| 1. |
- Berg Hansen, Kristoffer, et al.
(författare)
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Myocardial efficiency in patients with different aetiologies and stages of heart failure
- 2022
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Ingår i: European Heart Journal Cardiovascular Imaging. - : Oxford University Press (OUP). - 2047-2404 .- 2047-2412. ; 23:3, s. 328-337
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Tidskriftsartikel (refereegranskat)abstract
- Aims: Myocardial external efficiency (MEE) is the ratio of cardiac work in relation with energy expenditure. We studied MEE in patients with different aetiologies and stages of heart failure (HF) to discover the role and causes of deranged MEE. In addition, we explored the impact of patient characteristics such as sex, body mass index (BMI), and age on myocardial energetics.Methods and results: Cardiac energetic profiles were assessed with C-11-acetate positron emission tomography (PET) and left ventricular ejection fraction (LVEF) was acquired with echocardiography. MEE was studied in 121 participants: healthy controls (n = 20); HF patients with reduced (HFrEF; n = 25) and mildly reduced (HFmrEF; n = 23) LVEF; and patients with asymptomatic (AS-asymp; n = 38) and symptomatic (AS-symp; n = 15) aortic stenosis (AS). Reduced MEE coincided with symptoms of HF irrespective of aetiology and declined in tandem with deteriorating LVEF. Patients with AS-symp and HFmrEF had reduced MEE as compared with controls (22.2 +/- 4.9%, P = 0.041 and 20.0 +/- 4.2%, P < 0.001 vs. 26.1 +/- 5.8% in controls) and a further decline was observed in patients with HFrEF (14.7 +/- 6.3%, P < 0.001). Disproportionate left ventricular hypertrophy was a major cause of reduced MEE. Female sex (P < 0.001), a lower BMI (P = 0.001), and advanced age (P = 0.03) were associated with a lower MEE.Conclusion: MEE was reduced in patients with HFrEF, HFmrEF, and HF due to pressure overload and MEE may therefore constitute a treatment target in HF. Patients with LVH, advanced age, female sex, and low BMI had more pronounced reduction in MEE and personalized treatment within these patient subgroups could be relevant.
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| 2. |
- Christensen, Nana L, et al.
(författare)
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Detection and correction of patient motion in dynamic 15O-water PET MPI.
- 2023
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Ingår i: Journal of Nuclear Cardiology. - : Elsevier. - 1071-3581 .- 1532-6551. ; 30:6, s. 2736-2749
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Patient motion constitutes a limitation to 15O-water cardiac PET imaging. We examined the ability of image readers to detect and correct patient motion using simulated motion data and clinical patient scans.METHODS: Simulated data consisting of 16 motions applied to 10 motion-free scans were motion corrected using two approaches, pre-analysis and post-analysis for motion identification. Both approaches employed a manual frame-by-frame correction method. In addition, a clinical cohort was analyzed for assessment of prevalence and effect of motion and motion correction.RESULTS: Motion correction was performed on 94% (pre-analysis) and 64% (post-analysis) of the scans. Large motion artifacts were corrected in 91% (pre-analysis) and 74% (post-analysis) of scans. Artifacts in MBF were reduced in 56% (pre-analysis) and 58% (post-analysis) of the scans. The prevalence of motion in the clinical patient cohort (n = 762) was 10%. Motion correction altered exam interpretation in only 10 (1.3%) clinical patient exams.CONCLUSION: Frame-by-frame motion correction after visual inspection is useful in reducing motion artifacts in cardiac 15O-water PET. Reviewing the initial results (parametric images and polar maps) as part of the motion correction process, reduced erroneous corrections in motion-free scans. In a large clinical cohort, the impact of motion correction was limited to few patients.
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| 3. |
- Hoff, Camilla Molich, et al.
(författare)
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Quantitative and qualitative comparison of Rubidium-82 and Oxygen-15 water cardiac PET.
