Predictors of In-Hospital Mortality in Type A Acute Aortic Syndrome: Data From the RENADA-RO Registry.

BACKGROUND: This study aimed to analyse the baseline characteristics of patients admitted with acute type A aortic syndrome (ATAAS) and to identify the potential predictors of in-hospital mortality in surgically managed patients. METHODS: Data regarding demographics, clinical presentation, laboratory work-up, and management of 501 patients with ATAAS enrolled in the National Registry of Aortic Dissections-Romania registry from January 2011 to December 2022 were evaluated. The primary endpoint was in-hospital all-cause mortality. Multivariate logistic regression was conducted to identify independent predictors of mortality in patients with acute Type A aortic dissection (ATAAD) who underwent surgery. RESULTS: The mean age was 60±11 years and 65% were male. Computed tomography was the first-line diagnostic tool (79%), followed by transoesophageal echocardiography (21%). Cardiac surgery was performed in 88% of the patients. The overall mortality in the entire cohort was 37.9%, while surgically managed ATAAD patients had an in-hospital mortality rate of 29%. In multivariate logistic regression, creatinine value (OR 6.76), ST depression on ECG (OR 6.3), preoperative malperfusion (OR 5.77), cardiogenic shock (OR 5.77), abdominal pain (OR 4.27), age ≥70 years (OR 3.76), and syncope (OR 3.43) were independently associated with in-hospital mortality in surgically managed ATAAD patients. CONCLUSIONS: Risk stratification based on the variables collected at admission may help to identify ATAAS patients with high risk of death following cardiac surgery.

Successful open surgical treatment for persistent type II endoleak following thoracic endovascular aortic repair: a case report.

BACKGROUND: The occurrence of type II endoleaks after endovascular repair of aortic aneurysm has gradually gained increasing attention. We present a case of a patient with an expanding aneurysm after thoracic endovascular aortic repair (TEVAR) for a type II endoleak, in which successful direct ligations of the intercostal artery were performed using a sac incision without cardiopulmonary bypass (CPB) or graft replacement. CASE PRESENTATION: A 62-year-old male patient, previously treated with TEVAR for a descending thoracic aortic aneurysm, presented with ongoing chest discomfort. Based on the diagnosis of a growing aneurysm and type II endoleak, the patient was prepared for CPB and aortic cross-clamping, as a precautions against the possibility of a type I endoleak. A longitudinal opening of the thoracic aortic aneurysm sac was performed following left thoracotomy. Visual confirmation identified the T5 level intercostal artery as the source of the endoleak, and after confirming the absence of a type I endoleak, multiple ligations were applied to the intercostal artery. Follow-up computed tomography confirmed the absence of endoleaks or sac growth. CONCLUSION: In a case involving TEVAR for a thoracic aortic aneurysm, open suture ligations were used to treat type II endoleaks without having to resort to CPB, resulting in successful outcomes.

Lead Acetate-Injected Mice is an Animal Model for Extrapolation of Calcifying Response to Humans Due to Low Involvement of Bone Resorption.

Vascular calcification affects the prognosis of patients with renal failure. Bisphosphonates are regarded as candidate anti-calcifying drugs because of their inhibitory effects on both calcium-phosphate aggregation and bone resorption. However, calcification in well-known rodent models is dependent upon bone resorption accompanied by excessive bone turnover, making it difficult to estimate accurately the anti-calcifying potential of drugs. Therefore, models with low bone resorption are required to extrapolate anti-calcifying effects to humans. Three bisphosphonates (etidronate, alendronate, and FYB-931) were characterised for their inhibitory effects on bone resorption in vivo and calcium-phosphate aggregation estimated by calciprotein particle formation in vitro. Then, their effects were examined using two models inducing ectopic calcification: the site where lead acetate was subcutaneously injected into mice and the transplanted, aorta obtained from a donor rat. The inhibitory effects of bisphosphonates on bone resorption and calcium-phosphate aggregation were alendronate > FYB-931 > etidronate and FYB-931 > alendronate = etidronate, respectively. In the lead acetate-induced model, calcification was most potently suppressed by FYB-931, followed by alendronate and etidronate. In the aorta-transplanted model, only FYB-931 suppressed calcification at a high dose. In both the models, no correlation was observed between calcification and bone resorption marker, tartrate-resistant acid phosphatase (TRACP). Results from the lead acetate-induced model showed that inhibitory potency against calcium-phosphate aggregation contributed to calcification inhibition. The two calcification models, especially the lead acetate-induced model, may be ideal for the extrapolation of calcifying response to humans because of calcium-phosphate aggregation rather than bone resorption as its mechanism.

