Stenotic Severity Research Articles

Stenosis severity and heart rate effects on left coronary artery hemodynamics and myocardial oxygen balance: A comprehensive assessment using pressure gradient

The estimation of pressure drop across stenotic arteries can provide valuable information about the hemodynamic features. Nevertheless, the temporal behavior of pressure in stenotic arteries is not well reported for realistic pulsatile flows. This research investigates the pressure drop across a left coronary artery model for different degrees of stenotic severity and heart rates. The zones prone to further atherogenic degeneration are identified using time-averaged wall shear stress (TAWSS) and oscillatory shear index (OSI). A unique attempt has been made to quantify the effect of stenosis severity and elevated heart rate on coronary perfusion pressure (CPP) and endocardial viability ratio (EVR), which is an indicator of myocardial oxygen supply-demand balance. We have predicted reductions in both CPP and EVR as stenosis severity increases. The aforementioned metrics exhibit a notable drop when confronted with a moderate stenosis at an increased heart rate, implying that the hemodynamic consequences of a moderate stenosis during an elevated heart rate may be comparable to those of a severe stenosis during a state of rest. The current computational investigation has the potential to reduce the need for in vivo hemodynamic assessments of stenosis. In addition, the wall shear stress-based mechanical parameters, such as TAWSS and OSI, can indicate the atherogenic and thrombogenic regions in the stenosed vessels.

Influence of Abdominal Obesity on the Relationship of Low-Density Lipoprotein Cholesterol with Atherosclerosis and Cardiovascular Risk in Rheumatoid Arthritis

Methods. Coronary artery calcium, number of coronary plaques, and extensive ( 5 plaques) or obstructive (>50% stenosis) disease was evaluated with computed tomography angiography in 150 patients at baseline and 101 patients 6.9±0.4 years later. Cardiovascular events were recorded. Oxidized LDL was measured with monoclonal antibody E06. Serum cholesterol loading capacity on macrophages was measured as intracellular cholesterol content with a fluorometric assay. Results. Abdominal obesity was not associated with per-patient number of coronary plaques or coronary artery calcium score at baseline. Low LDLc positively associated with number of plaques (b 2.13 [95% confidence interval 1.03 to 3.22]), likelihood of extensive or obstructive plaque (odds ratio 6.58, 95% confidence interval [1.63 to 26.46]), and log-transformed CAC (b 1.90 [0.89 to 2.91]) exclusively in nonobese patients (p-for-interaction <0.001, 0.061, and 0.001 respectively). Low LDLc associated with increased likelihood of >median oxidized LDL and higher ratio of cholesterol loading capacity to LDLc in nonobese patients (p-for-interaction 0.041 and 0.001 respectively). Abdominal obesity negatively associated with likelihood of plaque stenosis progression (odds ratio 0.19 [0.07 to 0.54]). Low LDLc associated with greater likelihood of per-segment plaque formation (OR 4.68 [2.26 to 9.66]) and increased stenotic severity (odds ratio 5.35 [1.62 to 17.67]) only in nonobese patients (p-for-interaction 0.002 and 0.040 respectively). Abdominal obesity was not linked to cardiovascular risk (Hazard Ratio 1.57, 95% confidence interval [0.66-3.73]). Low LDLc associated with higher cardiovascular risk in nonobese (Hazard Ratio 7.94 [1.52 to 41.36]) but not obese patients (p-for-interaction=0.017). Conclusion. Abdominal obesity was not linked to plaque progression or cardiovascular risk in RA. Only in nonobese patients, low LDLc associated with higher atherosclerosis burden, plaque progression and cardiovascular risk. This may reflect higher oxidation and macrophage cholesterol loading capacity of LDL when LDLc is <70mg/dl.

