Fast Approximate Quantification of Endovascular Stent Graft Displacement Forces in the Bovine Aortic Arch Variant.

PURPOSE: Displacement forces (DFs) identify hostile landing zones for stent graft deployment in thoracic endovascular aortic repair (TEVAR). However, their use in TEVAR planning is hampered by the need for time-expensive computational fluid dynamics (CFD). We propose a novel fast-approximate computation of DFs merely exploiting aortic arch anatomy, as derived from the computed tomography (CT) and a measure of central aortic pressure. MATERIALS AND METHODS: We tested the fast-approximate approach against CFD gold-standard in 34 subjects with the "bovine" aortic arch variant. For each dataset, a 3-dimensional (3D) model of the aortic arch lumen was reconstructed from computed tomography angiography and CFD then employed to compute DFs within the aortic proximal landing zones. To quantify fast-approximate DFs, the wall shear stress contribution to the DF was neglected and blood pressure space-distribution was averaged on the entire aortic wall to reliably approximate the patient-specific central blood pressure. Also, DF values were normalized on the corresponding proximal landing zone area to obtain the equivalent surface traction (EST). RESULTS: Fast-approximate approach consistently reflected (r2=0.99, p<0.0001) the DF pattern obtained by CFD, with a -1.1% and 0.7° bias in DFs magnitude and orientation, respectively. The normalized EST progressively increased (p<0.0001) from zone 0 to zone 3 regardless of the type of arch, with proximal landing zone 3 showing significantly greater forces than zone 2 (p<0.0001). Upon DF normalization to the corresponding aortic surface, fast-approximate EST was decoupled in blood pressure and a dimensionless shape vector (S) reflecting aortic arch morphology. S showed a zone-specific pattern of orientation and proved a valid biomechanical blueprint of DF impact on the thoracic aortic wall. CONCLUSION: Requiring only a few seconds and quantifying clinically relevant biomechanical parameters of proximal landing zones for arch TEVAR, our method suits the real preoperative decision-making process. It paves the way toward analyzing large population of patients and hence to define threshold values for a future patient-specific preoperative TEVAR planning.

Non-invasive estimation of vascular compliance and distensibility in the arm vessels: a novel ultrasound-based protocol.

Background: Performance and durability of arterio-venous grafts depend on their ability to mimic the mechanical behavior of the anastomized blood vessels. To select the most suitable synthetic graft, in vivo evaluation of the radial deformability of peripheral arteries and veins could be crucial; however, a standardized non-invasive strategy is still missing. Herein, we sought to define a novel and user-friendly clinical protocol for in vivo assessment of the arm vessel deformability. Methods: A dedicated protocol, applied on 30 volunteers, was specifically designed to estimate both compliance and distensibility of the brachial and radial arteries, and of the basilic and cephalic veins. Bi-dimensional ultrasound imaging was used to acquire cross-sectional areas (CSAs) of arteries in clinostatic configuration, and CSAs of veins combining clinostatic and orthostatic configurations. Arterial pulse pressure was measured with a digital sphygmomanometer, while venous hydrostatic pressure was derived from the arm length in orthostatic configuration. Results: For each participant, all CSAs were successfully extracted from ultrasound images. The basilic vein and the radial artery exhibited the largest (21.5±8.9 mm2) and the smallest (3.4±1.0 mm2) CSAs, respectively; CSA measurements were highly repeatable (Bland-Altman bias <10% and Pearson correlation ≥0.90, for both arteries and veins). In veins, compliance and distensibility were higher than in arteries; compliance was significantly higher (P<0.0001) in the brachial than in the radial artery (3.52×10-4 vs. 1.3×10-4 cm2/mmHg); it was three times larger in basilic veins than in cephalic veins (17.4×10-4 vs. 5.6×10-4 cm2/mmHg, P<0.0001). Conclusions: The proposed non-invasive protocol proved feasible, effective and adequate for daily clinical practice, allowing for the estimation of patient-specific compliance and distensibility of peripheral arteries and veins. If further extended, it may contribute to the fabrication of biohybrid arterio-venous grafts, paving the way towards patient-tailored solutions for vascular access.

