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1.
  • Akhter, Tansim, 1967-, et al. (author)
  • Individual Common Carotid Artery Wall Layer Dimensions, but Not Carotid Intima-Media Thickness, Indicate Increased Cardiovascular Risk in Women With Preeclampsia : An investigation using non-invasive high-frequency ultrasound
  • 2013
  • In: Circulation Cardiovascular Imaging. - 1941-9651 .- 1942-0080. ; 6:5, s. 762-768
  • Journal article (peer-reviewed)abstract
    • Background Preeclampsia (PE) is associated with increased risk of cardiovascular disease later in life. Ultrasound assessment of the common carotid artery intima-media thickness (IMT) during or after PE has not indicated any increased cardiovascular risk. Methods and Results We used high-frequency ultrasound (22 MHz) to estimate the individual common carotid artery IMTs in 55 women at PE diagnosis and in 64 women with normal pregnancies at a similar stage. All were re-examined about 1 year postpartum. A thick intima, thin media, and high intima/media (I/M) ratio are signs of a less healthy artery wall. PE was associated with a significantly thicker mean common carotid artery intima, thinner media, and higher I/M ratio than in normal pregnancy (mean I/M difference, 0.21; 95% confidence interval, 0.17-0.25; P<0.0001). After adjustment for first trimester body mass index and mean arterial pressure, differences in intima thickness and I/M remained significant. About 1 year postpartum, these values had improved in both groups, but group differences remained significant (all adjusted P<0.0001). There were no significant differences in IMT between groups. In receiver-operating characteristic curve analysis, intima thickness and I/M were strongly predictive of prevalent PE (area under the curve, approximate to 0.95), whereas IMT was not (area under the curve, 0.49). Conclusions The arteries of women with PE were negatively affected during pregnancy and 1 year postpartum compared with women with normal pregnancies, indicating increased cardiovascular risk. Estimation of intima thickness and I/M ratio seem preferable to estimation of common carotid artery IMT in imaging cardiovascular risk in PE. Results from this pilot study warrant further confirmation.
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  • Bang, Casper N., et al. (author)
  • Four-Group Classification of Left Ventricular Hypertrophy Based on Ventricular Concentricity and Dilatation Identifies a Low-Risk Subset of Eccentric Hypertrophy in Hypertensive Patients
  • 2014
  • In: Circulation Cardiovascular Imaging. - 1941-9651 .- 1942-0080. ; 7:3, s. 422-429
  • Journal article (peer-reviewed)abstract
    • Background-Left ventricular hypertrophy (LVH; high LV mass [LVM]) is traditionally classified as concentric or eccentric based on LV relative wall thickness. We evaluated the prediction of subsequent adverse events in a new 4-group LVH classification based on LV dilatation (high LV end-diastolic volume [EDV] index) and concentricity (mass/end-diastolic volume [M/EDV](2/3)) in hypertensive patients. Methods and Results-In the Losartan Intervention for Endpoint Reduction (LIFE) echocardiography substudy, 939 hypertensive patients with measurable LVM at baseline were randomized to a mean of 4.8 years of losartan- or atenolol-based treatment. Patients with LVH (LVM/body surface area >= 116 and >= 96 g/m(2) in men and woman, respectively) were divided into 4 groups-concentric nondilated (increased M/EDV, normal EDV), eccentric dilated (increased EDV, normal M/EDV), concentric dilated (increased M/EDV and EDV), and eccentric nondilated (normal M/EDV and EDV)-and compared with patients with normal LVM. Time-varying LVH classes were tested for association with all-cause and cardiovascular mortality and a composite end point of myocardial infarction, stroke, heart failure, and cardiovascular death in multivariable Cox analyses. At baseline, the LVs were categorized as eccentric nondilated in 12%, eccentric dilated in 20%, concentric nondilated in 29%, concentric dilated in 14%, and normal LVM in 25%. Treatment changed the prevalence of 4 LVH groups to 23%, 4%, 5%, and 7%; 62% had normal LVM after 4 years. In time-varying Cox analyses, compared with normal LVM, those with eccentric dilated and both concentric nondilated and dilated LVH had increased risks of all-cause or cardiovascular mortality or the composite end point, whereas the eccentric nondilated group did not. Conclusions-Hypertensive patients with relatively mild LVH without either increased LV volume or concentricity have similar risk of all-cause mortality or cardiovascular events because hypertensive patients with normal LVM seem to be a low-risk group.
