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Journal of Nuclear Cardiology 05/2013; · 2.67 Impact Factor
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ABSTRACT: Revascularization procedures, including percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG), are performed in many patients with coronary artery disease. Despite the effectiveness of these procedures, different follow-up strategies need to be considered for the management of patients after revascularization. Stress myocardial perfusion single-photon emission computed tomography (MPS) is a suitable imaging method for the evaluation of patients who have undergone PCI or CABG, and it has been used in the follow-up of such patients. Radionuclide imaging is included in the follow-up strategies after PCI and CABG in patients with symptoms, but guidelines warn against routine testing of all asymptomatic patients after revascularization. After PCI, in the absence of symptoms, radionuclide imaging is recommended and indicated as appropriate after incomplete or suboptimal revascularization and in specific asymptomatic patient subsets. On the other hand, the value of MPS late after CABG in risk stratification has been demonstrated even in the absence of symptoms. Thus, given the adverse outcome associated with silent ischaemia, it can be speculated that all patients regardless of clinical status should undergo stress testing late after revascularization. Larger prospective studies are needed to assess whether stress MPS will have an impact on the outcome in asymptomatic patients after revascularization.
European Journal of Nuclear Medicine 04/2013; · 4.53 Impact Factor
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ABSTRACT: BACKGROUND: Transient ischemic dilation (TID) of the left ventricle during stress myocardial perfusion SPECT (MPS) has been shown to be a useful marker of severe coronary artery disease (CAD). However, investigations in diabetic patients with available coronary angiographic data are still limited. We evaluated the incremental diagnostic value of TID in identifying the presence of angiographically severe CAD in diabetic patients. METHODS AND RESULTS: TID ratio values were automatically derived from rest-stress MPS in 242 diabetic patients with available coronary angiography data. A cutoff of ≥1.19 was considered to represent TID. Severe CAD (≥70% stenosis in the proximal left anterior descending artery or the left main artery, or ≥90% stenosis in two or three vessels) was identified in 69 (29%) patients. At multivariate analysis, the best independent predictors of severe CAD were summed stress score and TID (both P < .001). At incremental analysis, the addition of TID improved the power of a model including clinical data and summed stress score, increasing the global χ(2) value from 14.3 to 28.2 (P < .01). The best cutoff of summed stress score for identifying patients with severe CAD was ≥8. When the TID ratio was considered in patients with summed stress score between 3 and 7, the sensitivity for diagnosing severe CAD significantly improved from 71% to 77% (P < .05). In the overall study population, the net reclassification improvement by adding TID to a model including clinical data and summed stress score in the prediction of severe CAD was 0.40 (P < .005). CONCLUSIONS: TID ratios obtained from rest-stress MPS provide incremental diagnostic information to standard perfusion analysis for the identification of severe and extensive CAD in diabetic patients.
Journal of Nuclear Cardiology 10/2012; · 2.67 Impact Factor
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ABSTRACT: This study assessed the reproducibility and accuracy of 2-deoxy-2[(18)F]fluoro-D-glucose ((18)F-FDG) for non-invasive quantification of myocardial infarct size in mice by a high-resolution positron emission tomography (PET)/computed tomography (CT) system.
Mice were studied by (18)F-FDG PET/CT 1 week after induction of myocardial infarction by permanent coronary occlusion or sham procedure. In a subset of mice, PET/CT was repeated 2 days apart to assess the reproducibility of infarct size measurements. Histological analysis was used as reference method to validate imaging data. The average difference in infarct size measurements between the first and the second study was -0.42% ± 2.07% (95% confidence interval -2.6 to 1.75) with a repeatability coefficient of 4.05%. At Bland-Altman analysis, the lower and upper limits of agreement between the two repeated studies were -4.46% and 3.63%, respectively, and no correlation between difference and mean was found (P = .89). The concordance correlation coefficient was 0.99 (P < .001) and the intraclass coefficient of correlation was 0.99. A high correlation between PET/CT and histology was found for measurement of infarct size (P < .001). Using Bland-Altman analysis, the mean difference in infarct size measurement (PET/CT minus histology) was 1.9% (95% confidence interval 0.94% to 2.86%).