Psoas Cross-Sectional Measurements Using Manual CT Segmentation before and after Endovascular Aortic Repair (EVAR).

Sarcopenia has been associated with an increased incidence of adverse outcomes, including higher mortality, after endovascular aortic repair (EVAR). We aim to use computed tomography (CT) to quantify changes in total psoas muscles area (PMA) and psoas muscle density (PMD) after EVAR, and to evaluate the reproducibility of both measurements. PMA and PMD were assessed via manual segmentation of the psoas muscle on pre- and post-operative CT scans belonging to consecutive patients who underwent EVAR. Wilcoxon test was used to compare PMA and PMD before and after EVAR, and inter- and intra-reader agreements of both methods were evaluated through Bland−Altman analysis. A total of 50 patients, 42 of them males (84%), were included in the study. PMA changes from 1243 mm2 (1006−1445 mm2) to 1102 mm2 (IQR 937−1331 mm2), after EVAR (p < 0.001). PMD did not vary between pre-EVAR (33 HU, IQR 26.5−38.7 HU) and post-EVAR (32 HU, IQR 26−37 HU, p = 0.630). At inter-reader Bland−Altman analysis, PMA showed a bias of 64.0 mm2 and a coefficient of repeatability (CoR) of 359.2 mm2, whereas PMD showed a bias of −2.43 HU and a CoR of 6.19 HU. At intra-reader Bland−Altman analysis, PMA showed a bias of −81.1 mm2 and a CoR of 394.6 mm2, whereas PMD showed a bias of 1.41 HU and a CoR of 6.36 HU. In conclusion, PMA decreases after EVAR. A good intra and inter-reader reproducibility was observed for both PMA and PMD. We thus propose to use PMA during the follow-up of patients who underwent EVAR to monitor muscle depletion after surgery.

A Deep Learning-Based and Fully Automated Pipeline for Thoracic Aorta Geometric Analysis and Planning for Endovascular Repair from Computed Tomography.

Feasibility assessment and planning of thoracic endovascular aortic repair (TEVAR) require computed tomography (CT)-based analysis of geometric aortic features to identify adequate landing zones (LZs) for endograft deployment. However, no consensus exists on how to take the necessary measurements from CT image data. We trained and applied a fully automated pipeline embedding a convolutional neural network (CNN), which feeds on 3D CT images to automatically segment the thoracic aorta, detects proximal landing zones (PLZs), and quantifies geometric features that are relevant for TEVAR planning. For 465 CT scans, the thoracic aorta and pulmonary arteries were manually segmented; 395 randomly selected scans with the corresponding ground truth segmentations were used to train a CNN with a 3D U-Net architecture. The remaining 70 scans were used for testing. The trained CNN was embedded within computational geometry processing pipeline which provides aortic metrics of interest for TEVAR planning. The resulting metrics included aortic arch centerline radius of curvature, proximal landing zones (PLZs) maximum diameters, angulation, and tortuosity. These parameters were statistically analyzed to compare standard arches vs. arches with a common origin of the innominate and left carotid artery (CILCA). The trained CNN yielded a mean Dice score of 0.95 and was able to generalize to 9 pathological cases of thoracic aortic aneurysm, providing accurate segmentations. CILCA arches were characterized by significantly greater angulation (p = 0.015) and tortuosity (p = 0.048) in PLZ 3 vs. standard arches. For both arch configurations, comparisons among PLZs revealed statistically significant differences in maximum zone diameters (p < 0.0001), angulation (p < 0.0001), and tortuosity (p < 0.0001). Our tool allows clinicians to obtain objective and repeatable PLZs mapping, and a range of automatically derived complex aortic metrics.

