with a slice thickness of 0.6 mm.

Groen JM, Greuter MJ, Schmidt B, Suess C, Vliegenthart R, Oudkerk M. · Department of Radiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands. · Invest Radiol. · Pubmed #18007157 No free full text.

Abstract: OBJECTIVE: The purpose of this study was to investigate the influence of heart rate, slice thickness, and calcification density on absolute value and variability of calcium score using 64-slice multidetector computed tomography (MDCT). METHODS AND MATERIALS: Three artificial arteries containing each 3 lesions with varying density were scanned using a moving cardiac phantom at rest and at 50 to 110 beats per minute (bpm) at 10-bpm intervals on a 64-slice MDCT. Images were reconstructed at slice thicknesses (increment) of 0.6 (0.4), 0.75 (0.5), 1.5 (1.5), and 3.0 (3.0) mm. The amount of calcium was expressed as an Agatston score, volume score, and equivalent mass. RESULTS: Absolute coronary artery calcium (CAC) scores decreased [average -37% for low density calcification (LDC)] or increased [average +32% for high density calcification (HDC)] at heart rates over 60 bpm depending on slice thickness and scoring method. Thinner slice thicknesses yielded higher CAC scores. Variability of the CAC scores increased with increasing heart rates especially for low density calcifications (8% at rest vs. 50% at 110 bpm). Variability also increased for thicker slices (average 6% for 0.6 mm vs. 18% for 3.0 mm). Variability was lower for HDC compared with LDC (approximately 5% for HDC vs. 27% for LDC at 70 bpm, averaged over all methods and slice thicknesses). CONCLUSION: CAC-scoring is strongly influenced by cardiac motion, calcification density, and slice thickness. CAC scores increase for high density calcifications and decrease for low density calcifications at increasing heart rates. Heart rate should be reduced on 64-slice MDCT to obtain a lower degree of variability of CAC-scoring, preferably below 70 bpm. A thinner slice thickness further enhances the reproducibility.

Greuter MJ, Dijkstra H, Groen JM, Vliegenthart R, de Lange F, Renema WK, de Bock GH, Oudkerk M. · Department of Radiology, University Medical Center Groningen, University of Groningen, Groningen. The Netherlands. · Med Phys. · Pubmed #17926954 No free full text.

Abstract: The objective of our study was the determination of the influence of the sequential and spiral acquisition modes on the concordance and deviation of the calcium score on 64-slice multi-detector computed tomography (MDCT) scanners in comparison to electron beam tomography (EBT) as the gold standard. Our methods and materials were an anthropomorphic cardio CT phantom with different calcium inserts scanned in sequential and spiral acquisition modes on three identical 64-slice MDCT scanners of manufacturer A and on three identical 64-slice MDCT scanners of manufacturer B and on an EBT system. Every scan was repeated 30 times with and 15 times without a small random variation in the phantom position for both sequential and spiral modes. Significant differences were observed between EBT and 64-slice MDCT data for all inserts, both acquisition modes, and both manufacturers of MDCT systems. High regression coefficients (0.90-0.98) were found between the EBT and 64-slice MDCT data for both scoring methods and both systems with high correlation coefficients (R2>0.94). System A showed more significant differences between spiral and sequential mode than system B. Almost no differences were observed in scanners of the same manufacturer for the Agatston score and no differences for the Volume score. The deviations of the Agatston and Volume scores showed regression dependencies approximately equal to the square root of the absolute score. The Agatston and Volume scores obtained with 64-slice MDCT imaging are highly correlated with EBT-obtained scores but are significantly underestimated (-10% to -2%) for both sequential and spiral acquisition modes. System B is more independent of acquisition mode to calcium score than system A. The Volume score shows no intramanufacturer dependency and its use is advocated versus the Agatston score. Using the same cut points for MDCT-based calcium scores as for EBT-based calcium scores can result in classifying individuals into a too low risk category. System information and scanprotocol is therefore needed for every calcium score procedure to ensure a correct clinical interpretation of the obtained calcium score results.

