Lumen Volume Research Articles

Abstract 11126: Longitudinal MRI-Based Superficial Femoral Artery Velocity Measurements in Peripheral Artery Disease: An Analysis of the Effect of Lipid Modification on Peripheral Artery Disease After Endovascular Intervention Trial (ELIMIT)

Introduction: Peripheral artery disease (PAD) causes lower extremity dysfunction and is associated with an increased risk of cardiovascular mortality and morbidity. We analyzed longitudinal associations of non-invasive 2-dimensional-phase-contrast magnetic resonance imaging (2D-PC-MRI) velocity markers of the distal superficial femoral artery (SFA) with characteristics of PAD. Hypothesis: Longitudinal changes in MRI-based measures of SFA velocity are associated with changes in SFA lumen volumes in PAD. Methods: A total of 33 (11 diabetic, 22 non-diabetic) PAD patients, who completed baseline and 2-year follow-up MRI were included in this secondary analysis of ELIMIT. Electrocardiographically-gated 2D-PC-MRI was performed at a proximal and a distal imaging location of the distal SFA territory. SFA lumen, wall, and total vessel volumes were averaged over all distal SFA MRI slices. Results: Baseline characteristics did not differ between diabetic and non-diabetic PAD patients (Table). Proximal and distal SFA velocity measures did not differ between baseline and 2-years (41.98: IQR (23.58, 72.6) cm/s; vs. 40.31: IQR (26.69, 61.29) cm/s; p=0.30, for maximum SFA velocity). The velocity amplitude (defined as the difference between the SFA minimum and maximum velocity) was significantly lower in the distal compared to the proximal SFA location at both baseline and at the 2-year visit (p=0.003, p<0.001). In a pooled analysis of all 33 PAD patients, the 2-year change of the average SFA velocity was significantly associated with the 2-year change in the averaged SFA lumen volume (beta: 0.00011, r 2 : 0.175, p=0.017). In a subgroup analysis, a similar pattern was observed in diabetic patients (beta: 0.00006, r 2 : 0.714, p=0.001), but not in non-diabetics (beta: -0.000019, r 2 : 0.0095, p=0.68). Conclusion: Longitudinal 2D-PC-MRI SFA velocity changes are associated with 2-year SFA lumen changes. 2D-PC-MRI velocity measures may be of interest in assessing PAD.

Abstract 12657: Clinical, Laboratory, and Coronary Plaque Predictors of Atherosclerotic Non-Response to Statin Therapy

Introduction: Statins reduce major cardiovascular events, but residual risk remains. The study examined determinants of atherosclerotic statin non-response in patients using statins. Hypothesis: We hypothesized that a comprehensive evaluation of atherosclerosis identifies patients that progress atherosclerosis despite the use of statin therapy. Methods: The multi-center PARADIGM registry included patients who underwent serial CCTA ≥2 years apart, with whole-heart coronary tree quantification of vessel, lumen and plaque, and matching of baseline and follow-up coronary segments and lesions. Patients with statin use at baseline and follow-up CCTA were included. Atherosclerotic statin non-response was defined as an absolute increase in percent atheroma volume (PAV) of 1.0% or more per year. A secondary endpoint was defined by the additional requirement of progression of low-attenuation plaque or fibro-fatty plaque. Results: We included 649 patients (62.0±9.0 years, 63.5% male) on statin therapy and 205 (31.5%) experienced atherosclerotic statin non-response. Age, diabetes, hypertension, and all atherosclerotic plaque features (high risk plaque [HRP] features, calcified and noncalcified PAV, and lumen volume) were significantly different between patients with and without atherosclerotic statin non response, while only diabetes, the number of high risk plaque features, noncalcified and calcified PAV were independently associated with atherosclerotic statin non-response (OR:1.41 (0.95-2.11), OR:1.15 (1.09-1.21), OR:1.06 (1.02-1.10), OR:1.07 (1.03-1.12), respectively). For the secondary endpoint (N=125, 19.2%), only non-calcified PAV and number of HRP features were the independent determinants (OR:1.08 (1.03-1.13) and OR:1.21 (1.06-1.21), respectively). Conclusions: In patients treated with statins, baseline plaque characterization by plaque burden and high risk plaque is associated with atherosclerotic statin non-response defined as important progression of coronary atherosclerosis. Patients with the highest plaque burden including HRP were at highest risk for plaque progression, despite statin therapy. These patients may need additional therapies for further risk reduction.

