Hemodynamic Analysis Research Articles

Model-predicted brain temperature computational imaging by multimodal noninvasive functional neuromonitoring of cerebral oxygen metabolism and hemodynamics: MRI-derived and clinical validation.

Brain temperature, a crucial yet under-researched neurophysiological parameter, is governed by the equilibrium between cerebral oxygen metabolism and hemodynamics. Therapeutic hypothermia has been demonstrated as an effective intervention for acute brain injuries, enhancing survival rates and prognosis. The success of this treatment hinges on the precise regulation of brain temperature. However, the absence of comprehensive brain temperature monitoring methods during therapy, combined with a limited understanding of human brain heat transmission mechanisms, significantly hampers the advancement of hypothermia-based neuroprotective therapies. Leveraging the principles of bioheat transfer and MRI technology, this study conducted quantitative analyses of brain heat transfer during mild hypothermia therapy. Utilizing MRI, we reconstructed brain structures, estimated cerebral blood flow and oxygen consumption parameters, and developed a brain temperature calculation model founded on bioheat transfer theory. Employing computational cerebral hemodynamic simulation analysis, we established an intracranial arterial fluid dynamics model to predict brain temperature variations across different therapeutic hypothermia modalities. We introduce a noninvasive, spatially resolved, and optimized mathematical bio-heat model that synergizes model-predicted and MRI-derived data for brain temperature prediction and imaging. Our findings reveal that the brain temperature images generated by our model reflect distinct spatial variations across individual participants, aligning with experimentally observed temperatures.

Abstract Tu116: Neurofibromin 2 regulates metabolic gene expression and cardiac responses to pressure overload stress

Background: Neurofibromin 2 (NF2) is a tumor suppressor that can engage multiple signaling pathways to modulate cell proliferation and survival. We previously demonstrated that NF2 mediates cardiomyocyte apoptosis and cardiac injury caused by acute myocardial infarction. Research Aim: The role of NF2 in heart failure remains uncharacterized. This study sought to determine whether NF2 modulates heart failure due to chronic stress. Approach: We generated cardiomyocyte-specific NF2 knockout (cKO) mice, and used transverse aortic constriction (TAC) to generate chronic pressure overload (PO) stress, which elicits cardiac remodeling and failure. Complementary cell-based experiments were performed in neonatal rat ventricular myocytes (NRVMs). We analyzed cardiac function by echocardiographic and hemodynamic analysis. We used RNAseq, ChIP, Seahorse metabolic profiling, and biochemical analyses to investigate underlying mechanisms. Results: We found that NF2 is transiently upregulated in wild-type mouse myocardium in response to early phase of PO, but is downregulated during heart failure. Following TAC, NF2 cKO hearts unexpectedly showed significantly worsened cardiac function, compared to controls. RNAseq analysis indicated downregulation of several metabolic pathways and impaired ERR activity in NF2 cKO hearts. qPCR confirmed significantly reduced ERRβ and ERRγ transcripts and decreased metabolic gene expression. Experiments employing NRMVs confirmed that NF2 promoted expression of ERRβ and ERRγ, and DNA pulldown assays demonstrated NF2 association with ERRβ and ERRγ proximal promoters. Analysis of NRVM bioenergetics demonstrated that NF2 depletion impaired mitochondrial respiration, which was reversed by concomitant expression of ERRγ. Moreover, AAV9-mediated restoration of ERRγ in NF2 cKO mice normalized cardiac function in response to PO. Because NF2 does not directly bind DNA, ongoing studies are leveraging a proteomics-based approach to identify the mediator linking NF2 to ERR isoform expression. Conclusion: Based on these findings, we conclude that transient upregulation of myocardial NF2 expression during PO stress is compensatory and regulates metabolic gene expression according to energy demand.