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  • Coenen, Adriaan, et al. (author)
  • Diagnostic Accuracy of a Machine-Learning Approach to Coronary Computed Tomographic Angiography-Based Fractional Flow Reserve Result From the MACHINE Consortium
  • 2018
  • In: Circulation Cardiovascular Imaging. - : LIPPINCOTT WILLIAMS & WILKINS. - 1941-9651 .- 1942-0080. ; 11:6
  • Journal article (peer-reviewed)abstract
    • Background: Coronary computed tomographic angiography (CTA) is a reliable modality to detect coronary artery disease. However, CTA generally overestimates stenosis severity compared with invasive angiography, and angiographic stenosis does not necessarily imply hemodynamic relevance when fractional flow reserve (FFR) is used as reference. CTA-based FFR (CT-FFR), using computational fluid dynamics (CFD), improves the correlation with invasive FFR results but is computationally demanding. More recently, a new machine-learning (ML) CT-FFR algorithm has been developed based on a deep learning model, which can be performed on a regular workstation. In this large multicenter cohort, the diagnostic performance ML-based CT-FFR was compared with CTA and CFD-based CT-FFR for detection of functionally obstructive coronary artery disease. Methods and Results: At 5 centers in Europe, Asia, and the United States, 351 patients, including 525 vessels with invasive FFR comparison, were included. ML-based and CFD-based CT-FFR were performed on the CTA data, and diagnostic performance was evaluated using invasive FFR as reference. Correlation between ML-based and CFD-based CT-FFR was excellent (R=0.997). ML-based (area under curve, 0.84) and CFD-based CT-FFR (0.84) outperformed visual CTA (0.69; Pamp;lt;0.0001). On a per-vessel basis, diagnostic accuracy improved from 58% (95% confidence interval, 54%-63%) by CTA to 78% (75%-82%) by ML-based CT-FFR. The per-patient accuracy improved from 71% (66%-76%) by CTA to 85% (81%-89%) by adding ML-based CT-FFR as 62 of 85 (73%) false-positive CTA results could be correctly reclassified by adding ML-based CT-FFR. Conclusions: On-site CT-FFR based on ML improves the performance of CTA by correctly reclassifying hemodynamically nonsignificant stenosis and performs equally well as CFD-based CT-FFR.
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  • Engblom, Henrik, et al. (author)
  • Rapid Initial Reduction of Hyperenhanced Myocardium After Reperfused First Myocardial Infarction Suggests Recovery of the Peri-Infarction Zone One-Year Follow-Up by MRI
  • 2009
  • In: Circulation Cardiovascular Imaging. - 1942-0080. ; 2:1, s. 47-55
  • Journal article (peer-reviewed)abstract
    • Background-The time course and magnitude of infarct involution, functional recovery, and normalization of infarct-related electrocardiographic (ECG) changes after acute myocardial infarction (MI) are not completely known in humans. We sought to explore these processes early after MI and during infarct-healing using cardiac MRI. Methods and Results-Twenty-two patients with reperfused first-time MI were examined by MRI and ECG at 1, 7, 42. 182, and 365 days after infarction. Global left ventricular function and regional wall thickening were assessed by cine MRI, and injured myocardium was depicted by delayed contrast-enhanced MRI. Infarct size by ECG was estimated by QRS scoring. The reduction of hyperenhanced myocardium occurred predominantly during the first week after infarction (64% of the 1-year reduction). Furthermore, during the first week the amount of nonhyperenhanced myocardium increased significantly (P<0.001,), although the left ventricular mass remained unchanged. Left ventricular ejection fraction increased gradually, whereas the greater the regional transmural extent of hyperenhancement at day 1, the later the recovery of regional wall thickening. Regional wall thickening decreased progressively with increasing initial transmural extent of hyperenhancement (P-trend<0.0001). The time course and magnitude of decrease in QRS score corresponded with the reduction of hyperenhanced myocardium. Conclusions-The early reduction of hyperenhanced myocardium May reflect recovery of hyperenhanced, reversibly injured myocardium), which must be considered when predicting functional recovery from delayed contrast-enhanced MRI findings early after infarction. Also, the time course and magnitude for reduction of hyperenhanced myocardium were associated with normalization of infarct-related ECG changes. (Circ Cardiovasc Imaging. 2009;2:47-55.)
