Stephan Achenbach

Justus-Liebig-Universität Gießen, Gieben, Hesse, Germany

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Publications (656)3804.48 Total impact

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    ABSTRACT: The goal of this study was to examine the diagnostic performance of noninvasive fractional flow reserve (FFR) derived from coronary computed tomography angiography (CTA) (FFRCT) in relation to coronary calcification severity. FFRCT has shown promising results in identifying lesion-specific ischemia. The extent to which the severity of coronary calcification affects the diagnostic performance of FFRCT is not known. Coronary calcification was assessed by using the Agatston score (AS) in 214 patients suspected of having coronary artery disease who underwent coronary CTA, FFRCT, and FFR (FFR examination was performed in 333 vessels). The diagnostic performance of FFRCT (≤0.80) in identifying vessel-specific ischemia (FFR ≤0.80) was investigated across AS quartiles (Q1 to Q4) and for discrimination of ischemia in patients and vessels with a low-mid AS (Q1 to Q3) versus a high AS (Q4). Coronary CTA stenosis was defined as lumen reduction >50%. Mean ± SD per-patient and per-vessel AS were 302 ± 468 (range 0 to 3,599) and 95 ± 172 (range 0 to 1,703), respectively. There was no statistical difference in diagnostic accuracy, sensitivity, or specificity of FFRCT across AS quartiles. Discrimination of ischemia by FFRCT was high in patients with a high AS (416 to 3,599) and a low-mid AS (0 to 415), with no difference in area under the receiver-operating characteristic curve (AUC) (0.86 [95% confidence interval (CI): 0.76 to 0.96] vs. 0.92 [95% CI: 0.88 to 0.96]) (p = 0.45). Similarly, discrimination of ischemia by FFRCT was high in vessels with a high AS (121 to 1,703) and a low-mid AS (0 to 120) (AUC: 0.91 [95% CI: 0.85 to 0.97] vs. 0.95 [95% CI: 0.91 to 0.98]; p = 0.65). Diagnostic accuracy and specificity of FFRCT were significantly higher than for stenosis assessment in each AS quartile at the per-patient (p < 0.001) and per-vessel (p < 0.05) level with similar sensitivity. In vessels with a high AS, FFRCT exhibited improved discrimination of ischemia compared with coronary CTA alone (AUC: 0.91 vs. 0.71; p = 0.004), whereas on a per-patient level, the difference did not reach statistical significance (AUC: 0.86 vs. 0.72; p = 0.09). FFRCT provided high and superior diagnostic performance compared with coronary CTA interpretation alone in patients and vessels with a high AS. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
    JACC. Cardiovascular imaging 08/2015; DOI:10.1016/j.jcmg.2015.06.003 · 6.99 Impact Factor
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    ABSTRACT: Coronary computed tomography angiography (CTA) is being increasingly used for direct, noninvasive evaluation of the coronary arteries. Beyond stenosis, coronary CTA also permits assessment of atherosclerotic plaque (including total and noncalcified plaque burden) and coronary artery remodeling, previously only measurable through invasive techniques. It has been shown that coronary plaque volume for noncalcified and mixed plaques and the arterial remodeling index correlate closely with corresponding measures from invasive intravascular ultrasound. Several studies have also shown a strong relationship between adverse plaque features imaged by coronary CTA and acute coronary syndrome, major adverse cardiovascular events, and ischemia. The aim of this review is to summarize current methods for quantitative measurement of atherosclerotic plaque features from coronary CTA and to discuss the clinical implications of noncalcified plaque as detected by CTA and reported in the current literature.