Geluk CA, Dikkers R, Perik PJ, Tio RA, Götte MJ, Hillege HL, Vliegenthart R, Houwers JB, Willems TP, Oudkerk M, Zijlstra F. · Thoraxcenter, Department of Cardiology, University Medical Center Groningen, Hanzeplein 1, PB 30001, 9700 RB, Groningen, The Netherlands. · Eur Radiol. · Pubmed #17901959 links to  free full text

Abstract: We determined the efficiency of a screening protocol based on coronary calcium scores (CCS) compared with exercise testing in patients with suspected coronary artery disease (CAD), a normal ECG and troponin levels. Three-hundred-and-four patients were enrolled in a screening protocol including CCS by electron beam computed tomography (Agatston score), and exercise testing. Decision-making was based on CCS. When CCS>or=400, coronary angiography (CAG) was recommended. When CCS<10, patients were discharged. Exercise tests were graded as positive, negative or nondiagnostic. The combined endpoint was defined as coronary event or obstructive CAD at CAG. During 12+/-4 months, CCS>or=400, 10-399 and <10 were found in 42, 103 and 159 patients and the combined endpoint occurred in 24 (57%), 14 (14%) and 0 patients (0%), respectively. In 22 patients (7%), myocardial perfusion scintigraphy was performed instead of exercise testing due to the inability to perform an exercise test. A positive, nondiagnostic and negative exercise test result was found in 37, 76 and 191 patients, and the combined endpoint occurred in 11 (30%), 15 (20%) and 12 patients (6%), respectively. Receiver-operator characteristics analysis showed that the area under the curve of 0.89 (95% CI: 0.85-0.93) for CCS was superior to 0.69 (95% CI: 0.61-0.78) for exercise testing (P<0.0001). In conclusion, measurement of CCS is an appropriate initial screening test in a well-defined low-risk population with suspected CAD.

Elias-Smale SE, Kardys I, Oudkerk M, Hofman A, Witteman JC. · Department of Epidemiology & Biostatistics, Erasmus Medical Center, Rotterdam, The Netherlands. · Atherosclerosis. · Pubmed #17714718 No free full text.

Abstract: AIMS: Although prospective studies have unequivocally shown that C-reactive protein (CRP) is an independent predictor of future cardiovascular events, studies on the association between CRP and atherosclerosis have provided inconsistent results. We investigated the association of CRP with extent and progression of atherosclerosis in multiple vessel beds in a large, population-based cohort study. METHODS: In the Rotterdam Study, standardized measurements of coronary and extra-coronary atherosclerosis were performed in 1962 persons and 6582 persons, respectively. Progression of extra-coronary atherosclerosis during a mean follow-up period of 6.4 years was assessed in 3757 persons. RESULTS: Independent and graded associations were found of CRP with the number of carotid plaques and carotid plaque progression ((OR 1.72; 95% CI 1.14-2.59) for severe progression in participants with CRP>3mg/dl versus participants with CRP<1mg/dl). Similarly, CRP was independently and graded related to ankle-brachial-index (ABI) and worsening ABI over the years ((OR 1.99; 95% CI 1.37-2.88) for severe progression in participants with CRP>3mg/dl versus participants with CRP<1mg/dl). Although CRP was independently related to the highest level of carotid intima-media thickness (IMT), the association with change in IMT was not significant. Furthermore, there was an independent, graded relation between CRP and aortic calcification, but no independent association was observed with progression of aortic calcification, nor with the amount of coronary calcification. CONCLUSION: In this population-based study, independent and graded associations were present of CRP with extent and progression of carotid plaques and ABI, while associations with carotid IMT and aortic and coronary calcification were less pronounced.

Geluk CA, Dikkers R, Kors JA, Tio RA, Slart RH, Vliegenthart R, Hillege HL, Willems TP, de Jong PE, van Gilst WH, Oudkerk M, Zijlstra F. · Department of Cardiology, Thoraxcenter, University Medical Center Groningen, University of Groningen, The Netherlands. · BMC Cardiovasc Disord. · Pubmed #17629903 links to  free full text