In a mice model of permanent coronary occlusion non-invasive measurement of infarct size with high-resolution (18)F-FDG, PET/CT has excellent reproducibility and accuracy. These findings support the use of this methodology in serial studies.
Journal of Nuclear Cardiology 03/2012; 19(3):492-9. · 2.67 Impact Factor
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ABSTRACT: Different species have been used to reproduce myocardial infarction models but in the last years mice became the animals of choice for the analysis of several diseases, due to their short life cycle and the possibility of genetic manipulation. Many techniques are currently used for cardiovascular imaging in mice, including X-ray computed tomography (CT), high-resolution ultrasound, magnetic resonance imaging, and nuclear medicine procedures. Cardiac positron emission tomography (PET) allows to examine noninvasively, on a molecular level and with high sensitivity, regional changes in myocardial perfusion, metabolism, apoptosis, inflammation, and gene expression or to measure changes in anatomical and functional parameters in heart diseases. Currently hybrid PET/CT scanners for small laboratory animals are available, where CT adds high-resolution anatomical information. This paper reviews mouse models of myocardial infarction and discusses the applications of dedicated PET/CT systems technology, including animal preparation, anesthesia, radiotracers, and images postprocessing.
Journal of Biomedicine and Biotechnology 01/2012; 2012:541872. · 2.44 Impact Factor
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ABSTRACT: The assessment of coronary flow reserve (CFR) may be useful for the functional evaluation of coronary artery disease (CAD). Invasive techniques, such as intracoronary Doppler ultrasound and pressure-derived method, directly assess CFR velocity and fractional flow reserve. Positron emission tomography (PET) has emerged as an accurate noninvasive technique to quantify CFR. Nevertheless, this approach has not been applied to routine studies because of its high cost and complexity. Recently, attempts to estimate CFR with single-photon emission computed tomography (SPECT) tracers have been made in order to obtain, with noninvasive methods, data for quantitative functional assessment of CAD. This review analyzes the relative merit and limitations of CFR measurements by cardiac imaging techniques and describes the potential clinical applications.
Monaldi archives for chest disease = Archivio Monaldi per le malattie del torace / Fondazione clinica del lavoro, IRCCS [and] Istituto di clinica tisiologica e malattie apparato respiratorio, Università di Napoli, Secondo ateneo 12/2011; 76(4):192-7.
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ABSTRACT: Total occlusion of the abdominal aorta is unusual, and potentially catastrophic. It occurs in patients with advanced atherosclerotic occlusive disease, and can cause severe ischemic manifestations, depending on the site of obstruction. Prompt and appropriate diagnostic and therapeutic approaches are important whenever this condition is suspected, in order to avoid a fatal outcome. The development of a complex network of collaterals may prevent the manifestation of acute ischemic phenomena, and cause a delay in diagnosis and treatment. Here we report the clinical case of a 59-year-old man who was referred to our Department for evaluation of renal failure and refractory hypertension. Ultrasonography and 99mTc-DTPA scintigraphy showed a shrunken, non-functioning left kidney, while CT angiography and aortography showed the complete occlusion of the aorta from below the right renal artery down to the bifurcation of both common iliac arteries, with a critical stenosis of the origin of the right renal artery, an occlusion of the left renal artery as well as of the origin of the inferior mesenteric artery. The patient was referred to the surgery department for aorto-bifemoral bypass surgery and re-implantation of the right renal artery.
Monaldi archives for chest disease = Archivio Monaldi per le malattie del torace / Fondazione clinica del lavoro, IRCCS [and] Istituto di clinica tisiologica e malattie apparato respiratorio, Università di Napoli, Secondo ateneo 03/2011; 76(1):43-6.