Flexible adaptive sensing tonometry for medical-grade multi-parametric hemodynamic monitoring

Continuous hemodynamic monitoring in a wearable means can play a crucial role in managing hypertension and preventing catastrophic cardiovascular events. In this study, we have described the fully wearable tonometric device, referred to as flexible adaptive sensing tonometry (FAST), which is capable of continuous and accurate monitoring of hemodynamic parameters within the medical-grade precision. In particular, the FAST system integrates a 1 × 8 unit array of highly sensitive and highly flexible iontronic sensing (FITS) with 1 mm spatial resolution and a closed-loop motion system. The flexible tonometric architecture has been used to determine the radial arterial position with high sensitivity and high conformability, which simplifies the biaxial searching process of the traditional applanation tonometry into a highly efficient uniaxial applanation while keeping the medical-precision assessments. Importantly, a self-calibration algorithm can be automatically implemented during the applanation process, from which the intra-arterial blood pressure wave can be continuously predicted within the medical-grade precision, and subsequently, multi-parametric hemodynamic analysis can be performed in real-time. Experimental validations on health volunteers have demonstrated that the FAST measurements are all within the required accuracy of the clinical standards for continuous pulse wave assessments, blood pressure monitoring as well as other key hemodynamic parameter evaluations. Therefore, the FAST system, by integrating the flexible iontronic sensing array, provides a real-time, medical-grade hemodynamic monitoring solution in a continuously wearable manner, from which remote patient-centered monitoring can be delivered with both medical precision and convenience.

Numerical analysis of blood flow in the abdominal aorta under simulated weightlessness and earth conditions

Blood flow through the abdominal aorta and iliac arteries is a crucial area of research in hemodynamics and cardiovascular diseases. To get in to the problem, this study presents detailed analyses of blood flow through the abdominal aorta, together with left and right iliac arteries, under Earth gravity and weightless conditions, both at the rest stage, and during physical activity. The analysis were conducted using ANSYS Fluent software. The results indicate, that there is significantly less variation in blood flow velocity under weightless conditions, compared to measurement taken under Earth Gravity conditions. Study presents, that the maximum and minimum blood flow velocities decrease and increase, respectively, under weightless conditions. Our model for the left iliac artery revealed higher blood flow velocities during the peak of the systolic phase (systole) and lower velocities during the early diastolic phase (diastole). Furthermore, we analyzed the shear stress of the vessel wall and the mean shear stress over time. Additionally, the distribution of oscillatory shear rate, commonly used in hemodynamic analyses, was examined to assess the effects of blood flow on the blood vessels. Countermeasures to mitigate the negative effects of weightlessness on astronauts health are discussed, including exercises performed on the equipment aboard the space station. These exercises aim to maintain optimal blood flow, prevent the formation of atherosclerotic plaques, and reduce the risk of cardiovascular complications.

Analysis of hemodynamics and impedance using bioelectrical impedance analysis in hypovolemic shock-induced swine model

To treat hypovolemic shock, fluid infusion or blood transfusion is essential to address insufficient volume. Much controversy surrounds resuscitation in hypovolemic shock. We aimed to identify the ideal fluid combination for treating hypovolemic shock-induced swine model, analyzing bioelectrical impedance and hemodynamics. Fifteen female three-way crossbred pigs were divided into three different groups. The three resuscitation fluids were (1) balanced crystalloid, (2) balanced crystalloid + 5% dextrose water, and (3) balanced crystalloid + 20% albumin. The experiment was divided into three phases and conducted sequentially: (1) controlled hemorrhage (1 L bleeding, 60 min), (2) resuscitation phase 1 (1 L fluid infusion, 60 min), and (3) resuscitation phase 2 (1 L fluid infusion, 60 min). Bioelectrical impedance analysis was implemented with a segmental multifrequency bioelectrical impedance analyzer. A total of 61 impedance measurements were assessed for each pig at six different frequencies in five segments of the pig. Pulse rate (PR), mean arterial pressure (MAP), stroke volume (SV), and stroke volume variation (SVV) were measured using a minimally invasive hemodynamic monitoring device. The three-dimensional graph showed a curved pattern when infused with 1 L of balanced crystalloid + 1 L of 5% dextrose water and 1.6 L of balanced crystalloid + 400 ml of 20% albumin. The 1M impedance increased in all groups during the controlled hemorrhage, and continuously decreased from fluid infusion to the end of the experiment. Only balanced crystalloid + 20% albumin significantly restored MAP and SV to the same level as the start of the experiment after the end of fluid infusion. There were no significant differences in MAP and SV from the time of recovery to the initial value of 1M impedance to the end of fluid infusion in all groups. The change and the recovery of hemodynamic indices such as MAP and SV coincide with the change and the recovery of 1M impedance. Using balanced crystalloid mixed with 20% albumin in hypovolemic shock-induced swine model may be helpful in securing hemodynamic stability, compared with balanced crystalloid single administration.

