M. Prokop

High dietary menaquinone intake is associated with reduced coronary calcification

BACKGROUNDnDietary vitamin K is thought to decrease risk of cardiovascular disease by reducing coronary calcification, but inconsistent results are reported. This may be due to different effects of vitamin K(1) (phylloquinone) and vitamin K(2) (menaquinone, MK), but few studies included both.nnnMETHODSnWe investigated the association of intake of phylloquinone and menaquinone, including its subtypes (MK4-MK10), with coronary calcification in a cross-sectional study among 564 post-menopausal women. Phylloquinone and menaquinone intake was estimated using a food-frequency questionnaire.nnnRESULTSnSixty-two percent (n=360) of the women had coronary calcification based on 1.5-mm thick slices. Phylloquinone intake was not associated with coronary calcification with a relative risk (RR) of 1.17 (95%-confidence interval: 0.96-1.42; p(trend)=0.11) of the highest versus lowest quartile. Menaquinone intake was associated with decreased coronary calcification with an RR of 0.80 (95%-CI: 0.65-0.98; p(trend)=0.03).nnnCONCLUSIONnThis study shows that high dietary menaquinone intake, but probably not phylloquinone, is associated with reduced coronary calcification. Adequate menaquinone intakes could therefore be important to prevent cardiovascular disease.

Dynamics of the aorta before and after endovascular aneurysm repair: a systematic review.

OBJECTIVEnAn overview of the knowledge of thoracic (TAA), and abdominal aortic aneurysm (AAA) dynamics, before and after endovascular repair, is given.nnnMETHODSnMedline, EMBASE and the Cochrane database were searched for relevant articles. After inclusion and exclusion, 25 relevant articles reporting on aneurysm dynamics remained, allowing for comparison. Results provided in the included studies were assumed (statistically) significant if they were larger than the repeatability of the used method.nnnRESULTSnThe sample size of dynamic studies is limited and translational studies are missing. Magnetic resonance angiography (MRA) and computed tomographic angiography (CTA) were shown to have lower inter-observer variabilities than ultrasonography (US). The distension of several relevant stent-graft-landing zones during the cardiac cycle in both the abdominal and thoracic aorta are significant (mean diameter change of the AAA neck in the included studies ranged from 0.9 mm to 2.4 mm; mean area change of the thoracic aorta ranged from 4.8% to 12.7% at various levels). This distension remained preserved after stent-graft placement. Preoperatively, the renal arteries displace per heartbeat. Significant movement of the aorta in the anteroposterior (AP) and lateral direction, during the cardiac cycle, was observed.nnnCONCLUSIONnThe aorta exhibits a wide variety of morphologic changes throughout the cardiac cycle. CTA and MRA are reliable modalities to investigate aortic shape changes during the cardiac cycle. Significant changes per heartbeat are reported in the AAA neck and thoracic aorta. The renal artery displaces per heartbeat. The clinical relevance of dynamic imaging has not been proven yet, but dynamic changes of the aorta have to be taken into account in stent-graft selection and future stent-graft design.

Pilot study of dynamic cine CT angiography for the evaluation of abdominal aortic aneurysms: Implications for endograft treatment

Purpose: To utilize 40-slice electrocardiographically (ECG)-gated cine computed tomographic angiography (CTA) to characterize normal aortic motion during the cardiac cycle at relevant anatomical landmarks in preoperative abdominal aortic aneurysm (AAA) patients. Methods: In 10 consecutive preoperative AAA patients (10 men; mean age 78.8 years, range 69–86), an ECG-gated CTA dataset was acquired on a 40-slice CT scanner using a standard radiation dose. CTA quality was graded and scan time was measured. Pulsatility measurements at multiple relevant anatomical levels were performed in the axial plane. Changes in aortic circumference were determined for both the aortic wall and the luminal diameter. Results: All 10 CT scans were of good quality. All patients could be scanned in 14 to 33 seconds (mean 21). At each anatomical level measured, there was a 2.2- to 3.4-mm increase in the aortic wall circumference per cardiac cycle. A similar increase was observed in luminal circumference, with a 2.4- to 3.6-mm increase per cycle. Conclusion: This study introduces the concept of dynamic cine CTA imaging of aortic motion, providing insight into the pathophysiology of abdominal aortic and iliac pulsations. Patients with AAAs selected for EVAR demonstrate changes in aortic circumference with each cardiac cycle that may have consequences for endograft sizing and future design. The potential for graft migration, intermittent type I endoleak, and poor patient outcome following EVAR can be anticipated. Complex aortic dynamics deserve increased scrutiny in an effort to prevent potential complications.