- 2024
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Ingår i: Journal of Nuclear Cardiology. - 1071-3581 .- 1532-6551. ; , s. 101796-
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Differences in tracer characteristics may influence the interpretation of positron emission tomography myocardial perfusion imaging (MPI). We compare the reading of MPIs with a low-extraction retention tracer (82Rb) and a high-extraction non-retention tracer (15O-water) in a selected cohort of patients with known coronary artery disease (CAD).METHODS: Thirty-nine patients with known CAD referred to 82Rb MPI due to angina underwent rest and stress imaging with both tracers and experienced MPI readers provided blinded consensus reads of all studies. In addition, a comparison of regional and global quantitative measures of perfusion was performed.RESULTS: The results showed 74 % agreement in the reading of 82Rb and 15O-water MPI for regional reversible ischemia and global disease, and 82 % agreement for regional irreversible ischemia. The 15O-water MPI identified more cases of global disease (n = 12 (15O-water) vs n = 4 (82Rb), p = 0.03), whereas differences in reversible ischemia (n = 22 vs n = 16, p = 0.11) and, irreversible ischemia (n = 8 vs n = 11, p = 0.45) were not significant. The correlation between myocardial blood flow measured using the two tracers was similar to previous studies (R2 = 0.78) with wide limits of agreement (-0.93 to 0.84 ml/g/min).CONCLUSIONS: Agreement between consensus readings of 82Rb and 15O-water MPI was good in patients with known CAD. In this limited size study, no significant differences in the identification of reversible and irreversible ischemia found, whereas 15O-water MPI had a higher positive rate for suspected global disease.
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| 4. |
- Nielsen, Roni, et al.
(författare)
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Cardiovascular Effects of Treatment With the Ketone Body 3-Hydroxybutyrate in Chronic Heart Failure Patients
- 2019
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Ingår i: Circulation. - : LIPPINCOTT WILLIAMS & WILKINS. - 0009-7322 .- 1524-4539. ; 139:18, s. 2129-2141
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Myocardial utilization of 3-hydroxybutyrate (3-OHB) is increased in patients with heart failure and reduced ejection fraction (HFrEF). However, the cardiovascular effects of increased circulating plasma-3-OHB levels in these patients are unknown. Consequently, the authors' aim was to modulate circulating 3-OHB levels in HFrEF patients and evaluate: (1) changes in cardiac output (CO); (2) a potential doseresponse relationship between 3-OHB levels and CO; (3) the impact on myocardial external energy efficiency (MEE) and oxygen consumption (MVO 2); and (4) whether the cardiovascular response differed between HFrEF patients and age-matched volunteers.METHODS: Study 1: 16 chronic HFrEF patients (left ventricular ejection fraction: 37 +/- 3%) were randomized in a crossover design to 3-hour of 3-OHB or placebo infusion. Patients were monitored invasively with a Swan-Ganz catheter and with echocardiography. Study 2: In a doseresponse study, 8 HFrEF patients were examined at increasing 3-OHB infusion rates. Study 3 to 4: 10 HFrEF patients and 10 age-matched volunteers were randomized in a crossover design to 3-hour 3-OHB or placebo infusion. MEE and MVO 2 were evaluated using 11C-acetate positron emission tomography.RESULTS: 3-OHB infusion increased circulating levels of plasma 3-OHB from 0.4 +/- 0.3 to 3.3 +/- 0.4 mM (P< 0.001). CO rose by 2.0 +/- 0.2 L/min (P< 0.001) because of an increase in stroke volume of 20 +/- 2 mL (P< 0.001) and heart rate of 7 +/- 2 beats per minute (bpm) (P< 0.001). Left ventricular ejection fraction increased 8 +/- 1% (P< 0.001) numerically. There was a dose-response relationship with a significant CO increase of 0.3 L/min already at plasma-3-OHB levels of 0.7 mM (P< 0.001). 3-OHB increased MVO 2 without altering MEE. The response to 3-OHB infusion in terms of MEE and CO did not differ between HFrEF patents and age-matched volunteers.CONCLUSIONS: 3-OHB has beneficial hemodynamic effects in HFrEF patients without impairing MEE. These beneficial effects are detectable in the physiological concentration range of circulating 3-OHB levels. The hemodynamic effects of 3-OHB were observed in both HFrEF patients and age-matched volunteers. 3-OHB may potentially constitute a novel treatment principle in HFrEF patients.