Comparative analysis of mechanical wall shear stress and hemodynamics to study the influence of asymmetry in abdominal aortic aneurysm and descending thoracic aortic aneurysm

An aneurysm's rupture is commonly associated with its maximum diameter, yet biomechanical studies emphasize the significant influence of mechanical wall shear stress (WSS) in this process. This study focuses on two models of aortic aneurysms: abdominal aortic aneurysm and descending thoracic aortic aneurysm. Five cases, comprising two for model 1 and three for model 2, are examined to explore both axisymmetric and asymmetric shapes, as patient geometry may manifest as either fusiform (axisymmetric) or saccular (asymmetric), while maintaining a consistent aneurysm diameter and adjusting the bulge shape factor to induce asymmetry. Hemodynamic factors, including WSS and wall shear stress gradient, are computed to evaluate thrombus formation and rupture risk within the aneurysms. Our results indicate the presence of recirculation zones in both the medial and transverse planes, generating vortices within the aneurysm. These vortices are more prominent in asymmetric cases compared to axisymmetric cases, leading to increased blood residence time within the aneurysm and a higher likelihood of thrombus formation. Thrombus formation can further impede blood flow, heightening the risk of embolism or ischemic events. Rupture occurs when the WSS surpasses tissue strength; thus, if the tissue strength of all aneurysms is same, our findings suggest that rupture risk varies according to asymmetry. In the transverse direction, our results demonstrate that in model 1, case 1 exhibits uniform WSS on both sides, while in case 2, WSS is higher at the posterior sides of the aneurysm sac. Conversely, in model 2, WSS is higher at the anterior side of the aneurysm. In the medial direction of the aneurysm, WSS is highest for case 5, followed by case 3, case 4, case 2, and case 1, respectively, indicating elevated WSS when the anterior bulge dominates over the posterior bulge for each model. Overall, a higher rupture risk is observed in model 2 compared to model 1 due to increased mechanical stresses.

Investigation of a chronic single-stage sheep Fontan model

ObjectivesOur goal was to conduct a hemodynamic analysis of a novel animal model of Fontan physiology. Poor late-term outcomes in Fontan patients are believed to arise from Fontan-induced hemodynamics, but the mechanisms remain poorly understood. Recent advances in surgical experimentation have resulted in the development of a chronic sheep model of Fontan physiology; however, detailed analysis of this model is lacking. MethodsWe created a single-stage Fontan model in juvenile sheep with normal biventricular circulation. The superior vena cava was anastomosed to the main pulmonary artery, and the inferior vena cava was connected to the main pulmonary artery using an expanded polytetrafluoroethylene conduit. Longitudinal hemodynamics, including catheterization and magnetic resonance imaging were evaluated. ResultsFour out of 12 animals survived, with the longest surviving animal living 3 years after single-stage Fontan. We showed a significant era effect regarding survival (1 out of 8 and subsequently 3 out of 4 animals surviving beyond 2 months) attributed in large part to the procedural learning curve. Key characteristics of Fontan hemodynamics, namely systemic venous hypertension and low normal cardiac output, were observed. However, recapitulation of passive human Fontan hemodynamics is affected by volume loading of the right ventricle given an anatomic difference in sheep azygous venous anatomy draining to the coronary sinus. ConclusionsA significant learning curve exists to ensure long-term survival and future surgical modifications, including banding of the main pulmonary artery and ligation of the azygous to coronary sinus connection are promising strategies to improve the fidelity of model hemodynamics.

Systemic Deletion of ARRDC4 Improves Cardiac Reserve and Exercise Capacity in Diabetes.