HMG‐CoA reductase inhibition medicated hypocholesterolemic and antiatherosclerotic potential of phytoconstituents of an aqueous pod extract of Prosopis cineraria (L.) Druce: In silico, in vitro, and in vivo studies

AbstractHydrophilic bioactive compounds are copiously exhibited in aqueous extracts owed to solubility. The study was assigned to assess the ability of phytoconstituents of aqueous pod extract of Prosopis cineraria to inhibit 3‐hydroxy‐3‐methylglutary‐coenzyme A (HMG‐CoA) reductase activity and regression in atherosclerotic plaque through in vitro, in vivo, and in silico assessments along with phytochemistry of extract. The test extract exhibited 17 leading compounds as examined by Liquid Chromatograph Triple Quadrupole Mass Spectroscope. In vitro assay of test extract showed 78.1% inhibition of HMG‐CoA inhibition (IC50 was 0.03 μg/ml). In vivo assessments, hypercholesterolemia was induced by supplementing cholesterol powder and a high‐fat diet. The treatment of test extract caused significant (p ≤ 0.001) improvements in the lipid profile and antioxidant levels. Subsequently, the reductions in the atherosclerotic plaque and improved lumen volume were pointedly observed. In silico analyses of molecular docking revealed potent interaction capabilities of cloprostenol with the target protein of HMGR. The interactions were validated through structural simulations of the molecular dynamics such as root mean square fluctuation, the radius of gyration, and solvent accessible surface area. The druggability of potent compounds was also examined. The results revealed that phytoconstituents of the test extract could inhibit HMGR and regress atherosclerotic plaque.

Volume Changes in the Descending Aorta after Frozen Elephant Trunk and Conventional Hemi-Arch Repair after Acute Type A Aortic Dissection.

The aim of this study was to compare the mortality rates, re-intervention rates, and volumetric changes in aortas following surgery, in terms of the true lumen and false lumen changes, using conventional hemi-arch repair (CET) and frozen elephant trunk (FET) techniques. During the period from 2015 to 2018, 66 patients underwent surgical treatment for acute aortic dissection (Debakey type 1). Demographic and procedure-related data were evaluated. We measured volumetric change before surgical treatment, at discharge, and at 12- and 24-month time points based on computed tomography angiography. The study cohort was divided into two groups (FET vs. CET). The mean age of the patients was 56.9 ± 9.4 years in the FET group versus 63.6 ± 11 years in the CET group (p = 0.063). The mean follow-up time was 24 ± 6 and 25 ± 5 months for the FET and CET groups, respectively. There were no significant differences between the two groups in terms of the medical histories of the cohorts. The results showed a significant increase in true lumen volume after the FET procedure (within 24 months postoperatively; p = 0.005), and no significant changes in total (p = 0.392) or false lumen (p = 0.659) volumes were noted. After the CET procedure, there were significant increases in total and false lumen volumes (p = 0.013, p = 0.042), while no significant change in true lumen was observed (p = 0.219). The volume increase in true lumen after the FET procedure was higher compared to the CET group at all postoperative time points (at discharge, 12 months, and 24 months) without significant evidence (p = 0.416, p = 0.422, p = 0.268). At two years, the volume increase in false lumen was significantly higher among the CET group compared to the FET group (p = 0.02). The Kaplan–Meier curve analysis showed that patients who underwent the CET procedure underwent significantly more re-interventions due to false lumen expansion of the descending aorta (p = 0.047). Present study results indicate that the true and false lumen changes in the aorta following the FET and CET procedures were different. FET led to a significant increase in true lumen volume, while false lumen volume remained stable; however, after the CET procedure, significant false lumen enlargement was noted at mid-term follow-up time points. The re-intervention rate after CET was higher due to false lumen expansion.

Impact of vessel morphology on computed tomography derived fractional flow reserve (FFRCT) in normal coronary artery disease: a novel marker for the predictor of FFRCT changes

