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| 2. |
- Coenen, Adriaan, et al.
(författare)
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Diagnostic Accuracy of a Machine-Learning Approach to Coronary Computed Tomographic Angiography-Based Fractional Flow Reserve Result From the MACHINE Consortium
- 2018
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Ingår i: Circulation Cardiovascular Imaging. - : LIPPINCOTT WILLIAMS & WILKINS. - 1941-9651 .- 1942-0080. ; 11:6
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Tidskriftsartikel (refereegranskat)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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| 3. |
- Jablonowski, Robert, et al.
(författare)
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Cardiovascular magnetic resonance to predict appropriate implantable cardioverter defibrillator therapy in ischemic and nonischemic cardiomyopathy patients using late gadolinium enhancement border zone comparison of four analysis methods
- 2017
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Ingår i: Circulation: Cardiovascular Imaging. - 1941-9651. ; 10:9
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Tidskriftsartikel (refereegranskat)abstract
- Background: Late gadolinium enhancement (LGE) border zone on cardiac magnetic resonance imaging has been proposed as an independent predictor of ventricular arrhythmias. The purpose was to determine whether size and heterogeneity of LGE predict appropriate implantable cardioverter defibrillator (ICD) therapy in ischemic cardiomyopathy (ICM) and nonischemic cardiomyopathy (NICM) patients and to evaluate 4 LGE border-zone algorithms. Methods and Results: ICM and NICM patients who underwent LGE cardiac magnetic resonance imaging prior to ICD implantation were retrospectively included. Two semiautomatic algorithms, expectation maximization, weighted intensity, a priori information and a weighted border zone algorithm, were compared with a modified full-width half-maximum and a 2-3SD threshold-based algorithm (2-3SD). Hazard ratios were calculated per 1% increase in LGE. A total of 74 ICM and 34 NICM were followed for 63 months (1-140) and 52 months (0-133), respectively. ICM patients had 27 appropriate ICD events, and NICM patients had 7 ICD events. In ICM patients with primary prophylactic ICD, LGE border zone predicted ICD therapy in univariable and multivariable analysis measured by the expectation maximization, weighted intensity, a priori information, weighted border zone, and modified full-width half-maximum algorithms (hazard ratios 1.23, 1.22, and 1.05, respectively; P<0.05; negative predictive value 92%). For NICM, total LGE by all 4 methods was the strongest predictor (hazard ratios, 1.03-1.04; P<0.05), though the number of events was small. Conclusions: Appropriate ICD therapy can be predicted in ICM patients with primary prevention ICD by quantifying the LGE border zone. In NICM patients, total LGE but not LGE border zone had predictive value for ICD therapy. However, the algorithms used affects the predictive value of these measures.
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| 4. |
- Lauridsen, T. K., et al.
(författare)
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Echocardiographic findings predict in-hospital and 1-year mortality in left-sided native valve Staphylococcus aureus endocarditis: Analysis from the international collaboration on endocarditis-prospective echo cohort study
- 2015
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Ingår i: Circulation Cardiovascular Imaging. - 1941-9651. ; 8:7
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Tidskriftsartikel (refereegranskat)abstract
- Background: Staphylococcus aureus left-sided native valve infective endocarditis (LNVIE) has higher complication and mortality rates compared with endocarditis from other pathogens. Whether echocardiographic variables can predict prognosis in S aureus LNVIE is unknown. Methods and Results: Consecutive patients with LNVIE, enrolled between January 2000 and September 2006, in the International Collaboration on Endocarditis were identified. Subjects without S aureus IE were matched to those with S aureus IE by the propensity of having S aureus. Survival differences were determined using log-rank significance tests. Independent echocardiographic predictors of mortality were identified using Cox-proportional hazards models that included inverse probability of treatment weighting and surgery as a time-dependent covariate. Of 727 subjects with LNVIE and 1-year follow-up, 202 had S aureus IE. One-year survival rates were significantly lower for patients with S aureus IE overall (57% S aureus IE versus 80% non-S aureus IE; P<0.001) and in the propensity-matched cohort (59% S aureus IE versus 68% non-S aureus IE; P<0.05). Intracardiac abscess (hazard ratio, 2.93; 95% confidence interval, 1.52-5.40; P<0.001) and left ventricular ejection fraction <40% (odds ratio, 3.01; 95% confidence interval, 1.35-6.04; P=0.004) were the only independent echocardiographic predictors of in-hospital mortality in S aureus LNVIE. Valve perforation (hazard ratio, 2.16; 95% confidence interval, 1.21-3.68; P=0.006) and intracardiac abscess (hazard ratio, 2.25; 95% confidence interval, 1.26-3.78; P=0.004) were the only independent predictors of 1-year mortality. Conclusions: S aureus is an independent predictor of 1-year mortality in subjects with LNVIE. In S aureus LNVIE, intracardiac abscess and left ventricular ejection fraction <40% independently predicted in-hospital mortality and intracardiac abscess and valve perforation independently predicted 1-year mortality. © 2015 American Heart Association, Inc.
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| 5. |
- Nagueh, Sherif F., et al.
(författare)
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Interobserver Variability in Applying American Society of Echocardiography/European Association of Cardiovascular Imaging 2016 Guidelines for Estimation of Left Ventricular Filling Pressure
- 2019
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Ingår i: Circulation Cardiovascular Imaging. - 1941-9651 .- 1942-0080. ; 12:1
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Tidskriftsartikel (refereegranskat)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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| 6. |
- Nordlund, David, et al.
