| 51. |
- 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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| 53. |
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| 54. |
- Anttila, V., et al.
(författare)
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Synthetic mRNA Encoding VEGF-A in Patients Undergoing Coronary Artery Bypass Grafting: Design of a Phase 2a Clinical Trial
- 2020
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Ingår i: Molecular Therapy-Methods & Clinical Development. - : Elsevier BV. - 2329-0501. ; 18, s. 464-472
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Tidskriftsartikel (refereegranskat)abstract
- Therapeutic angiogenesis may improve outcomes in patients with coronary artery disease undergoing surgical revascularization. Angiogenic factors may promote blood vessel growth and regenerate regions of ischemic but viable myocardium. Previous clinical trials of vascular endothelial growth factor A (VEGF-A) gene therapy with DNA or viral vectors demonstrated safety but not efficacy. AZD8601 is VEGF-A(165) mRNA formulated in biocompatible citrate-buffered saline and optimized for high-efficiency VEGF-A expression with minimal innate immune response. EPICCURE is an ongoing randomized, double-blind, placebo-controlled study of the safety of AZD8601 in patients with moderately decreased left ventricular function (ejection fraction 30% 50%) undergoing elective coronary artery bypass surgery. AZD8601 3 mg, 30 mg, or placebo is administered as 30 epicardial injections in a 10-min extension of cardioplegia. Injections are targeted to ischemic but viable myocardial regions in each patient using quantitative O-15-water positron emission tomography (PET) imaging (stress myocardial blood flow < 2.3 mL/g/min; resting myocardial blood flow > 0.6 mL/g/min). Improvement in regional and global myocardial blood flow quantified with O-15-water PET is an exploratory efficacy outcome, together with echocardiographic, clinical, functional, and biomarker measures. EPICCURE combines high-efficiency delivery with quantitative targeting and follow-up for robust assessment of the safety and exploratory efficacy of VEGF-A mRNA angiogenesis (ClinicalTrials.gov: NCT03370887).
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| 55. |
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| 56. |
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| 57. |
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| 59. |
- Kalliokoski, K.K, et al.
(författare)
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Muscle fractal vascular branching pattern and microvascular perfusion heterogeneity in endurance-trained and untrained men
- 2003
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Ingår i: Journal of Physiology. - : Wiley. - 0022-3751 .- 1469-7793. ; 546:pt2, s. 529-35
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Tidskriftsartikel (refereegranskat)abstract
- Less heterogeneous skeletal muscle perfusion has recently been reported in endurance-trained compared to untrained men at macrovascular level. The causes of this difference in perfusion heterogeneity are unknown as is whether the same difference is observed in microvasculature. We hypothesised that the difference could be caused by changes in muscle vascular branching pattern. Perfusion was measured in resting and exercising muscle in 14 endurance-trained and seven untrained men using [(15)O]water and positron emission tomography. Fractal dimension (D) of perfusion distribution was calculated as a measure of fractal characteristics of muscle vascular branching pattern. Perfusion heterogeneity in microvascular units (1 mm(3) samples) was estimated using the measured heterogeneity in voxels of positron emission tomography (PET) images (relative dispersion, RD = S.D./mean) and corresponding D values. D was similar between the groups (exercising muscle 1.11 +/- 0.07 and 1.14 +/- 0.06, resting muscle 1.12 +/- 0.06 and 1.14 +/- 0.03, trained and untrained, respectively). Trained men had lower perfusion (151 +/- 44 vs. 218 +/- 87 ml min(-1) kg(-1), P < 0.05) and macrovascular perfusion heterogeneity (relative dispersion 21 +/- 5 vs. 25 +/- 5 %, P < 0.05) in exercising muscle than untrained men. Furthermore, estimated perfusion heterogeneity in microvascular units in exercising muscle was also lower in trained men (33 +/- 7 vs.48 +/- 19 %, P < 0.05). These results show that fractal vascular branching pattern is similar in endurance-trained and untrained men but perfusion is less heterogeneous at both the macro- and the microvascular level in endurance-trained men. Thus, changes in fractal branching pattern do not explain the differences in perfusion heterogeneity between endurance-trained and untrained men.
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