Inter-scan reproducibility of coronary calcium measurement using Multi Detector-Row Computed Tomography (MDCT)

PurposeTo assess inter-scan reproducibility of coronary calcium measurements obtained from Multi Detector-Row CT (MDCT) images and to evaluate whether this reproducibility is affected by different measurement protocols, slice thickness, cardiovascular risk factors and/or technical variables.DesignCross-sectional study with repeated measurements.Materials and methodsThe study population comprised 76 healthy women. Coronary calcium was assessed in these women twice in one session using 16-MDCT (Philips Mx 8000 IDT 16). Images were reconstructed with 1.5xa0mm slice thickness and 3.0xa0mm slice thickness. The 76 repeated scans were scored. The Agatston score, a volume measurement and a mass measurement were assessed. Reproducibility was determined by estimation of mean, absolute, relative difference, the weighted kappa value for agreement and the Intra-class correlation coefficient (ICCC).ResultsFifty-five participants (72.4%) had a coronary calcification of more than zero in Agatston (1.5xa0mm slice thickness). The reproducibility of coronary calcium measurements between scans in terms of ranking was excellent with Intra-class correlation coefficients of >0.98, and kappa values above 0.80. The absolute difference in calcium score between scans increased with increasing calcium levels, indicating that measurement error increases with increasing calcium levels. However, no relation was found between the mean difference in scores and calcium levels, indicating that the increase in measurement error is likely to result in random misclassification in calcium score. Reproducibility results were similar for 1.5xa0mm slices and for 3.0xa0mm slices, and equal for Agatston, volume and mass measurements.ConclusionInter-scan reproducibilility of measurement of coronary calcium using images from MDCT is excellent, irrespective of slice thickness and type of calcium parameter.

Reproductive factors, metabolic factors, and coronary artery calcification in older women.

Objective: Metabolic disturbances may explain the increased cardiovascular risk associated with reproductive factors. This cohort study investigated the relationship between reproductive factors and coronary artery calcification in elderly women and whether this relationship could be explained by metabolic disturbances. Design: In total, 568 postmenopausal women were included in this cross-sectional study. Information about the womens reproductive life was obtained by a questionnaire. Metabolic factors were measured during a single visit. Coronary artery calcification was assessed with a multislice computed tomography scanner and dichotomized as absent or present. Logistic regression analysis was used to assess the relationship between reproductive factors and coronary artery calcification. Crude and multivariate adjusted odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were calculated. In addition, ORs were adjusted for several metabolic and cardiovascular risk factors. Results: The mean age was 66.9 (± 5.5) years. Women with a history of irregular menstrual cycle lengths, as opposed to women with a history of regular menstrual cycles (26-30 d), had an increased risk of coronary artery calcification; multivariate-adjusted OR = 2.73 (95%CI: 1.24-5.98). Four or more pregnancies, compared with never pregnant, yielded an multivariate-adjusted OR of 1.89 (95% CI: 1.00-3.58). Having four children or more, compared with having no children, yielded a multivariate-adjusted OR of 1.97 (95% CI: 1.00-3.89). Adjustment for metabolic factors and other cardiovascular risk factors did not fully explain theses relationships. Conclusion: Multigravidity (more than four pregnancies), multiparity (more than four births), and irregular menstrual cycle lengths were related to an increased risk of coronary artery disease. These associations could not be explained by metabolic abnormalities.

