Predicting LVOT Obstruction in Transcatheter Mitral Valve Replacement for Failed Surgical Annuloplasty

Three-dimensional parametric modeling of bicuspid aortopathy and comparison with computational flow predictions

Bicuspid aortic valve (BAV)-associated ascending aneurysmal aortopathy (namely "bicuspid aortopathy") is a heterogeneous disease making surgeon predictions particularly challenging. Computational flow analysis can be used to evaluate the BAV-related hemodynamic disturbances, which likely lead to aneurysm enlargement and progression. However, the anatomic reconstruction process is time consuming so that predicting hemodynamic and structural evolution by computational modeling is unfeasible in routine clinical practice. The aim of the study was to design and develop a parametric program for three-dimensional (3D) representations of aneurysmal aorta and different BAV phenotypes starting from s…

Three-dimensional parametric modeling of bicuspid aortopathy and comparison with computational flow predictions

Bicuspid aortic valve (BAV)-associated ascending aneurysmal aortopathy (namely “bicuspid aortopathy”) is a heterogeneous disease making surgeon predictions particularly challenging. Computational flow analysis can be used to evaluate the BAV-related hemodynamic disturbances, which likely lead to aneurysm enlargement and progression. However, the anatomic reconstruction process is time consuming so that predicting hemodynamic and structural evolution by computational modeling is unfeasible in routine clinical practice. The aim of the study was to design and develop a parametric program for three-dimensional (3D) representations of aneurysmal aorta and different BAV phenotypes starting fr…

Imaging of calcified hepatic lesions: spectrum of diseases

Hepatic calcifications have been increasingly identified over the past decade due to the widespread use of high-resolution Computed Tomography (CT) imaging. Calcifications can be seen in a vast spectrum of common and uncommon diseases, from benign to malignant, including cystic lesions, solid neoplastic masses, and inflammatory focal lesions. The purpose of this paper is to present an updated review of CT imaging findings of a wide range of calcified hepatic focal lesions, which can help radiologists to narrow the differential diagnosis.

Patient-Specific Analysis of Ascending Thoracic Aortic Aneurysm with the Living Heart Human Model

In ascending thoracic aortic aneurysms (ATAAs), aneurysm kinematics are driven by ventricular traction occurring every heartbeat, increasing the stress level of dilated aortic wall. Aortic elongation due to heart motion and aortic length are emerging as potential indicators of adverse events in ATAAs

Biomechanical Determinants of Right Ventricular Failure in Pulmonary Hypertension.

Pulmonary hypertension (PH) is a disease characterized by progressive adverse remodeling of the distal pulmonary arteries, resulting in elevated pulmonary vascular resistance and load pressure on the right ventricle (RV), ultimately leading to RV failure. Invasive hemodynamic testing is the gold standard for diagnosing PH and guiding patient therapy. We hypothesized that lumped-parameter and biventricular finite-element (FE) modeling may lead to noninvasive predictions of both PH-related hemodynamic and biomechanical parameters that induce PH. We created patient-specific biventricular FE models that characterize the biomechanical response of the heart and coupled them with a lumped-paramete…

Optimizing Liver Division Technique for Procuring Left Lateral Segment Grafts: New Anatomical Insights.

Left liver lobe (left lateral segment) grafts (LLG) is currently the most commonly used graft to transplant children (2/3 of cases currently in Europe); it is prepared by liver division (DL) in both living (LD) and deceased donors (DD) settings. Technically speaking, classical DL is through the parenchyma of segment IV - dividing the main left glissonean pedicle left to the main biliary confluence (trans-hilar (TH) approach): historically, this technique was introduced by Bismuth and Pichlmayr in 1988 in DD setting, and applied one year later for the first successful living donor transplantations by Strong (Figure 1).