    Current Cardiovascular Imaging Reports 08/2015; 8(8). DOI:10.1007/s12410-015-9343-z
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    ABSTRACT: Purpose To evaluate the ability of magnetic resonance (MR) imaging to induce deoxyribonucleic acid (DNA) damage in patients who underwent cardiac MR imaging in daily routine by using γ-H2AX immunofluorescence microscopy. Materials and Methods This study complies with the Declaration of Helsinki and was performed according to local ethics committee approval. Informed patient consent was obtained. Blood samples from 45 patients (13 women, 32 men; mean age, 50.3 years [age range, 20-89 years]) were obtained before and after contrast agent-enhanced cardiac MR imaging. MR imaging-induced double-strand breaks (DSBs) were quantified in isolated blood lymphocytes by using immunofluorescence microscopy after staining the phosphorylated histone variant γ-H2AX. Twenty-nine patients were examined with a myocarditis protocol (group A), 10 patients with a stress-testing protocol (group B), and six patients with flow measurements and angiography (group C). Paired t test was performed to compare excess foci before and after MR imaging. Results The mean baseline DSB level before MR imaging and 5 minutes after MR imaging was, respectively, 0.116 DSB per cell ± 0.019 (standard deviation) and 0.117 DSB per cell ± 0.019 (P = .71). There was also no significant difference in DSBs in these subgroups (group A: DSB per cell before and after MR imaging, respectively, 0.114 and 0.114, P = .91; group B: DSB per cell before and after MR imaging, respectively, 0.123 and 0.124, P = .78; group C: DSB per cell before and after MR imaging, respectively, 0.114 and 0.115, P = .36). Conclusion By using γ-H2AX immunofluorescence microscopy, no DNA DSBs were detected after cardiac MR imaging. (©) RSNA, 2015 Online supplemental material is available for this article.
    Radiology 07/2015; DOI:10.1148/radiol.2015150555 · 6.21 Impact Factor
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    ABSTRACT: Pericoronary adipose tissue (PCAT) can promote atherosclerosis. Metabolically active and inactive PCAT may display different CT densities. However, CT density could be influenced by partial volume effects and image interpolation. To investigate whether PCAT density values in CT displays differences that are larger than those attributable to interpolation and partial volume effects, which would manifest themselves through the relationship between PCAT density and distance from the contrast-enhanced coronary lumen. PCAT density analysis was performed (417 non-atherosclerotic segments, 63 patients) using dual-source CT with a threshold-based measurement method. Changes in PCAT density values depending on distance from the contrast-enhanced coronary lumen and the influence of cardiovascular risk profile were analyzed. Mean PCAT density was -78.1 ± 5.6 HU. PCAT density decreased from proximal to distal segments in the LAD (-78.0 ± 7.3 vs. -82.4 ± 7.7 HU; p < 0.001). PCAT density was higher close to the lumen compared to more peripheral locations (-76.0 ± 6.7 vs. -78.5 ± 5.4 HU; p < 0.001). Decreasing PCAT density was significantly associated with higher epicardial adipose tissue (EAT) volume and body mass index. There was a trend of lower PCAT values with a family history of coronary artery disease. CT-measured attenuation of PCAT is influenced by EAT volume and body mass index. A decrease of PCAT attenuation with increasing distance from the vessel and from proximal to distal segments may suggest variations in CT density of PCAT due to partial volume effects and image interpolation rather than solely due to differences in tissue composition or metabolic activity. Copyright © 2015 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.
    Journal of cardiovascular computed tomography 07/2015; DOI:10.1016/j.jcct.2015.07.011 · 4.51 Impact Factor
  • Maksymilian P Opolski · Stephan Achenbach