Abstract Background Computed tomography (CT) derived fractional flow reserve (FFRCT) decreases continuously from the proximal to the distal segments of the vessel even in normal coronary arteries. It has been empirically proved that the degree of FFRCT decline varies based on vessel morphology even in the same vessel length. Purpose To investigate the vessel morphological factors that influence FFRCT in normal coronary arteries. Methods A total of 1402 outpatients with suspected CAD who underwent CT angiography (CTA) with FFRCT analysis between January 2017 and October 2021 were evaluated. Among them, 234 consecutive patients who underwent both CT angiography including FFRCT and invasive coronary angiography, resulting in <20% stenosis in right coronary artery (RCA) were evaluated. RCA vessels from ostium to just proximal site of the posterior descending branch were analysed and divided into two groups according to distal FFRCT: FFRCT >0.80 (n=219) and FFRCT ≤0.80 (n=15). FFRCT was measured at proximal and distal segments of the RCA. Vessel morphology (vessel length, lumen diameter and volume, and plaque volume) and left ventricular mass were assessed. The ratio of lumen volume and vessel length was defined as the V/L ratio. Results Whereas vessel length was almost the same between FFRCT >0.80 and ≤0.80 (>0.80 vs. ≤0.80, 115.9±17.3 vs. 119.6±28.7 mm), lumen volume (1135.2±369.3 vs. 906.2±362.6 mm3, p<0.05) and V/L ratio (9.8±2.6 vs. 7.5±2.3, p<0.01) were significantly higher in FFRCT >0.80. Distal FFRCT correlated with plaque-related parameters [low-attenuation plaque, intermediate-attenuation plaque, and calcified plaque (CP)] and vessel-related parameters (proximal and distal vessel diameter, vessel length, lumen volume, and V/L ratio). Among all vessel-related parameters, V/L ratio showed the highest correlation with distal FFRCT (r=0.44, p<0.0001) (Figure 1). Multivariable analysis showed that CP volume was the strongest predictor of distal FFRCT (β-coefficient = −0.38, p<0.0001), followed by V/L ratio (β-coefficient = 0.95, p=0.007). V/L ratio was the strongest predictor of a distal FFRCT ≤0.80 (cut-off 8.2, AUC 0.73, sensitivity 66.7%, specificity 69.3%, 95% CI 0.60–0.86) (Figure 2). Conclusions Our study findings suggest that the V/L ratio can be a measure to predict subclinical coronary perfusion disturbance. Funding Acknowledgement Type of funding sources: None.

Stent expansion evaluated by optical coherence tomography and subsequent outcomes

Abstract Background Regarding stent expansion indexes, previous optical coherence tomography (OCT) studies have shown minimal stent area (MSA) to be most predictive of adverse events. Purpose We sought to evaluate the impact of various stent expansion indexes by post-stent OCT on long-term clinical outcomes, and hence to find OCT-defined optimal stent expansion criteria. Methods Of the patients registered in the Yonsei OCT registry, a total of 1071 patients with 1123 native coronary artery lesions treated with new-generation drug-eluting stents under the OCT guidance and analyzable final post-stent OCT were included. Stent expansion indexes and different suboptimal stent expansion criteria were evaluated for their association with device-oriented clinical endpoints (DoCE) including cardiac death, target vessel-related myocardial infarction (TVMI) or stent thrombosis, and target lesion revascularization. Major safety events (MSE) included cardiac death, TVMI or stent thrombosis. Results The median follow-up period was 40.6 (interquartile range 22.0–50.0) months. As a continuous variable, MSA, adaptive volumetric stent expansion (stent volume/adaptive reference lumen volume) and overall volumetric stent expansion (stent volume/post-stent lumen volume) were significantly predictive of DoCE. As a categorical criteria, MSA <5.0 mm2 (hazard ratio [HR] 3.80; 95% confidence interval [CI] 1.53–9.45), MSA/distal reference lumen area <90% (HR 2.13; 95% CI 1.10–4.14), and overall volumetric stent expansion ≥96.6% (HR 2.38; 95% CI 1.09–5.22) were independently associated with DoCE after adjusting for confounders, and a total malapposition volume ≥7.0 mm3 (HR 3.38; 95% CI 1.05–10.93) was linked to MSE. Conclusions This OCT study highlights that sufficient stent expansion to achieve adequate absolute MSA and relative MSA by distal reference lumen area and alleviate significant malapposition is important to improve clinical outcome, but overall stent overexpansion may have deleterious effect. Funding Acknowledgement Type of funding sources: None.

High-density thrombus and maximum transverse diameter on multi-spiral computed tomography angiography combine to predict abdominal aortic aneurysm rupture.

ObjectiveWe attempted to measure maximum transverse diameter (MTD) of and CT values of ILT by using multi-spiral computed tomography angiography (MSCTA) to investigate the predictive value of MTD with different CT values of thrombus on the risk of AAA rupture.MethodsForty-five intact abdominal aortic aneurysms (IAAA) and 17 ruptured abdominal aortic aneurysms (RAAA) were included in this study. MTD and CT values in their planes were measured from MSCTA images and aneurysm lumen and thrombus volumes were calculated for the range of different CT values.ResultsThe median of maximum CT value of thrombus at the plane of MTD was higher in RAAA (107.0 HU) than the median in IAAA (84.5 HU) (P < 0.001). Univariate logistic regression analysis showed that the maximum CT value was a risk factor for RAAA (P < 0.001). It was further found that the area under the ROC curve for thrombus maximum CT value in the MTD plane to predict RAAA was 0.848 (P < 0.001), with a cut-off value of 97.5 HU, a sensitivity of 82.35%, and a specificity of 84.44%. And the MTD of the abnormal lumen combined with the maximum CT value at its plane predicted RAAA with an area under the ROC curve of 0.901, a sensitivity of 76.47%, and a specificity of 97.78%. The further analysis of thrombus volume in the range of different CT value showed that median thrombus volume in RAAA in the range of 30 HU~150 HU was 124.2 cm3 which was higher than the median of 81.4 cm3 in IAAA (P = 0.005). To exclude confounding factors (aneurysm volume), we calculated the standardized thrombus (ILT volume/total aneurysm volume), and the thrombus volume in the range of 30 HU~150 HU in RAAA was positively correlated with the standardized thrombus volume (ρ = 0.885, P < 0.001), while the thrombus volume in the range of −100 HU~30 HU was not correlated with it (ρ = 0.309, P = 0.228).ConclusionsHigh-density ILT shown on MSCTA in AAAs is associated with aneurysm rupture, and its maximum transverse diameter combined with the maximum CT value in its plane is a better predictor of RAAA.

