Artery Stenosis Research Articles

Unraveling the complex interplay between abnormal hemorheology and shape asymmetry in flow through stenotic arteries

Background and Objective:Stenosis or narrowing of arteries due to the buildup of plaque is a common occurrence in atherosclerosis and coronary artery disease (CAD), limiting blood flow to the heart and posing substantial cardiovascular risk. While the role of geometric irregularities in arterial stenosis is well-documented, the complex interplay between the abnormal hemorheology and asymmetric shape in flow characteristics remains unexplored. Methods:This study investigates the influence of varying hematocrit (Hct) levels, often caused by conditions such as diabetes and anemia, on flow patterns in an idealized eccentric stenotic artery using computational fluid dynamics simulations. We consider three physiological levels of Hct, 25%, 45%, and 65%, representing anemia, healthy, and diabetic conditions, respectively. The numerical simulations are performed for different combinations of shape eccentricity and blood rheological parameters, and hemodynamic indicators such as wall shear stress (WSS), oscillatory shear index (OSI), are relative residence time (RRT) are calculated to assess the arterial health. Results:Our results reveal the significant influence of Hct level on stenosis progression. CAD patients with anemia are exposed to lower WSS and higher OSI, which may increase the propensity for plaque progression and rupture. However, for CAD patients with high Hct level—as is often the case in diabetes—the WSS at the minimal lumen area increases rapidly, which may also lead to plaque rupture and cause adverse events such as heart attacks. These disturbances promote endothelial dysfunction, inflammation, and thrombus formation, thereby intensifying cardiovascular risk. Conclusions:Our findings underscore the significance of incorporating hemorheological parameters, such as Hct, into computational models for accurate assessment of flow dynamics. We envision that insights gained from this study will inform the development of tailored treatment strategies and interventions in CAD patients with common comorbidities such as diabetes and anemia, thus mitigating the adverse effects of abnormal hemorheology and reducing the ever-growing burden of cardiovascular diseases.

In-Stent Re-Endothelialization Strategies: Cells, Extracellular Matrix, and Extracellular Vesicles.

Arterial stenosis caused by atherosclerosis often requires stent implantation to increase the patency of target artery. However, such external devices often lead to in-stent restenosis due to inadequate re-endothelialization and subsequent inflammatory responses. Therefore, re-endothelialization strategies after stent implantation have been developed to enhance endothelial cell recruitment or to capture circulating endothelial progenitor cells. Notably, recent research indicates that coating stent surfaces with biogenic materials enhances the long-term safety of implantation, markedly diminishing the risk of in-stent restenosis. In this review, we begin by describing the pathophysiology of coronary artery disease and in-stent restenosis. Then, we review the characteristics and materials of existing stents used in clinical practice. Lastly, we explore biogenic materials aimed at accelerating re-endothelialization, including extracellular matrix, cells, and extracellular vesicles. This review helps overcome the limitations of current stents for cardiovascular disease and outlines the next phase of research and development.

Analyzing heat transfer and entropy generation in catheterized, stenosed arteries

A frequent cardiovascular condition that reduces blood flow is arterial stenosis. Tangent stress pressure, produced by a stenotic blood artery, diminishes the arterial side and results in an aneurysm. We explored the dynamics of entropy generation in blood stream via arteries observing mild overlapping stenosis, using a Prandtl fluid and focusing on the eccentric placement of catheters to enhance patient comfort. The governing equations assume conditions of mild stenosis and low Reynolds number, and applied the homotopy perturbation method. Several critical physical aspects are characterized, including velocity, temperature, impedance, entropy generation, wall shear stress, the Bejan number, and flow streamlines. The results show that a rise in the catheter radius tends to elevate impedance levels, whereas an increase in eccentricity, amplitude ratio, and inner cylinder speed leads to a decrease. These behaviors may serve to optimize catheter placement to minimize patient discomfort during medical interventions.