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| 5. |
- Vester, Mazen, et al.
(författare)
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Myocardial perfusion imaging by 15O-H2O positron emission tomography predicts clinical revascularization procedures in symptomatic patients with previous coronary artery bypass graft.
- 2023
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Ingår i: European Heart Journal Open. - 2752-4191. ; 3:3, s. oead044-
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Tidskriftsartikel (refereegranskat)abstract
- AIMS: We wanted to assess if 15O-H2O myocardial perfusion imaging (MPI) in a clinical setting can predict referral to coronary artery catheterization [coronary angiography (CAG)], execution of percutaneous coronary intervention (PCI), and post-PCI angina relief for patients with angina and previous coronary artery bypass graft (CABG).METHODS AND RESULTS: We analysed 172 symptomatic CABG patients referred for 15O-H2O positron emission tomography (PET) MPI at Aarhus University Hospital Department of Nuclear Medicine & PET Centre, of which five did not complete the scan. In total, 145 (87%) enrolled patients had an abnormal MPI. Of these, 86/145 (59%) underwent CAG within 3 months; however, no PET parameters predicted referral to CAG. During the CAG, 25/86 (29%) patients were revascularized by PCI. Relative flow reserve (RFR) (0.49 vs. 0.54 P = 0.03), vessel-specific myocardial blood flow (MBF) (1.53 vs. 1.88 mL/g/min, P < 0.01), and vessel-specific myocardial flow reserve (MFR) (1.73 vs. 2.13, P < 0.01) were significantly lower in patients revascularized by PCI. Receiver operating characteristic analysis of the vessel-specific parameters yielded optimal cutoffs of 1.36 mL/g/min (MBF) and 1.28 (MFR) to predict PCI. Angina relief was experienced by 18/24 (75%) of the patients who underwent PCI. Myocardial blood flow was an excellent predictor of angina relief on both a global [area under the curve (AUC) = 0.85, P < 0.01] and vessel-specific (AUC = 0.90, P < 0.01) level with optimal cutoff levels of 1.99 mL/g/min and 1.85 mL/g/min, respectively.CONCLUSION: For CABG patients, RFR, vessel-specific MBF, and vessel-specific MFR measured by 15O-H2O PET MPI predict whether subsequent CAG will result in PCI. Additionally, global and vessel-specific MBF values predict post-PCI angina relief.
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| 6. |
- Hansson, Nils Henrik, et al.
(författare)
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Evaluation of ECG-gated [(11)C]acetate PET for measuring left ventricular volumes, mass, and myocardial external efficiency
- 2016
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Ingår i: Journal of Nuclear Cardiology. - : Springer Science and Business Media LLC. - 1071-3581 .- 1532-6551. ; 23:4, s. 670-9
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Noninvasive estimation of myocardial external efficiency (MEE) requires measurements of left ventricular (LV) oxygen consumption with [(11)C]acetate PET in addition to LV stroke volume and mass with cardiovascular magnetic resonance (CMR). Measuring LV geometry directly from ECG-gated [(11)C]acetate PET might enable MEE evaluation from a single PET scan. Therefore, we sought to establish the accuracy of measuring LV volumes, mass, and MEE directly from ECG-gated [(11)C]acetate PET.METHODS: Thirty-five subjects with aortic valve stenosis underwent ECG-gated [(11)C]acetate PET and CMR. List mode PET data were rebinned into 16-bin ECG-gated uptake images before measuring LV volumes and mass using commercial software and compared to CMR. Dynamic datasets were used for calculation of mean LV oxygen consumption and MEE.RESULTS: LV mass, volumes, and ejection fraction measured by CMR and PET correlated strongly (r = 0.86-0.92, P < .001 for all), but were underestimated by PET (P < .001 for all except ESV P = .79). PET-based MEE, corrected for bias, correlated fairly with PET/CMR-based MEE (r = 0.60, P < .001, bias -3 ± 21%, P = .56). PET-based MEE bias was strongly associated with LV wall thickness.CONCLUSIONS: Although analysis-related improvements in accuracy are recommended, LV geometry estimated from ECG-gated [(11)C]acetate PET correlate excellently with CMR and can indeed be used to evaluate MEE.