Evolutionary functional morphology of the proboscis and feeding apparatus of hawk moths (Sphingidae: Lepidoptera).

The morphology of the proboscis and associated feeding organs was studied in several nectar-feeding hawk moths, as well as a specialized honey-feeder and two supposedly nonfeeding species. The proboscis lengths ranged from a few millimeters to more than 200 mm. Despite the variation in proboscis length and feeding strategy, the principle external and internal composition of the galeae, the stipes pump, and the suction pump were similar across all species. The morphology of the smooth and slender proboscis is highly conserved among all lineages of nectar-feeding Sphingidae. Remarkably, they share a typical arrangement of the sensilla at the tip. The number and length of sensilla styloconica are independent from proboscis length. A unique proboscis morphology was found in the honey-feeding species Acherontia atropos. Here, the distinctly pointed apex displays a large subterminal opening of the food canal, and thus characterizes a novel type of piercing proboscis in Lepidoptera. In the probably nonfeeding species, the rudimentary galeae are not interlocked and the apex lacks sensilla styloconica; galeal muscles, however, are present. All studied species demonstrate an identical anatomy of the stipes, and suction pump, regardless of proboscis length and diet. Even supposedly nonfeeding Sphingidae possess all organs of the feeding apparatus, suggesting that their proboscis rudiments might still be functional. The morphometric analyses indicate significant positive correlations between galea lumen volume and stipes muscle volume as well as the volume of the food canal and the muscular volume of the suction pump. Size correlations of these functionally connected organs reflect morphological fine-tuning in the evolution of proboscis length and function.

Comparison of Longitudinal Skeletal Thigh Muscle Findings With Magnetic Resonance Imaging in Patients With Peripheral Artery Disease With–Versus–Without Diabetes Mellitus

The aim of this secondary analysis of ELIMIT (The Effect of Lipid Modification on Peripheral Artery Disease after Endovascular Intervention Trial) was to determine longitudinal changes over 24months in skeletal thigh muscle volumes and individual muscle compartments in patients with peripheral artery disease (PAD) with and without diabetes. A total of 48 patients with available magnetic resonance imaging of the distal superficial femoral artery at baseline and 2years were included in this analysis. Muscle volumes and superficial femoral artery wall, lumen, and total vessel volumes were quantified. Intrareader reproducibility of muscle tracings was assessed with the intraclass correlation coefficient using a 2-way model. Baseline characteristics were similar between patients with PAD with and without diabetes, except for smoking history (p=0.049), cholesterol levels (p <0.050), and calf walking pain (p=0.049). Interobserver reproducibility of the muscle volume tracings was excellent for all muscle groups (all intraclass correlation coefficients >0.86, confidence interval 0.69 to 0.94). Total muscle and total leg volumes increased significantly between baseline and 24months among patients with PAD without diabetes (31 ± 6.4cm3 vs 32 ± 7.0cm3, p <0.001; 18 ± 4.4cm3 vs 19 ± 4.8cm3, p=0.045), whereas there was no change in patients with PAD and diabetes. Total muscle volume was inversely associated with age and body mass index in patients with PAD both with and without diabetes (p <0.05). In conclusion, magnetic resonance imaging-quantified thigh muscle volumes are highly reproducible and may be of interest in assessing PAD patients with and without diabetes.

