Arterial dissection in scuba divers: a potential adverse manifestation of the physiological effects of immersion.

Introduction: Aortic dissections and dissections of cervical, cerebral, and coronary arteries have been previously reported in scuba divers. These incidents may be the consequence of a variety of physiological effects. We review the reported cases of arterial dissection in scuba divers and discuss potential contributing factors related to immersion and diving. Methods: Medline, CINAHL Plus, and SPORTDiscus were searched for published reports of arterial dissection and the Australasian Diving Safety Foundation fatality database was searched for additional cases from Australia. Identified cases were recorded and scrutinised for possible contributing factors. Results: Nineteen cases of arterial dissection, both fatal and non-fatal, were identified. These included cervical or intracranial artery dissection (n = 14), aortic dissection (n = 4), and coronary artery dissection (n = 1). There were 14 male and five female victims; mean age 44 years (SD 14, range 18-65). Contributing factors may include a combination of vasoconstriction and blood redistribution, untreated hypertension, increased pulse pressure, abnormal neck movement or positioning, constrictive and burdensome equipment, exercise, increased gas density and circuit resistance with concomitant elevated work of breathing, atheroma, and possibly the mammalian dive response. Conclusions: Dissecting aneurysms of the aorta or cervical, cerebral, and coronary arteries should be considered as a potential complication of scuba diving. The development of aneurysms associated with scuba diving is likely multifactorial in pathogenesis. Detailed reporting is important in the evaluation of cases. The potential role of the mammalian dive response as a contributing factor requires further evaluation.

Patient-specific compliant simulation framework informed by 4DMRI-extracted pulse wave Velocity: Application post-TEVAR.

We introduce a new computational framework that utilises Pulse Wave Velocity (PWV) extracted directly from 4D flow MRI (4DMRI) to inform patient-specific compliant computational fluid dynamics (CFD) simulations of a Type-B aortic dissection (TBAD), post-thoracic endovascular aortic repair (TEVAR). The thoracic aortic geometry, a 3D inlet velocity profile (IVP) and dynamic outlet boundary conditions are derived from 4DMRI and brachial pressure patient data. A moving boundary method (MBM) is applied to simulate aortic wall displacement. The aortic wall stiffness is estimated through two methods: one relying on area-based distensibility and the other utilising regional pulse wave velocity (RPWV) distensibility, further fine-tuned to align with in vivo values. Predicted pressures and outlet flow rates were within 2.3 % of target values. RPWV-based simulations were more accurate in replicating in vivo hemodynamics than the area-based ones. RPWVs were closely predicted in most regions, except the endograft. Systolic flow reversal ratios (SFRR) were accurately captured, while differences above 60 % in in-plane rotational flow (IRF) between the simulations were observed. Significant disparities in predicted wall shear stress (WSS)-based indices were observed between the two approaches, especially the endothelial cell activation potential (ECAP). At the isthmus, the RPWV-driven simulation indicated a mean ECAP>1.4 Pa-1 (critical threshold), indicating areas potentially prone to thrombosis, not captured by the area-based simulation. RPWV-driven simulation results agree well with 4DMRI measurements, validating the proposed pipeline and facilitating a comprehensive assessment of surgical decision-making scenarios and potential complications, such as thrombosis and aortic growth.

Mean Pressure Gradient and Fractional Flow Reserve at A Superficial Femoral Artery Dissection after Drug-Coated Balloon Angioplasty.

OBJECTIVES: Residual dissection is a concern in endovascular treatment with a DCB, and there is limited knowledge of hemodynamics at a dissection lesion. Therefore, the objective of this study is to evaluate the mean pressure gradient (MPG) and fractional flow reserve (FFR) at a residual dissection after DCB angioplasty for the superficial femoral artery (SFA). METHODS: A total of 59 cases with residual SFA dissection treated with DCB angioplasty at a single center were analyzed retrospectively. The dissection was classified into 6 types (A-F). The primary endpoints were MPG and FFR at a residual dissection lesion after DCB angioplasty, using evaluation with a pressure wire. RESULTS: The median lesion length was 70 (40-130) mm with 24% popliteal involvement, and 11 cases (18%) had chronic total occlusion. A completion angiogram revealed dissection of types A (n = 33, 56%), B (n = 18, 31%), C (n = 7, 12%), and D (n = 1, 2%). The median MPGs in type A, B, and C cases were 0 (0-2), 0 (0-4), and 3 (0-6) mmHg, with a significant lower in type C cases than in type A cases (A vs C, P = .021). The median FFRs in type A, B, and C cases of 1.0 (.98-1.00), 1.0 (.96-1.00), and .98 (.95-1.00) did not differ significantly among dissection types (A vs B, P = .86; A vs C, P = .055; B vs C, P = .15). CONCLUSIONS: This is the first report of hemodynamics at a SFA dissection. The results suggest that low-grade dissection (types A or B) does not affect MPG and FFR at a SFA lesion. This indicates that a bailout stent may be unnecessary for patients with dissection of types A or B. A further investigation is needed to determine whether a scaffold is required for a SFA lesion with type C dissection.

