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Schindler TH, Cadenas J, Facta AD, Li Y, Olschewski M, Sayre J, Goldin J, Schelbert HR. Improvement in coronary endothelial function is independently associated with a slowed progression of coronary artery calcification in type 2 diabetes mellitus. Eur Heart J 2011; 30:3064-73. [PMID: 19914919 DOI: 10.1093/eurheartj/ehp482] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
AIMS To examine a relationship between alterations of structure and function of the arterial wall in response to glucose-lowering therapy in type 2 diabetes mellitus (DM) after a 1-year follow-up (FU). METHODS AND RESULTS In DM (n = 22) and in healthy controls (n = 17), coronary artery calcification (CAC) was assessed with electron beam tomography and carotid intima-media thickness (IMT) with ultrasound, whereas coronary function was determined with positron emission tomography-measured myocardial blood flow (MBF) at rest, during cold pressor testing (CPT), and during adenosine stimulation at baseline and after FU. The decrease in plasma glucose in DM after a mean FU of 14 +/- 1.9 months correlated with a lower progression of CAC and carotid IMT (r = 0.48, P < or = 0.036 and r = 0.46, P < or = 0.055) and with an improvement in endothelium-related DeltaMBF to CPT and to adenosine (r = 0.46, P < or = 0.038 and r = 0.36, P < or = 0.056). After adjusting for metabolic parameters by multivariate analysis, the increases in DeltaMBF to CPT after glucose-lowering treatment remained a statistically significant independent predictor of the progression of CAC (P < or = 0.001 by one-way analysis of variance). CONCLUSION In DM, glucose-lowering treatment may beneficially affect structure and function of the vascular wall, whereas the observed improvement in endothelium-related coronary artery function may also mediate direct preventive effects on the progression of CAC.
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Schindler TH, Schelbert HR, Quercioli A, Dilsizian V. Cardiac PET imaging for the detection and monitoring of coronary artery disease and microvascular health. JACC Cardiovasc Imaging 2010; 3:623-40. [PMID: 20541718 DOI: 10.1016/j.jcmg.2010.04.007] [Citation(s) in RCA: 278] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2010] [Revised: 04/21/2010] [Accepted: 04/26/2010] [Indexed: 12/11/2022]
Abstract
Positron emission tomography (PET) myocardial perfusion imaging in concert with tracer-kinetic modeling affords the assessment of regional myocardial blood flow (MBF) of the left ventricle in absolute terms (milliliters per gram per minute). Assessment of MBF both at rest and during various forms of vasomotor stress provides insight into early and subclinical abnormalities in coronary arterial vascular function and/or structure, noninvasively. The noninvasive evaluation and quantification of MBF and myocardial flow reserve (MFR) extend the scope of conventional myocardial perfusion imaging from detection of end-stage, advanced, and flow-limiting, epicardial coronary artery disease (CAD) to early stages of atherosclerosis or microvascular dysfunction. Recent studies have shown that impaired hyperemic MBF or MFR with PET, with or without accompanying CAD, is predictive of increased relative risk of death or progression of heart failure. Quantitative approaches that measure MBF with PET identify multivessel CAD and offer the opportunity to monitor responses to lifestyle and/or risk factor modification and to therapeutic interventions. Whether improvement or normalization of hyperemic MBF and/or the MFR will translate to improvement in long-term cardiovascular outcome remains clinically untested. In the meantime, absolute measures of MBF with PET can be used as a surrogate marker for coronary vascular health, and to monitor therapeutic interventions. Although the assessment of myocardial perfusion with PET has become an indispensable tool in cardiac research, it remains underutilized in clinical practice. Individualized, image-guided cardiovascular therapy may likely change this paradigm in the near future.
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Abstract
Quantification of regional myocardial blood flow and of its responses to targeted physiologic and pharmacologic interventions, which is now available with positron emitting tracers of blood flow and positron emission tomography (PET), extends the diagnostic potential of standard myocardial perfusion imaging. These noninvasive flow measurements serve as tools for quantifying functional consequences of epicardial coronary artery disease, as well as of impairments in microcirculatory reactivity that escape detection by standard perfusion imaging. Flow measurements are clinically useful for more comprehensively assessing the extent and severity of coronary vascular disease or impairments in microcirculatory function in noncoronary cardiac disease. Flow estimates in these disorders contain independent or unique prognostic information about future major cardiac events. Flow measurements are also useful for assessing the coronary risk, for predicting long-term cardiovascular events, and for monitoring the effectiveness of risk reduction strategies.