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    ABSTRACT: Coronary computed tomography angiography (CTA) is increasingly used to diagnose and rule out coronary artery disease. Beyond stenosis detection, the ability of CTA to visualize and characterize coronary atherosclerotic plaque, as well as to obtain 3-dimensional coronary vessel trajectories, has generated considerable interest in the context of pre-procedural planning for revascularization of chronic total occlusions (CTOs). Coronary CTA can characterize features that influence the success rate of percutaneous coronary intervention (PCI) for CTOs such as the extent of calcification, vessel tortuosity, stump morphology, presence of multiple occlusions, and lesion length. Single features and combined scoring systems based on CTA may be used to grade the level of difficulty of the CTOs before PCI and have been shown to predict procedural success rates in several trials. In addition, the procedure itself may be facilitated by real-time integration of 3-dimensional CTA data and fluoroscopic images in the catheterization laboratory. Finally, the ability of coronary CTA to assess anatomy, perfusion, and viability in 1 single examination makes it a potential "one stop shop" that predicts not only the likelihood of successful PCI but also the clinical benefit of CTO revascularization. Further research is clearly needed, but many experienced sites have already integrated coronary CTA into the routine planning and guiding of CTO procedures. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
    JACC. Cardiovascular imaging 07/2015; 8(7):846-858. DOI:10.1016/j.jcmg.2015.05.001 · 6.99 Impact Factor
  • C. Kuehn · F. Kerek · A. Steinkasserer · E. Zinser · S. Achenbach · B. Dietel
    Atherosclerosis 07/2015; 241(1):e42. DOI:10.1016/j.atherosclerosis.2015.04.150 · 3.97 Impact Factor
  • Atherosclerosis 07/2015; 241(1):e74. DOI:10.1016/j.atherosclerosis.2015.04.257 · 3.97 Impact Factor
  • J Kirchner · S Paule · C Beckendorf · S Achenbach · M Arnold
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    ABSTRACT: Thoracic impedance (TI) denotes the electrical resistance that is measured between the right ventricular lead and the can of an implantable cardioverter-defibrillator. It is used in medical diagnostics for fluid load monitoring in heart failure patients. We analysed TI for diurnal and weekly components that go along with the recurrent patterns of daily life.TI was measured in 53 patients over 280 d each with a resolution of 1 h. Information about the patients' professional occupation and typical sleeping rhythm was sought. Periodic signal components were identified in the amplitude spectrum, and their main characteristics were derived by cosinor analysis. The typical daily and weekly pattern were reconstructed by Fourier filtering.The Fourier spectrum indicates a strong circadian and a weaker circaseptan component in TI. The latter is significantly elevated in patients who regularly go to work, on error level [Formula: see text]. Cosinor analysis states a significant circadian rhythm in all patients ([Formula: see text]), with MESOR 61.8 [Formula: see text], amplitude 1.9 [Formula: see text], and acrophase 17.5 h. A significant weekly rhythm is found in 25 patients ([Formula: see text]), with amplitude 0.31 [Formula: see text] and acrophase typically on Wednesday. Both rhythms typically obtain their maximum during the 'active' phase of the period in daily life, i.e. in the afternoon and on working days, respectively, while the minimum is reached in the 'recreative' phase.Circadian and circaseptan variation are hence prevalent components of TI, which can induce impedance changes of several Ohms and thus be an error source for daily TI measurements.
    Physiological Measurement 06/2015; 36(7):1615-1628. DOI:10.1088/0967-3334/36/7/1615 · 1.62 Impact Factor
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    ABSTRACT: Data describing the prevalence, characteristics and management of coronary chronic total occlusions (CTOs) in patients undergoing coronary CT angiography (CCTA) have not been reported. The purpose of this study was to determine the prevalence, characteristics and treatment strategies of CTO identified by CCTA. We identified 23 745 patients who underwent CCTA for suspected coronary artery disease (CAD) from the prospective international CCTA registry. Baseline clinical data were collected, and allocation to early coronary revascularisation performed within 90 days of CCTA was determined. Multivariable hierarchical mixed-effects logistic regression reporting OR with 95% CI was performed. The prevalence of CTO was 1.4% (342/23 745) in all patients and 6.2% in patients with obstructive CAD (≥50% stenosis). The presence of CTO was independently associated with male sex (OR 3.12, 95% CI 2.39 to 4.08, p<0.001), smoking (OR 2.02, 95% CI 1.55 to 2.64, p<0.001), diabetes (OR 1.60, 95% CI 1.22 to 2.11, p=0.001), typical angina (OR 1.51, 95% CI 