Volumetric analysis on computed tomography Angiography in the management of thoracic aortic dissection in case of seven years follow-up period

Purpose. To establish the methods for estimating the volume of the true and false aortic canals applying computed tomography angiography (CTA) to a clinical case with hybrid stent-graft thoracic aorta with distal stent-graftinduced new entry associated (d-SINE) in the long-term follow-up period in comparison with a widely used technique of measuring diameters of the aorta on different levels.Materials and methods. Sequential analysis of CTA in a 7-year follow-up was performed. Aorta was divided into 3 segments, in each segment total aortic volumes (AV), volume of the true canal (TC), and volume of functional lumen of the false canal (FLFC) were calculated. The following were mathematically calculated: volume of the false canal (FC) via difference in volume between AV and TC, volume of the thrombosed lumen of FC as the difference between FC and FLFC, the coefficient of FC thrombosis, the degree of stent-graft opening. Mathematical assessment of excess volume of the graft was performed.Results. Modelling of aortic cavity, evaluation of changes in the volumes of TC and FC during a long-term follow-up, analysis of the factors inducing the development of the d-SINE syndrome were performed. When comparing the volume of the graft and the volume of the implantation zone, an excess of 234% was found, while the opening of the graft was 80%. When using the reference method based on the diameter of the true lumen of the aorta, the excess was 22% during one-year follow-up period showing no changes subsequently.Conclusion. Potentially, the method of measuring volumes based on CTA results can be used to complement the generally accepted method based on measuring diameters, since it does not require additional financial resources and has the potential to estimate effectiveness of treatment and identify complications predictors in the postoperative period to determine indications for reoperation.

Directional versus orbital atherectomy of femoropopliteal artery lesions: Angiographic and intravascular ultrasound outcomes.

The aim of this study was to compare the ability of two different atherectomy modalities, the directional atherectomy system (DAS) and the orbital atherectomy system (OAS), to modify plaque and augment luminal gain as evaluated by angiography and intravascular ultrasound (IVUS) in patients with symptomatic femoro-popliteal peripheral arterial disease (PAD). Atherectomy is frequently utilized in the treatment of complex PAD. To date, there are no head-to-head comparisons of existing devices and their selection is based mostly on operator preference rather than on supportive data. This was a single-center, prospective, randomized trial designed to assess the impact of DAS in comparison to OAS on atherosclerotic plaque. Pre- and postatherectomy lesion characterization was performed by angiography and IVUS. Drug-coated balloon (DCB) angioplasty was performed after atherectomy with similar analysis repeated. Sixty patients were randomized to undergo either DAS or OAS. Pretreatment angiographic and IVUS characteristics were similar in the DAS and OAS groups. DAS led to a greater reduction in plaque volume throughout the entire lesion (5.9% vs. 1.1%, p = 0.003). This corresponded to a greater increase in total vessel and lumen volume by IVUS (161.5 mm3 vs. 50.2 mm3 , p = 0.001; 178.6 mm3 vs. 47.0 mm3 , p = 0.004, respectively), as well as a reduction in angiographic stenosis (40% vs. 70%, p < 0.001). After DCB, 10 patients required stenting for suboptimal results in the OAS group compared with twoin the DAS group (p = 0.021). Compared to OAS, DAS demonstrated a greater plaque volume reduction and luminal gain with significantly fewer stents needed post-DCB.

Serial Changes in Coronary Plaque Formation Using CT Angiography in Patients Undergoing PCSK9-Inhibitor Therapy With 1-year Follow-up.

Previous studies have shown positive effects of intensive low-density lipoprotein (LDL)-lowering therapy on atheroma volume using invasive intravascular ultrasound. This study describes the changes in coronary plaque composition on coronary computed tomography angiography in patients treated with proprotein convertase subtilisin kexin type 9 (PCSK9) inhibitors. In this prospective study, coronary plaques were analyzed using third-generation dual-source computed tomography before and after 1 year of PCSK9-inhibitor treatment. Plaque markers included total plaque volume (TPV), calcified plaque volume (CPV), noncalcified plaque volume (NCPV), lumen volume and vessel volume (VV), minimal luminal area (MLA), minimal lumen diameter (MLD), corrected coronary opacification, eccentricity, remodeling index, and functional plaque parameters. Primary endpoint was defined as change in TPV; the secondary endpoint was TPV or CPV regression or nominal change in plaque parameters. We analyzed 74 coronary plaques in 23 patients (60±9y, 65% male). After 1 year of PCSK9-inhibitor treatment, LDL was reduced from 148 to 66mg/dL ( P <0.0001). Significant changes were found for VV (196 to 215mm 3 , P =0.0340), MLA (3.1 to 2.6mm 2 , P =0.0413), and MLD (1.7 to 1.4mm, P =0.0048). TPV, CPV, NCPV, lumen volume, and functional plaque parameters did not change significantly ( P >0.05). Coronary artery plaque analysis by coronary computed tomography angiography highlights that LDL lowering therapy affects plaque composition. The primary endpoint of TPV change was not reached; however, VV, MLA, and MLD changed significantly.