Unusual and very rare presentation of wrist pain in a man with acute anterior myocardial infarction, a case report and literature of review

BackgroundAs acute myocardial infarction (AMI) prevalence is increasing because of lifestyle changes, the incidence of atypical symptoms in acute coronary syndrome (ACS) is rising and making misdiagnosing of this fatal event more probable. To better approach the patients with atypical symptoms, we tend to present a rare case of AMI with wrist pain.Case reportA 41-year-old man presented to the emergency room (ER) with severe both-hand wrist pain and mild epigastric pain. His electrocardiogram (ECG) showed anterior ST-elevation myocardial infarction (MI) with an ejection fraction of 35–40%. His angiography showed severe left anterior descending artery (LAD), and first obtuse marginal artery (OM1) artery stenosis. He underwent Primary percutaneous coronary intervention (PCI). The patient recovered without serious complications and was discharged the day after PCI.DiscussionIn this rare case of AMI with wrist pain, it is important to know that atypical symptoms can be present at various levels of symptoms, which prevents future misdiagnosis.

Rheological analysis of magnetized trihybrid nanofluid drug carriers in unsteady blood flow through a single-stenotic artery

In this work, we use the Casson fluid model to analyze the blood flow through a cylindrical stenosis artery. Blood is utilized as a base fluid and aluminium oxide (Al2O3), copper (Cu), and titanium oxide (TiO2) of cylindrical shapes are used as nanoparticles (NPs), which bind to blood to form TiO2−Cu−Al2O3/Blood tri-hybrid nanofluid (THNF). Mathematical analysis has been conducted by considering the blood as a non-Newtonian fluid. The flow is subjected to an external magnetic field that is applied in the radial direction while considering the arterial vessels with a wall permeability effect. For the solution of nonlinear resultant equations, the homotopy analysis method (HAM) is utilized. The present model has been validated by comparing the results of our proposed model with existing work. Key factors like velocity, flow rate, temperature, and wall shear stress are calculated at a precise height of the stenosis. It is noted that the Casson fluid parameter improves the temperature profile. Additionally, it has been noted that tri-hybrid nanofluids have a higher thermal conductivity than hybrid nanofluids (HNFs). Implanting the tri-hybrid nanoparticles (Cu, Al2O3 and TiO2) in the blood leads to promote its axial velocity. When the outer magnetic field is functional in the direction radial to flow of the blood, the velocity profile experiences a substantial decrease, while temperature and concentration profiles are rather less changed. The applications of these simulations include the diffusion of nanodrugs and the magnetic targeted treatment of stenosed artery diseases.

The evolution and future directions of bypass surgery.

Cerebral bypass surgery is one of the most complex and elegant procedures in neurosurgery. It involves several meticulous steps that test the skills of even the most prepared neurosurgeons. This surgery has transcended its traditional role in arterial stenosis and atherosclerosis, expanding its applications to include flow preservation techniques for complex conditions such as aneurysms, tumors, and vascular malformations. The decreased number of procedures performed across many hospitals reflects the development of newer endovascular therapies but is also due to the results of the extracranial-intracranial bypass study, the Carotid Occlusion Surgery Study, and the Carotid and Middle Cerebral Artery Occlusion Surgery Study, which have raised questions about the efficacy of cerebral bypass surgery for individuals with carotid artery occlusion who are prone to ischemic stroke. Despite this, there is still a potential benefit of bypass surgery for patients with hemodynamic impairment refractory to medical management. Also, revascularization in moyamoya vasculopathy is an effective strategy for preventing ischemic and hemorrhagic events in both children and adults. Additionally, innovations in the technique, such as the flow-regulated bypass and intraoperative flow assessment, aim to minimize perioperative morbidity. Despite bypass surgery being less performed in this current era, the teaching and development of these skills are still encouraged for future neurosurgeons, as a role for bypass will exist for the foreseeable future.