Exercise intolerance is an independent predictor of poor prognosis in diabetes. The underlying mechanism of the association between hyperglycemia and exercise intolerance remains undefined. We recently demonstrated that the interaction between ARRDC4 (arrestin domain-containing protein 4) and GLUT1 (glucose transporter 1) regulates cardiac metabolism. To determine whether this mechanism broadly impacts diabetic complications, we investigated the role of ARRDC4 in the pathogenesis of diabetic cardiac/skeletal myopathy using cellular and animal models. High glucose promoted translocation of MondoA into the nucleus, which upregulated Arrdc4 transcriptional expression, increased lysosomal GLUT1 trafficking, and blocked glucose transport in cardiomyocytes, forming a feedback mechanism. This role of ARRDC4 was confirmed in human muscular cells from type 2 diabetic patients. Prolonged hyperglycemia upregulated myocardial Arrdc4 expression in multiple types of mouse models of diabetes. We analyzed hyperglycemia-induced cardiac and skeletal muscle abnormalities in insulin-deficient mice. Hyperglycemia increased advanced glycation end-products and elicited oxidative and endoplasmic reticulum stress leading to apoptosis in the heart and peripheral muscle. Deletion of Arrdc4 augmented tissue glucose transport and mitochondrial respiration, protecting the heart and muscle from tissue damage. Stress hemodynamic analysis and treadmill exhaustion test uncovered that Arrdc4-knockout mice had greater cardiac inotropic/chronotropic reserve with higher exercise endurance than wild-type animals under diabetes. While multiple organs were involved in the mechanism, cardiac-specific overexpression using an adenoassociated virus suggests that high levels of myocardial ARRDC4 have the potential to contribute to exercise intolerance by interfering with cardiac metabolism through its interaction with GLUT1 in diabetes. Importantly, the ARRDC4 mutation mouse line exhibited greater exercise tolerance, showing the potential therapeutic impact on diabetic cardiomyopathy by disrupting the interaction between ARRDC4 and GLUT1. ARRDC4 regulates hyperglycemia-induced toxicities toward cardiac and skeletal muscle, revealing a new molecular framework that connects hyperglycemia to cardiac/skeletal myopathy to exercise intolerance.

Hemodynamic analysis of thoracic endovascular aortic repair with left subclavian artery reconstructed by chimney stent.

The purpose of this study was to investigate the hemodynamic consequences of thoracic endovascular aortic repair which reconstructed left subclavian artery by chimney stent (ch-TEVAR). Two patients who underwent thoracic endovascular aortic repair (TEVAR) and left subclavian artery (LSA) reconstruction using chimney stents were selected. Preoperative and postoperative CTA images were collected to reconstruct hemodynamic models for comparing and analyzing blood pressure, blood flow velocity, and wall shear stress in the aortic arch and its major branches. Concurrently, morphological alterations and position of chimney stent were also assessed. After the reconstruction of LSA in ch-TEVAR, no endoleak was seen, but the stent in LSA was compressed. The blood flow velocity of the LSA increased and disordered, the pressure was reduced, and the WSS was increased. Even more, there were a large amount of turbulence found in the LSA of one case, and its LSA was blocked. Chimney stent reduces the occurrence of endoleak due to its excellent deformation ability, but the compressed stent has a greater impact on the hemodynamics of LSA and eventually leads to LSA occlusion; in order to keep the LSA unobstructed, it is necessary to pay attention to the position of the chimney stent and keep it straight and do not fold or twist. Chimney stent has little influence on the aortic arch and the rest of the aortic arch branches.

Transfer learning on physics-informed neural networks for tracking the hemodynamics in the evolving false lumen of dissected aorta

Aortic dissection is a life-threatening event that is responsible for significant morbidity and mortality in individuals ranging in age from children to older adults. A better understanding of the complex hemodynamic environment inside the aorta enables clinicians to assess patient-specific risk of complications and administer timely interventions. In this study, we propose to develop and validate a new computational framework, warm-start physics-informed neural networks (WS-PINNs), to address the limitations of the current approaches in analyzing the hemodynamics inside the false lumen (FL) of type B aortic dissection vessels reconstructed from apolipoprotein null mice infused with AngII, thereby significantly reducing the amount of required measurement data and eliminating the dependency of predictions on the accuracy and availability of the inflow/outflow boundary conditions. Specifically, we demonstrate that the WS-PINN models allow us to focus on assessing the 3D flow field inside FL without modeling the true lumen and various branched vessels. Furthermore, we investigate the impact of the spatial and temporal resolutions of MRI data on the prediction accuracy of the PINN model, which can guide the data acquisition to reduce time and financial costs. Finally, we consider the use of transfer learning to provide faster results when looking at similar but new geometries. Our results indicate that the proposed framework can enhance the capacity of hemodynamic analysis in vessels with aortic dissections, with the promise of eventually leading to improved prognostic ability and understanding of the development of aneurysms.

Myocardial SERCA2 Protects Against Cardiac Damage and Dysfunction Caused by Inhaled Bromine.