Effects of moderate dose rosuvastatin on carotid plaque in patients with diabetes mellitus evaluated by magnetic resonance imaging

Objective: To observe the effect of lipid regulating therapy on carotid atherosclerotic plaque in diabetic patients. Methods: The REACH study, conducted between March 2009 and February 2012, enrolled asymptomatic patients with magnetic resonance imaging (MRI) confirmed carotid atherosclerotic plaque, who had never taken lipid-lowering drugs. Patients were treated with a moderate dose of rosuvastatin for 24 months. Blood lipid levels were measured and carotid MRI was performed at baseline, 3 and 24 months after treatment. The volume of carotid wall and lipid-rich necrotic core (LRNC) were measured by image analysis software. This study retrospectively analyzed patients in the REACH study. Patients were divided into diabetes group and non-diabetic group. The changes of blood lipid level and MRI parameters of carotid atherosclerotic plaque were compared between the two groups and their correlation was analyzed. Results: A total of 38 patients with carotid atherosclerotic plaque were included in this study, including 13 patients (34.2%) in the diabetic group and 25 patients (65.8%) in the non-diabetic group. Baseline parameters were comparable between the two groups, except higher HbA1c level in diabetes group (P<0.05). Compared with baseline, the total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) and triglyceride (TG) levels were significantly decreased at 3 and 24 months in both two groups (P<0.05). The change of high-density lipoprotein cholesterol (HDL-C) in diabetes group was not obvious, while it was significantly increased in non-diabetic group at 24 months ((1.38±0.33) mmol/l vs. (1.26±0.26) mmol/l, P<0.05). MRI results showed that the volume and percentage of LRNC remained unchanged at 3 months, slightly decreased at 24 months (64.86 (45.37, 134.56) mm3 vs. 75.76 (48.20, 115.64) mm3, P>0.05) and (15.84% (11.47%, 24.85%) vs. 16.95% (11.64%, 22.91%), P>0.05) in diabetic group. In non-diabetic group, the volume and percentage of LRNC were significantly decreased at 3 months (63.01 (44.25, 188.64) mm3 vs. 72.49 (51.91, 199.59) mm3, P<0.05) and (13.76% (8.81%, 27.64%) vs. 16.04% (11.18%, 27.05%), P<0.05) respectively. Both parameters further decreased to (55.63 (27.18, 179.40) mm3) and (12.71% (8.39%, 24.41%)) at 24 months (both P<0.05). Wall volume, lumen volume and percent wall volume (PWV) were not affected post therapy in both two groups(P>0.05). There were no correlations between the changes of plaque parameters including volume and percentage of LRNC, wall volume, lumen volume, PWV and the changes of blood lipid parameters (TC, LDL-C, HDL-C and TG) in 3 and 24 months (P>0.05). Conclusion: Lipid-lowering therapy possesses different effects on carotid atherosclerotic plaque in diabetic and non-diabetic patients, and the LRNC improvement is more significant in non-diabetic patients as compared to diabetic patients.

False Lumen Flow Assessment by Magnetic Resonance Imaging and Long-Term Outcomes in Uncomplicated Aortic Dissection

BackgroundDespite the absence of clinical complications after an acute aortic dissection (AD) with persistent patent false lumen (FL), a high risk for clinical events may persist. ObjectivesThe aim of this study was to assess the natural evolution of noncomplicated AD and ascertain whether different FL flow patterns by magnetic resonance imaging (MRI) have independent prognostic value for AD-related events beyond established morphologic parameters. MethodsOne hundred thirty-one consecutive patients, 78 with surgically treated type A dissections and 53 with medically treated type B dissections, were followed up prospectively after acute AD with persistent patent FL in the descending aorta. Maximum aortic diameter, true lumen compression, entry tear, and partial FL thrombosis by computed tomography were assessed. Systolic antegrade true lumen and FL flow volumes and diastolic antegrade and retrograde flows were analyzed by MRI during the first year after AD. ResultsAfter a median follow-up period of 8.0 years (IQR: 4.6-10.9 years), 43 patients presented aorta-related events (25 died and 18 required endovascular treatment). FL systolic antegrade flow ≥30% with respect to total systolic antegrade flow and retrograde diastolic flow ≥80% with respect to total diastolic FL flow were predictors of aortic events. In multivariate analysis, aortic diameter >45 mm (HR: 2.91), type B dissection (HR: 2.44), and MRI flow pattern (HR: 16.87) were independent predictors of AD-related events. ConclusionsHigh systolic antegrade flow volume in the FL with significant diastolic retrograde flow assessed by MRI and aortic diameter >45 mm identify patients with higher risk for complications in whom more aggressive management would be indicated.

A new noninvasive and patient-specific hemodynamic index for the severity of renal stenosis and outcome of interventional treatment.