Endovascular aneurysm repair alters renal artery movement: a preliminary evaluation using dynamic CTA.

Purpose: To observe the natural renal artery motion during cardiac cycles in patients with abdominal aortic aneurysm (AAA) and how the implantation of stent-grafts may distort this movement. Methods: Data on 29 renal arteries from 15 male patients (mean age 72.6 years, range 66–83) treated with Talent or Excluder stent-grafts were acquired using an electrocardiographically (ECG)-gated dynamic 64-slice CT scanner. ECG-triggered retrospective reconstructions were made at 8 equidistant time points over the R-R cardiac cycle. The gated datasets were reconstructed perpendicular to the center flow lumen of each renal artery at 1.2 and 2.4 cm from the renal ostium. Center of mass displacement was determined per cardiac cycle for pre- and post-EVAR renal arteries and compared. Results: Normal renal artery motion in AAA patients was impressive, with up to 3-mm movement both near and distant from the aorta (mean 2.0±0.6 mm, range 1.1–3.0). EVAR inhibited proximal renal motion, resulting in a 31% decrease in maximal movement (mean 1.4±0.7 mm, range 0.7–2.0; p≤0.05). Distal renal artery motion was unaffected by EVAR, with motion similar to the pre-EVAR state. Conclusion: ECG-gated dynamic CTA is feasible on a 64-slice scanner with a standard radiation dose and can detect potentially serious consequences of EVAR. EVAR alters renal artery motion by limiting proximal motion while leaving distal motion unaffected.

Dynamic Cine-Computed Tomography Angiography Imaging of Standard and Fenestrated Endografts: Differing Effects on Renal Artery Motion

Different endograft configurations (fenestrated, transrenal, infrarenal) may varyingly affect aortic side branch movement. Renal artery motion was evaluated with 64-slice dynamic cine-computed tomography angiography before and after endovascular aneurysm repair in 16 patients (46 renal arteries). Center-of-mass displacement of the renals was determined per heartbeat for before repair for 3 different endografts; differences were compared, with significance at P < 0.5. Preoperative renal artery motion is significant (1.2 [SD 0.5] mm, range, 0.6-2.). Neither transrenal nor infrarenal endografts alter renal artery motion compared with before repair (P < .05). Renal artery motion after fenestrated endovascular repair with renal stents reduces motion to 25% of the preoperative value (0.3 [SD, 0.1] mm, range, 0.2-0.5 mm; P = .01). Endograft implantation without stented side branches does not change renal artery motion, potentially allowing significant movement of the renal artery relative to the fenestration. Routine stenting of fenestrations limits postoperative renal artery motion to 0.3 mm, thereby preventing significant branch movement in relation the fenestration.

Simultaneous aortic and coronary assessment in abdominal aortic aneurysm patients by thoraco-abdominal 64-detector-row CT angiography: estimate of the impact on preoperative management: a pilot study.

OBJECTIVESnTo estimate the influence of information on the coronary arteries obtained from routine thoraco-abdominal CT angiography (CTA) on pre-operative clinical management in abdominal aortic aneurysm (AAA) patients.nnnMETHODSnTwenty-eight AAA patients underwent pre-operative thoraco-abdominal electrocardiography (ECG)-gated 64-detector-row CTA to evaluate aortic pulsatility for prosthesis size matching. Retrospectively, the coronaries were reconstructed from the same data set and scored on a per segment basis for stenosis (0%, <or=50% or >50%) and grading confidence (poor, adequate or high). An experienced cardiologist was presented information on patient characteristics obtained from patient records and CTA findings. Suggested changes in European Society of Cardiology guidelines based patient management based on CTA information were scored.nnnRESULTSnOn CTA, 17 patients (61%) had significant coronary disease (>50% stenosis) including left main (n=4), single (n=7) and multiple (n=6) vessel disease. Grading confidence was adequate or high in 86% of proximal and middle segments. Based on CTA findings, patient management would have been changed in 4 out of the 28 patients (14%; 95% CI 1-27%) by adding coronary angiography (n=4). In five patients who underwent coronary artery bypass grafting previously, CT did not change management but confirmed graft patency.nnnCONCLUSIONSnInformation on coronary pathology and coronary bypass graft patency can be readily obtained from thoraco-abdominal CTA and may alter pre-operative patient management, as shown in 14% of AAA patients in our study.