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Pasquale Perrone-Filardi,
Santo Dellegrottaglie,
James H F Rudd,
Pierluigi Costanzo,
Caterina Marciano,
Enrico Vassallo,
Fabio Marsico,
Donatella Ruggiero, Maria Piera Petretta,
Massimo Chiariello,
Alberto Cuocolo
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ABSTRACT: Functional characterization of atherosclerosis is a promising application of molecular imaging. Radionuclide-based techniques for molecular imaging in the large arteries (e.g. aorta and carotids), along with ultrasound and magnetic resonance imaging (MRI), have been studied both experimentally and in clinical studies. Technical factors including cardiac and respiratory motion, low spatial resolution and partial volume effects mean that noninvasive molecular imaging of atherosclerosis in the coronary arteries is not ready for prime time. Positron emission tomography imaging with fluorodeoxyglucose can measure vascular inflammation in the large arteries with high reproducibility, and signal change in response to anti-inflammatory therapy has been described. MRI has proven of value for quantifying carotid artery inflammation when iron oxide nanoparticles are used as a contrast agent. Macrophage accumulation of the iron particles allows regression of inflammation to be measured with drug therapy. Similarly, contrast-enhanced ultrasound imaging is also being evaluated for functional characterization of atherosclerotic plaques. For all of these techniques, however, large-scale clinical trials are mandatory to define the prognostic importance of the imaging signals in terms of risk of future vascular events.
European Journal of Nuclear Medicine 12/2010; 38(5):969-75. · 4.53 Impact Factor
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ABSTRACT: We assessed predictors and temporal characteristics of cardiac risk in patients undergoing stress single-photon emission computed tomography after coronary artery bypass grafting.
Stress cardiac tomography was performed in 362 patients 5 years after coronary artery bypass grafting. Cardiac death and myocardial infarction were considered as events. Cox proportional hazards analysis was used to identify predictors of events and parametric survival analysis to predict time to events.
During a median follow-up of 27 months, 22 cardiac events occurred (6.1% cumulative event rate). At multivariable Cox analysis, ischemia at cardiac tomography (hazards ratio 3.7, 95% confidence interval 1.5-9.1; P = .004), and diabetes (hazards ratio 3.6, 95% confidence interval 1.5-8.5; P = .006) resulted in independent predictors of events. Event-free survival was 96% in patients with normal cardiac tomography, 86% in those with abnormal tomography without ischemia, and 70% in those with (log-rank 10.6, P for trend = .008). The parametric survival model revealed that the cardiac risk was greater for all time intervals and accelerated more over time in patients with ischemia than in those without (chi(2) 21.4, P < .0001). Patients without diabetes and normal cardiac tomography remained below a defined risk level (5%) for the entire follow-up period.
Stress cardiac tomography performed 5 years after coronary artery bypass grafting is useful to characterize the risk of cardiac events and its temporal variation. Parametric survival model estimates the predicted time to risk and the level of risk at specific time intervals after coronary artery bypass grafting.
The Journal of thoracic and cardiovascular surgery 07/2008; 136(1):46-51. · 3.41 Impact Factor
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Giovanni Esposito,
Cinzia Perrino,
Tohru Ozaki,
Hideyuki Takaoka,
Nicole Defer, Maria Piera Petretta,
Maria Carmen De Angelis,
Lan Mao,
Jacques Hanoune,
Howard A Rockman,
Massimo Chiariello
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ABSTRACT: ss-adrenergic receptors (ssARs) are powerful regulators of cardiac function in vivo, activating heterotrimeric G proteins and the effector molecule adenylyl cyclase (AC). Interestingly, cardiac-specific overexpression of different AC isoforms leads to variable changes in cardiac function. Whether AC overexpression affects intrinsic cardiac contractility in an isoform-specific fashion determining a change in exercise capacity is currently unknown.
To address this issue, we performed load-independent measurements of cardiac systolic and diastolic function by pressure-volume (PV) loop analysis in intact wild-type mice (WT) and transgenic mice overexpressing the AC isoforms 5 or 8.