Effect of stenotic shapes and arterial wall elasticity on the hemodynamics

The present study employs an arbitrary Lagrangian–Eulerian fluid–structure interaction approach to investigate pulsatile blood flow through a deformable stenosed channel. The flow is modeled by solving the incompressible continuity and momentum equations using finite element-based commercial solver COMSOL Multiphysics®. In this work, we explore the effects of different stenotic shapes—elliptical, round, and sinusoidal, degrees of stenosis (30%, 50%, and 70%), and arterial wall stiffnesses—0.5, 1.5, and 2.5 MPa on the velocity profile, pressure and wall shear stress distribution, and wall deformation. The oscillatory shear index (OSI) is analyzed to predict further plaque formation in the stenosed artery. We find that the flow velocity, wall shear stress, and pressure difference across the stenosed region increase with an increase in the stenotic severity and artery stiffness. The velocity profiles intersect at a radial location in the stenotic region termed critical radius, where relative magnitudes get reversed. With the increase in stenotic severity, the wall displacement decreases at the throat and increases at the upstream side. With the increase in wall stiffness, the wall deformation decreases, and shear stress increases, thereby increasing the pressure drop across the stenosed region. At a lower mass flow rate and a higher degree of stenosis, the vortices are formed upstream and downstream of the stenosed region for all stenotic shapes. The vorticity magnitude is found to be more than 21% higher for sinusoidal stenotic shape than round and elliptical ones. The effect of stenotic profile on the pressure drop characteristics shows that blood experiences maximum wall shear stress for the sinusoidal stenotic geometry, whereas the pressure drop is the maximum for the elliptical stenotic shape. The elliptical stenotic shape is more prone to further plaque formation than round and sinusoidal stenotic shapes. At lower Womersley number (Wo=2.76) corresponding to 60 beats per min heart beat rate, secondary vortices are formed downstream of the channel, causing higher OSI.

Comparative histological analysis of the alae nasi in French bulldogs with brachycephalic obstructive airway syndrome and unaffected non-brachycephalic dogs.

Brachycephalic dogs are characterised by a short and flat nose. This cranial conformation is associated with brachycephalic obstructive airway syndrome, a respiratory syndrome primarily characterised by stenotic nares, a hyperplastic soft palate and a hypoplastic trachea, among other malformations, with secondary abnormalities resulting in upper airway obstruction METHODS: In this study, we aimed to characterise and compare the histological features of tissue samples harvested from the alae nasi of French bulldogs and non-brachycephalic dogs. Samples from the alae nasi of 11 French bulldogs and 13 non-brachycephalic dogs were collected. Four-μm-thick, paraffin-embedded sections were obtained from each tissue sample and mounted on glass slides, followed by staining with haematoxylin and eosin, periodic acid-Schiff and toluidine blue for histological examination. The only variation observed between the samples obtained from French bulldogs and those obtained from non-brachycephalic dogs concerned the presence of cartilage in the specimens. Cartilage was absent in 10 of 11 French bulldogs but present in nine of 13 non-brachycephalic dogs; this difference was statistically significant (p < 0.05). The findings of this study need further validation in future prospective studies. It would be useful to examine the entire nostril wing, to include additional brachycephalic breeds, a larger number of subjects spanning a wider age range and degree of stenotic nares severity, a larger tissue sample, and a broadening of the control group to include dolichocephalic and mesaticephalic dogs. This study found an absence of cartilage in French bulldog nare specimens compared to those from non-brachycephalic dogs. This absence of cartilage may contribute to brachycephalic obstructive airway syndrome, although histological examination of the entire wing of the nostrils is needed to confirm this hypothesis.

Length and location of post-PIRCS predict percutaneous transluminal angioplasty and stenting-related restenosis in nasopharyngeal cancer

PurposePost-irradiated carotid stenosis (PIRCS) commonly occurs in patients with nasopharyngeal cancer (NPC) after receiving radiotherapy. A high in-stent restenosis (ISR) is observed in these patients after percutaneous transluminal angioplasty and stenting (PTAS) for PIRCS. Risk factors for ISR in these patients remain unclear. MethodsData were retrospectively analyzed from 68 NPC patients with 70 lesions treated with PTAS for PIRCS. The median follow-up was 40 months (range: 4–120). Evaluations of demographic and clinical characteristics included stenotic severity, stenotic lesion length (SLL), stenotic lesion location, and ISR-related stroke during follow-up. The risk for ISR was evaluated using multiple Cox regression analysis. ResultsThe median age of the patients was 61 (35–80) years and 94.1% were male. The median stenosis was 80% (60–99%) and the median SLL was 2.6 cm (0.6–12.0 cm) before PTAS. Compared to those without ISR, patients with longer SLL were at significantly greater risk of developing significant ISR, defined as > 50% after PTAS (hazard ratio [HR] and 95% confidence interval [CI]: 2.06 [1.30–3.28]). PTAS for lesions from the internal carotid artery (ICA) to common carotid artery (CCA) was associated with a significantly greater risk of ISR than lesions located only in the ICA (HR: 9.58 [1.79–51.34]). The baseline cut-off value for SLL that best predicted significant ISR was 1.6 cm (area under the curve 0.700, sensitivity 83.3% and specificity 62.5%). ConclusionStenotic lesions located from the ICA to CCA with longer SLL at baseline appear to predict ISR in NPC patients with PIRCS after PTAS. Intensive post-procedural follow-up is advised for this patient population.