A novel technique for H-shaped reinforcement of double-barreled aorta in surgical treatment of chronic aortic dissection.

Anastomosis of the prosthetic graft to the double-barreled aorta with intimal flap fenestration is a useful technique in surgery for chronic aortic dissection. Conversely, anastomosis to the false lumen's outer wall is prone to complications such as pseudoaneurysms, but little is known about the technique of reinforcing the double-barreled aorta. In this report, we describe a surgical case of chronic aortic dissection in which an H-shaped prosthetic graft was sutured to both aortic lumens, including the intimal flap, to prevent complications at the anastomosis site.

Complex aortic plaques: hidden danger in aortic stenosis. Role of transesophageal echocardiography.

Aortic stenosis is associated with aortic plaques in up to 85% of cases because they share risk factors and pathogenic pathways. Intrinsically, complex aortic plaques carry a high risk of stroke, which has also been demonstrated in the context of aortic stenosis, especially in patients who underwent percutaneous or surgical replacement. Transesophageal echocardiography (TEE) is the imaging test of choice to detect plaques in the thoracic aorta and classify them as complex plaques. Furthermore, the 3D modality allows us to better specify its dimensions and anatomical characteristics, such as added thrombi or the presence of ulcers inside. This review aims to evaluate the use of TEE to detect complex aortic plaques in patients with an indication for percutaneous or surgical aortic valve replacement. To highlight the association between aortic stenosis and complex aortic plaques, we attached to the review some TEE studies from our experience.

La estenosis aórtica se asocia con placas aórticas hasta en un 85% de los casos, porque comparten factores de riesgo y vías patogénicas. Intrínsecamente, las placas aórticas complejas conllevan un alto riesgo de accidente cerebrovascular, lo que también se ha demostrado en el contexto de estenosis aórtica, especialmente en pacientes sometidos a reemplazo percutáneo o quirúrgico. La ecocardiografía transesofágica (ETE) es la prueba de imagen de elección para detectar placas en la aorta torácica y clasificarlas como placas complejas. Además, la modalidad 3D nos permite precisar mejor sus dimensiones y características anatómicas como trombos añadidos o la presencia de úlceras en su interior. Esta revisión tiene como objetivo evaluar el uso de ETE para detectar placas aórticas complejas en pacientes con indicación de reemplazo valvular aórtico percutáneo o quirúrgico. Para resaltar la asociación de estenosis aórtica y placas aórticas complejas adjuntamos a la revisión algunos estudios de ETE de nuestra experiencia.

Review of speckle tracking analysis to measure the size, shape, and contractility of the fetal heart in fetuses with congenital heart defects.

Evaluation of the fetal heart involves two approaches. The first describes a screening protocol in which the heart is imaged in transverse planes that includes the four-chamber view (4CV), left and right outflow tracts, and the 3-vessel-tracheal view. The second approach is a fetal echocardiogram that requires additional cardiac images as well as evaluating ventricular function using diagnostic tools such as M-mode and pulsed Doppler ultrasound. Speckle tracking analysis of the ventricular and atrial endocardium of the fetal heart has focused primarily on computing longitudinal global strain. However, the technology enabling this measurement to occur has recently been adapted to enable the clinician to obtain numerous additional measurements of the size, shape, and contractility of the ventricles and atrial chambers. By using the increased number of measurements derived from speckle tracking analysis, we have reported the ability to screen for tetralogy of Fallot, D-transposition of the great arteries (D-TGA), and coarctation of the aorta by only imaging the 4CV. In addition, we have found that measurements derived from speckle tracking analysis of the ventricular and atrial chambers can be used to compute the risk for emergent neonatal balloon atrial septostomy in fetuses with D-TGA. The purpose of this review is to consolidate our experience in one source to provide perspective on the benefits of speckle tracking analysis to measure the size, shape, and contractility of the ventricles and atria imaged in the 4CV in fetuses with congenital heart defects.