Abstract: BACKGROUND: Asymptomatic subjects at intermediate coronary risk may need diagnostic testing for risk stratification. Both measurement of coronary calcium scores and exercise testing are well established tests for this purpose. However, it is not clear which test should be preferred as initial diagnostic test. We evaluated the prevalence of documented coronary artery disease (CAD) according to calcium scores and exercise test results. METHODS: Asymptomatic subjects with ST-T changes on a rest ECG were selected from the population based PREVEND cohort study and underwent measurement of calcium scores by electron beam tomography and exercise testing. With calcium scores > or =10 or a positive exercise test, myocardial perfusion imaging (MPS) or coronary angiography (CAG) was recommended. The primary endpoint was documented obstructive CAD (>/=50% stenosis). RESULTS: Of 153 subjects included, 149 subjects completed the study protocol. Calcium scores > or =400, 100-399, 10-99 and <10 were found in 16, 29, 18 and 86 subjects and the primary endpoint was present in 11 (69%), 12 (41%), 0 (0%) and 1 (1%) subjects, respectively. A positive, nondiagnostic and negative exercise test was present in 33, 27 and 89 subjects and the primary endpoint was present in 13 (39%), 5 (19%) and 6 (7%) subjects, respectively. Receiver operator characteristics analysis showed that the area under the curve, as measure of diagnostic yield, of 0.91 (95% CI 0.84-0.97) for calcium scores was superior to 0.74 (95% CI 0.64-0.83) for exercise testing (p = 0.004). CONCLUSION: Measurement of coronary calcium scores is an appropriate initial non-invasive test in asymptomatic subjects at increased coronary risk.

Wijpkema JS, Dorgelo J, Willems TP, Tio RA, Jessurun GA, Oudkerk M, Zijlstra F. · Department of Cardiology, University Medical Centre Groningen, University of Groningen, the Netherlands. · Neth Heart J. · Pubmed #17612701 links to  free full text

Abstract: BACKGROUND.: New developments have made 16-slice multidetector computed tomography (MDCT) a promising technique for detecting significant coronary stenoses. At present, there is a paucity of data on the relation between fractional flow reserve (FFR) measurement and MDCT stenosis detection. OBJECTIVE.: The aim of this study was to investigate the relation between the anatomical severity of coronary artery disease detected by MDCT and functional severity measured by fractional flow reserve (FFR). METHODS.: We studied 53 patients (39 men and 14 women, age 62.5+/-8.1 years) with single-vessel disease scheduled for percutaneous coronary intervention (PCI). All patients underwent MDCT scanning one day prior to PCI and FFR was measured before PCI in the target vessel. RESULTS.: MDCT analysis could be performed in 52 of 53 patients (98.1%) and all patients had adequate FFR and quantitative coronary angiography (QCA) measurements. The mean stenosis diameters calculated by MDCT and QCA were 67.0+/-11.6% and 60.8+/-11.6% respectively. No significant relation was found between MDCT and QCA (r=0.22, p=0.12) The mean FFR in all patients was 0.67+/-0.18. A relation of r=-0.46 (p=0.0006) between QCA and FFR was found. In contrast, no relation between MDCT and FFR could be demonstrated (r=-0.09, p=0.50). Furthermore, a high incidence of false-positive and false-negative findings was present in both diagnostic modalities. CONCLUSION.: There is no clear relation between the anatomical and functional severity of coronary artery disease as defined by MDCT and FFR. Therefore, functional assessment of coronary artery disease remains mandatory for clinical decisionmaking. (Neth Heart J 2007;15:5-11.).

Kardys I, Vliegenthart R, Oudkerk M, Hofman A, Witteman JC. · Department of Epidemiology and Biostatistics, Erasmus Medical Center, Rotterdam, the Netherlands. · Am J Epidemiol. · Pubmed #17566064 links to  free full text

Abstract: The female advantage in coronary heart disease occurrence is not completely understood. To characterize gender differences in cardiovascular disease by vascular site, the authors compared degrees of coronary, carotid, peripheral, and aortic atherosclerosis in men and women aged>or=55 years from the population-based Rotterdam Study (Rotterdam, the Netherlands). Data were collected between 1997 and 2000. A subset of 2,013 participants had data on both coronary calcification and one or more measures of extracoronary atherosclerosis, including intima-media thickness (IMT), carotid plaques, ankle-arm index (AAI), and aortic calcification. The multivariable-adjusted male:female odds ratios for calcium score>1,000 were 7.8 (95% confidence interval (CI): 3.2, 19.3), 5.4 (95% CI: 2.8, 10.2), and 3.0 (95% CI: 1.7, 5.2) in the lowest, middle, and highest age tertiles, respectively. For IMT>1.0 mm, severe carotid plaques, AAI<0.90, and severe aortic calcification, ratios did not decline with age. Overall multivariable-adjusted male:female odds ratios for these measures were 2.9 (95% CI: 2.0, 4.1), 2.0 (95% CI: 1.4, 2.8), 0.9 (95% CI: 0.7, 1.3), and 1.0 (95% CI: 0.8, 1.5), respectively. The authors conclude that the gender difference in atherosclerosis is larger in the coronary vessels than in other vascular beds. Remarkably, it is absent in the aorta and the lower-extremity vessels. Factors causing this site-specific gender difference require further investigation.