Analysis of hemodynamic parameters on two-layered blood flow in a curved artery

Arterial stenosis is the thickening of the arterial wall due to the growth of aberrant tissues that prevent adequate blood flow in the human circulatory system and induces cardiovascular diseases. Mild stenosis, may lead to serious or permanent damage if remains uncured. There are differences in the curvature response and material composition between the outer layers and the core. There are several locations in blood vessels where they are curved, which affects the blood flow and shear stress. The Navier-Stokes equation in the cylindrical polar coordinate system has been extended by incorporating curvature term in two-layered blood flow along the axial direction with appropriate boundary conditions. Mathematical expressions for hemodynamic parameters such as velocity profile, volumetric flow rate, pressure drop, and shear stress have been calculated analytically in the case of a curve artery with stenosis. Moreover, we have analyzed the effect of stenosis on different hemodynamic parameters with the variation of core and peripheral-layer viscosity and curvature. Flow quantities are affected by the habitancy of stenosis and stipulate different blood flow behavior in both layers in the case of curved artery. This modeling technique may help researchers in medicine, mathematical biology, and bio-engineering.

Intracranial vasculopathy: an important organ damage in young adult patients with late-onset Pompe disease

BackgroundLate-onset Pompe disease (LOPD) is mainly characterized by progressive limb-girdle muscle weakness and respiratory impairment, whereas stroke and cerebrovascular abnormalities have been insufficiently studied in LOPD. This study aimed to evaluate the frequency and pattern of intracranial artery and brain parenchyma abnormalities in LOPD patients.ResultsNeuroimaging data from 30 Chinese adult LOPD patients were collected from our center. Seven patients (7/30) had acute cerebral infarction or hemorrhage. Brain magnetic resonance angiography (MRA) or computed tomography angiography (CTA) revealed artery abnormalities in 23 patients (23/30). Dilative arteriopathy was found in 19 patients (19/30), with vertebrobasilar dolichoectasia found in 17 patients and dilatation of the anterior circulation arteries found in 8 patients. The maximum diameter of the basilar artery was correlated with disease duration (p < 0.05). In addition, aneurysms (7/30) and fenestrations (3/30) were discovered. There were 14 patients with arterial stenosis (14/30), and both anterior and posterior circulation involvement occurred in 9 patients (9/14). Stenosis and dilative arteriopathy simultaneously occurred in 10 patients (10/30). White matter hyperintensities were present in 13 patients (13/28). Microbleeds, predominantly located in the cerebellum and brainstem, were detected in 7 patients (7/22) via susceptibility-weighted imaging.ConclusionsIntracranial vasculopathy involving both large arteries and small vessels is an important organ damage in LOPD patients. LOPD should be considered a key differential diagnosis in young adults with cryptogenic stroke, and a series of imaging evaluations of the brain and intracranial blood vessels is recommended as a routine workup in adult LOPD patients.

Quantitative Analysis of Hemodynamic Changes in Branch Arteries Covered by Flow Diverters.

Understanding post-treatment hemodynamic alterations and their association with the patency of covered branch arteries is limited. This study aims to identify hemodynamic changes after flow diverter stenting and investigate their correlation with the patency status of covered branch arteries. All patients treated with pipeline embolization device for anterior cerebral artery aneurysms at our center between 2016 and 2020 were screened for inclusion. Quantitative digital subtraction angiography was used to analyze changes in hemodynamic parameters pre- and post-stenting. The patency status of covered branch arteries after stenting was categorized as either patent or flow impairment (defined as artery stenosis or occlusion). A total of 71 patients, encompassing 89 covered branch arteries, were enrolled. Flow impairment was observed in 11.2% (10/89) of the branches. The mean transit time and full width at half maximum (FWHM) in covered branches were significantly prolonged post-stenting (P = .004 and .023, respectively). Flow-impaired branch arteries exhibited hemodynamic shifts contrary to those in patent branch arteries. Specifically, flow-impaired branches showed marked reductions in time to peak, FWHM, and mean transit time (decreases of 32.8%, 32.6%, and 29%, respectively; P = .006, .002, and .002, respectively). Further multivariate analysis revealed that reductions in FWHM in the branches (odds ratio = 0.97, 95% CI: 0.95-0.99, P = .007) and smoking (odds ratio = 14.5, 95% CI: 1.39-151.76, P = .026) were independent predictors of flow impairment of covered branches. Pipeline embolization device stenting can cause a reduction in blood flow in branch arteries. Compared with patent branches, flow-impaired branches exhibit an increase in blood flow velocity after stenting. Smoking and ΔFWHM in the covered branches indicate flow impairment.