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  • Hill, JA, et al. (author)
  • Medical Misinformation
  • 2019
  • In: Circulation. Cardiovascular imaging. - 1942-0080. ; 12:2, s. e008809-
  • Journal article (other academic/artistic)
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  • Nagueh, Sherif F., et al. (author)
  • Interobserver Variability in Applying American Society of Echocardiography/European Association of Cardiovascular Imaging 2016 Guidelines for Estimation of Left Ventricular Filling Pressure
  • 2019
  • In: Circulation Cardiovascular Imaging. - 1941-9651 .- 1942-0080. ; 12:1
  • Journal article (peer-reviewed)abstract
    • BACKGROUND:Assessment of left ventricular (LV) filling pressure is among the important components of a comprehensive echocardiographic report. Previous studies noted wide limits of agreement using 2009 American Society of Echocardiography/European Association of Echocardiography guidelines, but reproducibility of 2016 guidelines update in estimating LV filling pressure is unknown.METHODS:Echocardiographic and hemodynamic data were obtained from 50 patients undergoing cardiac catheterization for clinical indications. Clinical and echocardiographic findings but not invasive hemodynamics were provided to 4 groups of observers, including experienced echocardiographers and cardiology fellows. Invasively acquired LV filling pressure was the gold standard.RESULTS:In group I of 8 experienced echocardiographers from the guidelines writing committee, sensitivity for elevated LV filling pressure was 92% for all observers, and specificity was 93 +/- 6%. Fleiss kappa-value for the agreement in group I was 0.80. In group II of 4 fellows in training, sensitivity was 91 +/- 2%, and specificity was 95 +/- 2%. Fleiss kappa-value for the agreement in group II was 0.94. In group III of 9 experienced echocardiographers who had not participated in drafting the guidelines, sensitivity was 88 +/- 5%, and specificity was 91 +/- 7%. Fleiss kappa-value for the agreement in group III was 0.76. In group IV of 7 other fellows, sensitivity was 91 +/- 3%, and specificity was 92 +/- 5%. Fleiss kappa-value for the agreement in group IV was 0.89.CONCLUSIONS:There is a good level of agreement and accuracy in the estimation of LV filling pressure using the American Society of Echocardiography/European Association of Cardiovascular Imaging 2016 recommendations update, irrespective of the experience level of the observer.
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  • Nchimi, Alain, et al. (author)
  • Multifactorial Relationship Between F-18-Fluoro-Deoxy-Glucose Positron Emission Tomography Signaling and Biomechanical Properties in Unruptured Aortic Aneurysms
  • 2014
  • In: Circulation Cardiovascular Imaging. - 1941-9651 .- 1942-0080. ; 7:1, s. 82-91
  • Journal article (peer-reviewed)abstract
    • Background The relationship between biomechanical properties and biological activities in aortic aneurysms was investigated with finite element simulations and F-18-fluoro-deoxy-glucose (F-18-FDG) positron emission tomography. Methods and Results The study included 53 patients (45 men) with aortic aneurysms, 47 infrarenal (abdominal aortic) and 6 thoracic (thoracic aortic), who had 1 F-18-FDG positron emission tomography/computed tomography. During a 30-month period, more clinical events occurred in patients with increased F-18-FDG uptake on their last examination than in those without (5 of 18 [28%] versus 2 of 35 [6%]; P=0.03). Wall stress and stress/strength index computed by finite element simulations and F-18-FDG uptake were evaluated in a total of 68 examinations. Twenty-five (38%) examinations demonstrated 1 aneurysm wall area of increased F-18-FDG uptake. The mean number of these areas per examination was 1.6 (18 of 11) in thoracic aortic aneurysms versus 0.25 (14 of 57) in abdominal aortic aneurysms, whereas the mean number of increased uptake areas colocalizing with highest wall stress and stress/strength index areas was 0.55 (6 of 11) and 0.02 (1 of 57), respectively. Quantitatively, F-18-FDG positron emission tomographic uptake correlated positively with both wall stress and stress/strength index (P<0.05). F-18-FDG uptake was particularly high in subjects with personal history of angina pectoris and familial aneurysm. Conclusions Increased F-18-FDG positron emission tomographic uptake in aortic aneurysms is strongly related to aneurysm location, wall stress as derived by finite element simulations, and patient risk factors such as acquired and inherited susceptibilities.