Graft Fungal Infection After Ascending Aorta Replacement.

Aortic graft infection is an uncommon but highly fatal complication. Correct diagnosis and timely treatment are somewhat challenging. This study presents a case report of successful recognition and treatment of this complication.

The molecular and cellular hematopoietic stem cell specification niche.

Hematopoietic stem cells (HSCs) are a population of tissue-specific stem cells that reside in the bone marrow of adult mammals where they self-renew and continuously regenerate the adult hematopoietic lineages over the life of the individual. Prominence as a stem cell model and clinical usefulness has driven interest in understanding the physiological processes that lead to specification of HSCs during embryonic development. High efficiency directed differentiation of HSCs by instruction of defined progenitor cells using sequentially defined instructive molecules and conditions remains impossible, indicating that comprehensive knowledge of the complete set of precursor intermediate identities and required inductive inputs remains incompletely understood. Recently, interest in the molecular and cellular microenvironment where HSCs are specified from endothelial precursors-the "specification niche"-has increased. Here we review recent progress in understanding these niche spaces across vertebrate phyla, as well as how a better characterization of the origin and molecular phenotypes of the niche cell populations has helped inform and complicate previous understanding of signaling required for HSC emergence and maturation.

The Burden of Major Complications on Failure-to-Rescue After Surgery for Acute Type A Aortic Dissections: An analysis of over 19,000 patients.

INTRODUCTION: The relationship between the number and type of postoperative complications and mortality in the setting for surgery for Type A Aortic Dissection (ATAAD) remains underexplored despite the critical role in the Failure-to-Rescue (FTR) metric. METHODS: Retrospective study using data from the Society of Thoracic Surgeons Adult Cardiac Surgical Database, encompassing ATAAD surgeries between January 2018 and December 2022. Patients were categorized based on the number of major complications. The primary outcome was FTR. We employed Multilevel Regression and Classification and Regression Tree models. RESULTS: We included 19,243 patients, with a median age of 61 years and 33.3% were women. Regarding complications, 47.7% of patients had none, 20.2% had one, 12.7% had two, and 19.4% experienced three or more. The most common complications were prolonged mechanical ventilation (30.3%), unplanned reoperations (19.5%), and renal failure (17.2%). Cardiac arrest was observed in 7.1% of cases. FTR increased from 13% in patients with one complication to over 30% in those with four or more. Cardiac arrest (aOR 10.9) and renal failure (aOR 5.3) showed the highest odds for mortality, followed by limb ischemia (aOR 2.7), stroke (aOR 2.6), and gastrointestinal complications (aOR 2.4). Hospitals in the top performance quartile consistently showed lower FTR rates across all levels of complication. CONCLUSION: The study validates a dose-response association between postoperative complications and mortality for ATAAD. Top-performing hospitals consistently show lower FTR rates independently of the number of complications. Further research should focus on the timing of complications and interventions to reduce the burden of complications.

Tritium-Labeled Nanodiamonds as an Instrument to Analyze Bioprosthetic Valve Coatings: A Case of Using a Nanodiamond Containing Coating on a Pork Aorta.

Coatings with xenogenic materials, made of detonation nanodiamonds, provide additional strength and increase elasticity. A functionally developed surface of nanodiamonds makes it possible to apply antibiotics. Previous experiments show the stability of such coatings; however, studies on stability in the bloodstream and calcification of the material in natural conditions have yet to be conducted. Tritium-labeled nanodiamonds (negative and positive) were obtained by the tritium activation method and used to develop coatings for a pork aorta to analyze their stability in a pig's bloodstream using a radiotracer technique. A chitosan layer was applied from a solution of carbonic acid under high-pressure conditions to prevent calcification. The obtained materials were used to prepare a porcine conduit, which was surgically stitched inside the pig's aorta for four months. The aorta samples, including nanodiamond-coated and control samples, were analyzed for nanodiamond content and calcium, using the radiotracer and ICP-AES methods. A histological analysis of the materials was also performed. The obtained coatings illustrate a high in vivo stability and low levels of calcification for all types of nanodiamonds. Even though we did not use additional antibiotics in this case, the development of infection was not observed for negatively charged nanodiamonds, opening up prospects for their use in developing coatings.