(författare)
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Extent of myocardium at risk for left anterior descending artery, right coronary artery, and left circumflex artery occlusion depicted by contrast-enhanced steady state free precession and T2-weighted short tau inversion recovery magnetic resonance imaging
- 2016
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Ingår i: Circulation Cardiovascular Imaging. - 1941-9651. ; 9:7
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Tidskriftsartikel (refereegranskat)abstract
- Background - Contrast-enhanced steady state free precession (CE-SSFP) and T2-weighted short tau inversion recovery (T2-STIR) have been clinically validated to estimate myocardium at risk (MaR) by cardiovascular magnetic resonance while using myocardial perfusion single-photon emission computed tomography as reference standard. Myocardial perfusion single-photon emission computed tomography has been used to describe the coronary perfusion territories during myocardial ischemia. Compared with myocardial perfusion single-photon emission computed tomography, cardiovascular magnetic resonance offers superior image quality and practical advantages. Therefore, the aim was to describe the main coronary perfusion territories using CE-SSFP and T2-STIR cardiovascular magnetic resonance data in patients after acute ST-segment-elevation myocardial infarction. Methods and Results - CE-SSFP and T2-STIR data from 2 recent multicenter trials, CHILL-MI and MITOCARE (n=215), were used to assess MaR. Angiography was used to determine culprit vessel. Of 215 patients, 39% had left anterior descending artery occlusion, 49% had right coronary artery occlusion, and 12% had left circumflex artery occlusion. Mean extent of MaR using CE-SSFP was 44±10% for left anterior descending artery, 31±7% for right coronary artery, and 30±9% for left circumflex artery. Using T2-STIR, MaR was 44±9% for left anterior descending artery, 30±8% for right coronary artery, and 30±12% for left circumflex artery. MaR was visualized in polar plots, and expected overlap was found between right coronary artery and left circumflex artery. Detailed regional data are presented for use in software algorithms as a priori information on the extent of MaR. Conclusions - For the first time, cardiovascular magnetic resonance has been used to show the main coronary perfusion territories using CE-SSFP and T2-STIR. The good agreement between CE-SSFP and T2-STIR from this study and myocardial perfusion single-photon emission computed tomography from previous studies indicates that these 3 methods depict MaR accurately in individual patients and at a group level. Clinical Trial Registration - URL: http://www.clinicaltrials.gov. Unique identifiers: NCT01379261 and NCT01374321.
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| 7. |
- Salerno, Michael, et al.
(författare)
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Recent Advances in Cardiovascular Magnetic Resonance
- 2017
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Ingår i: Circulation: Cardiovascular Imaging. - 1941-9651. ; 10:6
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Tidskriftsartikel (refereegranskat)abstract
- Cardiovascular magnetic resonance imaging has become the gold standard for evaluating myocardial function, volumes, and scarring. Additionally, cardiovascular magnetic resonance imaging is unique in its comprehensive tissue characterization, including assessment of myocardial edema, myocardial siderosis, myocardial perfusion, and diffuse myocardial fibrosis. Cardiovascular magnetic resonance imaging has become an indispensable tool in the evaluation of congenital heart disease, heart failure, cardiac masses, pericardial disease, and coronary artery disease. This review will highlight some recent novel cardiovascular magnetic resonance imaging techniques, concepts, and applications.
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| 8. |
- Stoll, Victoria M., et al.
(författare)
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Left Ventricular Flow Analysis Novel Imaging Biomarkers and Predictors of Exercise Capacity in Heart Failure
- 2019
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Ingår i: Circulation Cardiovascular Imaging. - : LIPPINCOTT WILLIAMS & WILKINS. - 1941-9651 .- 1942-0080. ; 12:5
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Tidskriftsartikel (refereegranskat)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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| 9. |
- Stuijfzand, Wijnand J, et al.
(författare)
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Relative flow reserve derived from quantitative perfusion imaging may not outperform stress myocardial blood flow for identification of hemodynamically significant coronary artery disease
- 2015
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Ingår i: Circulation Cardiovascular Imaging. - 1941-9651 .- 1942-0080. ; 8:1
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Tidskriftsartikel (refereegranskat)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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| 10. |
- Granström, Karl, 1981, et al.
(författare)
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Approximate Multi-Hypothesis Multi-Bernoulli Multi-Object Filtering Made Multi-Easy
- 2016
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Ingår i: IEEE Transactions on Signal Processing. - : Institute of Electrical and Electronics Engineers (IEEE). - 1941-0476 .- 1053-587X. ; 64:7, s. 1784-1797
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Tidskriftsartikel (refereegranskat)abstract
- In multiple target tracking (MTT) it becomes necessary to use a multihypothesis approach if the trajectories of two or more targets cross. However, multihypothesis approaches, e.g., the multiple hypothesis tracker (MHT) or the emerging generalized labelled multi-Bernoulli (GLMB) filter, are computationally demanding. In this paper, we propose a simple multi-Bernoulli (MB) filter and a post processing method, which together deliver a multihypothesis tracking estimate at a computational cost that is only slightly larger than the cost of a single-hypothesis tracking filter even for many targets. The proposed MB filter is shown to be similar to the labeled MB filter, itself an approximation of the multihypothesis GLMB filter. In a simulation study with multiple targets and several trajectory crossings, the proposed filter is shown to be capable of correctly estimating the multihypothesis output. The filter is also tasked with presenting to an operator a principled perspective on a scene with many feasible track switches.
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