Cubic autocatalysis implementation in blood for non-Newtonian tetra hybrid nanofluid model through bounded artery

Abstract Tetra hybrid nanofluids are significant due to their unique properties like thermal and electrical conductivity enhancement, increased heat transfer, and improved fluid flow characteristics. This attempt proposes a tetra hybrid cross nanofluid model with the implementation of cubic autocatalysis in the context of blood flow passing through a stenosis artery. The model includes the effects of nanofluid, magnetic field, thermal radiation, and the cubic autocatalysis mechanism. This research investigates the innovative application of cubic autocatalysis within the context of blood flow through a tetra hybrid cross nanofluid model, specifically designed to simulate conditions within a stenosis horizontal artery. The equations governing the fluid flow are solved using the bvp5c method, and the numerical solutions are obtained for various parameter values. Specifically, the cubic autocatalysis mechanism profoundly impacts the velocity and concentration profiles of the blood flow. The proposed model and the obtained results provide new insights into the physics of blood flow passing through stenosis arteries. They may have important implications for the diagnosis and treatment of cardiovascular diseases. This article has a unique combination of tetra hybrid cross nanofluid model, cubic autocatalysis, and blood flow passing through the stenosis artery. These facts are not typically studied together in the context of blood flow.

Multifaceted simulation: Finite volume and finite element modeling of blood flow in multiple stenosed arteries

Cardiovascular illnesses are a primary global health concern because they are frequently brought on by arterial stenosis. The complicated hemodynamics of blood flow via elliptically shaped arteries with numerous stenotic lesions along their top and bottom walls are examined in this paper. Carreau fluid model is used with Navier–Stokes equations in this study. The complete comparative study is done by using the Finite Element and Finite Volume Methods. This study uses commercial software to examine blood flow velocity, pressure and temperature distributions under various physiological situations at Reynolds number 30. Our results illuminate the interaction between flow dynamics, stenosis characteristics, and arterial geometry. The novelty of the work is to investigate how stenosis size, shape, and location affect pressure gradients, and flow disturbances. These observations provide helpful direction for understanding disease progression, designing treatments, and possibly new stent designs. The future direction of this research may involve further exploration of the interplay between hemodynamics and arterial stenosis by incorporating advanced computational models. Additionally, studies focusing on in vivo validation and clinical applications could enhance the translational impact of the findings. Collaborations between researchers, clinicians, and engineers may pave the way for personalized treatment strategies and innovations in cardiovascular care based on a deeper understanding of the intricate dynamics within diseased arteries.

Hemodynamic parameters and diabetes mellitus in community-dwelling middle-aged adults and elders: a community-based study