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Dilsizian V, Bacharach SL, Beanlands RS, Bergmann SR, Delbeke D, Gropler RJ, Knuuti J, Schelbert HR, Travin MI. PET myocardial perfusion and metabolism clinical imaging. J Nucl Cardiol 2009. [DOI: 10.1007/s12350-009-9094-9] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Knaapen P, Camici PG, Marques KM, Nijveldt R, Bax JJ, Westerhof N, Götte MJW, Jerosch-Herold M, Schelbert HR, Lammertsma AA, van Rossum AC. Coronary microvascular resistance: methods for its quantification in humans. Basic Res Cardiol 2009; 104:485-98. [PMID: 19468781 PMCID: PMC2722717 DOI: 10.1007/s00395-009-0037-z] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2008] [Revised: 05/11/2009] [Accepted: 05/13/2009] [Indexed: 12/20/2022]
Abstract
Coronary microvascular dysfunction is a topic that has recently gained considerable interest in the medical community owing to the growing awareness that microvascular dysfunction occurs in a number of myocardial disease states and has important prognostic implications. With this growing awareness, comes the desire to accurately assess the functional capacity of the coronary microcirculation for diagnostic purposes as well as to monitor the effects of therapeutic interventions that are targeted at reversing the extent of coronary microvascular dysfunction. Measurements of coronary microvascular resistance play a pivotal role in achieving that goal and several invasive and noninvasive methods have been developed for its quantification. This review is intended to provide an update pertaining to the methodology of these different imaging techniques, including the discussion of their strengths and weaknesses.
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Schindler TH, Campisi R, Dorsey D, Prior JO, Olschewski M, Sayre J, Schelbert HR. Effect of hormone replacement therapy on vasomotor function of the coronary microcirculation in post-menopausal women with medically treated cardiovascular risk factors. Eur Heart J 2009; 30:978-86. [PMID: 19251725 DOI: 10.1093/eurheartj/ehp013] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
AIMS The aim of this study was to evaluate the effect of hormone replacement therapy (HRT) on coronary vasomotor function in post-menopausal women (PM) with medically treated cardiovascular risk factors (RFs) in a cross-sectional and a longitudinal follow-up (FU) study. METHODS AND RESULTS Myocardial blood flow (MBF) response to cold pressor testing (CPT) and during pharmacologically induced hyperaemia was measured with positron emission tomography in pre-menopausal women (CON), in PM with HRT and without HRT, and repeated in PM after a mean FU of 24 +/- 14 months. When compared with CON at baseline, the endothelium-related change in MBF (DeltaMBF) to CPT progressively declined in PM with HRT and without HRT (0.35 +/- 0.23 vs. 0.24 +/- 0.20 and 0.16 +/- 0.12 mL/g/min; P = 0.171 and P = 0.021). In PM without HRT and in those with HRT at baseline but with discontinuation of HRT during FU, the endothelium-related DeltaMBF to CPT was significantly less at FU than at baseline (0.05 +/- 0.19 vs. 0.16 +/- 0.12 and -0.03 +/- 0.14 vs. 0.25 +/- 0.18 mL/g/min; P = 0.023 and P = 0.001), whereas no significant change was observed in PM with HRT (0.19 +/- 0.22 vs. 0.23 +/- 0.22 mL/g/min; P = 0.453). Impaired hyperaemic MBFs when compared with CON were not significantly altered from those at baseline exam. CONCLUSION Long-term administration of oestrogen may contribute to maintain endothelium-dependent coronary function in PM with medically treated cardiovascular RFs.