Biomarkers Predict In-Hospital Major Adverse Cardiac Events in COVID-19 Patients: A Multicenter International Study.

BACKGROUND: The COVID-19 pandemic carries a high burden of morbidity and mortality worldwide. We aimed to identify possible predictors of in-hospital major cardiovascular (CV) events in COVID-19. METHODS: We retrospectively included patients hospitalized for COVID-19 from 10 centers. Clinical, biochemical, electrocardiographic, and imaging data at admission and medications were collected. Primary endpoint was a composite of in-hospital CV death, acute heart failure (AHF), acute myocarditis, arrhythmias, acute coronary syndromes (ACS), cardiocirculatory arrest, and pulmonary embolism (PE). RESULTS: Of the 748 patients included, 141(19%) reached the set endpoint: 49 (7%) CV death, 15 (2%) acute myocarditis, 32 (4%) sustained-supraventricular or ventricular arrhythmias, 14 (2%) cardiocirculatory arrest, 8 (1%) ACS, 41 (5%) AHF, and 39 (5%) PE. Patients with CV events had higher age, body temperature, creatinine, high-sensitivity troponin, white blood cells, and platelet counts at admission and were more likely to have systemic hypertension, renal failure (creatinine ≥ 1.25 mg/dL), chronic obstructive pulmonary disease, atrial fibrillation, and cardiomyopathy. On univariate and multivariate analysis, troponin and renal failure were associated with the composite endpoint. Kaplan-Meier analysis showed a clear divergence of in-hospital composite event-free survival stratified according to median troponin value and the presence of renal failure (Log rank p < 0.001). CONCLUSIONS: Our findings, derived from a multicenter data collection study, suggest the routine use of biomarkers, such as cardiac troponin and serum creatinine, for in-hospital prediction of CV events in patients with COVID-19.

Carotid Phase-Contrast Magnetic Resonance before Treatment: 4D-Flow versus Standard 2D Imaging.

The purpose of this study was to evaluate the level of agreement between flow/velocity data obtained from 2D-phase-contrast (PC) and 4D-flow in patients scheduled for treatment of carotid artery stenosis. Image acquisition was performed using a 1.5 T scanner. We compared mean flow rates, vessel areas, and peak velocities obtained during the acquisition with both techniques in 20 consecutive patients, 15 males and 5 females aged 69 ± 5 years (mean ± standard deviation). There was a good correlation between both techniques for the CCA flow (r = 0.65, p < 0.001), whereas for the ICA flow and ECA flow the correlation was only moderate (r = 0.4, p = 0.011 and r = 0.45, p = 0.003, respectively). Correlations of peak velocities between methods were good for CCA (r = 0.56, p < 0.001) and moderate for ECA (r = 0.41, p = 0.008). There was no correlation for ICA (r = 0.04, p = 0.805). Cross-sectional area values between methods showed no significant correlations for CCA (r = 0.18, p = 0.269), ICA (r = 0.1, p = 0.543), and ECA (r = 0.05, p = 0.767). Conclusion: the 4D-flow imaging provided a good correlation of CCA and a moderate correlation of ICA flow rates against 2D-PC, underestimating peak velocities and overestimating cross-sectional areas in all carotid segments.

Pre-admission acetylsalicylic acid therapy and impact on in-hospital outcome in COVID-19 patients: The ASA-CARE study.