Hemodynamic parameters have been correlated with stroke, hypertension, and arterial stenosis. While only a few small studies have examined the link between hemodynamics and diabetes mellitus (DM). This case-control study enrolled 417 DM patients and 3475 non-DM controls from a community-based cohort. Peak systolic velocity (PSV), end-diastolic velocity (EDV), blood flow velocity (MFV), pulsatility index (PI), and the resistance index (RI) of the common carotid arteries were measured by color Doppler ultrasonography. Generalized linear regression analyses showed that as compared to the non-DM controls, the age-sex-adjusted means of PSV, EDV, and MFV were − 3.28 cm/sec, − 1.94 cm/sec, and − 2.38 cm/sec, respectively, lower and the age-sex-adjusted means of RI and PI were 0.013 and 0.0061, respectively, higher for the DM cases (all p-values < 0.0005). As compared to the lowest quartiles, the multivariable-adjusted ORs of DM for the highest quartiles of PSV, EDV, MFV, RI, and PI were 0.59 (95% confidence interval [CI] 0.41–0.83), 0.45 (95% CI 0.31–0.66), 0.53 (95% CI 0.37–0.77), 1.61 (95% CI 1.15–2.25), and 1.58 (95% CI 1.12–2.23), respectively. More importantly, the additions of EDV significantly improved the predictabilities of the regression models on DM. As compared to the model contained conventional CVD risk factors alone, the area under the receiver operating curve (AUROC) increased by 1.00% (95% CI 0.29–1.73%; p = 0.0059) and 0.80% (95% CI 0.15–1.46%; p = 0.017) for models that added EDV in continuous and quartile scales, respectively. Additionally, the additions of PSV and MFV also significantly improved the predictabilities of the regression models (all 0.01 < p-value < 0.05). This study reveals a significant correlation between DM and altered hemodynamic parameters. Understanding this relationship could help identify individuals at higher risk of DM and facilitate targeted preventive strategies to reduce cardiovascular complications in DM patients.

Literature Review on the Association between Cerebral Large Artery Disease and Cerebral Microbleeds

CMBs are small areas of hemorrhage in the brain, often seen on neuroimaging studies, that have been associated with various cerebrovascular pathologies. Large-artery atherosclerosis and resulting vascular stenosis are major contributors to ischemic stroke. Given the structural continuity between intracranial large and small vessels, their susceptibility to hemodynamic influences, and their shared risk factors, they may coexist in the same individual. This article reviews recent advances in understanding the interplay between large artery atherosclerosis (LAA) and cerebral microbleeds (CMB). Methods: A comprehensive search of electronic databases including PubMed, MEDLINE, and Google Scholar was conducted using relevant keywords such as "cerebral large artery disease," "cerebral microbleeds," "arterial stenosis," and "atherosclerosis." Articles published in English between [2010] and [2024] were considered for inclusion. Studies investigating the relationship between LAA and CMBs through neuroimaging, pathological examination, or clinical correlations were selected for review. Results: The review identified a range of studies exploring the association between LAA and CMBs. Several cross-sectional imaging studies have demonstrated a significant correlation between LAA severity and the presence, number, and distribution of CMBs. Histopathological investigations have revealed microvascular alterations in regions affected by LAA, potentially contributing to CMB formation. The evidence indicates a correlation between cerebrovascular microbleeds (CMBs) and large artery diseases, impacting the prognosis of individuals with cerebral infarction resulting from large artery atherosclerosis (LAA). Keywords: Cerebral infarction; Large-artery atherosclerosis; Cerebral microbleeds.

Volumetric microscopy of cerebral arteries with a miniaturized optical coherence tomography imaging probe.

Endovascular interventions are increasingly becoming the preferred approach for treating strokes and cerebral artery diseases. These procedures rely on sophisticated angiographical imaging guidance, which encounters challenges because of limited contrast and spatial resolution. Achieving a more precise visualization of the underlying arterial pathology and neurovascular implants is crucial for accurate procedural decision-making. In a human study involving 32 patients, we introduced the clinical application of a miniaturized endovascular neuro optical coherence tomography (nOCT) imaging probe. This technology was designed to navigate the tortuous paths of the cerebrovascular circulation and to offer high-resolution imaging in situ. The nOCT probe is compatible with standard neurovascular microcatheters, integrating with the procedural workflow used in clinical routine. Equipped with a miniaturized optical fiber and a distal lens, the probe illuminates the tissue and collects the backscattered, near-infrared light. While rotating the fiber and the lens at high speed, the probe is rapidly retracted, creating a spiral-shaped light pattern to comprehensively capture the arterial wall and implanted devices. Using nOCT, we demonstrated volumetric microscopy of cerebral arteries in patients undergoing endovascular procedures. We imaged the anterior and posterior circulation of the brain, including distal segments of the internal carotid and middle-cerebral arteries, as well as the vertebral, basilar, and posterior cerebral arteries. We captured a broad spectrum of neurovascular pathologies, such as brain aneurysms, ischemic stroke, arterial stenoses, dissections, and intracranial atherosclerotic disease. nOCT offered artifact-free, high-resolution visualizations of intracranial artery pathology and neurovascular devices.