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Schelbert HR. Coronary Circulatory Function Abnormalities in Insulin Resistance. J Am Coll Cardiol 2009; 53:S3-8. [DOI: 10.1016/j.jacc.2008.09.053] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2008] [Revised: 09/16/2008] [Accepted: 09/29/2008] [Indexed: 11/28/2022]
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Zhang XL, Liu XJ, Hu SS, Thomas S, Tian YQ, Gao RL, Wu QY, Wei HX, Yang XB, Wang H, He ZX, Schelbert HR. [Impact of viable myocardium assessed by 99Tcm-MIBI SPECT and 18F-FDG PET imaging on clinical outcome of patients with left ventricular aneurysm underwent revascularization]. ZHONGHUA XIN XUE GUAN BING ZA ZHI 2008; 36:999-1003. [PMID: 19102913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
OBJECTIVE To evaluate the impact of viable myocardium assessed by (99)Tc()m-MIBI SPECT and (18)F-fluorodeoxyglucose (FDG) PET imaging in patients with left ventricular aneurysm (LVA) underwent revascularization (RVS). METHODS Forty-six consecutive patients with LVA (mean LVEF 36% +/- 7%), underwent (99)Tc(m)-sestamibi SPECT and (18)F-FDG PET examinations and received RVS therapy, were followed-up for a mean period of 80 +/- 27 months. Viable myocardium in aneurysm was defined as perfusion-metabolism mismatch score (MMS) >/= 2.0. Patients were divided into four groups by aneurysm viability and aneurysmectomy. Group A1 (n = 8): viability-; Group A2 (n = 15): viability-, aneurysmectomy; Group B1 (n = 10): viability +; and Group B2 (n = 13): viability +, aneurysmectomy. RESULTS The cardiac event rates during follow up were similar among groups [A1 (25%, 2/8), B1 (40%, 6/15), A2 (20%, 2/10) and B2 (31%, 4/13; P > 0.05)]. After revascularization, LVEF was improved (> 10%) in groups A2, B1 and B2 (P < 0.05). Multivariate logistic regression analysis showed that LV-MMS (OR = 2.34, 95% CI 1.08 - 5.06, P < 0.05), distal vessel disease (OR = 0.008, 95% CI 0.001 - 0.560, P < 0.05) and nonaneurysm perfusion score (OR = 0.24, 95% CI 0.07 - 0.85, P < 0.05) were significantly associated with the improvement of LVEF after revascularization. CONCLUSIONS Long term cardiac events rate post revascularization was not affected by viable myocardium or aneurysmectomy in LVA patients. Viable myocardium in LVA patients was associated with better LVEF improvement after revascularization.
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Schindler TH, Facta AD, Prior JO, Cadenas J, Zhang XL, Li Y, Sayre J, Goldin J, Schelbert HR. Structural alterations of the coronary arterial wall are associated with myocardial flow heterogeneity in type 2 diabetes mellitus. Eur J Nucl Med Mol Imaging 2008; 36:219-29. [PMID: 18704406 DOI: 10.1007/s00259-008-0885-z] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2007] [Accepted: 07/11/2008] [Indexed: 11/26/2022]
Abstract
PURPOSE To determine the relationship between carotid intima-media thickness (IMT), coronary artery calcification (CAC), and myocardial blood flow (MBF) at rest and during vasomotor stress in type 2 diabetes mellitus (DM). METHODS In 68 individuals, carotid IMT was measured using high-resolution vascular ultrasound, while the presence of CAC was determined with electron beam tomography (EBT). Global and regional MBF was determined in milliliters per gram per minute with (13)N-ammonia and positron emission tomography (PET) at rest, during cold pressor testing (CPT), and during adenosine (ADO) stimulation. RESULTS There was neither a relationship between carotid IMT and CAC (r = 0.10, p = 0.32) nor between carotid IMT and coronary circulatory function in response to CPT and during ADO (r = -0.18, p = 0.25 and r = 0.10, p = 0.54, respectively). In 33 individuals, EBT detected CAC with a mean Agatston-derived calcium score of 44 +/- 18. There was a significant difference in regional MBFs between territories with and without CAC at rest and during ADO-stimulated hyperemia (0.69 +/- 0.24 vs. 0.74 +/- 0.23 and 1.82 +/- 0.50 vs. 1.95 +/- 0.51 ml/g/min; p < or = 0.05, respectively) and also during CPT in DM but less pronounced (0.81 +/- 0.24 vs. 0.83 +/- 0.23 ml/g/min; p = ns). The increase in CAC was paralleled with a progressive regional decrease in resting as well as in CPT- and ADO-related MBFs (r = -0.36, p < or = 0.014; r = -0.46, p < or = 0.007; and r = -0.33, p < or = 0.041, respectively). CONCLUSIONS The absence of any correlation between carotid IMT and coronary circulatory function in type 2 DM suggests different features and stages of early atherosclerosis in the peripheral and coronary circulation. PET-measured MBF heterogeneity at rest and during vasomotor stress may reflect downstream fluid dynamic effects of coronary artery disease (CAD)-related early structural alterations of the arterial wall.
