Imaging for the assessment of the arrhythmogenic potential of mitral valve prolapse.

Mitral valve prolapse (MVP) is the most common valve disease in the western world and recently emerged as a possible substrate for sudden cardiac death (SCD). It is estimated an annual risk of sudden cardiac death of 0.2 to 1.9% mostly caused by complex ventricular arrhythmias (VA). Several mechanisms have been recognized as potentially responsible for arrhythmia onset in MVP, resulting from the combination of morpho-functional abnormality of the mitral valve, structural substrates (regional myocardial hypertrophy, fibrosis, Purkinje fibers activity, inflammation), and mechanical stretch. Echocardiography plays a central role in MVP diagnosis and assessment of severity of regurgitation. Several abnormalities detectable by echocardiography can be prognostic for the occurrence of VA, from morphological alteration including leaflet redundancy and thickness, mitral annular dilatation, and mitral annulus disjunction (MAD), to motion abnormalities detectable with "Pickelhaube" sign. Additionally, speckle-tracking echocardiography may identify MVP patients at higher risk for VA by detection of increased mechanical dispersion. On the other hand, cardiac magnetic resonance (CMR) has the capability to provide a comprehensive risk stratification combining the identification of morphological and motion alteration with the detection of myocardial replacement and interstitial fibrosis, making CMR an ideal method for arrhythmia risk stratification in patients with MVP. Finally, recent studies have suggested a potential role in risk stratification of new techniques such as hybrid PET-MR and late contrast enhancement CT. The purpose of this review is to provide an overview of the mitral valve prolapse syndrome with a focus on the role of imaging in arrhythmic risk stratification. CLINICAL RELEVANCE STATEMENT: Mitral valve prolapse is the most frequent valve condition potentially associated with arrhythmias. Imaging has a central role in the identification of anatomical, functional, mechanical, and structural alterations potentially associated with a higher risk of developing complex ventricular arrhythmia and sudden cardiac death. KEY POINTS: • Mitral valve prolapse is a common valve disease potentially associated with complex ventricular arrhythmia and sudden cardiac death. • The mechanism of arrhythmogenesis in mitral valve prolapse is complex and multifactorial, due to the interplay among multiple conditions including valve morphological alteration, mechanical stretch, myocardial structure remodeling with fibrosis, and inflammation. • Cardiac imaging, especially echocardiography and cardiac magnetic resonance, is crucial in the identification of several features associated with the potential risk of serious cardiac events. In particular, cardiac magnetic resonance has the advantage of being able to detect myocardial fibrosis which is currently the strongest prognosticator.

Accuracy and Reliability of Left Atrial Appendage Morphology Assessment by Three-Dimensional Transesophageal Echocardiographic Glass Rendering Modality: A Comparative Study With Computed Tomography.

BACKGROUND: Contrast-enhanced computed tomography is the reference-standard imaging technique to assess left atrial appendage (LAA) morphology. The aim of this study was to evaluate the accuracy and reliability of two-dimensional and new three-dimensional (3D) transesophageal echocardiographic rendering modalities in assessing LAA morphology. METHODS: Seventy consecutive patients who underwent both computed tomography and transesophageal echocardiography (TEE) were retrospectively enrolled. The traditional LAA morphology classification system (LAAcs; chicken wing, cauliflower, cactus, and windsock) and a new simplified LAAcs based on the LAA bend angle were used for the analysis. LAA morphology was independently assessed by two trained readers using three different modalities: two-dimensional TEE, 3D TEE with multiplanar reconstruction, and a new 3D transesophageal echocardiographic rendering modality with improved transparency (Glass). The new LAAcs and traditional LAAcs were compared in terms of intra- and interrater reliability. RESULTS: With the new LAAcs, two-dimensional TEE was fairly accurate in identifying LAA morphology (κ = 0.43, P < .05), with moderate interrater (κ = 0.50, P < .05) and substantial intrarater (κ = 0.65, P < .005) agreement. Three-dimensional TEE showed higher accuracy and reliability: 3D TEE with multiplanar reconstruction had almost perfect accuracy (κ = 0.85, P < .001) and substantial (κ = 0.79, P < .001) interrater reliability, while 3D TEE with Glass had substantial accuracy (κ = 0.70, P < .001) and almost perfect (κ = 0.84, P < .001) interrater reliability. Intrarater agreement was almost perfect for both 3D transesophageal echocardiographic modalities (κ = 0.85, P < .001). Accuracy was considerably lower when the traditional LAAcs was used, with 3D TEE with Glass being the most reliable technique (κ = 0.75, P < .05). The new LAAcs showed higher inter- and intrarater reliability compared with the traditional LAAcs (interrater, κ = 0.85 vs κ = 0.49; intrarater, κ = 0.94 vs κ = 0.68; P < .05). CONCLUSIONS: Three-dimensional TEE is an accurate, reliable, and feasible alternative to computed tomography in assessing LAA morphology with the new LAAcs. The new LAAcs shows higher reliability rates than the traditional one.