Modeling and numerical simulation of non-Newtonian arterial blood flow for mild to severe stenosis

The fundamental cause of coronary heart disease is thought to be atherosclerosis. Blood flow in arteries under plaque formation is widely studied using both experimental and theoretical methods in literature. This paper presents a comprehensive study on the mathematical modelling and numerical simulation of non-Newtonian blood flow in an idealized stenosed artery. Non-Newtonian behavior of blood flow is assumed by Casson and Quemada fluid models. An analysis is performed for four forms of stenosis, 50%, 60%, 70%, and 80%, which are defined by a narrowing of the artery's diameter. The mathematical model for non-Newtonian fluid transport is presented in the form of highly nonlinear coupled partial differential equations. A finite-volume approach is used to solve the system of equations numerically. The solutions are obtained using a hybrid mesh with hexahedron and tetrahedron control volumes. Numerical solutions are validated first with experimental results from the literature for a Newtonian fluid, and then the results are extended to non-Newtonian fluid models. It can be observed that the non-Newtonian nature of the fluid model influences flow dynamics and is a significant aspect to consider for arteries with small diameter. The velocity and pressure drop rise as the degree of stenosis develops. Wall shear is substantially larger in stenotic passages and severity of stenosis is directly related with this increasing behavior.

Impact of Coronary Artery Disease on The Outcomes of Catheter Ablation in Patients with Atrial Fibrillation.

The objective of this study is to investigate the possible impact of coronary artery disease (CAD) on clinical outcomes of catheter ablation in patients with atrial fibrillation (AF). Patients with AF who underwent coronary computed tomography and catheter ablation were enrolled. The presence of stenotic severity and plaque, characteristics of coronary arteries, clinical data, and adverse outcomes of catheter ablation were analysed. A total of 243 patients were enrolled, 100 (41%) patients with CAD. The CHA2DS2-VASc (congestive heart failure, hypertension, age ≥ 75 years, diabetes mellitus, stroke or transient ischemic attack, vascular disease, age 65-74 years, and sex category) score of AF patients with CAD was significantly (P<0.001) higher than of those without CAD. Presence of stenotic artery and plaques increased significantly with increase of CHA2DS2-VASc score (P<0.05). There was no significant (P=0.342) difference in AF recurrence between patients with and without CAD (30% versus 24%). Age, AF type, duration of AF, heart failure, CHA2DS2-VASc score, left ventricular ejection fraction, and left atrial diameter were significantly (P<0.05) correlated with AF recurrence in univariant analysis. Multivariable analysis revealed that duration of AF (hazard ratio [HR] 1.769), heart failure (HR 1.821), and left atrial diameter (HR 1.487, P=0.022) remained significant independent predictors of AF recurrence. Patients with AF and concomitant CAD were significantly (P=0.030) associated with a worse outcome. CAD concomitant with AF may be associated with a worse clinical outcome even though CAD does not significantly affect the risk of AF recurrence after ablation therapy.