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Strauss HW, Miller DD, Wittry MD, Cerqueira MD, Garcia EV, Iskandrian AS, Schelbert HR, Wackers FJ, Balon HR, Lang O, Machac J. Procedure guideline for myocardial perfusion imaging 3.3. J Nucl Med Technol 2008; 36:155-61. [PMID: 18703619 DOI: 10.2967/jnmt.108.056465] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Zhang X, Liu XJ, Hu S, Schindler TH, Tian Y, He ZX, Gao R, Wu Q, Wei H, Sayre JW, Schelbert HR. Long-Term Survival of Patients with Viable and Nonviable Aneurysms Assessed by 99mTc-MIBI SPECT and 18F-FDG PET: A Comparative Study of Medical and Surgical Treatment. J Nucl Med 2008; 49:1288-98. [DOI: 10.2967/jnumed.107.046730] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Cerqueira MD, Berman DS, Di Carli MF, Schelbert HR, Th. Wackers FJ, Williams KA. Task Force 5: Training in Nuclear Cardiology. J Am Coll Cardiol 2008; 51:368-74. [DOI: 10.1016/j.jacc.2007.11.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Schindler TH, Zhang XL, Vincenti G, Mhiri L, Lerch R, Schelbert HR. Role of PET in the evaluation and understanding of coronary physiology. J Nucl Cardiol 2007; 14:589-603. [PMID: 17679069 PMCID: PMC1995749 DOI: 10.1016/j.nuclcard.2007.05.006] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Schindler TH, Zhang XL, Prior JO, Cadenas J, Dahlbom M, Sayre J, Schelbert HR. Assessment of intra- and interobserver reproducibility of rest and cold pressor test-stimulated myocardial blood flow with 13N-ammonia and PET. Eur J Nucl Med Mol Imaging 2007; 34:1178-88. [PMID: 17334762 DOI: 10.1007/s00259-007-0378-5] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2006] [Accepted: 01/04/2007] [Indexed: 10/23/2022]
Abstract
PURPOSE We investigated the intraobserver reproducibility of myocardial blood flow (MBF) measurements with PET at rest and during cold pressor test (CPT), and the interobserver agreement. METHODS Twenty normal volunteers were studied. Using (13)N-ammonia, MBF was measured at rest and during CPT and measurement was repeated in a 1-day session (short-term reproducibility; SR). After a follow-up of 2 weeks, MBF was measured again at rest and during CPT and compared with the initial baseline measurement (long-term reproducibility; LR). In addition, adenosine-induced hyperemic MBF increases were assessed. RESULTS Assessment of the SR did not show a significant absolute difference in MBF at rest, MBF during CPT or the endothelium-related change in MBF from rest to CPT (DeltaMBF) (0.09 +/- 0.10, 0.11 +/- 0.09, and 0.08 +/- 0.05 ml/g/min; p = NS), and they were linearly correlated (r = 0.72, r = 0.76 and r = 0.84; p < 0.0001). Corresponding values for standard error of the estimate (SEE), as indicative for the range of MBF measurement error, were 0.14, 0.14, and 0.09 ml/g/min. The LR yielded relatively higher but non-significant absolute differences in the MBF at rest, MBF during CPT and DeltaMBF (0.10 +/- 0.10, 0.14 +/- 0.10, and 0.19 +/- 0.10 ml/g/min; p = NS), and paired MBFs significantly correlated (r = 0.75, r = 0.71, and r = 0.60; p < 0.001). Corresponding SEEs were 0.13, 0.15, and 0.16 ml/g/min. The interobserver analysis yielded a high correlation for MBF at rest, MBF during CPT, and hyperemic MBF (r = 0.96, SEE=0.04; r = 0.78, SEE=0.11; and r = 0.87, SEE=0.28; p < 0.0001, respectively), and also a good interobserver correlation for DeltaMBF (r = 0.62, SEE=0.09; p < 0.003). CONCLUSION Short- and long-term MBF responses to CPT, as an index for endothelium-related coronary vasomotion, can be measured reproducibly with (13)N-ammonia PET. In addition, the high interobserver reproducibility for repeat analysis of MBF values suggests the measurements to be largely operator independent.