Here we show that cardiac overexpression of either AC5 or AC8 transgenic mice determined an increase in intrinsic cardiac contractility. Interestingly, AC8 transgenic mice displayed a significantly greater increase in cardiac contractility and improved active phase of relaxation. Despite these differences detected by PV loop analysis, both AC5 and AC8 mice showed a marked increase in exercise capacity on treadmill testing.
Our results demonstrate that load-independent measurements of cardiac function are needed to compare different groups of genetically-modified mouse models and to detect subtle AC isoform-specific changes in cardiac performance.
Archiv für Kreislaufforschung 02/2008; 103(1):22-30. · 7.35 Impact Factor
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ABSTRACT: The present study aimed to evaluate the prognostic value of B-type natriuretic peptide (N-proBNP), renal dysfunction and anemia in chronic heart failure (CHF) patients.
We analyzed data from a prospective cohort of 153 patients (mean age 64 years) with CHF referred to our hospital center. Clinical, echocardiographic and laboratory data were drawn during hospital recovery in all patients. Kidney dysfunction was defined as a glomerular filtration rate (GFR) < 60 ml/min and anemia as a hematocrit < 35%. After discharge, patients attended the outpatient clinic of our institution.
Kidney dysfunction was diagnosed in 37% of cases, whereas anemia was present in 25% of patients. During follow-up (median time 456 days), 32 patients died. Multivariate Cox proportional hazard model revealed that N-proBNP [hazard ratio (HR) = 1.002; P < 0.001] and GFR (HR = 0.972; P < 0.005) were significant predictors for mortality after adjustment for confounding variables. Kaplan-Maier analysis demonstrated a progressive decrease in survival from lowest to highest tertiles of N-proBNP values (log rank = 28.7; P < 0.001) and from higher to lower GFR values (log rank = 5.63; P < 0.01). Moreover, parametric survival analysis by the Weibull model demonstrated that the estimated probability of survival adjusted for N-proBNP values was higher in patients with GFR > or = 60 ml/min than in those with GFR < 60 ml/min (P < 0.001).
Increased N-proBNP and decreased kidney function, but not anemia, are independent risk factors for mortality in patients with CHF.
Journal of Cardiovascular Medicine 12/2007; 8(11):909-16. · 1.51 Impact Factor
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ABSTRACT: Strain rate is a promising echocardiographic technique which adds further information to that obtained with two-dimensional echocardiography and tissue Doppler imaging (TDI). The present study aimed to evaluate the effects of acute isotonic volume expansion on left ventricular function in patients with idiopathic dilated cardiomyopathy (DCM) utilizing TDI and strain rate measurements.
Ten patients with DCM and a left ventricular ejection fraction (LVEF) </= 40% underwent two-dimensional echocardiography during volume expansion (0.9% NaCl; 0.25 ml/kg/min for 120 min). Peak systolic tissue velocity and peak systolic strain rate were measured at baseline and at the end of volume loading.
Mean LVEF was 32 +/- 9% at baseline and remained unchanged after volume loading. Similarly, peak systolic velocity was 2.21 cm/s at baseline and remained unchanged after volume expansion. By contrast, peak systolic strain rate significantly reduced from -1.08 +/- 0.37/s to -0.76 +/- 0.12/s (P < 0.05).
In patients with DCM, peak systolic strain rate significantly reduces with volume loading in the absence of change in LVEF or peak systolic velocities at TDI. Because strain rate is a relative load-independent index of systolic function, the reduction observed is probably related to the decrease in left ventricular systolic performance that follows volume loading in heart failure patients. Thus, peak systolic strain rate appears to be more useful than TDI velocities to evaluate left ventricular dynamics during volume loading in patients with depressed left ventricular function.
Journal of Cardiovascular Medicine 01/2007; 7(12):852-8. · 1.51 Impact Factor