Myocardial sarcoendoplasmic reticulum calcium ATPase 2 (SERCA2) activity is critical for heart function. We have demonstrated that inhaled halogen (chlorine or bromine) gases inactivate SERCA2, impair calcium homeostasis, increase proteolysis, and damage the myocardium ultimately leading to cardiac dysfunction. To further elucidate the mechanistic role of SERCA2 in halogen-induced myocardial damage, we used bromine-exposed cardiac-specific SERCA2 knockout (KO) mice [tamoxifen-administered SERCA2 (flox/flox) Tg (αMHC-MerCreMer) mice] and compared them to the oil-administered controls. We performed echocardiography and hemodynamic analysis to investigate cardiac function 24 hours after bromine (600 ppm for 30 minutes) exposure and measured cardiac injury markers in plasma and proteolytic activity in cardiac tissue and performed electron microscopy of the left ventricle (LV). Cardiac-specific SERCA2 knockout mice demonstrated enhanced toxicity to bromine. Bromine exposure increased ultrastructural damage, perturbed LV shape geometry, and demonstrated acutely increased phosphorylation of phospholamban in the KO mice. Bromine-exposed KO mice revealed significantly enhanced mean arterial pressure and sphericity index and decreased LV end diastolic diameter and LV end systolic pressure when compared with the bromine-exposed control FF mice. Strain analysis showed loss of synchronicity, evidenced by an irregular endocardial shape in systole and irregular vector orientation of contractile motion across different segments of the LV in KO mice, both at baseline and after bromine exposure. These studies underscore the critical role of myocardial SERCA2 in preserving cardiac ultrastructure and function during toxic halogen gas exposures. SIGNIFICANCE STATEMENT: Due to their increased industrial production and transportation, halogens such as chlorine and bromine pose an enhanced risk of exposure to the public. Our studies have demonstrated that inhalation of these halogens leads to the inactivation of cardiopulmonary SERCA2 and results in calcium overload. Using cardiac-specific SERCA2 KO mice, these studies further validated the role of SERCA2 in bromine-induced myocardial injury. These studies highlight the increased susceptibility of individuals with pathological loss of cardiac SERCA2 to the effects of bromine.

Artificial neural networks analysis predicts long-term fistula function in hemodialysis patients following percutaneous transluminal angioplasty

Kidney failure is particularly common in the United States, where it affects over 700,000 individuals. It is typically treated through repeated sessions of hemodialysis to filter and clean the blood. Hemodialysis requires vascular access, in about 70% of cases through an arteriovenous fistula (AVF) surgically created by connecting an artery and vein. AVF take 6 weeks or more to mature. Mature fistulae often require intervention, most often percutaneous transluminal angioplasty (PTA), also known as fistulaplasty, to maintain the patency of the fistula. PTA is also the first-line intervention to restore blood flow and prolong the use of an AVF, and many patients undergo the procedure multiple times. Although PTA is important for AVF maturation and maintenance, research into predictive models of AVF function following PTA has been limited. Therefore, in this paper we hypothesize that based on patient-specific information collected during PTA, a predictive model can be created to help improve treatment planning. We test a set of rich, multimodal data from 28 patients that includes medical history, AVF blood flow, and interventional angiographic imaging (specifically excluding any post-PTA measurements) and build deep hybrid neural networks. A hybrid model combining a 3D convolutional neural network with a multi-layer perceptron to classify AVF was established. We found using this model that we were able to identify the association between different factors and evaluate whether the PTA procedure can maintain primary patency for more than 3 months. The testing accuracy achieved was 0.75 with a weighted F1-score of 0.75, and AUROC of 0.75. These results indicate that evaluating multimodal clinical data using artificial neural networks can predict the outcome of PTA. These initial findings suggest that the hybrid model combining clinical data, imaging and hemodynamic analysis can be useful to treatment planning for hemodialysis. Further study based on a large cohort is needed to refine the accuracy and model efficiency.