Probability for surgical treatment in patients with lumbar spinal stenosis according to the stenotic lesion severity: a 5–10-year follow-up study

BackgroundWe aimed (1) to clarify difference in the natural history of lumbar spinal stenosis (LSS) with respect to surgical treatment according to severity of stenosis on magnetic resonance imaging (MRI) using qualitative grading system and (2) to estimate surgical probabilities depending on radiological severity.MethodsWith the design of retrospective observational study, a total of 1,248 patients diagnosed with LSS between 2011 and 2014 at our hospital were followed up for the mean duration of 7.7 years (5.17–9.8 years). We investigated severity of central and foraminal stenoses on initial MRI using qualitative grading system and whether surgical treatment was performed. Logistic regression models were used to identify risk factors for surgery.ResultsDuring the mean follow-up period of 7.7 years, grade 3 maximal central stenosis showed the highest percentage of surgical treatment (57.9%–62.3%) with no significant difference in surgical probabilities according to concomitant foraminal stenosis. Surgical probabilities in grade 2 and 3 maximal foraminal stenosis, were 22.2%–62.3% and 33.3%–57.9%, respectively, depending on concomitant central stenosis. Maximal central stenosis of grades 1, 2, and 3 (odds ratio [OR]: 1.79, 2.21, and 6.26, respectively), and maximal foraminal stenosis of grades 2 and 3 (OR: 2.22 and 2.12, respectively) were significant risk factors for surgical treatment.ConclusionsThe high grades of maximal central and foraminal stenoses were risk factors for surgical treatment. Surgical probabilities were 57.9%–62.3% in grade 3 maximal central stenosis, 22.2%–62.3% and 33.3%–57.9%, respectively, in grade 2 and 3 maximal foraminal stenosis during the mean follow-up period of 7.7 years. These results indicate that the natural history of LSS differs according to grade of maximal central and foraminal stenoses.

Increased coronary pericoronary adipose tissue attenuation in diabetic patients compared to non-diabetic controls: A propensity score matching analysis

BackgroundPericoronary adipose tissue (PCAT) attenuation is an indicator of active inflammation of perivascular adipose tissue, which is supposed to increase in diabetic patients. We aimed to investigate the PCAT attenuation values and high-risk plaque (HRP) features in diabetic and non-diabetic subjects with different stenotic extents. MethodsConsecutive type 2 diabetes patients and non-diabetic patients with chest pain and intermediate pre-test probability of coronary artery disease (CAD) were prospectively enrolled and underwent coronary computed tomography angiography (CCTA). At per-patient level, PCAT attenuation values of three major epicardial coronary vessels, as well as HRP features were measured. PCAT attenuation values and HRP features were compared between diabetic and non-diabetic subjects according to the presence or absence of obstructive stenosis. Results1700 patients (mean age: 65.5 ​± ​11.7, 940 males) were divided into two groups according to presence of obstructive stenosis on CCTA. Propensity score matching was performed in further analysis. RCAPCAT was significantly higher in diabetic subjects than that in non-diabetic subjects, regardless of the presence of obstructive stenosis (−83.60 ​± ​9.51 HU vs. −88.58 ​± ​9.37 HU, p ​< ​0.001) or absence of obstructive stenosis (−83.70 ​± ​10.32 HU vs. −88.76 ​± ​8.28 HU, p ​< ​0.001). In contrast, HRP features were more commonly presented in diabetic patients with obstructive stenosis than in those without obstructive stenosis. According to subgroup analysis based on acquisition tube voltage, RCAPCAT was the only parameter showing consistent difference between diabetic and non-diabetic patients. ConclusionsRCAPCAT was significantly higher in diabetic patients than that in non-diabetic patients regardless of stenotic severity and plaque vulnerability.

Lipoprotein(a), Immunity, and Inflammation in Polyvascular Atherosclerotic Disease.

Background and aims: lipoprotein(a) (Lp(a)) is a genetically determined risk factor for coronary artery disease and its complications, although data on the association with other vascular beds and the severity of atherosclerosis is limited. The aim of this study was to evaluate the association of atherosclerosis of various vascular beds with Lp(a), as well as its autoantibodies and generalized inflammatory markers. Material and methods: this study included 1288 adult patients with clinical and imaging examination of three vascular beds (coronary, carotid, and lower limb arteries). Patients were categorized according to the number of affected vascular beds (with at least one atherosclerotic stenosis ≥50%): 0 (n = 339), 1 (n = 470), 2 (n = 315), 3 (n = 164). We assessed blood cell count, lipid profile, C-reactive protein, circulating immune complexes, Lp(a), and its autoantibodies. Results: the number of affected vascular beds was associated with an increasing level of Lp(a) and a lower level of IgM autoantibodies to Lp(a). Hyperlipoproteinemia(a) (Lp(a) ≥ 30 mg/dL) was detected more frequently in patients with atherosclerosis. In logistic regression analysis adjusted for age, sex, hypertension, type 2 diabetes, and smoking, an elevated Lp(a) level was independently associated with stenotic atherosclerosis and lesion severity. There was a positive association of the number of affected vascular beds with C-reactive protein (r = 0.21, p < 0.01) and a negative association with circulating immune complexes (r = −0.29, p < 0.01). The neutrophil-to-lymphocyte ratio was significantly higher and the lymphocyte-to-monocyte ratio was significantly lower in patients with atherosclerosis compared to the controls (p < 0.01). Conclusion: Lp(a), C-reactive protein, circulating immune complexes, and neutrophil-to-lymphocyte ratio are associated with the stenotic atherosclerosis of different vascular beds. Lp(a) levels increase and IgM autoantibodies to Lp(a) decrease with the number of affected vascular beds.