In Vivo Strain Analysis of Dilated Ascending Thoracic Aorta by ECG-Gated CT Angiographic Imaging

Accurate assessment of aortic extensibility is a requisite first step for elucidating the pathophysiology of an ascending thoracic aortic aneurysm (ATAA). This study aimed to develop a framework for the in vivo evaluation of the full-field distribution of the aortic wall strain by imaging analysis of electrocardiographic- (ECG) gated thoracic data of 34 patients with ATAA. Seven healthy controls (i.e., non-aneurysmal aorta) from patients who underwent ECG-gated CT angiography for coronary artery diseases were included for comparison. To evaluate the systolic function, ECG-gated computed tomography (CT) angiography was used to generate patient-specific geometric meshes of the ascending aorta…

Statistical shape analysis of ascending thoracic aortic aneurysm: Correlation between shape and biomechanical descriptors

An ascending thoracic aortic aneurysm (ATAA) is a heterogeneous disease showing different patterns of aortic dilatation and valve morphologies, each with distinct clinical course. This study aimed to explore the aortic morphology and the associations between shape and function in a population of ATAA, while further assessing novel risk models of aortic surgery not based on aortic size. Shape variability of n = 106 patients with ATAA and different valve morphologies (i.e., bicuspid versus tricuspid aortic valve) was estimated by statistical shape analysis (SSA) to compute a mean aortic shape and its deformation. Once the computational atlas was built, principal component analysis (PCA) allow…

On the severity of aortic stenosis in ascending aortic aneurysm: A computational tool to examine ventricular-arterial interaction and aortic wall stress

Abstract An ascending thoracic aortic aneurysm (ATAA) is a life-threatening cardiovascular consequence of vessel dilatation that portends adverse events and death. From a clinical perspective, ATAA should not be treated as an isolated disease, and surgery is often carried out in the presence of AS, aortic insufficiency or a calcified valve leaflet. Aortic stenosis (AS) is common in ATAAs and leads to both vessel rigidity and left ventricular (LV) impairment. In this study, lumped-parameter modeling and computational analysis were used to assess the change in the wall shear stress (WSS) and intramural wall stress of patient-specific ATAA models with different degrees of AS (i.e., mild to sev…

Valvular Heart Disease

Valvular heart disease (VHD) refers to a wide spectrum of cardiac disorders that affect a large number of patients. Echocardiography is still considered the pivotal imaging method to evaluate the cardiac valves. However, echocardiography has some intrinsic limitations due to operator dependence and patient habitus. In the last two decades three-dimensional techniques such as magnetic resonance imaging (MRI) and computed tomography (CT) have provided valuable assessment of VHD. MRI overcomes the limitation of the poor acoustic window of echocardiography without ionizing radiation. Nowadays, MRI aims to be considered as the reference standard for imaging cardiac valves because of the improved…

Simulation of left ventricular outflow tract (LVOT) obstruction in transcatheter mitral valve-in-ring replacement.

Left ventricular outflow tract (LVOT) obstruction is a feared complication of transcatheter mitral valve replacement (TMVR). This procedure leads to an elongation of LVOT in the left ventricle (namely, the neoLVOT), ultimately portending hemodynamic impairment and death. This study sought to understand the biomechanical implications of LVOT obstruction in two patients who underwent TMVR as an "off-label" application of the Edwards SAPIEN 3 (S3) Ultra transcatheter heart valve (THV). A computational framework of TMVR was developed to assess the neoLVOT area and quantify the sub-aortic flow structure. We observed that the annuloplasty ring serves as the key anchor zone of S3 Ultra THV. A good…

Transjugular intrahepatic portosystemic shunt (TIPS) complications: what diagnostic radiologists should know

Transjugular intrahepatic portosystemic shunt (TIPS) is an effective therapy for portal hypertension complications and can successfully treat variceal bleeding and refractory ascites. Although TIPS is relatively safe, procedural- or shunt-related morbidity can reach 20%, and procedural complications have a fatality rate of 2%. Delayed recognition and treatment of TIPS complications can lead to life-threatening clinical scenarios. Complications can vary from stent migration or malpositioning to nontarget organ injury, TIPS dysfunction, encephalopathy, or liver failure. This review aims to outline the role of diagnostic radiology in assessing post-TIPS complications.[GRAPHICS].