Recommendations in pre-procedural imaging assessment for transcatheter aortic valve implantation intervention: Italian Society of Cardiology (SIC)-Italian Society of Medical and Interventional Radiology (SIRM) position paper part 1 (Clinical Indication and Basic Technical Aspects, Heart Team, Role of Echocardiography).

Non-invasive cardiovascular imaging owns a pivotal role in the preoperative assessment of patients for transcatheter aortic valve implantation (TAVI), providing a wide range of crucial information to select the patients who will benefit the most and have the procedure done safely. Although advanced cardiac imaging with cardiac computed tomography is routinely used for a detailed anatomic assessment before TAVI, echocardiography remains the first imaging modality to assess aortic stenosis severity and to provide essential functional information. This document results from the collaboration between the Italian Society of Cardiology (SIC) and the Italian Society of Medical and Interventional Radiology (SIRM), aiming to produce an updated consensus statement about the pre-procedural imaging assessment in patient for TAVI. The writing committee is composed of radiologists and cardiologists, experts in the field of cardiac imaging and structural heart diseases. Part 1 of the document, after a brief overview of the clinical indication and basic technical aspects of TAVI, will focus on the role of echocardiography in TAVI pre-procedural planning.

Recommendations in pre-procedural imaging assessment for TAVI intervention: SIC-SIRM position paper part 2 (CT and MR angiography, standard medical reporting, future perspectives).

Non-invasive cardiovascular imaging owns a pivotal role in the preoperative assessment of patient candidates for transcatheter aortic valve implantation (TAVI), providing a wide range of crucial information to select the patients who will benefit the most and have the procedure done safely. This document has been developed by a joined group of experts of the Italian Society of Cardiology and the Italian Society of Medical and Interventional Radiology and aims to produce an updated consensus statement about the pre-procedural imaging assessment in candidate patients for TAVI intervention. The writing committee consisted of members and experts of both societies who worked jointly to develop a more integrated approach in the field of cardiac and vascular radiology. Part 2 of the document will cover CT and MR angiography, standard medical reporting, and future perspectives.

SIRM-SIC appropriateness criteria for the use of Cardiac Computed Tomography. Part 1: Congenital heart diseases, primary prevention, risk assessment before surgery, suspected CAD in symptomatic patients, plaque and epicardial adipose tissue characterization, and functional assessment of stenosis.

In the past 20 years, Cardiac Computed Tomography (CCT) has become a pivotal technique for the noninvasive diagnostic work-up of coronary and cardiac diseases. Continuous technical and methodological improvements, combined with fast growing scientific evidence, have progressively expanded the clinical role of CCT. Recent large multicenter randomized clinical trials documented the high prognostic value of CCT and its capability to increase the cost-effectiveness of the management of patients with suspected CAD. In the meantime, CCT, initially perceived as a simple non-invasive technique for studying coronary anatomy, has transformed into a multiparametric "one-stop-shop" approach able to investigate the heart in a comprehensive way, including functional, structural and pathophysiological biomarkers. In this complex and revolutionary scenario, it is urgently needed to provide an updated guide for the appropriate use of CCT in different clinical settings. This manuscript, endorsed by the Italian Society of Medical and Interventional Radiology (SIRM) and by the Italian Society of Cardiology (SIC), represents the first of two consensus documents collecting the expert opinion of Radiologists and Cardiologists about current appropriate use of CCT.

Quantitative assessment of lung involvement on chest CT at admission: Impact on hypoxia and outcome in COVID-19 patients.