Pressure- and Velocity-Based Physiological Assessment of Stenotic Lesions at Hyperemia in Superficial Femoral Artery Disease: Importance of Hyperemic Stenosis Resistance.

Background: In superficial femoral artery (SFA) stenosis, stenosis resistance may increase, but the relationship between stenosis resistance and stenotic severity remains to be seen. This study aimed to investigate the physiological response, through a hyperemic condition, and the pathophysiological significance of Doppler flow and stenosis resistance in SFA.Methods: Twenty-four limbs with focal stenosis of the SFA were analyzed. We assessed the fractional flow reserve (FFR), hyperemic stenosis resistance (h-SR), and vascular flow reserve (VFR) of the SFA with a pressure/Doppler flow sensor-tipped combination guidewire before and after endovascular therapy (EVT).Results: FFR, h-SR, and VFR changed significantly after EVT. h-SR was more strongly correlated with % area stenosis, measured by intravascular ultrasound than FFR (FFR: r=−0.716, h-SR: r=0.741, p<0.0001, respectively). However, VFR was not associated with % area stenosis. A receiver operating characteristic curve showed cut-offs h-SR >0.36 mmHg·sec/cm, and FFR <0.88 predicted >75% area stenosis with area under curves of 0.883 and 0.828, respectively.Conclusion: h-SR can indicate stenotic severity in an SFA focal lesion more prominently than FFR and may be a new physiological index to determine indication for EVT. VFR was not feasible for assessment in SFA focal stenosis.

Prediction of Plaque Progression in Coronary Arteries Based on a Novel Hemodynamic Index Calculated From Virtual Stenosis Method.

RationalePredicting the sites in coronary arteries that are susceptible to plaque deposition is essential for the development of clinical treatment strategies and prevention. However, to date, no physiological biomarkers for this purpose have been developed. We hypothesized that the possibility of plaque deposition at a specific site in the coronary artery is associated with wall shear stress (WSS) and fractional flow reserve (FFR).Background and ObjectiveWe proposed a new biomarker called the stenosis susceptibility index (SSI) using the FFR and WSS derived using virtual stenosis method. To validate the clinical efficacy of this index, we applied the method to actual pilot clinical cases. This index non-invasively quantifies the vasodilation effects of vascular endothelial cells relative to FFR variation at a specific coronary artery site.Methods and ResultsUsing virtual stenosis method, we computed maximum WSS and FFR according to the variation in stenotic severity at each potential stenotic site and then plotted the variations of maximum WSS (y-axis) and FFR (x-axis). The slope of the graph indicated a site-specific SSI value. Then we determined the most susceptible sites for plaque deposition by comparing SSI values between the potential sites. Applying this method to seven patients revealed 71.4% in per-patient basis analysis 77.8% accuracy in per-vessel basis analysis in percutaneous coronary intervention (PCI) site prediction.ConclusionThe SSI index can be used as a predictive biomarker to identify plaque deposition sites. Patients with relatively smaller SSI values also had a higher tendency for myocardial infarction. In conclusion, sites susceptible to plaque deposition can be identified using the SSI index.

Coronary Atherosclerotic Plaque Vulnerability Rather than Stenosis Predisposes to Non-ST Elevation Acute Coronary Syndromes.