Long-term cardiovascular inflammation and fibrosis in a murine model of vasculitis induced by Lactobacillus casei cell wall extract.

Background: Kawasaki disease (KD), an acute febrile illness and systemic vasculitis, is the leading cause of acquired heart disease in children in industrialized countries. KD leads to the development of coronary artery aneurysms (CAA) in affected children, which may persist for months and even years after the acute phase of the disease. There is an unmet need to characterize the immune and pathological mechanisms of the long-term complications of KD. Methods: We examined cardiovascular complications in the Lactobacillus casei cell wall extract (LCWE) mouse model of KD-like vasculitis over 4 months. The long-term immune, pathological, and functional changes occurring in cardiovascular lesions were characterized by histological examination, flow cytometric analysis, immunofluorescent staining of cardiovascular tissues, and transthoracic echocardiogram. Results: CAA and abdominal aorta dilations were detected up to 16 weeks following LCWE injection and initiation of acute vasculitis. We observed alterations in the composition of circulating immune cell profiles, such as increased monocyte frequencies in the acute phase of the disease and higher counts of neutrophils. We determined a positive correlation between circulating neutrophil and inflammatory monocyte counts and the severity of cardiovascular lesions early after LCWE injection. LCWE-induced KD-like vasculitis was associated with myocarditis and myocardial dysfunction, characterized by diminished ejection fraction and left ventricular remodeling, which worsened over time. We observed extensive fibrosis within the inflamed cardiac tissue early in the disease and myocardial fibrosis in later stages. Conclusion: Our findings indicate that increased circulating neutrophil counts in the acute phase are a reliable predictor of cardiovascular inflammation severity in LCWE-injected mice. Furthermore, long-term cardiac complications stemming from inflammatory cell infiltrations in the aortic root and coronary arteries, myocardial dysfunction, and myocardial fibrosis persist over long periods and are still detected up to 16 weeks after LCWE injection.

The Impact of Close Proximity of Left Atrium to Descending Aorta on Left Inferior Pulmonary Vein Triggers or Drivers of Atrial Fibrillation: A Risk Score Model.

BACKGROUND: Prior studies have investigated cardiac anatomy and clinical parameters as predictors for pulmonary vein and non-pulmonary vein triggers. OBJECTIVES: To assess the link between the descending aorta to left inferior pulmonary vein (Dao-LIPV) distance and the occurrence of triggers and drivers in atrial fibrillation (AF) ablation procedures. METHODS: Drug-refractory AF patients who underwent first-time index catheter ablation from January 2010 to December 2019 were retrospectively assembled. The Dao-LIPV distance was measured from pre-ablation pulmonary vein computed tomography. Patients were categorized based on the presence of LIPV triggers and/or drivers. Multivariate logistic regression was used to identify risk factors. RESULTS: A total of 886 consecutive patients with drug-refractory AF were studied, and 63 (7.1%) patients were identified to have LIPV triggers and/or drivers. The Dao-LIPV distance had a better predictive performance (AUC: 0.70) compared to persistent AF (AUC: 0.57). Multivariate logistic regression analysis showed that Dao-LIPV distance ≤ 2.5 mm (Odds ratio [OR] 3.96 [95% CI 2.15-7.29], p <0.001) and persistent AF (OR 1.73 [95% CI 1.02-2.94], p=0.044) were independent predictors for the presence of LIPV triggers and/or drivers. A risk score model was established to predict the probability of LIPV triggers or drivers with persistent AF (10.2%), Dao-LIPV distance ≤ 2.5mm (11.4%), and both (15.0%). CONCLUSIONS: The close proximity of the Dao-LIPV was correlated to the presence of LIPV triggers or drivers. We developed a risk score model indicating that persistent AF and Dao-LIPV distances ≤ 2.5mm significantly increase the risk of LIPV triggers/drivers, aiding electrophysiologists in preparing for and performing catheter ablation more effectively.