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  • Seemann, Felicia, et al. (author)
  • Noninvasive Quantification of Pressure-Volume Loops From Brachial Pressure and Cardiovascular Magnetic Resonance
  • 2019
  • In: Circulation. Cardiovascular imaging. - 1942-0080. ; 12:1, s. 008493-008493
  • Journal article (peer-reviewed)abstract
    • BACKGROUND: Pressure-volume (PV) loops provide a wealth of information on cardiac function but are not readily available in clinical routine or in clinical trials. This study aimed to develop and validate a noninvasive method to compute individualized left ventricular PV loops. METHODS: The proposed method is based on time-varying elastance, with experimentally optimized model parameters from a training set (n=5 pigs), yielding individualized PV loops. Model inputs are left ventricular volume curves from cardiovascular magnetic resonance imaging and brachial pressure. The method was experimentally validated in a separate set (n=9 pig experiments) using invasive pressure measurements and cardiovascular magnetic resonance images and subsequently applied to human healthy controls (n=13) and patients with heart failure (n=28). RESULTS: There was a moderate-to-excellent agreement between in vivo-measured and model-calculated stroke work (intraclass correlation coefficient, 0.93; bias, -0.02±0.03 J), mechanical potential energy (intraclass correlation coefficient, 0.57; bias, -0.04±0.03 J), and ventricular efficiency (intraclass correlation coefficient, 0.84; bias, 3.5±2.1%). The model yielded lower ventricular efficiency ( P<0.0001) and contractility ( P<0.0001) in patients with heart failure compared with controls, as well as a higher potential energy ( P<0.0001) and energy per ejected volume ( P<0.0001). Furthermore, the model produced realistic values of stroke work and physiologically representative PV loops. CONCLUSIONS: We have developed the first experimentally validated, noninvasive method to compute left ventricular PV loops and associated quantitative measures. The proposed method shows significant agreement with in vivo-derived measurements and could support clinical decision-making and provide surrogate end points in clinical heart failure trials.
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  • Steigner, Michael L, et al. (author)
  • Iodinated Contrast Opacification Gradients in Normal Coronary Arteries Imaged With Prospectively ECG-Gated Single Heart Beat 320-Detector Row Computed Tomography
  • 2010
  • In: CIRCULATION-CARDIOVASCULAR IMAGING. - : Lippincott Williams & Wilkins. - 1941-9651 .- 1942-0080. ; 3:2, s. 179-186
  • Journal article (peer-reviewed)abstract
    • Background-To define and evaluate coronary contrast opacification gradients using prospectively ECG-gated single heart beat 320-detector row coronary angiography (CTA). Methods and Results-Thirty-six patients with normal coronary arteries determined by 320 x 0.5-mm detector row coronary CTA were retrospectively evaluated with customized image postprocessing software to measure Hounsfield Units at 1-mm intervals orthogonal to the artery center line. Linear regression determined correlation between mean Hounsfield Units and distance from the coronary ostium (regression slope defined as the distance gradient G(d)), lumen cross-sectional area (G(a)), and lumen short-axis diameter (G(s)). For each gradient, differences between the 3 coronary arteries were analyzed with ANOVA. Linear regression determined correlations between measured gradients, heart rate, body mass index, and cardiac phase. To determine feasibility in lesions, all 3 gradients were evaluated in 22 consecutive patients with left anterior descending artery lesions andgt;= 50% stenosis. For all 3 coronary arteries in all patients, the gradients G(a) and G(s) were significantly different from zero (P andlt; 0.0001), highly linear (Pearson r values, 0.77 to 0.84), and had no significant difference between the left anterior descending, left circumflex, and right coronary arteries (P andgt; 0.503). The distance gradient G(d) demonstrated nonlinearities in a small number of vessels and was significantly smaller in the right coronary artery when compared with the left coronary system (P andlt; 0.001). Gradient variations between cardiac phases, heart rates, body mass index, and readers were low. Gradients in patients with lesions were significantly different (P andlt; 0.021) than in patients considered normal by CTA. Conclusions-Measurement of contrast opacification gradients from temporally uniform coronary CTA demonstrates feasibility and reproducibility in patients with normal coronary arteries. For all patients, the gradients defined with respect to the coronary lumen cross-sectional area and short-axis diameters are highly linear, not significantly influenced by the coronary artery (left anterior descending artery versus left circumflex versus right coronary artery), and have only small variation with respect to patient parameters. Preliminary evaluation of gradients across coronary artery lesions is promising but requires additional study.