Background Non-ST elevation acute coronary syndromes (NSTE-ACS) may arise from moderately stenosed atherosclerotic lesions that suddenly undergo transformation to vulnerable plaques complicated by rupture and thrombosis. Objective Assessment and tissue characterization of the coronary atherosclerotic lesions among NSTE-ACS patients compared to those with stable angina. Methodology Evaluation of IVUS studies of 312 coronary lesions was done by 2 different experienced IVUS readers, 216 lesions in 66 patients with NSTE-ACS (group I) versus 96 lesions in 50 patients with stable angina (group II). Characterization of coronary plaques structure was done using colored-coded iMap technique. Results The Syntax score was significantly higher in group I compared to group II (18.7 ± 7.8 vs. 8.07 ± 2.5, p=0.001). Body mass index (BMI) was significantly higher in group II while triglycerides levels were higher in group I (P=0.01 & P=0.04, respectively). History of previous MI and PCI was significantly higher in group I (P=0.016 & P=0.001, respectively). The coronary lesions of NSTE-ACS patients had less vessel area (9.86 ± 3.8 vs 11.36 ± 2.9, p=0.001), stenosis percentage (54.7 ± 14.9% vs 68.6 ± 8.7%, p=0.001), and plaque burden (54.4 ± 14.7 vs 67.8 ± 9.8, p=0.001) with negative remodeling index (0.95 ± 20 vs 1.02 ± 0.14, p=0.008) compared to the stable angina group. On the other hand, they had more lipid content (21.8 ± 7.03% vs 7.26 ± 3.47%, p=0.001), necrotic core (18.08 ± 10.19% vs 15.83 ± 4.9%, p=0.02), and calcifications (10.4 ± 5.2% vs 4.19 ± 3.29%, p=0.001) while less fibrosis (51.67 ± 7.07% vs 70.37 ± 11.7%, p=0.001) compared to the stable angina patients. Syntax score and core composition especially calcification and lipid content were significant predictors to NSTE-ACS. Conclusions The vulnerability rather than the stenotic severity is the most important factor that predisposes to non-ST segment elevation acute coronary syndromes. The vulnerability is related to the lesion characteristics especially lipidic core and calcification while lesion fibrosis favours lesion stability.

Diagnostic accuracy of a deep learning approach to calculate FFR from coronary CT angiography

BackgroundThe computational fluid dynamics (CFD) approach has been frequently applied to compute the fractional flow reserve (FFR) using computed tomography angiography (CTA). This technique is efficient. We developed the DEEPVESSEL-FFR platform using the emerging deep learning technique to calculate the FFR value out of CTA images in five minutes. This study is to evaluate the DEEPVESSEL-FFR platform using the emerging deep learning technique to calculate the FFR value from CTA images as an efficient method.MethodsA single-center, prospective study was conducted and 63 patients were enrolled for the evaluation of the diagnostic performance of DEEPVESSEL-FFR. Automatic quantification method for the three-dimensional coronary arterial geometry and the deep learning based prediction of FFR were developed to assess the ischemic risk of the stenotic coronary arteries. Diagnostic performance of the DEEPVESSEL-FFR was assessed by using wire-based FFR as reference standard. The primary evaluation factor was defined by using the area under receiver-operation characteristics curve (AUC) analysis.ResultsFor per-patient level, taking the cut-off value ≤ 0.8 referring to the FFR measurement, DEEPVESSEL-FFR presented higher diagnostic performance in determining ischemia-related lesions with area under the curve of 0.928 compare to CTA stenotic severity 0.664. DEEPVESSEL-FFR correlated with FFR (R = 0.686, P < 0.001), with a mean difference of –0.006 ± 0.0091 (P = 0.619). The secondary evaluation factors, indicating per vessel accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were 87.3%, 97.14%, 75%, 82.93%, and 95.45%, respectively.ConclusionDEEPVESSEL-FFR is a novel method that allows efficient assessment of the functional significance of coronary stenosis.

High-sensitivity cardiac troponin I is a biomarker for occult coronary plaque burden and cardiovascular events in patients with rheumatoid arthritis.