Change in abdominal obesity and risk of coronary calcification

Background A prospective follow-up study was conducted to examine the relationship between 9u2005year change in abdominal obesity and risk of coronary artery calcification (CAC). Methods Data on coronary risk factors for 573 postmenopausal women were collected at baseline (1993–1997) and follow-up (2002–2004). At follow-up, the women underwent a multidetector CT to assess coronary calcium using the Agatston score. Markers of abdominal obesity were waist and hip circumference, waist-to-hip ratio (WHR) and body mass index. Results Compared to subjects whose waist circumference remained below the median at both occasions, those with a waist above the median had a 1.5-fold (95% CI 1.0 to 2.3) increased risk of CAC. Women whose waist rose over the 9u2005year period had a 2.2-fold (95% CI 1.1 to 4.2) increased risk of CAC, whereas women whose WHR became lower had a non-significant 1.5-fold increased risk of CAC (95% CI 0.7 to 3.0). In contrast, change in body mass index or hip circumference was not related to risk of CAC. Conclusion This study supports the existing evidence that persistent abdominal obesity, as well as an increase in abdominal fat, relates to an increased risk of coronary atherosclerosis.

Effect of Stenting on Cerebral CT Perfusion in Symptomatic and Asymptomatic Patients with Carotid Artery Stenosis

These authors assessed the effects of carotid stenting in both asymptomatic and symptomatic patients using CT perfusion. Forty-five patients had stenoses >70%; 31 were symptomatic, the rest were not. Patients underwent CT perfusion before and after stenting and MTT, CBV, and CBF were studied. All 3 parameters changed significantly after stenting: CBF increased, MTT decreased, and CBV decreased. Conclusion: stenting improves CBF in both asymptomatic and symptomatic patients. Decreased CBV may indicate impaired autoregulation. BACKGROUND AND PURPOSE: The introduction of CAS has led to increased treatment of both symptomatic and asymptomatic patients with internal carotid stenosis. This study was performed to compare the effect of stent placement on cerebral perfusion in symptomatic and asymptomatic patients using CT perfusion. MATERIALS AND METHODS: We included 45 patients with carotid artery stenosis of ≥70% who underwent arterial stent placement. Thirty-one patients were treated because of symptoms; 14 asymptomatic patients were treated before coronary artery bypass grafting. Patients underwent CTP before and after stent placement. We calculated MTT, CBV, and CBF, and derived relative numbers that compared treated with untreated hemispheres: ratios of CBV and CBF and difference in MTT. We compared the effect of carotid stent placement on cerebral perfusion in symptomatic and asymptomatic patients. RESULTS: All perfusion parameters changed significantly after treatment in symptomatic patients: rCBF increased from 0.81 to 0.93 (P < .001), rCBV decreased from 1.02 to 0.95 (P < .05), and dMTT decreased from 1.29 to 0.14 (P < .001). In asymptomatic patients only, rCBF changed significantly with an increase from 0.92 to 1.03 (P < .05). When we compared symptomatic and asymptomatic patients before treatment, rCBF in symptomatic patients was significantly lower. The decrease of rCBV after treatment in symptomatic patients resulted in a significantly lower value than in asymptomatic patients. CONCLUSIONS: Carotid artery stent placement improves blood flow in the affected hemisphere in symptomatic and asymptomatic patients. CBF before treatment is more strongly impaired in patients with symptomatic carotid stenosis. Compensatory hyperemia on the symptomatic side before treatment (rCBV > 1) turns into hypoxemia after treatment, suggesting impaired autoregulation in these patients.