| 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. |
- Larsen, Anders Hostrup, et al.
(författare)
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A randomised, double-blind, placebo-controlled trial of metformin on myocardial efficiency in insulin-resistant chronic heart failure patients without diabetes
- 2020
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Ingår i: European Journal of Heart Failure. - : WILEY. - 1388-9842 .- 1879-0844. ; 22:9, s. 1628-1637
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Tidskriftsartikel (refereegranskat)abstract
- AimsThe present study tested the hypothesis that metformin treatment may increase myocardial efficiency (stroke work/myocardial oxygen consumption) in insulin-resistant patients with heart failure and reduced ejection fraction (HFrEF) without diabetes. Methods and resultsThirty-six HFrEF patients (ejection fraction 378%; median age 66years) were randomised to metformin (n = 19) or placebo (n = 17) for 3months in addition to standard heart failure therapy. The primary endpoint was change in myocardial efficiency expressed as the work metabolic index (WMI), assessed by C-11-acetate positron emission tomography and transthoracic echocardiography. Compared with placebo, metformin treatment (1450 +/- 550 mg/day) increased WMI [absolute mean difference, 1.0mmHg.mL.m(-2).10(6); 95% confidence interval (CI) 0.1 to 1.8; P = 0.03], equivalent to a 20% relative efficiency increase. Patients with above-median plasma metformin levels displayed greater WMI increase (25% vs. -4%; P = 0.02). Metformin reduced myocardial oxygen consumption (-1.6mL O-2.100 g(-1).min(-1); P = 0.014). Cardiac stroke work was preserved (-2J; 95% CI -11 to 7; P = 0.69). Metformin reduced body weight (-2.2kg; 95% CI -3.6 to -0.8; P = 0.003) and glycated haemoglobin levels (-0.2%; 95% CI -0.3 to 0.0; P = 0.02). Changes in resting and exercise ejection fraction, global longitudinal strain, and exercise capacity did not differ between groups. ConclusionMetformin treatment in non-diabetic HFrEF patients improved myocardial efficiency by reducing myocardial oxygen consumption. Measurement of circulating metformin levels differentiated responders from non-responders. These energy-sparing effects of metformin encourage further large-scale investigations in heart failure patients without diabetes.
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| 3. |
- 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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| 4. |
- 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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| 5. |
- 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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| 6. |
- 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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| 7. |
- 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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| 8. |
- Jochumsen, Mads Ryo, et al.
(författare)
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Potential synergy between PSMA uptake and tumour blood flow for prediction of human prostate cancer aggressiveness
- 2021
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Ingår i: EJNMMI Research. - : Springer Nature. - 2191-219X. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- Background Both prostate-specific membrane antigen (PSMA) uptake and tumour blood flow (TBF) correlate with International Society of Urological Pathology (ISUP) Grade Group (GG) and hence prostate cancer (PCa) aggressiveness. The aim of the present study was to evaluate the potential synergistic benefit of combining the two physiologic parameters for separating significant PCa from insignificant findings. Methods From previous studies of [Rb-82]Rb positron emission tomography (PET) TBF in PCa, the 43 patients that underwent clinical [Ga-68]Ga-PSMA-11 PET were selected for this retrospective study. Tumours were delineated on [Ga-68]Ga-PSMA-11 PET or magnetic resonance imaging. ISUP GG was recorded from 52 lesions. Results [Ga-68]Ga-PSMA-11 maximum standardized uptake value (SUVmax) and [Rb-82]Rb SUVmax correlated moderately with ISUP GG (rho = 0.59 and rho = 0.56, both p < 0.001) and with each other (r = 0.65, p < 0.001). A combined model of [Ga-68]Ga-PSMA-11 and [Rb-82]Rb SUVmax separated ISUP GG > 2 from ISUP GG 1-2 and benign with an area-under-the-curve of 0.85, 96% sensitivity, 74% specificity, and 95% negative predictive value. The combined model performed significantly better than either tracer alone did (p < 0.001), primarily by reducing false negatives from five or six to one (p <= 0.025). Conclusion PSMA uptake and TBF provide complementary information about tumour aggressiveness. We suggest that a combined analysis of PSMA uptake and TBF could significantly improve the negative predictive value and allow non-invasive separation of significant from insignificant PCa.
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| 9. |
- Rosengren, Sara, et al.