Atlas-Based Evaluation of Hemodynamic in Ascending Thoracic Aortic Aneurysms

Atlas-based analyses of patients with cardiovascular diseases have recently been explored to understand the mechanistic link between shape and pathophysiology. The construction of probabilistic atlases is based on statistical shape modeling (SSM) to assess key anatomic features for a given patient population. Such an approach is relevant to study the complex nature of the ascending thoracic aortic aneurysm (ATAA) as characterized by different patterns of aortic shapes and valve phenotypes. This study was carried out to develop an SSM of the dilated aorta with both bicuspid aortic valve (BAV) and tricuspid aortic valve (TAV), and then assess the computational hemodynamic of virtual models ob…

Assessment of atrial diastolic function in patients with hypertrophic cardiomyopathy by cine magnetic resonance imaging

Purpose: This study was conducted to assess the role of atrial function by cardiac magnetic resonance (CMR) for the evaluation of diastolic physiology in patients with hypertrophic cardiomyopathy (HCM) compared to healthy controls. Materials and methods: We enrolled 23 consecutive patients affected by HCM and 43 healthy subjects as age-matched control cases (CC). CMR was performed through acquisition of cine steady-state free precession sequences using a 1.5-T scanner. Image postprocessing was carried out using Tracking Tool software. Results: Atrial volumes were significantly higher in patients with HCM compared to CC: maximum atrial volume (p = 0.007) and minimum atrial volume (p = 0.01).…

Imaging of hepatocellular carcinoma recurrence after liver transplantation

Abstract Liver transplantation (LT) provides the highest survival benefit to patients with unresectable hepatocellular carcinoma (HCC). The Milan criteria have been developed for the selection of LT candidates with the goal of improving survival and maintaining an acceptable risk of HCC recurrence. Despite this, recurrence of HCC after LT occurs in up to 20% of cases and represents a major concern due to the poor prognosis of these patients. Furthermore, several extended criteria for the selection of LT candidates have been proposed to account for the growing demand for organs and the resultant increase in the risk of HCC recurrence. Radiologists should be aware that HCC can recur after LT…

Shear Stress and Aortic Strain Associations With Biomarkers of Ascending Thoracic Aortic Aneurysm

This study aims to investigate the association of wall shear stress (WSS) and aortic strain with circulating biomarkers including matrix metalloproteinases (MMP), tissue inhibitors of metalloproteinase (TIMP), and exosomal level of microRNA (miRNA) in ascending aortic aneurysms of patients with bicuspid or tricuspid aortic valve.A total of 76 variables from 125 patients with ascending aortic aneurysms were collected from (1) blood plasma to measure plasma levels of miRNAs and protein activity; (2) computational flow analysis to estimate peak systolic WSS and time-average WSS (TAWSS); and (3) imaging analysis of computed tomography angiography to determine aortic wall strain. Principal compo…

Early distal remodeling after elephant trunk repair of thoraco-abdominal aortic aneurysms

Hemodynamic alterations occur when the elephant trunk (ET) technique is adopted to treat extensive aortic aneurysms. In planning the 2nd stage operation to complete ET repair, surgeons must weigh an adequate recovery time after initial surgery against the risk of postoperative ET-related complications. The purpose of this study was to understand the mechanistic link between the flow alteration caused by the ET graft and the development of premature aortic rupture before the 2nd stage operation. Specifically, fluid-structure interaction (FSI) analysis was performed using the CT imaging data of aorta at different stages of ET repair, and then computational variables were compared to those obs…