1.12 to 2.06, p=0.008), hypertension (OR 1.47, 95% CI 1.14 to 1.88, p=0.003), family history of CAD (OR 1.30, 95% CI 1.01 to 1.67, p=0.04) and age (OR 1.06, 95% CI 1.05 to 1.07, p<0.001). Most patients with CTO (61%) were treated medically, while 39% underwent coronary revascularisation. In patients with severe CAD (≥70% stenosis), CTO independently predicted revascularisation by coronary artery bypass grafting (OR 3.41, 95% CI 2.06 to 5.66, p<0.001), but not by percutaneous coronary intervention (p=0.83). CTOs are not uncommon in a contemporary CCTA population, and are associated with age, gender, angina status and CAD risk factors. Most individuals with CTO undergoing CCTA are managed medically with higher rates of surgical revascularisation in patients with versus without CTO. ClinicalTrials.gov identifier NCT01443637. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
    Heart (British Cardiac Society) 06/2015; 101(15). DOI:10.1136/heartjnl-2014-306616 · 6.02 Impact Factor
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    ABSTRACT: The use of extravascular femoral closure devices in patients undergoing coronary angiography/intervention has not been sufficiently evaluated. We sought to define the impact of an extravascular polyglycolic acid (PGA) plug for the closure of a femoral access site in patients undergoing coronary angiography and/or percutaneous coronary intervention. In this prospective, single-blind, multicenter trial we randomly assigned 319 patients to vessel closure with Angio-Seal(®) or Exo-Seal(®). We hypothesized that the use of an extravascular closure device is not inferior to an anchor/plug-mediated device regarding the occurrence of the composite primary endpoint: hematoma > 5 cm, significant groin bleeding (TIMI major bleed), false aneurysm, and device failure. There was no significant difference in patient baseline characteristics or procedural results. After 24 h the primary endpoint occurred in nine patients (5.6 %) in the Angio-Seal(®) group and in 13 patients (8.2 %) inthe Exo-Seal(®) group (p = 0.38). Hematoma > 5 cm was noted in three patients (1.9 %) receiving Angio-Seal(®) vs. two patients (1.3 %) receiving Exo-Seal(®) (p = 0.99). In one patient (0.6 %) of the Exo-Seal(®) group, TIMI major bleeding occurred, requiring transfusion (p = 0.49). There were four (2.5 %) false aneurysms found in patients treated with Angio-Seal(®) and two (1.3 %) in patients treated with Exo-Seal(®) (p = 0.68). There was a trend for a higher incidence of device failure in the Exo-Seal(®) group (1.2 vs. 5.2 %, p = 0.06). At telephone interview after 30 days, there was no significant difference found regarding the events readmission with surgery of puncture site, infection, bleeding, hematoma, or pain. In the present study, there were no significant differences found regarding the occurrence of hematoma > 5 cm, major bleeding, false aneurysm, and device failure between Angio-Seal(®) and Exo-Seal(®) 24 h after device implantation.
    Herz 06/2015; DOI:10.1007/s00059-015-4306-3 · 0.91 Impact Factor
  • S Achenbach
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    ABSTRACT: Stable coronary artery disease is one of the most frequent conditions encountered in cardiology. The diagnostic algorithm encompasses several steps, the first of which is a clinical assessment with an electrocardiogram (ECG) and echocardiography to determine the probability of disease. No further work-up is recommended if the probability of coronary artery disease remains below 15 %. For patients with an intermediate probability between 15 % and 85 %, noninvasive diagnostic testing for ischemia and coronary computed tomography (CT) angiography are recommended. In the case of a positive result, medicinal therapy should be started in order to lower the event risk and alleviate symptoms. Patients with large areas of inducible ischemia and patients who remain symptomatic in spite of medicinal therapy should undergo invasive angiography. Revascularization options include bypass surgery and, more liberally than previously, percutaneous coronary intervention with stent placement and must be decided on the basis of patient characteristics. Consultation in the form of a "heart team" is recommended. After revascularization, medicinal therapy must be continued on a lifelong basis. The widely practiced routine of annual ischemia testing in patients with known coronary artery disease is not enforced by current guidelines.