Patients with RA display greater occult coronary atherosclerosis burden and experience higher cardiovascular morbidity and mortality compared with controls. We here explored whether pro-inflammatory cytokines and high-sensitivity cardiac troponin I (hs-cTnI), a biomarker of myocardial injury, correlated with plaque burden and cardiovascular events (CVEs) in RA. We evaluated 150 patients with 64-slice coronary CT angiography. Coronary artery calcium, number of segments with plaque (segment involvement score), stenotic severity and plaque burden were assessed. Lesions were described as non-calcified, mixed or fully calcified. Blood levels of hs-cTnI and pro-inflammatory cytokines were assessed during coronary CT angiography. Subjects were followed over 60 (s.d. 26) months for both ischaemic [cardiac death, non-fatal myocardial infarction (MI), stroke, peripheral arterial ischaemia] and non-ischaemic (new-onset heart failure hospitalization) CVEs. Plasma hs-cTnI correlated with all coronary plaque outcomes (P < 0.01). Elevated hs-cTnI (⩾1.5 pg/ml) further associated with significant calcification, extensive atherosclerosis, obstructive plaque and any advanced mixed or calcified plaques after adjustments for cardiac risk factors or Framingham D'Agostino scores (all P < 0.05). Eleven patients suffered a CVE (1.54/100 patient-years), eight ischaemic and three non-ischaemic. Elevated hs-cTnI predicted all CVE risk independent of demographics, cardiac risk factors and prednisone use (P = 0.03). Conversely, low hs-cTnI presaged a lower risk for both extensive atherosclerosis (P < 0.05) and incident CVEs (P = 0.037). Plasma hs-cTnI independently associated with occult coronary plaque burden, composition and long-term incident CVEs in patients with RA. Low hs-cTnI forecasted a lower risk for both extensive atherosclerosis as well as CVEs. hs-cTnI may therefore optimize cardiovascular risk stratification in RA.

Noninvasive Assessment of Stenotic Severity and Plaque Characteristics by Coronary CT Angiography in Patients Scheduled for Carotid Artery Revascularization.

Aims: Coronary artery atherosclerosis in patients needing carotid revascularization has not been fully clarified. The aim of this study was to evaluate the stenotic severity and plaque characteristics of coronary arteries by coronary computed tomography angiography (CTA) in patients scheduled for carotid-artery stenting (CAS) or carotid endarterectomy (CEA).Methods: We performed coronary CTA after carotid ultrasound (US) in 164 patients (81.7% male, aged 68.1 ± 12.2 years) from 2014 to 2016. Of all, 70 were scheduled for CAS or CEA (CAS/CEA group) and 94 were not (non-CAS/CEA group). Carotid US and coronary CTA were compared for the evaluation of stenotic severity and plaque characteristics of each vessel between CAS/CEA and non-CAS/CEA groups.Results: Between the two groups, there were significant differences in the presence of significant stenosis (SS: ≥ 70% stenosis of coronary artery) (55.7% vs. 39.4%, P = 0.038), triple-vessel disease (TVD)/left main trunk (LMT) (SS in each of three epicardial vessels and/or LMT) (24.3% vs. 7.5%, P = 0.0025), and high-risk plaque (HRP: positive remodeling and/or low attenuation) (55.7% vs. 24.5%, P < 0.0001). CAS/CEA was independently associated with TVD/LMT (OR = 2.30, 95%CI: 1.14–8.59, P = 0.026) and HRP (OR = 3.17, 95%CI: 1.57–6.54, P = 0.0012) in multivariable logistic regression analysis. Similarly, vulnerable plaque (78.6% vs. 2.1%, P < 0.0001) as well as severe stenosis of carotid artery (98.6% vs. 0%, P < 0.0001) was seen more often in CAS/CEA than in non-CAS/CEA group.Conclusions: The prevalence of TVD/LMT and HRP determined by coronary CTA is higher in patients needing CAS/CEA than in those without. Management of systemic atherosclerosis is required in the perioperative period of CAS/CEA.