Bioconvective peristaltic transport of hydromagnetic Sutterby nanofluid through a chemically activated porous channel with gyrotactic microorganisms

The main target of this article is to analyze the role of activation energy and thermal radiation effects on the bioconvective peristaltic transport of Sutterby nanofluid in a two-dimensional flexible porous channel with heat and mass transfer. Also, the consequences of Hall current, heat source, and complaint wall properties along with an inclined magnetic field are taken into consideration. The proposed system of governing equations is simplified by using lubrication approximation and solved numerically using MATLAB's bvp5c solver. Further, numerical observations are analyzed to figure out the consequence of different physical parameters on the flow characteristics. According to the observations, it is identified that the Sutterby nanofluid velocity declines with the climb in the damping force parameter, while it enhances with the upsurge in the Darcy number. The Sutterby fluid temperature profile strengthens when the influence of the heat generation and Brinkman number increase, while it depicts the reverse effect with the elevation in the fluid parameter and radiation parameter. The temperature ratio and activation energy parameters were found to have a significant impact on the fluid concentration. The volume of the trapped fluid bolus is an enhancing function of the channel's non-uniformity parameter. Moreover, current work reveals its applicability to recognize the hemodynamic flow analysis and other biofluid movements in the human body and industrial sectors.

A model with multiple intracranial aneurysms: possible hemodynamic mechanisms of aneurysmal initiation, rupture and recurrence

BackgroundHemodynamic factors play an important role in aneurysm initiation, growth, rupture, and recurrence, while the mechanism of the hemodynamic characteristics is still controversial. A unique model of multiple aneurysms (initiation, growth, rupture, and recurrence) is helpful to avoids the confounders and further explore the possible hemodynamic mechanisms of aneurysm in different states.MethodsWe present a model with multiple aneurysms, and including the states of initiation, growth, rupture, and recurrence, discuss the proposed mechanisms, and describe computational fluid dynamic model that was used to evaluate the likely hemodynamic effect of different states of the aneurysms.ResultsThe hemodynamic analysis suggests that high flow impingement and high WSS distribution at normal parent artery was found before aneurysmal initiation. The WSS distribution and flow velocity were decreased in the new sac after aneurysmal growth. Low WSS was the risk hemodynamic factor for aneurysmal rupture. High flow concentration region on the neck plane after coil embolization still marked in recanalized aneurysm.ConclusionsAssociations have been identified between high flow impingement and aneurysm recanalization, while low WSS is linked to the rupture of aneurysms. High flow concentration and high WSS distribution at normal artery associated with aneurysm initiation and growth, while after growth, the high-risk hemodynamics of aneurysm rupture was occurred, which is low WSS at aneurysm dome.

Artificial Intelligence–Enabled Quantitative Coronary Plaque and Hemodynamic Analysis for Predicting Acute Coronary Syndrome

BackgroundA lesion-level risk prediction for acute coronary syndrome (ACS) needs better characterization. ObjectivesThis study sought to investigate the additive value of artificial intelligence–enabled quantitative coronary plaque and hemodynamic analysis (AI-QCPHA). MethodsAmong ACS patients who underwent coronary computed tomography angiography (CTA) from 1 month to 3 years before the ACS event, culprit and nonculprit lesions on coronary CTA were adjudicated based on invasive coronary angiography. The primary endpoint was the predictability of the risk models for ACS culprit lesions. The reference model included the Coronary Artery Disease Reporting and Data System, a standardized classification for stenosis severity, and high-risk plaque, defined as lesions with ≥2 adverse plaque characteristics. The new prediction model was the reference model plus AI-QCPHA features, selected by hierarchical clustering and information gain in the derivation cohort. The model performance was assessed in the validation cohort. ResultsAmong 351 patients (age: 65.9 ± 11.7 years) with 2,088 nonculprit and 363 culprit lesions, the median interval from coronary CTA to ACS event was 375 days (Q1-Q3: 95-645 days), and 223 patients (63.5%) presented with myocardial infarction. In the derivation cohort (n = 243), the best AI-QCPHA features were fractional flow reserve across the lesion, plaque burden, total plaque volume, low-attenuation plaque volume, and averaged percent total myocardial blood flow. The addition of AI-QCPHA features showed higher predictability than the reference model in the validation cohort (n = 108) (AUC: 0.84 vs 0.78; P < 0.001). The additive value of AI-QCPHA features was consistent across different timepoints from coronary CTA. ConclusionsAI-enabled plaque and hemodynamic quantification enhanced the predictability for ACS culprit lesions over the conventional coronary CTA analysis. (Exploring the Mechanism of Plaque Rupture in Acute Coronary Syndrome Using Coronary Computed Tomography Angiography and Computational Fluid Dynamics II [EMERALD-II]; NCT03591328)

RELATIONSHIP OF PARAMETERS OF CENTRAL HEMODYNAMICS AND ARTERIAL STIFFNESS WITH COGNITIVE FUNCTIONS IN PATIENTS WITH ESSENTIAL HYPERTENSION