BACKGROUND: The aim of this study was to quantify COVID-19 pneumonia features using CT performed at time of admission to emergency department in order to predict patients' hypoxia during the hospitalization and outcome. METHODS: Consecutive chest CT performed in the emergency department between March 1st and April 7th 2020 for COVID-19 pneumonia were analyzed. The three features of pneumonia (GGO, semi-consolidation and consolidation) and the percentage of well-aerated lung were quantified using a HU threshold based software. ROC curves identified the optimal cut-off values of CT parameters to predict hypoxia worsening and hospital discharge. Multiple Cox proportional hazards regression was used to analyze the capability of CT quantitative features, demographic and clinical variables to predict the time to hospital discharge. RESULTS: Seventy-seven patients (median age 56-years-old, 51 men) with COVID-19 pneumonia at CT were enrolled. The quantitative features of COVID-19 pneumonia were not associated to age, sex and time-from-symptoms onset, whereas higher number of comorbidities was correlated to lower well-aerated parenchyma ratio (rho = -0.234, p = 0.04) and increased semi-consolidation ratio (rho = -0.303, p = 0.008). Well-aerated lung (≤57%), semi-consolidation (≥17%) and consolidation (≥9%) predicted worst hypoxemia during hospitalization, with moderate areas under curves (AUC 0.76, 0.75, 0.77, respectively). Multiple Cox regression identified younger age (p < 0.01), female sex (p < 0.001), longer time-from-symptoms onset (p = 0.049), semi-consolidation ≤17% (p < 0.01) and consolidation ≤13% (p = 0.03) as independent predictors of shorter time to hospital discharge. CONCLUSION: Quantification of pneumonia features on admitting chest CT predicted hypoxia worsening during hospitalization and time to hospital discharge in COVID-19 patients.

Computed Tomography Assessment of Fat Distribution and Staple-Line Leak Risk After Sleeve Gastrectomy.

PURPOSE: Sleeve gastrectomy (SG) has become the most frequent bariatric procedure and staple-line leak represents its most feared complication. Visceral obesity, a core component of the metabolic syndrome, has been associated with worst postoperative outcomes after various abdominal surgical procedures, and can be estimated by computed tomography (CT). The aim of this study was to assess the impact of radiologically determined visceral obesity in the risk of staple-line leak after SG. MATERIAL AND METHODS: A retrospective analysis of a prospective database was performed in consecutive patients undergoing SG. Several anthropometric variables were measured on a preoperative CT scan. Multivariate analysis was performed to determine preoperative risk factors for staple-line leak. RESULTS: During the study period, 377 patients were included in the analysis. The median BMI was 39.7 kg/m2 (36.5-43.5) and 8 patients (2.1%) presented a gastric leak. After multivariate analysis, visceral obesity defined by visceral fat area (VFA)/body surface area (BSA) ≥ 85 cm2/m2 was the only independent predictive factor for gastric leak (OR = 5312). CONCLUSION: CT scan-assessed visceral obesity defined by a VFA/BSA ratio ≥ 85 cm2/m2 is associated with an increased risk of gastric leak after SG. Preoperatively radiological examination in patients suspected of visceral obesity would be useful to optimize preoperative management.

The Suv420h histone methyltransferases regulate PPAR-γ and energy expenditure in response to environmental stimuli.

Obesity and its associated metabolic abnormalities have become a global emergency with considerable morbidity and mortality. Epidemiologic and animal model data suggest an epigenetic contribution to obesity. Nevertheless, the cellular and molecular mechanisms through which epigenetics contributes to the development of obesity remain to be elucidated. Suv420h1 and Suv420h2 are histone methyltransferases responsible for chromatin compaction and gene repression. Through in vivo, ex vivo, and in vitro studies, we found that Suv420h1 and Suv420h2 respond to environmental stimuli and regulate metabolism by down-regulating peroxisome proliferator-activated receptor gamma (PPAR-γ), a master transcriptional regulator of lipid storage and glucose metabolism. Accordingly, mice lacking Suv420h proteins activate PPAR-γ target genes in brown adipose tissue to increase mitochondria respiration, improve glucose tolerance, and reduce adipose tissue to fight obesity. We conclude that Suv420h proteins are key epigenetic regulators of PPAR-γ and the pathways controlling metabolism and weight balance in response to environmental stimuli.

Contrast-enhanced ultrasound for ovary assessment in a murine model: preliminary findings on the protective role of a gonadotropin-releasing hormone analogue from chemotherapy-induced ovarian damage.

The prolonged, gonadotoxic effect of chemotherapy can finally lead to infertility in female cancer survivors. There is controversial evidence regarding the protective role of gonadotropin-releasing hormone analogue (GnRH-a) on chemotherapy-induced ovarian damage. In the present study on a murine model, ultrasound (US) and contrast-enhanced US (CEUS) were firstly used to characterise ovarian glands in normal conditions to validate a preclinical model. In addition, preliminary findings were obtained on anatomical and vascular ovarian changes induced by GnRH-a based on decapeptyl administration. Ovaries were accurately assessed with US and CEUS in a murine model placed in prone position, providing quantitative and reproducible information. Ovaries were identified in 40/40 cases and CEUS analysis was successfully performed in 20/20 cases with 100% technical success. A statistically significant increase of the diameter of the dominant follicle at US and a statistically significant reduced vascularisation at CEUS in decapeptyl-treated mice compared to untreated control mice were recorded. Further studies using US and CEUS in the murine model combining GnRH-a and chemotherapeutic agents will be needed to obtain more translational information useful for clinical practice.