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| 7. |
- Harms, Hendrik J., et al.
(författare)
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Association of right ventricular myocardial blood flow with pulmonary pressures and outcome in cardiac amyloidosis
- 2023
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Ingår i: JACC Cardiovascular Imaging. - : Elsevier. - 1936-878X .- 1876-7591.
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Tidskriftsartikel (refereegranskat)abstract
- Background: Cardiac amyloidosis (CA) is a restrictive and infiltrative cardiomyopathy, characterized by increased biventricular filling pressures and low output. Symptoms are predominantly of right heart origin. The role of right ventricular (RV) myocardial blood flow (MBF) in CA has not been studied.Objectives: This study aimed to first associate RV MBF measured by using positron emission tomography (PET) with reference standards of RV pressures and then to explore its prognostic value in CA.Methods: Cardiac PET was performed at rest in 52 patients with CA and 9 healthy control subjects. MBF was quantified from the right and left ventricles by using 11C-acetate, 15O-water, or both (n = 25). RV pressure was measured invasively or by echocardiography. Associations between biventricular MBF toward symptoms, RV function, and outcome (death or acute heart failure) were studied in patients with CA.Results: MBF of the right ventricle (MBFRV) and the ratio of MBFRV and MBF of the left ventricle (MBFRV/LV) for the 2 tracers were significantly correlated (r > 0.92). MBFRV was directly correlated with RV systolic pressures with both tracers (P ≤ 0.005). MBFLV was inversely correlated with wall thickness (P < 0.0001). MBFRV/LV was significantly associated with N-terminal pro–B-type natriuretic peptide levels, New York Heart Association functional class, RV pressures, and RV systolic function (all; P < 0.001). Twenty-six cardiac events (25 deaths) occurred during follow-up (median 44 months). MBFRV/LV higher than 56% was associated with a diagnosis of pulmonary hypertension (AUC: 0.96 [95% CI: 0.91-1.00]; P < 0.0001); and predicted outcome with hazard ratio 9.0 (95% CI: 4.2-14.5), P < 0.0001).Conclusions: Measurements of MBFRV using PET are feasible, as confirmed with 2 different tracers. Imbalance between RV and LV myocardial perfusion is associated with increased RV load and adverse events in cardiac amyloidosis.
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| 8. |
- Harms, Hendrik J, et al.
(författare)
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Automatic calculation of myocardial external efficiency using a single 11C-acetate PET scan.
- 2018
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Ingår i: Journal of Nuclear Cardiology. - : Springer Science and Business Media LLC. - 1071-3581 .- 1532-6551. ; 25:6, s. 1937-1944
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Myocardial external efficiency (MEE) is defined as the ratio of kinetic energy associated with cardiac work [forward cardiac output (FCO)*mean systemic pressure] and the chemical energy from oxygen consumed (MVO2) by the left ventricular mass (LVM). We developed a fully automated method for estimating MEE based on a single 11C-acetate PET scan without ECG-gating.METHODS AND RESULTS: Ten healthy controls, 34 patients with aortic valve stenosis (AVS), and 20 patients with mitral valve regurgitation (MVR) were recruited in a dual-center study. MVO2 was calculated using washout of 11C -acetate activity. FCO and LVM were calculated automatically using dynamic PET and parametric image formation. FCO and LVM were also obtained using cardiac magnetic resonance (CMR) in all subjects. The correlation between MEEPET-CMR and MEEPET was high (r = 0.85, P < 0.001) without significant bias. MEEPET was 23.6 ± 4.2% for controls and was lowered in AVS (17.2 ± 4.3%, P < 0.001) and in MVR (18.0 ± 5.2%, P = 0.004). MEEPET was strongly associated with both NYHA class (P < 0.001) and the magnitude of valvular dysfunction (mean aortic gradient: P < 0.001, regurgitant fraction: P = 0.009).CONCLUSION: A single 11C-acetate PET yields accurate and automated MEE results on different scanners. MEE might provide an unbiased measurement of the phenotypic response to valvular disease.