Objective: To conduct a correlation analysis of central hemodynamics and arterial stiffness parameters with cognitive functions in patients with essential hypertension (EH). Design and method: The study included 111 male and female patients with grades I–III AH according to the classification (ESC/ESH, 2018). The average age of the patients was 54.6±10.8 years, the average duration of AH was 8.8±5.52 years. The state of arterial stiffness was assessed by applanation tonometry using the SphygmoCor apparatus (AtCor Medical, Australia). Cognitive functions were assessed using neuro-psychological tests: the Mini-Cog test (drawing a clock, reproducing words) and the Montreal Cognitive Assessment Scale (MOCA). Results: The correlation analysis between the parameters of central hemodynamics and arterial stiffness revealed a negative correlation between the pulse wave velocity (PWV) and the severity of cognitive impairment, in particular, with the overall Mini-Cog score (R=-0.24, p=0.01), as well as central pulse pressure (CPP) with a total score on the Mini-Cog test (R=-0.27, p=0.007). Conclusions: Thus, an increase in pulse wave velocity and central pulse pressure correlates with the severity of cognitive impairment in EH patients.

Abstract 3021: An Examination Of Emerging Techniques Forquantification Of Systemic-to-pulmonary Collateral Vessel Burden Using Imaging Modalities

Introduction: The quantification of systemic-to-pulmonary collateral vessels (SPCs) and their effects on hemodynamics is a subjective standard that has been intriguing for physicians due to the implications they could have; in cases where there is significant collateral burden, occlusion of these SPCs may be desirable, though this can present with a risk of stroke due to errant embolization particles. No benchmark method of SPC flow assessment has been established. Quantitative analysis of systemic and pulmonary flow values is possible through the use of computational fluid dynamics (CFD). CFD models can provide advanced and accurate analysis of cardiovascular hemodynamics providing more information beyond routine imaging. Hypothesis: Current methods for quantifying SPC burden are inadequate and could be improved through the use of additional CFD analysis. Methods: A PubMed and Science Direct search was performed. Select inclusion and exclusion criteria were applied to search results. Results: The search resulted in a total of 155 unique articles. Of these, 94 articles were found to meet inclusion criteria, and 54 articles were settled on after reviewing articles for further exclusion criteria. Seven articles discussed the use of CT and catheterization for quantifying collateral burden while 43 described using MRI to provide flow values. Eight articles mentioned the use of CFD to quantify hemodynamics in patients with SPCs, and 25 articles provided specific formulas for collateral flow. Conclusions: Using cardiac magnetic resonance velocity mapping is currently regarded as the best method for quantifying SPC burden. The incorporation of CFD analysis with flow data acquired with CMR may be useful in simulating the effects of SPC burden prior to any intervention as well as in predicting the effects of SPC occlusion on patient hemodynamics.