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Machac J, Bacharach SL, Bateman TM, Bax JJ, Beanlands R, Bengel F, Bergmann SR, Brunken RC, Case J, Delbeke D, DiCarli MF, Garcia EV, Goldstein RA, Gropler RJ, Travin M, Patterson R, Schelbert HR. Positron emission tomography myocardial perfusion and glucose metabolism imaging. J Nucl Cardiol 2007; 13:e121-51. [PMID: 17174789 DOI: 10.1016/j.nuclcard.2006.08.009] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Czernin J, Schelbert HR. PET/CT in cancer patient management. Introduction. J Nucl Med 2007; 48 Suppl 1:2S-3S. [PMID: 17204715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023] Open
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Czernin J, Allen-Auerbach M, Schelbert HR. Improvements in cancer staging with PET/CT: literature-based evidence as of September 2006. J Nucl Med 2007; 48 Suppl 1:78S-88S. [PMID: 17204723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023] Open
Abstract
PET/CT with 18F-FDG is increasingly being used for staging, restaging, and treatment monitoring for cancer patients. CT is still frequently used only for attenuation correction and lesion localization. However, increasing sales of high-end scanners that combine PET with 64-detector CT strongly suggest that the field is moving toward a comprehensive concept, whereby diagnostic CT studies during intravenous contrast material application are combined with the highest-quality PET studies. At many institutions, in-line PET/CT has replaced separately acquired PET and CT examinations for many oncologic indications. This replacement has occurred despite the fact that only a relatively small number of well-designed prospective studies have verified imaging findings against the gold standard of histopathologic tissue evaluation. However, a large number of studies have used acceptable reference standards, such as pathology, imaging, and other clinical follow-up findings, for validating PET/CT findings. From these data, we believe, has emerged reliable evidence in support of the notion that PET/CT offers diagnostic advantages over its individual components for the major cancers.
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Dorbala S, Hassan A, Heinonen T, Schelbert HR, Di Carli MF. Coronary vasodilator reserve and Framingham risk scores in subjects at risk for coronary artery disease. J Nucl Cardiol 2006; 13:761-7. [PMID: 17174807 DOI: 10.1016/j.nuclcard.2006.09.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2006] [Accepted: 09/21/2006] [Indexed: 10/23/2022]
Abstract
BACKGROUND The relationship between coronary vasodilator reserve and risk of coronary heart disease (CHD) in subjects without coronary artery disease (CAD) is not well known. METHODS AND RESULTS We studied 289 subjects (mean age, 58 +/- 10 years) without overt CAD and at low (< 10%) to intermediate risk (10%-20%) for CHD based on Framingham risk scores (RAMPART [Relative and Absolute Myocardial Perfusion changes as measured by Positron Emission Tomography to Assess the Effects of ACAT Inhibition: A Double-Blind, Randomized, Controlled, Multicenter Trial]). Coronary flow reserve (CFR) and coronary vascular resistance (CVR) were calculated from rest and adenosine nitrogen 13 ammonia positron emission tomography studies. Framingham-estimated CHD risk was used to as a surrogate for outcomes. Compared with subjects with low-risk scores (n = 150), those with intermediate-risk scores (n = 139) had a higher minimal CVR (49.3 +/- 17.41 mm Hg x mL(-1) x min(-1) x g(-1) vs 52.4 +/- 16.4 mm Hg x mL(-1) x min(-1) x g(-1), P = .05) and lower CFR (2.8 +/- 1.0 vs 2.5 +/- 0.8, P = .02). CFR was inversely related to CHD risk (R = -0.2, P = .006), and CVR was directly related to CHD risk (R = 0.2, P < .001). The mean CFR was significantly lower in patients in the first quartile of CHD risk compared with those in the fourth quartile (2.3 +/- 0.7 vs 2.8 +/- 1.0, P = .02), and the minimal CVR was significantly higher (44 +/- 15 mm Hg x mL(-1) x min(-1) x g(-1) vs 53 +/- 14 mm Hg x mL(-1) x min(-1) x g(-1), P < or = .05). CONCLUSIONS In subjects without clinical CAD and at low to intermediate risk, CFR assessed by positron emission tomography is inversely related to estimated 10-year CHD risk.