Assessment of Remote Myocardium Heterogeneity in Patients with Ventricular Tachycardia Using Texture Analysis of Late Iodine Enhancement (LIE) Cardiac Computed Tomography (cCT) Images.

PURPOSE: Diffuse remodeling of myocardial extra-cellular matrix is largely responsible for left ventricle (LV) dysfunction and arrhythmias. Our hypothesis is that the texture analysis of late iodine enhancement (LIE) cardiac computed tomography (cCT) images may improve characterization of the diffuse extra-cellular matrix changes. Our aim was to extract volumetric extracellular volume (ECV) and LIE texture features of non-scarred (remote) myocardium from cCT of patients with recurrent ventricular tachycardia (rVT), and to compare these radiomic features with LV-function, LV-remodeling, and underlying cardiac disease. PROCEDURES: Forty-eight patients suffering from rVT were prospectively enrolled: 5/48 with idiopathic VT (IVT), 23/48 with post-ischemic dilated cardiomyopathy (ICM), 9/48 with idiopathic dilated cardiomyopathy (IDCM), and 11/48 with scars from a previous healed myocarditis (MYO). All patients underwent echocardiography to assess LV systolic and diastolic function and cCT with pre-contrast, angiographic, and LIE scan to obtain end-diastolic volume (EDV), ECV, and first-order texture parameters of Hounsfield Unit (HU) of remote myocardium in LIE [energy, entropy, HU-mean, HU-median, standard deviation (SD), and mean absolute deviation (MAD)]. RESULTS: Energy, HU mean, and HU median by cCT texture analysis correlated with ECV (rho = 0.5650, rho = 0.5741, rho = 0.5068; p < 0.0005). cCT-derived ECV, HU-mean, HU-median, SD, and MAD correlated directly to EDV by cCT and inversely to ejection fraction by echocardiography (p < 0.05). SD and MAD correlated with diastolic function by echocardiography (rho = 0.3837, p = 0.0071; rho = 0.3330, p = 0.0208). MYO and IVT patients were characterized by significantly lower values of SD and MAD when compared with ICM and IDCM patients, independently of LV-volume systolic and diastolic function. CONCLUSIONS: Texture analysis of LIE may expand cCT capability of myocardial characterization. Myocardial heterogeneity (SD and MAD) was associated with LV dilatation, systolic and diastolic function, and is able to potentially identify the different patterns of structural remodeling characterizing patients with rVT of different etiology.

Cross-sectional assessment of the effect of kidney and kidney-pancreas transplantation on resting left ventricular energy metabolism in type 1 diabetic-uremic patients: a phosphorous-31 magnetic resonance spectroscopy study.

OBJECTIVES: To test whether left ventricular (LV) dysfunction affecting type 1 diabetic-uremic patients was associated with abnormal heart high-energy phosphates (HEPs) and to ascertain whether these alterations were also present in recipients of kidney or kidney-pancreas transplantation. BACKGROUND: Heart failure is the major determinant of mortality in patients with diabetic uremia. Both uremia and diabetes induce alterations of cardiac HEPs metabolism. METHODS: Magnetic resonance imaging and phosphorous magnetic resonance spectroscopy of the LV were performed in the resting state by means of a 1.5-T clinical scanner. Eleven diabetic-uremic patients, 5 nondiabetic patients with uremia, 11 diabetic recipients of kidney transplantation, and 16 diabetic recipients of combined kidney-pancreas transplantation were studied in a cross-sectional fashion. Eleven nondiabetic recipients of kidney-only transplant and 13 healthy subjects served as control groups. RESULTS: Uremic patients had higher LV mass, diastolic dysfunction, and lower phosphocreatine (PCr)/adenosine triphosphate (ATP) ratio in comparison with recipients of kidney-pancreas or nondiabetic recipients of kidney transplant. In diabetic recipients of kidney transplant the PCr/ATP ratio was higher than in uremic patients but was lower than in the controls. Recipients of combined kidney-pancreas transplant had a higher ratio than uremic patients but no difference was found in comparison with controls. CONCLUSIONS: Altered resting myocardial HEPs metabolism may contribute to LV dysfunction in diabetic-uremic patients. In diabetic recipients of kidney transplantation, a certain degree of LV metabolic and functional impairment was found. In combined kidney-pancreas recipients the resting LV metabolism and function were not different than in controls.