    Herz 06/2015; 40(4):645-56. DOI:10.1007/s00059-015-4237-z · 0.91 Impact Factor
  • Stephan Achenbach · Andrew J. Einstein · Maros Ferencik
  • M Hell · S Achenbach · M Arnold
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    ABSTRACT: Die Computertomographie (CT) spielt eine wesentliche und zunehmend wichtige Rolle in der präinterventionellen Diagnostik bei Patienten, die für eine kathetergestützte Aortenklappenimplantation (TAVI) vorgesehen sind. Die CT-Bildgebung (sie muss zwingend mit Kontrastmittel durchgeführt werden) ermöglicht eine umfassende Beurteilung sowohl des Zugangsweges als auch der Geometrie und der Dimensionen von Aortenwurzel und Aortenklappe. Um zu entscheiden, ob die Klappenimplantation transfemoral erfolgen kann, müssen der minimale Gefäßdurchmesser, die Tortuosität und die Kalzifizierung der Iliakal- und Femoralgefäße beurteilt werden. Die Größenvermessung des Aortenannulus dient der Ermittlung der zu implantierenden Prothesengröße – dabei ist die CT der 2-dimensionalen Echokardiographie eindeutig überlegen. Zudem gestattet die CT eine genaue Bestimmung des Abstands zwischen Koronarostien und Aortenannulus, der Tiefe der Sinus valsalvae und der Dimensionen der Aorta ascendens – je nach eingesetztem Klappentyp müssen hierbei besondere Grenzwerte beachtet werden. Schließlich ermöglicht die CT die Bestimmung geeigneter Angulationen, um während der Implantation mittels Fluoroskopie eine exakt orthogonale Projektion der Aortenklappenebene zu erreichen. Dies führt zu einer Reduktion der bei der Implantation notwendigen Kontrastmittelmenge. In den meisten Zentren wird die CT des Herzens und der Gefäße als Routineverfahren bei allen Patienten eingesetzt, die für den kathetergestützten Aortenklappenersatz vorgesehen sind, und liefert umfassende Informationen, welche die prozedurale Qualität erheblich verbessern. Abstract Computed tomography (CT) plays an important role in the preinterventional work-up of patients referred for transcatheter aortic valve implantation (TAVI). Contrast-enhanced CT allows a comprehensive examination with evaluation of both the vascular access route as well as aortic valve and aortic root geometry. Analysis of the minimum luminal vessel diameter, tortuosity and vascular calcification are important to determine the ability to perform the procedure via a transfemoral access. The size of the aortic annulus can be accurately measured by CT to aid selection of the appropriate prosthesis and the use of CT for prosthesis sizing has been associated with a decreased incidence of paravalvular leakage as compared to 2-dimensional echocardiography. In addition CT permits accurate assessment of aortic root anatomy, distance between coronary ostia and the annulus plane as well as the dimensions of the ascending aorta. Furthermore, suitable fluoroscopic projections that permit an exact orthogonal visualization of the aortic annulus plane by fluoroscopy during the procedure can be extracted from the CT data set. In summary, CT permits comprehensive imaging in TAVI candidates and optimizes procedural outcome.
    Herz 05/2015; DOI:10.1007/s00059-015-4232-4 · 0.91 Impact Factor
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    ABSTRACT: Coronary computed tomography angiography (CTA) allows the detection of obstructive coronary artery disease. However, its ability to predict the hemodynamic significance of stenoses is limited. We assessed differences in plaque characteristics and contrast density difference between hemodynamically significant and non-significant stenoses, as defined by invasive fractional flow reserve (FFR). Lesion characteristics of 59 consecutive patients (72 lesions) in whom invasive FFR was performed in at least one coronary artery with moderate to high-grade stenoses in coronary CTA were evaluated by two experienced readers. Coronary CTA data sets were acquired on a second-generation dual-source CT scanner using retrospectively ECG-gated spiral acquisition or prospectively ECG-triggered axial acquisition mode. Plaque volume and composition (non-calcified, calcified), remodeling index as well as contrast density difference (defined as the percentage decline in luminal CT attenuation/cross-sectional area over the lesion) were assessed using a semi-automatic software tool (Autoplaq). Additionally, the transluminal attenuation gradient (defined as the linear regression coefficient between intraluminal CT attenuation and length from the ostium) was determined. Differences in lesion characteristics between hemodynamically significant (invasively measured FFR ≤0.80) and non-significant lesions (FFR >0.80) were determined. Mean patient age was 64±11 years with 44 males (75%). 21 out of 72 coronary artery lesions (29%) were hemodynamically significant according to invasive FFR. Mean invasive FFR was 0.66±0.12 vs. 0.91±0.05 for hemodynamically significant versus non-significant lesions. Hemodynamically significant lesions showed a significantly greater percentage of non-calcified plaque compared to non-hemodynamically relevant lesions (51.3±15.3% vs. 43.6±16.5%, p=0.021). Contrast density difference was significantly increased in hemodynamically relevant lesions (26.0±20.2% vs. 16.6±10.9% for non-significant lesions; p=0.013). At a threshold of ≥24%, the contrast density difference predicted hemodynamically significant lesions with a specificity of 75%, sensitivity of 33%, PPV of 35% and NPV of 73%. The transluminal attenuation gradient showed no significant difference between hemodynamically significant and non-significant lesions (-1.4±1.4HU/mm vs. -1.1±1.3HU/mm, p=n.s.). Quantitative contrast density difference across coronary lesions in coronary CTA data sets may be applied as a non-invasive tool to identify hemodynamically significant stenoses. Copyright © 2015. Published by Elsevier Ireland Ltd.