BACKGROUND: Patients with coronavirus disease 2019 (COVID-19) exhibit high thrombotic risk. The evidence on a potential independent prognostic role of antiplatelet treatment in those patients is limited. The aim of the study was to evaluate the prognostic impact of pre-admission low-dose acetylsalicylic acid (ASA) in a wide series of hospitalized patients with COVID-19. METHODS: This cohort study included 984 COVID-19 patients stratified according to ASA intake before hospitalization: ASA+ (n = 253) and ASA- (n = 731). Patients were included in ASA+ group if they received it daily in the 7 days before admission. 213 (83%) were on ASA 100 mg daily. Primary endpoint was a composite of in-hospital death and/or need for respiratory support upgrade, secondary endpoints were in-hospital death and need for respiratory support upgrade. RESULTS: Mean age was 72 [62; 81] with 69% of male patients. ASA+ patients were significantly older, with higher prevalence of comorbidities. No significant differences regarding the degree of respiratory dysfunction were observed. At 30-day Kaplan-Meier analysis, ASA+ patients had higher survival free from the primary endpoint and need for respiratory support upgrade, conversely in-hospital death did not significantly differ between groups. At multivariate analysis ASA intake was independently associated with a lower probability of reaching primary endpoint (HR 0.697, 95% C.I. 0.525-0.924; p = 0.012). CONCLUSIONS: In COVID-19 patients undergoing hospitalization, pre-admission treatment with ASA is associated with better in-hospital outcome, mainly driven by less respiratory support upgrade.

COVID and venous thrombosis: systematic review of literature.

INTRODUCTION: We aimed to review the prevalence, the risk factors and the outcomes of venous thrombosis (VT) in patients hospitalized for COronaVirus Disease 19 (COVID-19). EVIDENCE ACQUISITION: Electronic bibliographic databases were searched using the words "COVID venous thrombosis". The review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement standards. EVIDENCE SYNTHESIS: The search of the literature retrieved 877 results. After assessment of full texts, 69 papers were included in the qualitative analysis and 23 of them in the quantitative evaluation. The analyzed studies included a total of 106,838 patients hospitalized for COVID-19 from January to December 2020. The pooled reported prevalence rate of VT was in median 16.7% (IQR 5.8-30%), being higher in ICU patients (60.8-85.4%). VT events were reported in about 75% of cases in the popliteal and calf veins. Signs and symptoms were present in 6.1% of cases. At quantitative evaluation, older age, D-dimer and obesity increased the odds to experience a VT (OR=3.54, 95% CI 0.65-6.43, P=0.01; OR=956.86, 95% CI 225.67-1668.05, P=0.01; OR=1.42, 95% CI 1.01-1.99, P=0.03 respectively). Female sex seemed to be protective against the odds of VT (OR=0.77, 95% CI 0.63-0.93, P=0.007). CONCLUSIONS: Among patients hospitalized for COVID-19, VT is a relatively common finding, with higher prevalence rates in ICU patients. VT occurs mostly in the distal regions of the lower limb and is asymptomatic in most cases. Older age, obesity and higher D-dimer values on admission increased the odds of VT, while female sex was protective against the odds of VT.

Blood flow helical pattern in type III arch configuration as a potential risk factor for type B aortic dissection.

OBJECTIVES: Abnormal helical flow (HF) in the aortic arch has been proposed as a causative factor for aortic dilatation and aortic dissections (ADs). Patients with type B AD present a high prevalence of type III arch configuration, which comprises recognized anatomic AD risk factors. Our aim was to assess whether the type III arch configures a consistent secondary HF pattern. METHODS: We employed computational fluid dynamics to compare HF features associated with type I-III arches. The intra-aortic blood flow pattern was regionally assessed through the Modified Arch Landing Areas Nomenclature (MALAN) for planning endovascular aortic repair. Aortic flow pathlines were extracted from the systolic aortic velocity field and objectively characterized through intrinsic shape indices of absolute curvature |κ| and absolute torsion |τ|. Absolute local normalized helicity was computed and mapped on aortic flow pathlines. RESULTS: The tendency of aortic flow pathlines to bend and rotate exacerbated in the isthmus of type III arch (MALAN 3/III), where the highest |κ| values (P < 0.0001) were paralleled by the lowest |τ| values (P = 0.010), demonstrating the persistence of a high rotational HF heavily insisting on 3/III. In 3/III area, local normalized helicity was higher than both 3/I and 3/II (P = 0.053). CONCLUSIONS: Type III arch configuration is associated with a specific, consistent and abnormal secondary HF pattern, which may account for its high prevalence in patients with type B AD.