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Schindler TH, Facta AD, Prior JO, Cadenas J, Hsueh WA, Quinones MJ, Schelbert HR. Improvement in coronary vascular dysfunction produced with euglycaemic control in patients with type 2 diabetes. Heart 2006; 93:345-9. [PMID: 16940388 PMCID: PMC1861464 DOI: 10.1136/hrt.2006.094128] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
OBJECTIVE To determine the effect of plasma glucose lowering on coronary circulatory function in type 2 diabetes mellitus. METHODS Twenty patients with type 2 diabetes and 18 weight-matched controls were studied. At baseline, myocardial blood flow (MBF) was measured with [(13)N]ammonia and positron emission tomography at rest, during cold pressor testing (CPT), and during adenosine hyperaemia. In diabetic patients, MBF and blood chemistry were analysed again after 3 months of glucose-lowering treatment with glyburide and metformin. RESULTS Although hyperaemic MBF did not differ significantly between the patients and controls (1.81 (0.38) v 1.97 (0.43) ml/min/g; mean (SD)), the CPT-induced MBF increase (DeltaMBF) was significantly less in diabetic patients than in controls (0.07 (0.07) v 0.25 (0.12) ml/min/g; p<0.001). Treatment with glyburide and metformin significantly decreased plasma glucose concentrations from 207 (76) to 134 (52) mg/dl (p<0.001). This decrease in plasma glucose was paralleled by a significant increase in DeltaMBF in response to CPT (0.20 (0.16) from 0.07 (0.07) ml/min/g; p<0.001), which tended to be lower than in controls at baseline (0.20 (0.16) v 0.25 (0.12) ml/min/g; p = NS). The decrease in plasma glucose concentrations correlated significantly with the improvement in DeltaMBF in response to CPT (r = 0.67, p<0.01). CONCLUSIONS Type 2 diabetes mellitus is associated with abnormal MBF response to CPT, which can be significantly improved by euglycaemic control with glyburide and metformin. The close association between the decrease in plasma glucose concentration and the improvement in coronary vasomotor function in response to CPT suggests a direct adverse effect of raised plasma glucose concentration on diabetes-related coronary vascular disease.
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Prior JO, Schindler TH, Facta AD, Hernandez-Pampaloni M, Campisi R, Dahlbom M, Schelbert HR. Determinants of myocardial blood flow response to cold pressor testing and pharmacologic vasodilation in healthy humans. Eur J Nucl Med Mol Imaging 2006; 34:20-7. [PMID: 16902794 DOI: 10.1007/s00259-006-0193-4] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2006] [Revised: 05/06/2006] [Accepted: 06/09/2006] [Indexed: 10/24/2022]
Abstract
PURPOSE Response of myocardial blood flow (MBF) to sympathetic stimulation with cold is modulated by endothelium-related factors and is typically altered in the presence of coronary risk factors. Determinants of flow response to cold pressor testing (CPT) in normal volunteers at low risk for CAD remain less well defined, especially relative to baseline conditions such as hemodynamics and MBF, plasma substrate and lipid levels, and total pharmacologically stimulated vasodilator capacity. METHODS In 50 normal volunteers (42+/-13 years; 31 women) without coronary risk factors, insulin resistance, or family history of diabetes/premature CAD, MBF was measured with (13)N-ammonia and PET at baseline, during CPT, and during pharmacologic hyperemia. RESULTS Sympathetic stimulation with CPT raised heart rate and blood pressure and thus MBF (Delta MBF=0.23+/-0.09 ml/min/g). MBF response, defined in absolute flow units as the difference between CPT and baseline, was independent of age, gender, heart rate, and blood pressure and rate-pressure product (RPP) at baseline as well as plasma substrate and lipid levels with the exception of an association with HDL cholesterol (rho=0.40, p=0.005) but depended on the change in RPP from rest (rho=0.33, p=0.019). Finally, changes in coronary vascular resistance in response to CPT were associated with changes in pharmacologic vasodilation (rho=0.56, p<0.0001). CONCLUSION MBF response to sympathetic stimulation with cold (NO-mediated endothelium-dependent vasomotion), reflecting the functional state of the coronary endothelium, was independent of gender, age, and resting heart conditions. It was modulated by HDL cholesterol levels, even in healthy volunteers, and also related to pharmacologically stimulated vasodilator capacity at the coronary vascular resistance level.