Heart anatomy

On the role of material properties in ascending thoracic aortic aneurysms

One of the obstacles standing before the biomechanical analysis of an ascending thoracic aortic aneurysm (ATAA) is the difficulty in obtaining patient-specific material properties. This study aimed to evaluate differences on ATAA-related stress predictions resulting from the elastostatic analysis based on the optimization of arbitrary material properties versus the application of patient-specific material properties determined from ex-vivo biaxial testing. Specifically, the elastostatic analysis relies the on the fact that, if the aortic wall stress does not depend on material properties, the aorta has to be statistically determinate. Finite element analysis (FEA) was applied to a group of …

401Prognostic role of late gadolinium enhancement in patients with low-intermediate 5 year HCM SCD risk score: a multicenter study

Computational modeling of bicuspid aortopathy: Towards personalized risk strategies.

This paper describes current advances on the application of in-silico for the understanding of bicuspid aortopathy and future perspectives of this technology on routine clinical care. This includes the impact that artificial intelligence can provide to develop computer-based clinical decision support system and that wearable sensors can offer to remotely monitor high-risk bicuspid aortic valve (BAV) patients. First, we discussed the benefit of computational modeling by providing tangible examples of in-silico software products based on computational fluid-dynamic (CFD) and finite-element method (FEM) that are currently transforming the way we diagnose and treat cardiovascular diseases. Then…

Simulation study of transcatheter heart valve implantation in patients with stenotic bicuspid aortic valve

Bicuspid aortic valve (BAV) anatomy has routinely been considered an exclusion in the setting of transcatheter aortic valve implantation (TAVI) because of the large dimension of the aortic annulus having a more calcified, bulky, and irregular shape. The study aims to develop a patient-specific computational framework to virtually simulate TAVI in stenotic BAV patients using the Edwards SAPIEN 3 valve (S3) and its improved version SAPIEN 3 Ultra and quantify stent frame deformity as well as the severity of paravalvular leakage (PVL). Specifically, the aortic root anatomy of n.9 BAV patients who underwent TAVI was reconstructed from pre-operative CT imaging. Crimping and deployment of S3 fram…

Transcatheter Heart Valve Implantation in Bicuspid Patients with Self-Expanding Device

Bicuspid aortic valve (BAV) patients are conventionally not treated by transcathether aortic valve implantation (TAVI) because of anatomic constraint with unfavorable outcome. Patient-specific numerical simulation of TAVI in BAV may predict important clinical insights to assess the conformability of the transcathether heart valves (THV) implanted on the aortic root of members of this challenging patient population. We aimed to develop a computational approach and virtually simulate TAVI in a group of n.6 stenotic BAV patients using the self-expanding Evolut Pro THV. Specifically, the structural mechanics were evaluated by a finite-element model to estimate the deformed THV configuration in …

Coronary CT angiography: a guide to examination, interpretation, and clinical indications

Introduction: The introduction of Cardiac Computed Tomography (CCT) has changed the paradigm in the field of diagnostic cardiovascular medicine. CCT is the primary tool in the assessment of suspected Coronary Artery Disease (CAD) and should be followed by functional assessment when needed to stratify disease and to plan potential interventional or surgical therapy. Areas Covered: We provided the current state of the knowledge on the main aspects of technique of examination, image interpretation and clinical indications. We have focused our attention on the basic routine applications and activities. Expert Opinion: The primary role of CCT in suspected CAD will progressively become the standa…

Assessing the quality of studies in meta-research: Review/guidelines on the most important quality assessment tools

Systematic reviews and meta-analyses pool data from individual studies to generate a higher level of evidence to be evaluated by guidelines. These reviews ultimately guide clinicians and stakeholders in health-related decisions. However, the informativeness and quality of evidence synthesis inherently depend on the quality of what has been pooled into meta-research projects. Moreover, beyond the quality of included individual studies, only a methodologically correct process, in relation to systematic reviews and meta-analyses themselves, can produce a reliable and valid evidence synthesis. Hence, quality of meta-research projects also affects evidence synthesis reliability. In this overview…

CAD Modeling for Evaluating LVOT Obstruction in Transcatheter Mitral Valve Replacement

