Coronary Revascularization in Patients With Stable Coronary Artery Disease: The Role of Imaging

: In the last decades, the effective management of some cardiovascular risk factors in the general population has led to a progressive decrease in the prevalence of coronary artery disease (CAD). Nevertheless, coronary heart disease remains the major cause of death in developed and developing countries and chronic coronary syndromes (CCS) are still a major target of utilization of non-invasive cardiac imaging and invasive procedures. Current guidelines recommend the use of non-invasive imaging in patients with CCS to identify subjects at higher risk to be referred for invasive coronary angiography and possible revascularization. These recommendations are challenged by two opposite lines of evidence. Recent trials have somewhat questioned the efficacy of coronary revascularization as compared with optimal medical therapy in CCS. As a consequence the role of imaging in these patients and in in patients with ischemic cardiomyopathy is under debate. On the other hand, real-life data indicate that a consistent proportion of patients undergo invasive procedure and are revascularized without any previous non-invasive imaging characterization. On top of this, the impact of COVID-19 pandemic on the sanitary systems caused a change in the current management of patients with CAD. In the present review we will discuss these conflicting data analyzing the evidence which has been recently accumulated as well as the gaps of knowledge which should still be filled

Automatic PET-CT Image Registration Method Based on Mutual Information and Genetic Algorithms

Hybrid PET/CT scanners can simultaneously visualize coronary artery disease as revealed by computed tomography (CT) and myocardial perfusion as measured by positron emission tomography (PET). Manual registration is usually required in clinical practice to compensate spatial mismatch between datasets. In this paper, we present a registration algorithm that is able to automatically align PET/CT cardiac images. The algorithm bases on mutual information (MI) as registration metric and on genetic algorithm as optimization method. A multiresolution approach was used to optimize the processing time. The algorithm was tested on computerized models of volumetric PET/CT cardiac data and on real PET/CT datasets. The proposed automatic registration algorithm smoothes the pattern of the MI and allows it to reach the global maximum of the similarity function. The implemented method also allows the definition of the correct spatial transformation that matches both synthetic and real PET and CT volumetric datasets

Myocardial blood flow regulation in infarcted patients with stress-induced normalization of negative T waves

The correlation of stress-induced normalization of negative T waves (NTW) with regional myocardial blood flow (MBF) regulation and tissue viability remains still dented

Heat shock protein 72 in heart failure

In the heart, Heat Shock Proteins (HSP) constitute an endogenous stress response that protect myocytes from damage. Although HSP are intracellular proteins, these can be found also in peripheral circulationwhere their increase is associated with early cardiovascular disease

Abnormal Glucose Tolerance Is Associated with a Reduced Myocardial Metabolic Flexibility in Patients with Dilated Cardiomyopathy

Dilated cardiomyopathy (DCM) is characterized by a metabolic shift from fat to carbohydrates and failure to increase myocardial glucose uptake in response to workload increments. We verified whether this pattern is influenced by an abnormal glucose tolerance (AGT). In 10 patients with DCM, 5 with normal glucose tolerance (DCM-NGT) and 5 with AGT (DCM-AGT), and 5 non-DCM subjects with AGT (N-AGT), we measured coronary blood flow and arteriovenous differences of oxygen and metabolites during Rest, Pacing (at 130 b/min), and Recovery. Myocardial lactate exchange and oleate oxidation were also measured. At Rest, DCM patients showed a reduced nonesterified fatty acids (NEFA) myocardial uptake, while glucose utilization increased only in DCM-AGT. In response to Pacing, glucose uptake promptly rose in N-AGT (from 72 ± 21 to 234 ± 73 nmol/min/g, p<0.05), did not change in DCM-AGT, and slowly increased in DCM-NGT. DCM-AGT sustained the extra workload by increasing NEFA oxidation (from 1.3 ± 0.2 to 2.9 ± 0.1 mol/min/gO2 equivalents, p<0.05), while DCM-NGT showed a delayed increase in glucose uptake. Substrate oxidation rates paralleled the metabolites data. The presence of AGT in patients with DCM exacerbates both the shift from fat to carbohydrates in resting myocardial metabolism and the reduced myocardial metabolic flexibility in response to an increased workload. This trial is registered with ClinicalTrial.gov NCT02440217

Insulin resistance is a major determinant of myocardial blood flow impairment in anginal patients

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Myocardial structural, perfusion and metabolic correlates of left bundle branch block mechanical derangement in patient with dilated cardiomyopathy

Background-Left bundle branch block (LBBB) influences upon regional left ventricular (LV) structure, perfusion and metabolism were not thoroughly investigated in dilated cardiomyopathy (DCM) patients. Methods and Results-Eleven DCM patients with LBBB (69?11 years, LV ejection fraction[EF]: 35?8%) and 7 DMC patients without LBBB (58?9 years, LV EF: 37?10%) were studied by cardiac magnetic resonance (CMR) and positron emission tomography (PET). Left ventricle was divided in 3 regions: septum, adjacent (anterior-inferior) and lateral. Regional midwall circumferential strain, maximum shortening (&#1013;peak) and strain rate were obtained from tagged CMR. Systolic stretch index (SSI) was calculated as positive strain rate (stretching) divided by total strain rate. Myocardial metabolic rate of glucose (MMRG), resting and hyperemic myocardial blood flow (MBF) were quantitated using 2-[18F]fluoro-2-deoxyglucose and [13N]ammonia PET, respectively. Conversely from non LBBB patients, LBBB patients showed highly inhomogeneous systolic deformation pattern which changed gradually moving from discoordinate [(SSI: 0.485 (0.284)] and poorly contracting (&#1013;peak: -1.14?0.96%) septum to coordinate [SSI: 0.002 (0.168)] and strongly contracting (&#1013;peak: -13.63?2.58%) lateral region (both P<0.0001). This pattern was closely matched to MMRG distribution disclosing lowest, intermediate and highest values respectively in the septum, adjacent and lateral regions (P<0.0001). Septal-to-lateral thickness ratio was lower in LBBB than non LBBB patients (P=0.03). In both groups, LV distribution of resting and hyperemic MBF and MBF reserve did not differ significantly. Conclusions-In DCM patients, the extensive LV contraction abnormalities induced by LBBB caused regional myocardial metabolic and structural remodeling without consistent changes in blood flows.-

Circulating adrenomedullin levels and Doppler-derived dP/dt in idopathic cardiomyopathy

Chronic heart failure (CHF) is characterized both by ventricular and vascular remodeling. Osteopontin (OP) is an extracellular matrix protein,that might have a role as a marker of ventricular remodelling, its expression being increased in myocardial tissue of CHF patients from biopsies. Adrenomedullin (AM), a potent vasodilator peptide secreted by endothelial cells, and endothelin (ET), a substance with long-acting vasocostrictor action, might express the paracrine vasomotor response to CHF progression