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Kreissl MC, Wu HM, Stout DB, Ladno W, Schindler TH, Zhang X, Prior JO, Prins ML, Chatziioannou AF, Huang SC, Schelbert HR. Noninvasive measurement of cardiovascular function in mice with high-temporal-resolution small-animal PET. J Nucl Med 2006; 47:974-80. [PMID: 16741307 PMCID: PMC4348007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/09/2023] Open
Abstract
UNLABELLED The aim of this study was to explore the feasibility of determining parameters of cardiovascular function in mice noninvasively by high-temporal-resolution imaging with a dedicated small-animal PET system. METHODS Twenty-five anesthetized mice (28.8 +/- 4.6 g) were injected via an intravenous catheter with a 30-microL bolus of (18)F-FDG (8-44 MBq). The first 9 s of data were reconstructed into 30 frames of 0.3 s using filtered backprojection. The time-activity curve derived from a left ventricle volume of interest was corrected for tracer recirculation and partial volume. Cardiac output was calculated by the Stewart-Hamilton method, in which cardiac output is total injected activity divided by the area under the left ventricle time-activity curve. Cardiac output divided by body weight was defined as cardiac index; cardiac output divided by heart rate yielded the stroke volume. In 5 mice, measurements were repeated 2-4 times to assess reproducibility. In 4 mice, the hemodynamic response to dobutamine was examined by measuring heart rate, cardiac output, and stroke volume. RESULTS The cardiac output averaged 20.4 +/- 3.4 mL/min; in the repeated measurements, the parameter displayed a mean percentage SD per mouse of 10% +/- 6%. The cardiac index averaged 0.73 +/- 0.19 mL/min/g and the stroke volume 45.0 +/- 6.9 microL, and both correlated with heart rate (r = 0.53, P = 0.007, and r = 0.49, P = 0.01, respectively). During dobutamine stress, heart rate increased from 423 +/- 50 to 603 +/- 30 beats/min (P = 0.002) and cardiac output increased from 18.5 +/- 1.9 to 32.0 +/- 4.2 mL/min (P = 0.008). CONCLUSION Parameters of cardiovascular function can be measured in mice noninvasively by radionuclide angiography using high-temporal-resolution small-animal PET. Measured values of cardiac output and stroke volume are reproducible and comparable to those obtained with MRI. The approach permits the monitoring of changes in cardiovascular function in response to pharmacologic intervention.