INFLUENCE OF CORONAVIRUS INFECTION ON VASCULAR REMODELING PARAMETERS IN PATIENTS WITH ARTERIAL HYPERTENSION

Objective: to evaluate the effect of COVID19 on arterial stiffness parameters and microalbuminuria (MAU) baseline and in dynamics against the background of antihypertensive therapy (AHT) in patients with arterial hypertension (AH). Design and method: 74 male and female patients with I-III degree of AH (ESH/ESC, 2018) were included in the study. Age was 53.54±1.92, duration of AH was 8.61.2 groups were identified: 1stgroup with AH who had suffered COVID19, no more than a month (N=42) and 2ndgroup with AH not suffered COVID19 (N=32).Vascular stiffness was determined by applanation tonometry using SphygmoCor apparatus (AtCor Medical, Australia); central systolic BP (CSBP), central diastolic BP (CDBP), central pulse pressure (CPP), aortic augmentation (AA), augmentation index (AIx), pulse wave velocity (PWV) were studied. The level of MAU was determined by enzymatic analysis on the biochemical analyser Daytona TM by Rendox (UK), which allows estimating MAU within the range of 30-300 mg/l and higher. The study was conducted before and after 6 months of AHT.p&lt;0.05. The results are presented as μ±SD Results: The level ofMAU in 2ndgroup being 25,5±20,3 mg/l, in 1stgroup being 32,8±27,9 mg/l, but the difference was not significant (p&gt;0,05). There was a significant decrease of MAU level in group I of patients: from 32,8±27,9 mg/l to 20,1±19,2,4 mg/l in dynamics (p&lt;0,02). In 1st group, cSBP decreased from 154.86±24.11 to 134.38±13.9 mmHg (p&lt;0.001) and in 2nd from 163.84±19.87 to 139.47±19.41 mmHg (p&lt;0.001); cPP in 1stgroup decreased from 74.79±22.02 to 53.67±13.32 mmHg (p&lt;0.001) and in 2ndgroup- from 78.84±14.48 to 54.71±12.46 mmHg (p&lt;0.001). (p&lt;0.001) and in 2ndgroup from 78.84±14.48 to 54.71±12.46 mmHg (p&lt;0.001); PWV in 1stgroup decreased from 10.6±2.3 to 9.32±2.21 m/s (p&lt;0.05) and in 2nd from 11.21±3.02 to 9.89±2.12 m/s (p&lt;0.001). AA was significantly reduced only in 2nd: 19.24±7.67 mmHg before and 14.31±7.57 mmHg after(p&lt;0.02) compared to 1stgroup: 15.67±6.97 before and 14.5±6.08 mmHg after treatment (p&gt;0.05). Conclusions: The analysis of central haemodynamics and arterial stiffness parameters revealed positive dynamics of 6-month AHT in both studied groups of patients with advantage in the 2ndgroup. AA index significantly decreased only in the 2ndgroup. The level of MAU initially exceeded normal values in the 1stgroup

Cardiovascular computed tomography in cardiovascular disease: An overview of its applications from diagnosis to prediction.

Cardiovascular computed tomography angiography (CTA) is a widely used imaging modality in the diagnosis of cardiovascular disease. Advancements in CT imaging technology have further advanced its applications from high diagnostic value to minimising radiation exposure to patients. In addition to the standard application of assessing vascular lumen changes, CTA-derived applications including 3D printed personalised models, 3D visualisations such as virtual endoscopy, virtual reality, augmented reality and mixed reality, as well as CT-derived hemodynamic flow analysis and fractional flow reserve (FFRCT) greatly enhance the diagnostic performance of CTA in cardiovascular disease. The widespread application of artificial intelligence in medicine also significantly contributes to the clinical value of CTA in cardiovascular disease. Clinical value of CTA has extended from the initial diagnosis to identification of vulnerable lesions, and prediction of disease extent, hence improving patient care and management. In this review article, as an active researcher in cardiovascular imaging for more than 20 years, I will provide an overview of cardiovascular CTA in cardiovascular disease. It is expected that this review will provide readers with an update of CTA applications, from the initial lumen assessment to recent developments utilising latest novel imaging and visualisation technologies. It will serve as a useful resource for researchers and clinicians to judiciously use the cardiovascular CT in clinical practice.

Comparison of Flow Reduction Efficacy of Nominal and Oversized Flow Diverters Using a Novel Measurement-assisted in Silico Method

PurposeThe high efficacy of flow diverters (FD) in the case of wide-neck aneurysms is well demonstrated, yet new challenges have arisen because of reported posttreatment failures and the growing number of new generation of devices. Our aim is to present a measurement-supported in silico workflow that automates the virtual deployment and subsequent hemodynamic analysis of FDs. In this work, the objective is to analyze the effects of FD deployment variability of two manufacturers on posttreatment flow reduction.MethodsThe virtual deployment procedure is based on detailed mechanical calibration of the flow diverters, while the flow representation is based on hydrodynamic resistance (HR) measurements. Computational fluid dynamic simulations resulted in 5 untreated and 80 virtually treated scenarios, including 2 FD designs in nominal and oversized deployment states. The simulated aneurysmal velocity reduction (AMVR) is correlated with the HR values and deployment scenarios.ResultsThe linear HR coefficient and AMVR revealed a power-law relationship considering all 80 deployments. In nominal deployment scenarios, a significantly larger average AMVR was obtained (60.3%) for the 64-wire FDs than for 48-wire FDs (51.9%). In oversized deployments, the average AMVR was almost the same for 64-wire and 48-wire device types, 27.5% and 25.7%, respectively.ConclusionThe applicability of our numerical workflow was demonstrated, also in large-scale hemodynamic investigations. The study revealed a robust power-law relationship between a HR coefficient and AMVR. Furthermore, the 64 wire configurations in nominal sizing produced a significantly higher posttreatment flow reduction, replicating the results of other in vitro studies.