A vessel length-based method to compute coronary fractional flow reserve from optical coherence tomography images

BackgroundHemodynamic simulation for quantifying fractional flow reserve (FFR) is often performed in a patient-specific geometry of coronary arteries reconstructed from the images from various imaging modalities. Because optical coherence tomography (OCT) images can provide more precise vascular lumen geometry, regardless of stenotic severity, hemodynamic simulation based on OCT images may be effective. The aim of this study is to perform OCT–FFR simulations by coupling a 3D CFD model from geometrically correct OCT images with a LPM based on vessel lengths extracted from CAG data with clinical validations for the present method.MethodsTo simulate coronary hemodynamics, we developed a fast and accurate method that combined a computational fluid dynamics (CFD) model of an OCT-based region of interest (ROI) with a lumped parameter model (LPM) of the coronary microvasculature and veins. Here, the LPM was based on vessel lengths extracted from coronary X-ray angiography (CAG) images. Based on a vessel length-based approach, we describe a theoretical formulation for the total resistance of the LPM from a three-dimensional (3D) CFD model of the ROI.ResultsTo show the utility of this method, we present calculated examples of FFR from OCT images. To validate the OCT-based FFR calculation (OCT–FFR) clinically, we compared the computed OCT–FFR values for 17 vessels of 13 patients with clinically measured FFR (M-FFR) values.ConclusionA novel formulation for the total resistance of LPM is introduced to accurately simulate a 3D CFD model of the ROI. The simulated FFR values compared well with clinically measured ones, showing the accuracy of the method. Moreover, the present method is fast in terms of computational time, enabling clinicians to provide solutions handled within the hospital.

Current Diagnosis and Treatment of Carotid Atherosclerotic Disease

Carotid atherosclerotic disease increases the risk for ischemic stroke and transient ischemic attack and challenges are presented when seeking the appropriate strategy of management. In this review, we will discuss the current diagnostic and treatment approaches of asymptomatic and symptomatic carotid stenosis. The de nition of carotid plaques, staging of stenotic severity, and noninvasive tests including carotid duplex ultrasound, computed tomographic angiography, magnetic resonance angiography and transcranial Doppler will be summarized. Optimal management for asymptomatic and symptomatic carotid stenosis with medical therapy, carotid artery stenting or carotid endarterectomy has been controversial and should be judged in speci c clinical settings. More clinical data are needed to better understand the correlation of different diagnostic measures and the disease progress and to optimize the treatment approach to improve patient outcomes.

A patient-specific virtual stenotic model of the coronary artery to analyze the relationship between fractional flow reserve and wall shear stress

ObjectiveAs the stenotic severity of a patient increases, fractional flow reserve (FFR) decreases, whereas the maximum wall shear stress (WSSmax) increases. However, the way in which these values can change according to stenotic severity has not previously been investigated. The aim of this study is to devise a virtual stenosis model to investigate variations in the coronary hemodynamic parameters of patients according to stenotic severity. MethodsTo simulate coronary hemodynamics, a three-dimensional (3D) coronary artery model of computational fluid dynamics is coupled with a lumped parameter model of the coronary micro-vasculature and venous system. ResultsTo validate the present method, we first simulated 13 patient-specific models of the coronary arteries and compared the results with those obtained clinically. Then, virtually narrowed coronary arterial models derived from the patient-specific cases were simulated to obtain the WSSmax and FFR values. The variations in FFR and WSSmax against the percentage of diameter stenosis in clinical cases were reproducible by the virtual stenosis models. We also found that the simulated FFR values were linearly correlated with the WSSmax values, but the linear slope varied by patient. ConclusionWe implemented 130 additional virtual models of stenosed coronary arteries based on data from 13 patients and obtained statistically meaningful results that were identical to the large-scale clinical studies. And the slope of the correlation line between FFR and WSSmax may help clinicians to design treatment plans for patients.

Management of Laryngotracheal Stenosis - Still Remains a Challenge for Successful Outcome

Abstract Management of laryngotracheal stenosis (LTS) is still an enigma and remains a challenge even for an expert surgical team. The treatment of LTS is quite difficult and often associated with significant risk and complications. Even with the availability of many surgical options, proper selection of surgical technique in each clinical situation is the key behind successful outcome. Selection of appropriate surgical repair depends on the site of stenotic segment, severity, duration, and cause of functional impairment. It requires meticulous preoperative evaluation and planning. No single approach is ideal and often several techniques may be needed before decannulation can be achieved. The purpose of this review article is to discuss the pathophysiology, pre-operative evaluation, surgical principle, surgical technique, graft materials in reconstruction and prevention of LTS and optimum stress given on different suitability of surgical techniques with application of suitable one in relation to site of stenosis and other stenosis parameters.