(författare)
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Diagnostic Accuracy of [11C]PIB Positron Emission Tomography for Detection of Cardiac Amyloidosis
- 2020
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Ingår i: JACC Cardiovascular Imaging. - : Elsevier BV. - 1936-878X .- 1876-7591. ; 13:6, s. 1337-1347
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: This dual-site study evaluated the diagnostic accuracy of the method.BACKGROUND: Pittsburgh compound ([11C]PIB) positron emission tomography (PIB-PET) has shown promise as a specific and noninvasive method for the diagnosis of cardiac amyloidosis (CA).METHODS: The study had 2 parts. In the initial study, 51 subjects were included, 36 patients with known CA and increased wall thickness (15 immunoglobulin light chain [AL] and 21 transthyretin [ATTR] amyloidosis) and 15 control patients (7 were nonamyloid hypertrophic and 8 healthy volunteers). Subjects underwent PIB-PET and echocardiography. Sensitivity and specificity of PIB-PET were established for 2 simple semiquantitative approaches, standardized uptake value ratio (SUVR) and retention index (RI). The second part of the study included 11 amyloidosis patients (5 AL and 6 hereditary ATTR) without increased wall thickness to which the optimal cutoff values of SUVR (>1.09) and RI (>0.037 min-1) were applied prospectively.RESULTS: The diagnostic accuracy of visual inspection of [11C]PIB uptake was 100% in discriminating CA patients with increased wall thickness from controls. Semiquantitative [11C]PIB uptake discriminated CA from controls with a 94% (95% confidence interval [CI]: 80% to 99%) sensitivity for both SUVR and RI and specificity of 93% (95% CI: 66% to 100%) for SUVR and 100% (95% CI: 75% to 100%) for RI. [11C]PIB uptake was significantly higher in AL-CA than in ATTR-CA patients (p < 0.001) and discriminated AL-CA from controls with 100% (95% CI: 88% to 100%) accuracy for both the semiquantitative measures. In the prospective group without increased wall thickness, RI was elevated compared to controls (p = 0.001) and 5 of 11 subjects were evaluated as [11C]PIB PET positive.CONCLUSIONS: In a dual-center setting, [11C]PIB PET was highly accurate in detecting cardiac involvement in the main amyloid subtypes, with 100% accuracy in AL amyloidosis. A proportion of amyloidosis patients without known cardiac involvement were [11C]PIB PET positive, indicating that the method may detect early stages of CA.
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| 10. |
- Rosengren, Sara, et al.
(författare)
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Outcome prediction by myocardial external efficiency from 11C-acetate positron emission tomography in cardiac amyloidosis
- 2024
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Ingår i: ESC Heart Failure. - : John Wiley & Sons. - 2055-5822. ; 11:1, s. 44-53
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Tidskriftsartikel (refereegranskat)abstract
- AimsThis study aimed to study the prognostic value of myocardial oxygen consumption (MVO2) and myocardial external efficiency (MEE) from 11C-acetate positron emission tomography (PET) in cardiac amyloidosis (CA) patients.Methods and resultsForty-eight CA patients, both transthyretin (ATTR) and immunoglobulin light chain (AL) amyloidosis, and 20 controls were included. All subjects were examined with 11C-acetate PET and echocardiography. MVO2, forward stroke volume (FSV), and left ventricular mass (LVM) were derived from 11C-acetate PET and used to calculate MEE. CA patients were followed for survival and the prognostic impact of clinical, echocardiographic, and 11C-acetate PET parameters was analysed. MVO2 and MEE were reduced in CA compared with controls, but without significant difference between deceased and surviving CA patients. The ratio of 11C-acetate PET-derived FSV and LVM was also reduced in CA and significantly lowered in deceased patients compared with survivors. In univariate analysis, New York Heart Association class, N-terminal pro-brain natriuretic peptide, and the 11C-acetate PET parameters FSV/LVM and MEE were the strongest prognostic factors. Of the 11C-acetate PET parameters, FSV/LVM was the strongest survival predictor with hazard ratio of 0.56 per 0.1 mL/g (95% confidence interval 0.39–0.81, P = 0.002) and independently prognostic in a multivariate model. MEE significantly separated deceased from surviving CA patients with the cut-off of 15.7% (P = 0.032). Survival was significantly shorter with FSV/LVM below 0.27 mL/g (P < 0.001), also when separating AL- and ATTR-CA.ConclusionsReduced MEE was associated with shorter survival in CA patients, but FSV/LVM was the strongest survival predictor and the only independently prognostic 11C-acetate PET parameter in multivariate analysis.
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