Dikkers R, Willems TP, Tio RA, Anthonio RL, Zijlstra F, Oudkerk M. · Department of Radiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, PO Box 30001, 9700 RB, Groningen, The Netherlands. · Int J Cardiovasc Imaging. · Pubmed #17086363 No free full text.

Abstract: PURPOSE: The purpose of this study is to assess the diagnostic accuracy of 64-MDCT in symptomatic patients after CABG and to explore the advantages of the 64-MDCT results on the CAG procedure. MATERIAL AND METHODS: From December 2004 until August 2005, 34 post-CABG patients (29 men, mean age 63.5 +/- 8.5 years) with 69 coronary artery bypass grafts were scanned on a 64-MDCT (Somatom Sensation 64, Siemens AG, Forchheim, Germany) prior to CAG. Angiograms and 64-MDCT images were evaluated for the existence of occlusions or significant stenosis (>or=50% lumen reduction) in bypass grafts and native coronary arteries. RESULTS: 64-MDCT had a sensitivity, a specificity, and a diagnostic accuracy of 100% for occlusion detection. For stenosis detection, sensitivity was 100%, specificity 98.7% and diagnostic accuracy 98.7%. For detecting significant stenosis in native coronary arteries, 64-MDCT had a sensitivity of 80.0%, specificity of 90.8%, and a diagnostic accuracy of 87.1%. Seventeen patients (50.0%) did not need invasive treatment, 14 patients (41.2%) underwent a percutaneous coronary intervention (PCI), and 3 patients (8.8%) underwent surgery. Treatment advice based on 64-MDCT was correct in 88.2% of patients and when 64-MDCT results would have been known 58.8% of diagnostic CAG procedures could have been prevented. CONCLUSION: In conclusion, 64-MDCT has a high diagnostic accuracy in detecting bypass graft stenosis and occlusions, and 64-MDCT based treatment advice was correct in 88.2% of patients.

van Popele NM, Mattace-Raso FU, Vliegenthart R, Grobbee DE, Asmar R, van der Kuip DA, Hofman A, de Feijter PJ, Oudkerk M, Witteman JC. · Department of Epidemiology and Biostatistics, Rotterdam, The Netherlands. · J Hypertens. · Pubmed #17082718 No free full text.

Abstract: OBJECTIVE: Aortic stiffness can lead to low diastolic blood pressure, thereby possibly limiting coronary perfusion. Therefore, the simultaneous occurrence of both aortic stiffness and coronary atherosclerosis can lead to an increased risk of subendocardial ischaemia. The aim of the present study was to investigate the association between aortic stiffness and coronary atherosclerosis. METHODS: The study was performed in 1757 subjects of the Rotterdam Study, a population-based study of elderly individuals. Aortic stiffness was assessed by measuring carotid-femoral pulse wave velocity (PWV). Coronary atherosclerosis was assessed by measuring coronary calcification using electron beam tomography and expressed as a total calcium score. The total calcium score was log-transformed because of its skewed distribution. The association between PWV and coronary calcification was first evaluated after adjustment for age, sex, mean arterial blood pressure and heart rate. RESULTS: Linear regression analyses showed that increased PWV was associated with a higher log total coronary calcium score [beta-regression coefficient 0.11, 95% confidence interval (CI) 0.07-0.15]. Compared with the lowest quartile of PWV, multivariate odds ratios and corresponding 95% CI for advanced coronary calcification in the second, third and fourth highest quartiles were 1.17 (0.79-1.74), 1.58 (1.07-2.34) and 2.12 (1.40-3.20), respectively. CONCLUSIONS: In this large population-based study performed in elderly subjects aortic stiffness was strongly and independently associated with coronary atherosclerosis.