Urgent Candy-Plug Technique for Distal False Lumen Occlusion in Chronic Aortic Dissection.

INTRODUCTION: This study aimed to assess the impact of urgency on early and midterm outcomes of the Candy-Plug (CP) technique for distal false lumen (FL) occlusion in thoracic endovascular aortic repair (TEVAR) for aortic dissection (AD). METHODS: The CP registry was reviewed, and patients were categorized into elective and urgent/emergent groups for analysis. Endpoints included technical success, clinical success, early (30-day) computed tomography angiography (CTA) findings, early (30-day) mortality, adverse events, aortic remodeling in patients with available CTA follow-up and re-intervention. RESULTS: A total of 155 patients received a custom-made Candy-Plug with 32 patients (44% males, mean age 61±9 years) were treated urgently vs. 123 patients (63% males, mean age 62±11 years) electively. The primary CP rate was higher in the urgent group; (28/32, (88%) in the urgent group vs. 96/123 (78%) in the elective group, p=051). The mean contrast volume was higher in the urgent group; (157±56ml in the urgent group vs. 130±71ml in the elective group, p=.017). Technical success was achieved in all patients in both groups. Clinical success was achieved in 25/32 (78%) patients in the urgent group vs. 113/123 (92%) in the elective group, p=.159. The early mortality rate was 4/32, (13%) patients in the urgent group vs. 1/123 (1%) in the elective group, p=.120). There was no statistically significant difference regarding the early adverse events between the urgent and elective CP groups. Early aortic-related re-interventions were required in 6/32 (19%) patients in the urgent group vs. 6/123 (5%) in the elective group, p=.094. Thoracic aortic aneurysm sac regression was lower in the urgent group (5/28, (18%) in the urgent group vs. 63/114 (55%) in the elective group, p=001). Stable thoracic aortic aneurysm sac was higher in the urgent group (22/28, (79%) in the urgent group vs. 47/114 (41%) in the elective group, p=000). An increase in thoracic aortic aneurysm sac occurred in 1/28 (4%) patient in the urgent group vs. 4/114 (4%) patients in the elective group, p=.096. CONCLUSION: The urgent use of the CP technique for distal FL occlusion in AD was feasible and effective. The decrease in aortic FL sac diameter may be affected by the urgent use of CP due to limited sizing availability. However, it achieved high rate of aortic remodeling.

Hybrid management of descending thoracic pseudoaneurysm in a patient with DiGeorge syndrome.

We present a case of a 42-year-old man with DiGeorge syndrome and congenital cardiac anomalies including a type B interrupted aortic arch who had previously undergone two bypasses between the ascending and descending thoracic aorta in childhood. He was found to have a 7.4-cm pseudoaneurysm of the descending thoracic aorta with the left subclavian artery arising from the aneurysm. The patient was treated with a single stage hybrid repair including left common carotid to subclavian bypass followed by thoracic endovascular aortic aneurysm repair.

Sutureless Aortic Valve Replacement vs. Transcatheter Aortic Valve Implantation in Patients with Small Aortic Annulus: Clinical and Hemodynamic Outcomes from a Multi-Institutional Study.