    European journal of radiology 05/2015; 35. DOI:10.1016/j.ejrad.2015.04.024 · 2.16 Impact Factor
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    ABSTRACT: Measurement of fractional flow reserve (FFR) constitutes the current gold standard to evaluate the hemodynamic significance of coronary stenoses. Limited data validate the intracoronary application of adenosine against standard intravenous infusion. We systematically compared FFR measurements during intracoronary and intravenous application of adenosine about agreement and reproducibility. We included 114 patients with an intermediate degree of stenosis in coronary angiography. Two FFR measurements were performed during intracoronary bolus injection (40 μg for the right and 80 μg for the left coronary artery, FFRic), and 2 FFR measurements during continuous intravenous infusion of adenosine (140 μg/kg per minute, FFRiv). FFR value, the time to reach FFR and patient discomfort (on a subjective scale from 0 for no symptoms to 5 for maximal discomfort) were recorded for each measurement. Mean time to FFR was 100±27 s for continuous intravenous infusion versus 23±14 s for intracoronary bolus administration of adenosine (P<0.001). Reported discomfort after intracoronary application was significantly lower compared with intravenous adenosine (subjective scale >0 in 35.1% versus 87.7% of the patients; P<0.001). Correlation between FFRiv and FFRic was extremely close (r=0.99; P<0.001) with no systematic bias in Bland-Altman analysis (bias 0.002 [confidence interval, -0.001 to 0.005]) and low intermethod variability (1.56%). Intramethod variability was not different between intravenous and intracoronary administration (1.47% versus 1.33%; P=0.5). Intracoronary bolus injection of adenosine (40 μg for the right and 80 μg for the left coronary artery) yields identical FFR results compared with intravenous infusion (140 μg/kg per minute), while requiring less time and offering superior patient comfort. © 2015 American Heart Association, Inc.
    Circulation Cardiovascular Interventions 05/2015; 8(5). DOI:10.1161/CIRCINTERVENTIONS.114.001781 · 6.98 Impact Factor
  • W Wüst · M Lell · M May · M Scharf · C Schlundt · S Achenbach · M Uder · A Schmid
    RöFo - Fortschritte auf dem Gebiet der R 04/2015; 187(S 01). DOI:10.1055/s-0035-1551005 · 1.96 Impact Factor
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    ABSTRACT: The geometry of the aortic annulus and implanted transcatheter aortic valve prosthesis might influence valve function. We investigated the influence of valve type and aortic valve calcification on post-implant geometry of catheter-based aortic valve prostheses. Eighty consecutive patients with severe aortic valve stenosis (mean age 82±6 years) underwent computed tomography before and after TAVI. Aortic annulus diameters were determined. Influence of prosthesis type and degree of aortic valve calcification on post-implant eccentricity were analysed. Aortic annulus eccentricity was reduced in patients after TAVI (0.21±0.06 vs. 0.08±0.06, p<0.0001). Post-TAVI eccentricity was significantly lower in 65 patients following implantation of a balloon-expandable prosthesis as compared to 15 patients who received a self-expanding prosthesis (0.06±0.05 vs. 0.15±0.07, p<0.0001), even though the extent of aortic valve calcification was not different. After TAVI, patients with a higher calcium amount retained a significantly higher eccentricity compared to patients with lower amounts of calcium. Patients undergoing TAVI with a balloon-expandable prosthesis show a more circular shape of the implanted prosthesis as compared to patients with a self-expanding prosthesis. Eccentricity of the deployed prosthesis is affected by the extent of aortic valve calcification. Copyright © 2015. Published by Elsevier Ireland Ltd.