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  • Stoll, Victoria M., et al. (author)
  • Left Ventricular Flow Analysis Novel Imaging Biomarkers and Predictors of Exercise Capacity in Heart Failure
  • 2019
  • In: Circulation Cardiovascular Imaging. - : LIPPINCOTT WILLIAMS & WILKINS. - 1941-9651 .- 1942-0080. ; 12:5
  • Journal article (peer-reviewed)abstract
    • Background: Cardiac remodeling, after a myocardial insult, often causes progression to heart failure. The relationship between alterations in left ventricular blood flow, including kinetic energy (KE), and remodeling is uncertain. We hypothesized that increasing derangements in left ventricular blood flow would relate to (1) conventional cardiac remodeling markers, (2) increased levels of biochemical remodeling markers, (3) altered cardiac energetics, and (4) worsening patient symptoms and functional capacity. Methods: Thirty-four dilated cardiomyopathy patients, 30 ischemic cardiomyopathy patients, and 36 controls underwent magnetic resonance including 4-dimensional flow, BNP (brain-type natriuretic peptide) measurement, functional capacity assessment (6-minute walk test), and symptom quantification. A subgroup of dilated cardiomyopathy and control subjects underwent cardiac energetic assessment. Left ventricular flow was separated into 4 components: direct flow, retained inflow, delayed ejection flow, and residual volume. Average KE throughout the cardiac cycle was calculated. Results: Patients had reduced direct flow proportion and direct-flow average KE compared with controls (Pamp;lt;0.0001). The residual volume proportion and residual volume average KE were increased in patients (Pamp;lt;0.0001). Importantly, in a multiple linear regression model to predict the patients 6-minute walk test, the independent predictors were age (beta=-0.3015; P=0.019) and direct-flow average KE (beta=0.280, P=0.035; R-2 model, 0.466, P=0.002). In contrast, neither ejection fraction nor left ventricular volumes were independently predictive. Conclusions: This study demonstrates an independent predictive relationship between the direct-flow average KE and a prognostic measure of functional capacity. Intracardiac 4-dimensional flow parameters are novel biomarkers in heart failure and may provide additive value in monitoring new therapies and predicting prognosis.