OBJECTIVE: This study aimed to compare hemodynamic performances and clinical outcomes of patients with small aortic annulus (SAA) who underwent aortic valve replacement by means of sutureless aortic valve replacement (SUAVR) or transcatheter aortic valve implantation (TAVI). METHODS: From 2015 to 2020, 622 consecutive patients with SAA underwent either SUAVR or TAVI. Through a 1:1 propensity score matching analysis, two homogeneous groups of 146 patients were formed. Primary endpoint: all cause-death at 36 months. Secondary endpoints: incidence of moderate to severe patient-prosthesis mismatch (PPM) and incidence of major adverse cardiovascular and cerebrovascular events (MACCEs). RESULTS: All-cause death at three years was higher in the TAVI group (SUAVR 12.2% vs. TAVI 21.0%, P=0.058). Perioperatively, comparable hemodynamic performances were recorded in terms of indexed effective orifice area (SUAVR 1.12 ± 0.23 cm2/m2 vs. TAVI 1.17 ± 0.28 cm2/m2, P=0.265), mean transvalvular gradients (SUAVR 12.9 ± 5.3 mmHg vs. TAVI 12.2 ± 6.2 mmHg, P=0.332), and moderate-to-severe PPM (SUAVR 4.1% vs. TAVI 8.9%, P=0.096). TAVI group showed a higher cumulative incidence of MACCEs at 36 months (SUAVR 18.1% vs. TAVI 32.6%, P<0.001). Pacemaker implantation (PMI) and perivalvular leak ≥ 2 were significantly higher in TAVI group and identified as independent predictors of mortality (PMI: hazard ratio [HR] 3.05, 95% confidence interval [CI] 1.34-6.94, P=0.008; PPM: HR 2.72, 95% CI 1.25-5.94, P=0.012). CONCLUSION: In patients with SAA, SUAVR and TAVI showed comparable hemodynamic performances. Moreover, all-cause death and incidence of MACCEs at follow-up were significantly higher in TAVI group.

Ascending Aortic Progression After Isolated Aortic Valve Replacement Among Patients with Bicuspid and Tricuspid Aortic Valves.

OBJECTIVES: The aims of the present study were to compare the long-term outcomes for ascending aortic dilatation and adverse aortic events after isolated aortic valve replacement between patients with bicuspid aortic valve (BAV) and tricuspid aortic valve ( TAV). METHODS: This retrospective study included 310 patients who had undergone isolated aortic valve replacement with an ascending aorta diameter ≤ 45 mm between January 2010 and September 2021. The patients were divided into BAV group (n=90) and TAV group (n=220). The differences in the dilation rate of the ascending aorta and long-term outcomes were analyzed. RESULTS: Overall survival was 89 ± 4% in the BAV group vs. 75 ± 6% in the TAV group at 10 years postoperatively (P=0.007), yet this difference disappeared after adjusting exclusively for age (P=0.343). The mean annual growth rate of the ascending aorta was similar between the two groups during follow-up (0.5 ± 0.6 mm/year vs. 0.4 ± 0.5 mm/year; P=0.498). Ten-year freedom from adverse aortic events was 98.1% in the BAV group vs. 95.0% in the TAV group (P=0.636). Multivariable analysis revealed preoperative ascending aorta diameter to be a significant predictor of adverse aortic events (hazard ratio: 1.76; 95% confidence interval: 1.33 to 2.38; P<0.001). CONCLUSION: Our study revealed that the long-term survival and the risks of adverse aortic events between BAV and TAV patients were similar after isolated aortic valve replacement. BAV was not a risk factor of adverse aortic events.

Type A Aortic Dissection Following Heart Transplantation.

Cannulation strategies in aortic arch surgeries are a matter of immense discussion. Majority of time deep hypothermic circulatory arrest (DHCA) is the way out, but it does come with its set of demerits. Here we demonstrate a case with aortic arch dissection dealt with dual cannulation strategy in axillary and femoral artery without need for DHCA and ensuring complete neuroprotection of brain and spinal cord without hinderance of time factor. Inception of new ideas like this may decrease the need for DHCA and hence its drawbacks, thus decreasing the morbidity and mortality associated.

The impact of the vitamin D and resveratrol administration on the stiffness and elasticity of T2DM rat aorta associated with the trace element and mineral levels.