Sudden rupture of small aneurysm of the radial artery in a patient with COVID-19 pneumonia.

In patients with COVID-19, even small radial aneurysm may suddenly rupture.

Implications of different definitions for aortic arch classification provided by contemporary guidelines on thoracic aortic repair.

Contemporary guidelines on thoracic aortic repair provide inconsistent reporting standards for the definition of aortic arch classification in Types I, II and III. The different reported criteria cannot be used interchangeably, due to a very low level of concordance, and this finding has relevant implications for the comparisons between studies using different classifications, and between different datasets of multicentre trials, which are not consistently analyzed with the same criteria. Also, the reported definitions, which were originally proposed for predicting difficult carotid stenting and therefore were conceived for healthy aortic arches, can be influenced by the pathological derangements of the aortic wall, including aneurysms and dissections. In this respect, the Madhwal's classification, which is based on the diameter of the left common carotid artery, appears to be the more suitable one for aortic arch classification in patients with thoracic aortic disease because it provides relevant clinical information along with an adequate reproducibility.

Impact of the coronavirus disease 2019 (COVID-19) pandemic on the care of patients with acute and chronic aortic conditions.

OBJECTIVES: To evaluate the impact of the coronavirus disease 2019 (COVID-19) pandemic on acute and elective thoracic and abdominal aortic procedures. METHODS: Forty departments shared their data on acute and elective thoracic and abdominal aortic procedures between January and May 2020 and January and May 2019 in Europe, Asia and the USA. Admission rates as well as delay from onset of symptoms to referral were compared. RESULTS: No differences in the number of acute thoracic and abdominal aortic procedures were observed between 2020 and the reference period in 2019 [incidence rates ratio (IRR): 0.96, confidence interval (CI) 0.89-1.04; P = 0.39]. Also, no difference in the time interval from acute onset of symptoms to referral was recorded (<12 h 32% vs > 12 h 68% in 2020, < 12 h 34% vs > 12 h 66% in 2019 P = 0.29). Conversely, a decline of 35% in elective procedures was seen (IRR: 0.81, CI 0.76-0.87; P < 0.001) with substantial differences between countries and the most pronounced decline in Italy (-40%, P < 0.001). Interestingly, in Switzerland, an increase in the number of elective cases was observed (+35%, P = 0.02). CONCLUSIONS: There was no change in the number of acute thoracic and abdominal aortic cases and procedures during the initial wave of the COVID-19 pandemic, whereas the case load of elective operations and procedures decreased significantly. Patients with acute aortic syndromes presented despite COVID-19 and were managed according to current guidelines. Further analysis is required to prove that deferral of elective cases had no impact on premature mortality.

Assessing QT interval in COVID-19 patients:safety of hydroxychloroquine-azithromycin combination regimen.

BACKGROUND: Hydroxychloroquine (HCQ) and azithromycin (AZT) have been proposed for COVID-19 treatment. Data available in the literature reported a potential increased risk of fatal arrhythmias under these therapies. The aim of this study was to assess the effects of these drugs on QT interval and outcome in a COVID-19 population. METHOD: A total of 112 consecutive COVID-19 patients were included in this analysis and were divided in 3 groups according to the receiving therapeutic regimens: 19 (17%) patients in Group 1 (no treatment), 40 (36%) in Group 2 (HCQ only), 53 (47%) in Group 3 (HCQ/AZT). RESULTS: A prolonged QTc interval was found in 61% of patients treated with HCQ alone or in combination with AZT, but only 4 (4%) patients showed a QTc > 500 ms. HCQ/AZT combination determined a greater increase of QTc duration compared to the other two strategies (Group 3 452 ± 26.4 vs Group 2 436.3 ± 28.4 vs Group 1 424.4 ± 24.3 ms, respectively; p < 0.001). Multivariate analysis demonstrated that HCQ/AZT combination (OR 9.02, p = 0.001) and older age (OR 1.04, p = 0.031) were independent predictors of QTc prolongation. The risk increased with age (incremental utility analysis p = 0.02). Twenty patients (18%) died, and no cardiac arrest neither arrhythmic fatalities were documented. CONCLUSIONS: The HCQ/AZT combination therapy causes a significantly increase of QT interval compared to HCQ alone. Older patients under such regimen are at higher risk of experiencing QT prolongation. The use of such drugs may be considered as safe relating to arrhythmic risk in the treatment of COVID-19 patients as no arrhythmic fatalities occurred.