    European journal of radiology 04/2015; 84(7). DOI:10.1016/j.ejrad.2015.04.003 · 2.16 Impact Factor
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    ABSTRACT: Purpose To evaluate the utility of multiple automated plaque measurements from coronary computed tomographic (CT) angiography in determining hemodynamic significance by using invasive fractional flow reserve (FFR) in patients with intermediate coronary stenosis. Materials and Methods The study was approved by the institutional review board. All patients provided written informed consent. Fifty-six intermediate lesions (with 30%-69% diameter stenosis) in 56 consecutive patients (mean age, 62 years; range, 46-88 years), who subsequently underwent invasive coronary angiography with assessment of FFR (values ≤0.80 were considered hemodynamically significant) were analyzed at coronary CT angiography. Coronary CT angiography images were quantitatively analyzed with automated software to obtain the following measurements: volume and burden (plaque volume × 100 per vessel volume) of total, calcified, and noncalcified plaque; low-attenuation (<30 HU) noncalcified plaque; diameter stenosis; remodeling index; contrast attenuation difference (maximum percent difference in attenuation per unit area with respect to the proximal reference cross section); and lesion length. Logistic regression adjusted for potential confounding factors, receiver operating characteristics, and integrated discrimination improvement were used for statistical analysis. Results FFR was 0.80 or less in 21 (38%) of the 56 lesions. Compared with nonischemic lesions, ischemic lesions had greater diameter stenosis (65% vs 52%, P = .02) and total (49% vs 37%, P = .0003), noncalcified (44% vs 33%, P = .0004), and low-attenuation noncalcified (9% vs 4%, P < .0001) plaque burden. Calcified plaque and remodeling index were not significantly different. In multivariable analysis, only total, noncalcified, and low-attenuation noncalcified plaque burden were significant predictors of ischemia (P < .015). For predicting ischemia, the area under the receiver operating characteristics curve was 0.83 for total plaque burden versus 0.68 for stenosis (P = .04). Conclusion Compared with stenosis grading, automatic quantification of total, noncalcified, and low-attenuation noncalcified plaque burden substantially improves determination of lesion-specific hemodynamic significance by FFR in patients with intermediate coronary lesions. (©) RSNA, 2015.
    Radiology 04/2015; DOI:10.1148/radiol.2015141648 · 6.21 Impact Factor
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    ABSTRACT: To develop a clinical cardiac risk algorithm for stable patients with suspected coronary artery disease based upon angina typicality and coronary artery disease risk factors. Between 2004 and 2011, 14,004 adults with suspected coronary artery disease referred for cardiac imaging were followed: 1) 9,093 patients for coronary computed tomography angiography (CCTA) (CCTA-1) followed for 2.0 years; 2) 2,132 patients for CCTA (CCTA-2) followed for 1·6 years, and 3) 2,779 patients for exercise myocardial perfusion scintigraphy (MPS) followed for 5.0 years. A best-fit model from CCTA-1 for prediction of death or myocardial infarction was developed, with integer values proportional to regression coefficients. Discrimination was assessed using C-statistic. The validated model was tested for estimation of the likelihood of obstructive coronary artery disease, defined as ≥50% stenosis, as compared to method of Diamond and Forrester. Primary outcomes included all-cause mortality and non-fatal myocardial infarction. Secondary outcomes included prevalent angiographically obstructive coronary artery disease. In CCTA-1, best-fit model discriminated individuals at risk of death or myocardial infarction (C-statistic 0·76). The integer model ranged from 3-13, corresponding to 3-year death risk or myocardial infarction of 0·25% to 53·8%. When applied to CCTA-2 and MPS cohorts, the model demonstrated C-statistics of 0·71 and 0·77. Both best-fit (C=0·76, 95% CI 0·746-0·771) and integer models (C=0·71, 95% CI 0·693-0·719) performed better than Diamond and Forrester (C=0·64; 95% CI, 0·628-0·659) for estimating obstructive coronary artery disease. For stable symptomatic patients with suspected coronary artery disease, we developed a history-based method for prediction of death and obstructive coronary artery disease. Copyright © 2015 Elsevier Inc. All rights reserved.