BACKGROUND: Type 2 diabetes mellitus (T2DM) is directly associated with increased aortic stiffness, reduced aortic elasticity, and aortic dissection, which are independent risk factors for cardiovascular death. Since Vit D and resveratrol have been reported due to their cardioprotective effects, in this study, we aim to evaluate the impact of Vit D and resveratrol treatment alone or in combination on the aortic health associated with trace element and mineral levels in a high-fructose diet/streptozotocin-induced T2DM model. METHODS: We investigated biomechanical changes of the aorta samples via a custom-built stretcher, where trace element and mineral levels in aorta samples were determined via inductively coupled plasma mass spectrometry (ICP-MS) following acidic microwave digestion. RESULTS: Vitamin D treatment ameliorated the adverse effects of T2DM on aortic stiffness, aortic elasticity, and relaxation modulus in diabetic rats. Trace element and mineral levels correlated with cardiovascular homeostasis, including Fe, Cu, Zn, Se, and Na, have been regulated upon Vit D treatment in diabetic and healthy rats. On the other hand, resveratrol treatment alone or in combination with Vit D did not show any positive effects on biomechanical properties and trace element metabolism of diabetic or healthy rats, according to our data. CONCLUSION: Vit D can be used in T2DM patients to protect their cardiovascular health and should be considered a promising targeted therapy approach via nanoparticles to target cardiovascular diseases in the future.

Factors that Influence Growth Rates of Abdominal Aortic Aneurysms. Analysis of a Mexican Cohort.

OBJECTIVE: Abdominal Aortic Aneurysms (AAA) growth remains a process not fully understood. The objective of this study was to analyze risk factors associated with changes in AAA diameter in a Mexican cohort. METHODS: An observational study in which we analyzed the entirely of patients in which an AAA was reported in a Computed Tomography (CT) study from 2014 to 2021 who had a follow-up CT. We divided them by groups depending on the diagnosis of type 2 diabetic mellitus and pharmacological history (diabetic vs non-diabetic, metformin vs non-metformin intake and statin vs non-statin intake). We compared pre and post follow-up AAA diameters using paired t-tests. A multivariate analysis was performed in order to identify independent variables associated with an increased growth rate. Statistical analysis was performed on Stata 17. RESULTS: During the studied period 72 (39.77%) patients had a follow-up CT. Mean age was 75 years (±9.05) and 52 (72.22%) were men. When comparing infra-renal largest diameter through time based on metformin intake, a significant difference was found only in the metformin non-intake group (42.05 ± 12.54 vs45.34 ± 12.06 [P = 0.02]), in contrast the metformin intake group measures were non-significantly different (36.13 ± 7.04 vs 37.00 ± 4.51; P = 0.57) through follow-up. In the multivariate analysis AAA largest diameter at diagnosis correlated with significantly increased growth rate (coeff = 0.06, P < 0.05). CONCLUSIONS: AAA diameters appear to change through time in a non-linear pattern influenced by different epidemiological and clinical factors. Metformin intake appears to promote a stability in AAA diameter growth in our studied population.

A comprehensive MRI-based computational model of blood flow in compliant aorta using radial basis function interpolation.

BACKGROUND: Properly understanding the origin and progression of the thoracic aortic aneurysm (TAA) can help prevent its growth and rupture. For a better understanding of this pathogenesis, the aortic blood flow has to be studied and interpreted in great detail. We can obtain detailed aortic blood flow information using magnetic resonance imaging (MRI) based computational fluid dynamics (CFD) with a prescribed motion of the aortic wall. METHODS: We performed two different types of simulations-static (rigid wall) and dynamic (moving wall) for healthy control and a patient with a TAA. For the latter, we have developed a novel morphing approach based on the radial basis function (RBF) interpolation of the segmented 4D-flow MRI geometries at different time instants. Additionally, we have applied reconstructed 4D-flow MRI velocity profiles at the inlet with an automatic registration protocol. RESULTS: The simulated RBF-based movement of the aorta matched well with the original 4D-flow MRI geometries. The wall movement was most dominant in the ascending aorta, accompanied by the highest variation of the blood flow patterns. The resulting data indicated significant differences between the dynamic and static simulations, with a relative difference for the patient of 7.47±14.18% in time-averaged wall shear stress and 15.97±43.32% in the oscillatory shear index (for the whole domain). CONCLUSIONS: In conclusion, the RBF-based morphing approach proved to be numerically accurate and computationally efficient in capturing complex kinematics of the aorta, as validated by 4D-flow MRI. We recommend this approach for future use in MRI-based CFD simulations in broad population studies. Performing these would bring a better understanding of the onset and growth of TAA.