CLINICAL CHARACTERISTICS OF PATIENTS WITH FIBROMUSCULAR DYSPLASIA WITH AND WITHOUT SPONTANEOUS CERVICAL ARTERY DISSECTION IN THE ARCADIA-POL STUDY

Objective: Fibromuscular dysplasia (FMD) is idiopathic, segmental, non-inflammatory, non-atherosclerotic disease affecting small and medium-sized arteries. FMD causes artery stenosis, although it may also lead to aneurysm, dissection, or arterial tortuosity. The aim of the study was to evaluate clinical characteristics of patients with spontaneous cervical artery dissection (SCeAD) and to assess prevalence of SCeAD among patients with FMD. Design and method: The ARCADIA-Pol is an ongoing study, initiated in 2015 at the Department of Hypertension, National Institute of Cardiology in Warsaw, Poland. Patients enrolled in the study met the inclusion criteria: presence or suspicion of FMD and/or radiologically documented episode of spontaneous dissection of any artery. Each patient underwent: clinical and 24h ambulatory blood pressure monitoring, biochemical tests, echocardiography, US Doppler of renal and carotid arteries and whole body angio-CT. We present data of 435 currently enrolled patients. Results: Among 435 patients included in the analysis SCeAD was confirmed in 77 subjects, most often in internal carotid arteries (68.8%). Mean age was 43,9 ± 9,6 years, majority of patients were women (64.9%). Hypertension (HT) was present in 59.7% patients, hypercholesterolemia in 44,2%. Among 77 subjects with SCeAD, the presence of typical FMD changes was confirmed in 35.1% cases. Patients with SCeAD and FMD were older and more often female as compared to those with SCeAD and without FMD. There were no differences in biochemical parameters or target organ damage parameters between SCeAD patients with and without FMD. Among 281 subjects with FMD, an episode of SCeAD was documented in 9.6% patients. Patients with FMD and SCeAD less often had HT. Women with FMD and SCeAD had more often a history of contraceptive pills use than those without SCeAD. No other differences were found between compared groups. Conclusions: FMD changes often coexist in patients with SCeAD (35.1%). In FMD patients complication of SCeAD occur relatively often (9.6%), which leads to conclusion that FMD is generalized arteriopathy. It is recommended to perform radiological screening in FMD patients to look for arterial complications in other vascular beds.

Fluid-solid coupling model and analysis on pulse wave propagation properties of iliac artery

In this work, we investigated the influence of the bifurcation geometry of the iliac artery on the propagation properties of the pulse wave, and applied software to establish the straight bifurcation and curved bifurcation bi-directional fluid-solid coupling finite element analysis models based on the iliac artery, and compared and analyzed the influence of the bifurcation angle of the blood vessel on the propagation characteristics of the pulse wave. It was found that the bifurcation geometry had a significant effect on the pulse wave propagation in the iliac arteries, and the pressure and velocity pulse wave amplitudes predicted by these two models had a good agreement with that before the vessel bifurcation in a cardiac cycle. The curvilinear bifurcation model predicted the pulse wave amplitude to be lower and the pressure drop to be smaller after the bifurcation, which was more in line with the actual situation of the human body. In addition, the bifurcation point is accompanied by the stress concentration phenomenon in the vessel wall, and there is a transient increase in the velocity pulse waveform amplitude, which was consistent with the fact that the bifurcation site is prone to phenomena such as arterial stenosis and hardening. The preliminary results of this paper will provide some reference for the use of pulse waveforms in the diagnosis of arterial diseases.