Renal arterial stenosis (RAS) often causes renovascular hypertension, which may result in kidney failure and life‐threatening consequences. Direct assessment of the hemodynamic severity of RAS has yet to be addressed. In this work, we present a computational concept to derive a new, noninvasive, and patient‐specific index to assess the hemodynamic severity of RAS and predict the potential benefit to the patient from a stenting therapy. The hemodynamic index is derived from a functional relation between the translesional pressure indicator (TPI) and lumen volume reduction (S) through a parametric deterioration of the RAS. Our in‐house computational platform, InVascular, for image‐based computational hemodynamics is used to compute the TPI at given S. InVascular integrates unified computational modeling for both image processing and computational hemodynamics with graphic processing unit parallel computing technology. The TPI–S curve reveals a pair of thresholds of S indicating mild or severe RAS. The TPI at S = 0 represents the pressure improvement following a successful stenting therapy. Six patient cases with a total of 6 aortic and 12 renal arteries are studied. The computed blood pressure waveforms have good agreements with the in vivo measured ones and the systolic pressure is statistical equivalence to the in‐vivo measurements with p < .001. Uncertainty quantification provides the reliability of the computed pressure through the corresponding 95% confidence interval. The severity assessments of RAS in four cases are consistent with the medical practice. The preliminary results inspire a more sophisticated investigation for real medical insights of the new index. This computational concept can be applied to other arterial stenoses such as iliac stenosis. Such a noninvasive and patient‐specific hemodynamic index has the potential to aid in the clinical decision‐making of interventional treatment with reduced medical cost and patient risks.

A 3D multi-agent-based model for lumen morphogenesis: the role of the biophysical properties of the extracellular matrix

The correct function of many organs depends on proper lumen morphogenesis, which requires the orchestration of both biological and mechanical aspects. However, how these factors coordinate is not yet fully understood. Here, we focus on the development of a mechanistic model for computationally simulating lumen morphogenesis. In particular, we consider the hydrostatic pressure generated by the cells’ fluid secretion as the driving force and the density of the extracellular matrix as regulators of the process. For this purpose, we develop a 3D agent-based-model for lumen morphogenesis that includes cells’ fluid secretion and the density of the extracellular matrix. Moreover, this computer-based model considers the variation in the biological behavior of cells in response to the mechanical forces that they sense. Then, we study the formation of the lumen under different-mechanical scenarios and conclude that an increase in the matrix density reduces the lumen volume and hinders lumen morphogenesis. Finally, we show that the model successfully predicts normal lumen morphogenesis when the matrix density is physiological and aberrant multilumen formation when the matrix density is excessive.

Abstract 286: Prediction Of Adverse Events Following Stent Graft Repair Of Type B Aortic Dissection From Imaging Modalities

Objectives: The prophylactic treatment of uncomplicated TBAD with TEVAR is controversial. This warrants the identification of a high-risk category of dissections that may particularly benefit from surgical intervention. The analysis of radiographic features presents a promising modality of assessing this high-risk cohort. We test the ability of aortic size and shape metrics from the literature to predict patient suitability for TEVAR from pre-operative imaging. Methods: We collected a single institutional retrospective cohort of 36 patients with TBAD who received TEVAR and had pre-operative and follow-up CTA imaging. We tested 8 aortic size and shape metrics. We segmented each patient’s aorta and true lumen from the pre-operative scan. Tortuosity, mean diameter, centerline curvature, and eccentricity were measured from the centerline. True and false lumen volumes and max diameter were calculated. The question mark angle, as previously defined by Li et al., was also measured. Univariate and multivariate logistic regression analyses were performed. Results: In the univariate analysis, pre-operative false lumen volume (OR 26.2 95% CI 2.72 to 252, p = .005), mean diameter (OR 9.6 95% CI 2.19 to 42.3, p = .003), and maximum diameter (OR 9.0 95% CI 2.12 to 38.3, p = .003) were all significantly associated with post-TEVAR outcomes. Tortuosity index (OR 2.7, 95% CI 1.14 to 6.37, p = .024) was the only significant shape parameter. In multivariate analysis, we found that pre-operative maximum diameter (OR 10.0, 95% CI 1.50 to 67.0, p &lt; .018) is a significant predictor of TEVAR outcomes independent of shape parameters, all of which were not significant. Conclusions: False lumen volume and maximum diameter can predict the occurrence of reintervention and type I endoleak following TEVAR for uncomplicated TBAD. While size measures are effective in explaining aortic dissection behavior, current shape measures are not as effective and better methodologies must be developed.

Differences in Plaque Characteristics and Myocardial Mass: Implications for Physiological Significance.