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  • Stuijfzand, Wijnand J, et al. (author)
  • Relative flow reserve derived from quantitative perfusion imaging may not outperform stress myocardial blood flow for identification of hemodynamically significant coronary artery disease
  • 2015
  • In: Circulation Cardiovascular Imaging. - 1941-9651 .- 1942-0080. ; 8:1
  • Journal article (peer-reviewed)abstract
    • BACKGROUND: Quantitative myocardial perfusion imaging is increasingly used for the diagnosis of coronary artery disease. Quantitative perfusion imaging allows to noninvasively calculate fractional flow reserve (FFR). This so-called relative flow reserve (RFR) is defined as the ratio of hyperemic myocardial blood flow (MBF) in a stenotic area to hyperemic MBF in a normal perfused area. The aim of this study was to assess the value of RFR in the detection of significant coronary artery disease.METHODS AND RESULTS: From a clinical population of patients with suspected coronary artery disease who underwent oxygen-15-labeled water cardiac positron emission tomography and invasive coronary angiography, 92 patients with single- or 2-vessel disease were included. Intermediate lesions (diameter stenosis, 30%-90%; n=75) were interrogated by FFR. Thirty-eight (41%) vessels were deemed hemodynamically significant (>90% stenosis or FFR≤0.80). Hyperemic MBF, coronary flow reserve, and RFR were lower for vessels with a hemodynamically significant lesion (2.01±0.78 versus 2.90±1.16 mL·min(-1)·g(-1); P<0.001, 2.27±1.03 versus 3.10±1.29; P<0.001, and 0.67±0.23 versus 0.93±0.15; P<0.001, respectively). The correlation between RFR and FFR was moderate (r=0.54; P<0.01). Receiver operator characteristic curve analysis showed an area under the curve of 0.82 for RFR, which was not significantly higher compared with that for hyperemic MBF and coronary flow reserve (0.76; P=0.32 and 0.72; P=0.08, respectively).CONCLUSIONS: Noninvasive estimation of FFR by quantitative perfusion positron emission tomography by calculating RFR is feasible, yet only a trend toward a slight improvement of diagnostic accuracy compared with hyperemic MBF assessment was determined.
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  • Vamvakidou, Anastasia, et al. (author)
  • Clinical Value of Stress Transaortic Flow Rate During Dobutamine Echocardiography in Reduced Left Ventricular Ejection Fraction, Low-Gradient Aortic Stenosis : A Multicenter Study
  • 2021
  • In: Circulation Cardiovascular Imaging. - 1941-9651 .- 1942-0080. ; 14:11
  • Journal article (peer-reviewed)abstract
    • BACKGROUND: Low rest transaortic flow rate (FR) has been shown previously to predict mortality in low-gradient aortic stenosis. However limited prognostic data exists on stress FR during low-dose dobutamine stress echocardiography. We aimed to assess the value of stress FR for the detection of aortic valve stenosis (AS) severity and the prediction of mortality.METHODS: This is a multicenter cohort study of patients with reduced left ventricular ejection fraction and low-gradient aortic stenosis (aortic valve area <1 cm2 and mean gradient <40 mm Hg) who underwent low-dose dobutamine stress echocardiography to identify the AS severity and presence of flow reserve. The outcome assessed was all-cause mortality.RESULTS: Of the 287 patients (mean age, 75±10 years; males, 71%; left ventricular ejection fraction, 31±10%) over a mean follow-up of 24±30 months there were 127 (44.3%) deaths and 147 (51.2%) patients underwent aortic valve intervention. Higher stress FR was independently associated with reduced risk of mortality (hazard ratio, 0.97 [95% CI, 0.94-0.99]; P=0.01) after adjusting for age, chronic kidney disease, heart failure symptoms, aortic valve intervention, and rest left ventricular ejection fraction. The minimum cutoff for prediction of mortality was stress FR 210 mL/s. Following adjustment to the same important clinical and echocardiographic parameters, among the three criteria of AS severity during stress, ie, the guideline definition of aortic valve area <1cm2 and aortic valve mean gradient ≥40 mm Hg, or aortic valve mean gradient ≥40 mm Hg, or the novel definition of aortic valve area <1 cm2 at stress FR ≥210 mL/s, only the latter was independently associated with mortality (hazard ratio, 1.72 [95% CI, 1.05-2.82]; P=0.03). Furthermore aortic valve area <1cm2 at stress FR ≥210 mL/s was the only severe aortic stenosis criterion that was associated with improved outcome following aortic valve intervention (P<0.001). Guideline-defined stroke volume flow reserve did not predict mortality.CONCLUSIONS: Stress FR during low-dose dobutamine stress echocardiography was useful for the detection of both AS severity and flow reserve and was associated with improved prediction of outcome following aortic valve intervention.
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