The current generation of transcatheter heart valves (THV), as the Edwards SAPIEN 3 Ultra (S3), is not specifically designed for mitral position implantation and has intrinsic design geometry that may make mitral implantation suboptimal. This study aimed to develop a computed-tomography (CT) based CAD workflow for the preoperative planning of transcatheter mitral valve replacement (TMVR) by evaluating the resulting obstruction in the left ventricular outflow tract (LVOT). Specifically, the computational framework to reconstruct heart anatomy and virtually deploy the THV into mitral valve annulus was developed and successively applied to the cases of two patients who experienced annuloplasty…

324Prognostic role of late gadolinium enhancement in patients with low or intermediate HCM SCD risk score: a multicenter study

Should subcutaneous implantable cardioverter-defibrillators be implanted in patients who are candidates for continuous flow left ventricular assist device?

Heart rate control with oral ivabradine in computed tomography coronary angiography: a randomized comparison of 7.5 mg vs 5 mg regimen.

Background: Heart rate (HR) reduction is essential to achieve optimal image quality and diagnostic accuracy with computed tomography coronary angiography (CTCA). Administration of oral ivabradine seems to be more effective than beta-blockade in reducing HR in patients referred for CTCA. Methods: Two-hundred-fifty-nine consecutive patients referred for CTCA were prospectively enrolled. Patients not receiving beta-blocker at baseline (group 1) and those with beta-blocker therapy (group 2) were enrolled in the study. Each group was randomized into 3 parallel arms with 1:1:1 allocation. Patients who did not receive beta-blocker at baseline: underwent CTCA without beta blocker (n=49), and receiv…

Prognostic Role of Late Gadolinium Enhancement in Patients With Hypertrophic Cardiomyopathy and Low-to-Intermediate Sudden Cardiac Death Risk Score

Sudden cardiac death (SCD) is the most life-threating complication of hypertrophic cardiomyopathy. Guidelines of the European Society of Cardiology (ESC) suggest the implantation of an implantable cardioverter defibrillator in primary prevention according to a 5-year risk SCD score >= 6%. The aim of the study is to evaluate the prognostic role of late gadolinium enhancement (LGE) in patients with a 5-year risk SCD score <6%. In this multicenter study, we performed cardiac magnetic resonance in 354 consecutive hypertrophic cardiomy-opathy patients (257 males, range of age 54 +/- 17) with a risk SCD score <6% (302 with <4% and 52 with >= 4 and <6% risk). Hard cardiac events,…

Deep learning approach for the segmentation of aneurysmal ascending aorta.

Diagnosis of ascending thoracic aortic aneurysm (ATAA) is based on the measurement of the maximum aortic diameter, but size is not a good predictor of the risk of adverse events. There is growing interest in the development of novel image-derived risk strategies to improve patient risk management towards a highly individualized level. In this study, the feasibility and efficacy of deep learning for the automatic segmentation of ATAAs was investigated using UNet, ENet, and ERFNet techniques. Specifically, CT angiography done on 72 patients with ATAAs and different valve morphology (i.e., tricuspid aortic valve, TAV, and bicuspid aortic valve, BAV) were semi-automatically segmented with Mimic…

In Silico Shear and Intramural Stresses are Linked to Aortic Valve Morphology in Dilated Ascending Aorta

Objective/Background: The development of ascending aortic dilatation in patients with bicuspid aortic valve (BAV) is highly variable, and this makes surgical decision strategies particularly challenging. The purpose of this study was to identify new predictors, other than the well established aortic size, that may help to stratify the risk of aortic dilatation in BAV patients.Methods: Using fluid-structure interaction analysis, both haemodynamic and structural parameters exerted on the ascending aortic wall of patients with either BAV ( n = 21) or tricuspid aortic valve (TAV; n = 13) with comparable age and aortic diameter (42.7 +/- 5.3 mm for BAV and 45.4 +/- 10.0 mm for TAV) were compared…