The mechanism of the fractional flow reserve (FFR) difference according to sex has not been clearly understood. This study sought to evaluate sex differences in coronary stenosis, plaque characteristics, and left ventricular (LV) mass and their implications for physiological significance. This was a post hoc analysis of a pooled population of multicenter, international prospective cohorts. Patients (166 women and 489 men) underwent coronary computed tomography angiography (CCTA) within 90days before invasive FFR measurements were included. The minimal lumen area, percent of plaque burden, whole vessel plaque volume by composition, high-risk plaque characteristics, and LV mass were analyzed from CCTA images. Among 1,188 vessels analyzed, the FFR value was higher in women than that in men (0.85 ± 0.13 vs 0.82 ± 0.14; P = 0.001) despite a similar percentage of diameter stenosis between the sexes (45.9% ± 18.9% vs 46.1% ± 17.7%; P = 0.920). The composition of fibrofatty plaque+ necrotic core (13.1% ± 16.9% vs 21.2% ± 19.9%; P< 0.001) and frequencies of low attenuation plaque (12.7% vs 24.5%; P< 0.001) and positive remodeling (33.8% vs 45.5%; P=0.001) were lower in women than in men. Vessel, plaque, and lumen volumes were significantly smaller in women than that in men (all P< 0.001); however, no sex difference was observed in any of these parameters after adjustment for LV mass (all P > 0.10). Sex was not an independent predictor of the FFR value after adjustment for stenosis severity, plaque characteristics, and LV mass. Higher FFR values for the same stenosis severity in women can be explained by fewer high-risk plaque characteristics and smaller myocardial mass in women than that in men. (CCTA-FFR Registry for RiskPrediction;NCT04037163).

Plaque contact surface area and lumen volume predict stroke risk in extracranial carotid artery stenosis

BackgroundThe standard indication for intervention in asymptomatic disease is currently percent stenosis in the internal carotid artery as measured by the North American Symptomatic Carotid Endarterectomy Trial (NASCET) method, which remains limited in discriminating power. Computed tomography angiography (CTA) is widely used to calculate NASCET stenosis, but also offers the opportunity to analyze carotid artery plaques from a morphological perspective that has not been widely used. We aim to improve stroke risk stratification of patients with carotid artery stenosis using plaque three-dimensional (3D) modeling and image analysis. MethodsPatients with computed tomography angiographies appropriate for 3D reconstruction were identified from a National Institutes of Health-designated stroke center database, and carotid arteries were segmented and analyzed using software algorithms to calculate contact surface area (CSA) between the plaque and blood flow, and volume of the flow lumen within the region of the plaque (lumen volume [LV]). These novel parameters factor in the 3D morphometry inherent to each carotid plaque and were compared between stroke and nonstroke groups. ResultsA total of 134 carotid arteries were analyzed, 33 of which were associated with an ipsilateral stroke. Plaques associated with stroke demonstrated statistically significant increases in average CSA (541.52 mm2) and LV (394.64 mm3) when compared with those not associated with stroke (371.18 mm2 and 245.92 mm3, respectively). When comparing area under the receiver operating characteristics curve between NASCET (0.65) percent stenosis, CSA (0.74), and LV (0.77), both CSA and LV demonstrated more favorable values in predicting stroke risk in patients with carotid stenosis. ConclusionsThe data presented here demonstrate morphological features of carotid plaques that are independent of NASCET criteria stratification and may present an improved method in assessing stroke risk in patients with carotid artery stenosis.

Assessment relationship between the femoral artery vasospasm and dorsal root ganglion cell degeneration in spinal subarachnoid hemorrhage: an experimental study.

Animal proof of principle study. To investigate neurodegeneration in rabbit L4-dorsal root ganglion (DRG) cells by creating experimental spinal subarachnoid hemorrhage (SAH), we aimed to show the neuronal pathway between L4-DRG and femoral artery. Ataturk University, Medical Faculty, Animal Laboratory, Erzurum, Turkey. This study was designed on 20 rabbits, which were randomly divided into three groups: Spinal SAH (n = 8), SHAM (n = 6), and control (n = 6) groups. Animals were followed for 20 days and then killed. Vasospasm index values of the femoral artery and neuron density of L4-DRG were analyzed. The number of degenerated neurons in DRG was higher in the spinal SAH than the control and SHAM groups (p < 0.001). But, the difference between the control group and the SHAM group was not significant. Normal neuron densities were significantly lower in the spine SAH group compared to the SHAM and the control groups. There was a statistically significant increase in vasospasm index values of the spinal SAH group compared to the other two groups (p < 0.001). Decreased volume of the femoral artery lumen was showed in animals with spinal SAH compared with control and SHAM groups. Increased degeneration of the L4 dorsal root ganglion in animals with spinal SAH was also demonstrated. Our findings might shed light on the planning of future experimental studies and evaluating the clinical relevance of such studies.