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Schindler TH, Facta AD, Prior JO, Campisi R, Inubushi M, Kreissl MC, Zhang XL, Sayre J, Dahlbom M, Schelbert HR. PET-measured heterogeneity in longitudinal myocardial blood flow in response to sympathetic and pharmacologic stress as a non-invasive probe of epicardial vasomotor dysfunction. Eur J Nucl Med Mol Imaging 2006; 33:1140-9. [PMID: 16639609 DOI: 10.1007/s00259-006-0069-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2005] [Accepted: 12/16/2005] [Indexed: 10/24/2022]
Abstract
PURPOSE We investigated whether a myocardial perfusion gradient during pharmacologically induced hyperemia also occurred during sympathetic stimulation with cold pressor testing (CPT), which commonly induces a paradoxical coronary vasoconstriction in individuals with coronary risk factors. METHODS Myocardial blood flow (MBF) was measured in absolute units (ml/g/min) with 13N-ammonia and PET at rest, during CPT, and during pharmacologic vasodilation in 59 participants with coronary risk factors ("at risk") and in 43 healthy individuals (controls). MBF was assessed globally as mean MBF, and in the mid and mid-distal myocardium of the left ventricle (LV). A decrease in MBF from mid to mid-distal LV myocardium was defined as MBF difference indicative of a perfusion gradient. RESULTS The change in mean MBF to CPT (DeltaMBF) in the at-risk group was significantly reduced compared with controls (0.05+/-0.19 vs 0.31+/-0.20 ml/g/min, p<0.0001), whereas mean MBF during pharmacologic vasodilation in the at-risk group tended to be lower than in controls (1.72+/-0.71 vs 2.00+/-0.64 ml/g/min, p=NS). Absolute MBFs during CPT and pharmacologic vasodilation were significantly lower in the mid-distal than in the mid LV myocardium, resulting in a significant MBF difference in the at-risk group (0.15+/-0.06 and 0.27+/-0.12 ml/g/min, p<0.0001) that was not observed in controls (0.007+/-0.05 and 0.014+/-0.10 ml/g/min, p=NS). In the at-risk group there was a significant correlation between the difference of mid to mid-distal MBF during CPT and that during pharmacologic vasodilation (r=0.43, p<0.004), suggesting functional alterations of epicardial vessels as the predominant cause for the observed MBF difference. CONCLUSION The relative decrease in MBF from the mid to the mid-distal left-ventricular myocardium suggests an intracoronary pressure decline during CPT and pharmacologic vasodilation, which is likely to reflect an impairment of flow-mediated epicardial vasomotor function.
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Schindler TH, Cardenas J, Prior JO, Facta AD, Kreissl MC, Zhang XL, Sayre J, Dahlbom M, Licinio J, Schelbert HR. Relationship between increasing body weight, insulin resistance, inflammation, adipocytokine leptin, and coronary circulatory function. J Am Coll Cardiol 2006; 47:1188-95. [PMID: 16545651 DOI: 10.1016/j.jacc.2005.10.062] [Citation(s) in RCA: 162] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2005] [Revised: 09/30/2005] [Accepted: 10/10/2005] [Indexed: 10/25/2022]
Abstract
OBJECTIVES We sought to evaluate effects of obesity, insulin resistance, and inflammation on coronary circulatory function and its relationship to leptin plasma levels. BACKGROUND It is not known whether obesity, commonly paralleled by insulin resistance, inflammation, and leptin, is independently associated with coronary circulatory dysfunction. METHODS Myocardial blood flow (MBF) responses to cold pressor test (CPT) and pharmacologic vasodilation was measured with positron emission tomography and 13N-ammonia. Study participants were divided into three groups based on their body mass index (BMI, kg/m2): control, 20 < or = BMI <25 (n = 19); overweight, 25 < or = BMI <30 (n = 21); and obese, BMI >30 (n = 32). RESULTS Body mass index was significantly correlated to the Homeostasis Model Assessment Index of insulin resistance and C-reactive protein levels (r = 0.60 and r = 0.47, p < 0.0001). Compared with control subjects, endothelium-related change in MBF (DeltaMBF) to CPT progressively declined in overweight and obese groups (0.32 +/- 0.09 vs. 0.21 +/- 0.19 and 0.07 +/- 0.16 ml/g/min; p < 0.03 and p < 0.0001). The dipyridamole-induced total vasodilator capacity was significantly lower in obese than in control subjects (1.77 +/- 0.51 vs. 2.04 +/- 0.37 ml/g/min, p < 0.02). On multivariate analysis, BMI (p < 0.012) and age (p < 0.035) were significant independent predictors of DeltaMBF. Finally, only in the obese group leptin plasma levels significantly correlated with DeltaMBF (r = 0.37, p < 0.036). CONCLUSIONS Increased body weight is independently associated with abnormal coronary circulatory function that progresses from an impairment in endothelium-related coronary vasomotion in overweight individuals to an impairment of the total vasodilator capacity in obese individuals. The findings that elevated leptin plasma levels in patients that are obese might exert beneficial effects on the coronary endothelium to counterbalance the adverse effects of increases in body weight on coronary circulatory function should be tested.
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Cerqueira MD, Berman DS, Di Carli MF, Schelbert HR, Wackers FJT, Williams KA. Task Force 5: Training in Nuclear Cardiology. J Am Coll Cardiol 2006; 47:898-904. [PMID: 16487871 DOI: 10.1016/j.jacc.2005.12.027] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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