Turbo spin-echo-based enhanced acceleration-selective arterial spin labeling without electrocardiography or peripheral pulse unit triggering and contrast enhancement for lower extremity MRA

PurposeLower extremity magnetic resonance angiography (MRA) without electrocardiography (ECG) or peripheral pulse unit (PPU) triggering and contrast enhancement is beneficial for diagnosing peripheral arterial disease (PAD) while avoiding synchronization failure and nephrogenic systemic fibrosis. This study aimed to compare the diagnostic performance of turbo spin-echo-based enhanced acceleration-selective arterial spin labeling (eAccASL) (TSE-Acc) of the lower extremities with that of turbo field-echo-based eAccASL (TFE-Acc) and triggered angiography non-contrast enhanced (TRANCE). MethodsNine healthy volunteers and a patient with PAD were examined on a 3.0 Tesla magnetic resonance imaging (MRI) system. The artery-to-muscle signal intensity ratio (SIR) and contrast-to-noise ratio (CNR) were calculated. The arterial visibility (1: poor, 4: excellent) and artifact contamination (1: severe, 4: no) were independently assessed by two radiologists. Phase-contrast MRI and digital subtraction angiography were referenced in a patient with PAD. Friedman's test and a post-hoc test according to the Bonferroni-adjusted Wilcoxon signed-rank test were used for the SIR, CNR, and visual assessment. p < 0.05 was considered statistically significant. ResultsNo significant differences in nearly all the SIRs were observed among the three MRA methods. Higher CNRs were observed with TSE-Acc than those with TFE-Acc (anterior tibial artery, p = 0.014; peroneal artery, p = 0.029; and posterior tibial artery, p = 0.014) in distal arterial segments; however, no significant differences were observed upon comparison with TRANCE (all p > 0.05). The arterial visibility scores exhibited similar trends as the CNRs. The artifact contamination scores with TSE-Acc were significantly lower (but within an acceptable level) compared to those with TFE-Acc. In the patient with PAD, the sluggish peripheral arteries were better visualized using TSE-Acc than those using TFE-Acc, and the collateral and stenosis arteries were better visualized using TSE-Acc than those using TRANCE. ConclusionPeripheral arterial visualization was better with TSE-Acc than that with TFE-Acc in lower extremity MRA without ECG or PPU triggering and contrast enhancement, which was comparable with TRANCE as the reference standard. Furthermore, TSE-Acc may propose satisfactory diagnostic performance for diagnosing PAD in patients with arrhythmia and chronic kidney disease.

Comparison of Postexercise Ankle Brachial Index in at Risk versus Diagnosed Peripheral Arterial Disease Population

Abstract Background: Peripheral arterial disease (PAD) is characterized by stenosis or occlusion in the arteries of the limb causing limitation in the distal blood flow. Out of the various risk factors identified, diabetes and cigarette smoking are the strongest predictors of PAD. PAD results from atherosclerosis of the vessel wall. Patients with lower extremity PAD have clinical presentation of intermittent claudication and atypical leg pain. In patients with arterial stenosis, there is a drop in pressure and flow across stenosis. Asymptomatic PAD approximately 20%–50% of total patients diagnosed with PAD. Ankle brachial index (ABI) is clinically widely used modality which helps to identify the disease. ABI test is the ratio of systolic ankle blood pressure and highest systolic brachial blood pressure. Population at risk with normal resting ABI may still have PAD. For such population, postexercise ABI is recommended. This study evaluated and compared ABI postexercise in normal healthy individuals without risk of PAD, at risk of PAD. Materials and Methods: This study is an observational study. Population with age more than 35 years were selected. Framingham Risk Score was taken for normal and at-risk population. Subjects were recruited in three groups: A, B, and C. ABI at rest was assessed. Individuals performed exercise treadmill test. Immediately, after completing the exercise, postexercise ABI was taken. Absolute systolic blood pressure values and postexercise ABI values were obtained in all three groups and then were compared. Data were analyzed using the SPSS software version 26. Results: The results of this study showed that for all the three groups, there was a significant difference in ABI at rest, postexercise ABI, and difference in systolic ankle pressure as P value was &lt;0.001. When the Chi-squared test was done for postexercise ABI and postsystolic ankle pressure in between Group B and Group C, there was no significant difference found as the P value was &gt;0.05. Conclusion: On comparison with at risk and normal individuals, no significant difference was found in terms of postexercise ABI and change in systolic ankle pressure.