Poor concordance between definitions of type III arch and implications for risk prediction and assessment for carotid artery stenting.

OBJECTIVE: The type III arch configuration has been inconsistently reported as a stroke risk factor during carotid artery stenting. However, at least three different methods for the definition of type III arch can be identified in the literature, related to the level of the origin of the innominate artery (IA). According to Casserly's definition, a type III arch presents with an origin of the IA below the horizontal plane of the inner curvature. According to Madhwal's definition, a type III arch has a distance greater than twice the diameter of the left common carotid artery between the highest point of the arch and the origin of the IA. According to MacDonald's definition, a type III arch presents with a distance of ≥2 cm between the highest point of the arch and the origin of the IA. Our aim was to assess the level of concordance between these different methods. METHODS: Anonymized thoracic computed tomography scans of 100 healthy patients were reviewed. Two of us independently stratified the selected cases as a type I to III arch, according to the three considered definitions. The interobserver level of concordance for each type III arch classification and level of concordance among the three definitions were assessed. RESULTS: The 100 selected patients (64% male) were 76 ± 7 years old. For each definition, the interobserver repeatability was almost perfect for all three (Madhwal, κ = 0.81; 95% confidence interval [CI], 0.71-0.99; MacDonald, κ = 0.82; 95% CI, 0.72-0.92; Casserly, κ = 0.84; 95% CI, 0.74-0.93). The level of concordance among the different definitions was very low (Madhwal vs MacDonald, 85% [P = .002]; 33% for type III arch; Madhwal vs Casserly, 60% [P < .0001]; 12% for type III arch; MacDonald vs Casserly, 75% [P < .0001]; 12% for type III arch). CONCLUSIONS: The three definitions of the type III arch have a very low level of concordance, which might account for the varying clinical relevance of this configuration. Our findings have relevant implications for risk prediction for carotid artery stenting based on the presence of a type III arch, for comparisons of the results from different studies, and for comparisons of different datasets from multicenter trials.

Factors affecting the occurrence of proximal endoleak after endovascular abdominal aortic repair for abdominal aneurysms.

OBJECTIVE: This retrospective study was performed to assess the clinical and radiological variables associated with proximal type IA endoleak (EL) in patients treated with elective endovascular repair for abdominal aortic aneurysms. METHODS: The chi-square test, t-test, and logistic regression analysis were performed as appropriate. A P value of <0.05 was considered statistically significant. RESULTS: The data of 79 patients were analyzed. No mortality occurred. During follow-up (median, 28.5 months; interquartile range, 12.8-43.0 months), 10 patients developed type IA EL. In the logistic regression analysis, undersizing of the endograft diameter by <10% significantly affected the occurrence of type IA EL. When the diameter was used for measurements, less oversizing was significantly associated with a higher risk of type IA EL. When the area was used for measurements, oversizing of >20% significantly affected the occurrence of type IA EL. CONCLUSION: When sizing endografts, a discrepancy was noted between the measurements of the diameter and area of the proximal neck. The area might represent a more accurate measurement than the axial diameter to optimize the proximal sealing and lower the risk of developing type IA EL.