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| 9. |
- Harms, Hendrik Johannes, et al.
(författare)
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Automatic extraction of forward stroke volume using dynamic PET/CT : a dual-tracer and dual-scanner validation in patients with heart valve disease.
- 2015
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Ingår i: EJNMMI Physics. - : Springer Science and Business Media LLC. - 2197-7364. ; 2:1
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The aim of this study was to develop and validate an automated method for extracting forward stroke volume (FSV) using indicator dilution theory directly from dynamic positron emission tomography (PET) studies for two different tracers and scanners.METHODS: 35 subjects underwent a dynamic (11)C-acetate PET scan on a Siemens Biograph TruePoint-64 PET/CT (scanner I). In addition, 10 subjects underwent both dynamic (15)O-water PET and (11)C-acetate PET scans on a GE Discovery-ST PET/CT (scanner II). The left ventricular (LV)-aortic time-activity curve (TAC) was extracted automatically from PET data using cluster analysis. The first-pass peak was isolated by automatic extrapolation of the downslope of the TAC. FSV was calculated as the injected dose divided by the product of heart rate and the area under the curve of the first-pass peak. Gold standard FSV was measured using phase-contrast cardiovascular magnetic resonance (CMR).RESULTS: FSVPET correlated highly with FSVCMR (r = 0.87, slope = 0.90 for scanner I, r = 0.87, slope = 1.65, and r = 0.85, slope = 1.69 for scanner II for (15)O-water and (11)C-acetate, respectively) although a systematic bias was observed for both scanners (p < 0.001 for all). FSV based on (11)C-acetate and (15)O-water correlated highly (r = 0.99, slope = 1.03) with no significant difference between FSV estimates (p = 0.14).CONCLUSIONS: FSV can be obtained automatically using dynamic PET/CT and cluster analysis. Results are almost identical for (11)C-acetate and (15)O-water. A scanner-dependent bias was observed, and a scanner calibration factor is required for multi-scanner studies. Generalization of the method to other tracers and scanners requires further validation.
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| 10. |
- Harms, Hendrik Johannes, et al.
(författare)
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Automatic Extraction of Myocardial Mass and Volume Using Parametric Images from Dynamic Nongated PET
- 2016
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Ingår i: Journal of Nuclear Medicine. - : Society of Nuclear Medicine. - 0161-5505 .- 1535-5667 .- 2159-662X. ; 57:9, s. 1382-1387
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Tidskriftsartikel (refereegranskat)abstract
- Dynamic cardiac PET is used to quantify molecular processes in vivo. However, measurements of left ventricular (LV) mass and volume require electrocardiogram-gated PET data. The aim of this study was to explore the feasibility of measuring LV geometry using nongated dynamic cardiac PET. Methods: Thirty-five patients with aortic-valve stenosis and 10 healthy controls underwent a 27-min C-11-acetate PET/CT scan and cardiac MRI (CMR). The controls were scanned twice to assess repeatability. Parametric images of uptake rate K-1 and the blood pool were generated from nongated dynamic data. Using software-based structure recognition, the LV wall was automatically segmented from K-1 images to derive functional assessments of LV mass (m(LV)) and wall thickness. End systolic and end-diastolic volumes were calculated using blood pool images and applied to obtain stroke volume and LV ejection fraction (LVEF). PET measurements were compared with CMR. Results: High, linear correlations were found for LV mass (r = 0.95), end-systolic volume (r = 0.93), and end-diastolic volume (r = 0.90), and slightly lower correlations were found for stroke volume (r = 0.74), LVEF (r = 0.81), and thickness (r = 0.78). Bland Altman analyses showed significant differences for m(LV) and thickness only and an overestimation for LVEF at lower values. Intra- and interobserver correlations were greater than 0.95 for all PET measurements. PET repeatability accuracy in the controls was comparable to CMR. Conclusion: LV mass and volume are accurately and automatically generated from dynamic C-11-acetate PET without electrocardiogram gating. This method can be incorporated in a standard routine without any additional workload and can, in theory, be extended to other PET tracers.
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