MHD flow of the novel quadruple hybrid nanofluid model in a stenosis artery with porous walls and thermal radiation: A Sisko model‐based analysis

AbstractThis study introduces a mathematical model that describes the Magnetohydrodynamics (MHD) flow of blood in a porous stenosis artery, incorporating a new hybrid nanofluid (HNF) model known as ‘Quadruple’ or the tetra‐(HNF) model. An innovative aspect of this study lies in the unexplored combination of tetra‐hybrid nanoparticles with the Sisko rheological model. The conventional Tiwari and Das (HNF) model has been expanded to accommodate the tetra‐(HNFs) case. To transform the governing partial differential equations into ordinary differential equations, a series of variable similarity transformations are employed. The resulting highly nonlinear simultaneous equations are efficiently solved using the shooting method. Numerical computations are conducted to investigate various parametric conditions, and graphs are utilized to visualize notable aspects of flow velocity and temperature. A comprehensive analysis is provided to illustrate the influence of flow parameters on wall shear stress and local Nusselt number, which are depicted through figures and tables. The study shows that the novel tetra‐HNF exhibits enhancements in blood flow when compared to nanofluids with a lower number of hybrids. Increasing the flow power index of non‐Newtonian Sisko model leads to improve convective heat transfer. Furthermore, parameters such as porosity, thermal radiation, and magnetic effects exhibit noticeable impacts on blood flow, temperature, and associated risks in constricted arteries.

Cerebrovascular disease in patients with antiphospholipid antibody syndrome: a transcranial Doppler and magnetic resonance imaging study.

Transcranial Doppler (TCD) and brain MRI may be useful in evaluating patients with APS, helping to stratify the risk of cerebrovascular ischaemic events in this population. This study aimed to assess the frequency of brain MRI abnormalities in patients with primary antiphospholipid syndrome, secondary antiphospholipid syndrome and SLE and correlate to TCD findings. The study, conducted over four years at two autoimmune disease referral centres, included 22 primary antiphospholipid syndrome patients, 24 secondary antiphospholipid syndrome patients, 27 SLE patients without APS and 21 healthy controls. All participants underwent TCD to assess cerebral haemodynamics, detect microembolic signals and evaluate right-to-left shunts, followed by brain MRI and magnetic resonance angiography. MRI scans were reviewed for acute microembolism, localized cortical infarctions, border infarctions, lacunar infarctions, ischaemic lesions, white matter hyperintensity, micro and macro haemorrhages and arterial stenosis ≥50% of the cervical carotid artery, by two neuroradiologists blinded to the clinical data. Brain MRI findings were similar between the groups, except for lacunar infarction, more frequent in patients with secondary antiphospholipid syndrome (P = 0.022). Patients with intracranial stenosis detected by TCD had a higher frequency of territorial infarction (40% vs 7.5%, P = 0.02), lacunar (40% vs 11.3%, P = 0.075) and border zone infarcts (20% vs 1.9%, P = 0.034). Patients with intracranial stenosis presented a higher frequency of territorial, lacunar and border zone infarcts, suggesting that evaluating the intracranial vasculature should not be neglected in patients with APS and stroke.