    The American journal of medicine 04/2015; DOI:10.1016/j.amjmed.2014.10.031 · 5.30 Impact Factor
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    ABSTRACT: Multidetector CT (MDCT) is performed to evaluate patients before transcatheter aortic valve implantation (TAVI). MDCT can uncover relevant nonvascular incidental findings. The use of venous phase imaging (VPI) in MDCT before TAVI has not been evaluated. To evaluate the incidence of nonvascular findings in MDCT before TAVI with effect on the TAVI procedure and the value of VPI in this setting. Sixty-four-slice MDCT angiography with VPI (100 mL contrast agent with 370-mg iopromide per mL) in 76 patients was retrospectively evaluated by 2 readers. Nonvascular findings were separately assessed on arterial and venous phase images and categorized in consensus as nonsignificant (no effect on TAVI), intermediate (further workup or surveillance necessary, no effect on TAVI), or significant (effect on TAVI). Radiation dose was recorded as dose-length product (DLP) and effective dose was calculated. A total of 169 findings were detected, of which 155 (91.7%) were nonsignificant, 13 (7.7%) were intermediate, and 1 (0.6%) was significant. TAVI was canceled in 1 patient (1.3%) because of suspected pancreatic cancer. No significant finding was seen on VPI only. Mean total DLP was 1137.9 mGy·cm (16.07 mSv) and the proportional mean DLP of VPI was 403 mGy·cm (6.85 mSv). The incidence of nonvascular significant findings in MDCT before TAVI is low and VPI in our series did not add value. However, it may be considered in selected patients. Copyright © 2015 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.
    Journal of cardiovascular computed tomography 04/2015; DOI:10.1016/j.jcct.2015.03.007 · 4.51 Impact Factor

Publication Stats

19k Citations
3,804.48 Total Impact Points

Institutions

  • 2011–2015
    • Justus-Liebig-Universität Gießen
      Gieben, Hesse, Germany
    • University of Ottawa
      • Division of Medical Oncology
      Ottawa, Ontario, Canada
    • Weill Cornell Medical College
      New York, New York, United States
    • Robert-Bosch Krankenhaus
      Stuttgart, Baden-Württemberg, Germany
    • The Prince Charles Hospital (Queensland Health)
      Brisbane, Queensland, Australia
  • 1991–2015
    • Universitätsklinikum Erlangen
      Erlangen, Bavaria, Germany
    • Friedrich-Alexander Universität Erlangen-Nürnberg
      • • Institute for Biomedicine of Aging
      • • Department of Cardiac Surgery
      • • Institute of Physics
      Erlangen, Bavaria, Germany
  • 2013
    • University of British Columbia - Vancouver
      • Division of Medical Oncology
      Vancouver, British Columbia, Canada
  • 2011–2013
    • Universitätsklinikum Gießen und Marburg
      Marburg, Hesse, Germany
  • 2012
    • Vitos Gießen-Marburg
      Giessen, Hesse, Germany
    • Deutsche Gesellschaft für Kardiologie – Herz- und Kreislaufforschung e.V.
      Crefeld, North Rhine-Westphalia, Germany
  • 2010–2012
    • Cedars-Sinai Medical Center
      • Cedars Sinai Medical Center
      Los Ángeles, California, United States
    • University of Maryland, Baltimore
      Baltimore, Maryland, United States
    • Emory University
      • Division of Cardiology
      Atlanta, GA, United States
  • 2009
    • Nuremberg University of Music
      Nuremberg, Bavaria, Germany
  • 2004–2009
    • Harvard University
      Cambridge, Massachusetts, United States
  • 2008
    • University of Dallas
      Irving, Texas, United States
  • 2003–2008
    • Massachusetts General Hospital
      • • Division of Cardiology
      • • Department of Radiology
      Boston, Massachusetts, United States
  • 2003–2006
    • Harvard Medical School
      • Department of Radiology
      Boston, Massachusetts, United States
  • 1998
    • Edel&weiss Clinic, Germany, Nuremberg
      Nuremberg, Bavaria, Germany