Physician Modified Endograft for Ruptured Dissecting Aortic Arch Aneurysm.

BACKGROUND: Endovascular repair of thoracic aortic aneurysms (TAA) in elective settings has demonstrated successful clinical outcomes. However, life-threatening conditions such as rupture are more often managed with open surgical repair due to the high complexity of arch endovascular repair, lack of available off-the-shelf devices, and limited long-term data. CASE SUMMARY: A 49-year-old female with a recent history of prior ascending aortic repair for Type A10 aortic dissection presented with chest pain and dyspnea. Chest computed tomography angiogram (CTA) revealed acute bilateral pulmonary emboli and a 6.2 cm post dissection aneurysm of the posterior aortic arch with the dissection extending to the right iliac artery. She was treated with thrombolysis and subsequently became hemodynamically unstable. Repeat CTA revealed a massive left hemithorax with concern for aortic arch rupture. Given significant cardiorespiratory compromise and recent open repair, she was considered unfit for redo open repair. Thoracic endovascular aortic repair (TEVAR) with a physician-modified endograft (PMEG) was planned. An Alpha Zenith endograft was modified adding an internal branch for the innominate artery and a fenestration for the left common carotid artery. The left subclavian artery was occluded with a microvascular plug and coil embolization up to the level of the vertebral artery. TEVAR PMEG extension to the celiac artery was performed followed by deployment of a Zenith dissection stent to the aortic bifurcation. Completion angiogram demonstrated successful aneurysm exclusion and patency of target vessels. CONCLUSION: Endovascular treatment of ruptured TAA with PMEGs is feasible. This approach may be an alternative for unfit patients for open repair in emergent settings.

Validation of classification system for isolated superior mesenteric artery dissections using image-based computational flow analysis.

BACKGROUND AND OBJECTIVE: The isolated superior mesenteric artery dissection (ISMAD) is a rare but potentially fatal vascular disorder. Classifications for ISMAD were previously proposed based on morphometric features. However, the classification systems were not standardized and verified yet. This study conducted computational flow analysis to validate the latest classification system of ISMAD and aid clinical decision-making based on hemodynamic parameters. METHODS: 62 patients with ISMAD were included and classified into different types according to false lumen structures (five types, Type I-V) and true lumen patency (two types, Type P and Type S) according to Qiu classification system. Computational fluid dynamics and three-dimensional structural analyses were conducted on the basis of computed tomography angiography datasets. Quantitative and qualitative functional analyses were performed via parameters of interest including volume flow of each minute, pressure drop, pressure gradient, the derivative parameters of wall shear stress such as time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), and the relative residence time (RRT). Statistical analyses were conducted among different ISMAD types. RESULTS: TAWSS, OSI and RRT showed significant difference among different types when classified using false lumen structures. In detail, Type IV showed significantly higher TAWSS than other types (p = 0.007). OSI was obviously higher in Type II (p = 0.015). Type IV also presented the lowest RRT (p = 0.005). The pressure drop, pressure gradient, OSI and RRT showed higher value in Type S than that in Type P, demonstrating a statistical significance with p values of 0.017, 0.041, 0.001 and 0.012, respectively. While Type P had larger volume flow than Type S (p = 0.041). CONCLUSIONS: The notable differences in hemodynamic features among different types demonstrated the feasibility of Qiu classification system. The evaluation based on hemodynamic simulation might also provide insights into risk identification and guide therapeutic decisions for ISMAD.

Haemodynamic effects of non-Newtonian fluid blood on the abdominal aorta before and after double tear rupture.

OBJECTIVES: Intimal tears caused by aortic dissection can weaken the arterial wall and lead to aortic aneurysms. However, the effect of different tear states on the blood flow behaviour remains complex. This study uses a novel approach that combines numerical haemodynamic simulation with in vitro experiments to elucidate the effect of arterial dissection rupture on the complex blood flow state within the abdominal aneurysm and the endogenous causes of end-organ malperfusion. MATERIALS AND METHODS: Based on the CT imaging data and clinical physiological parameters, the overall arterial models including aortic dissection and aneurysm with single tear and double tear were established, and the turbulence behaviours and haemodynamic characteristics of arterial dissection and aneurysm under different blood pressures were simulated by using non-Newtonian flow fluids with the pulsatile blood flow rate of the clinical patients as a cycle, and the results of the numerical simulation were verified by in vitro simulation experiments. RESULTS: Hemodynamic simulations revealed that the aneurysm and single-tear false lumen generated a maximum pressure of 320.591 mmHg, 267 % over the 120 mmHg criterion. The pressure differential generates reflux, leading to a WSS of 2247.9 Pa at the TL inlet and blood flow velocities of up to 6.41 m/s inducing extend of the inlet. DTD Medium FL instantaneous WP above 120 mmHg Standard 151 % Additionally, there was 82.5 % higher flow in the right iliac aorta than in the left iliac aorta, which triggered malperfusion. Thrombus was accumulated distal to the tear and turbulence. These results are consistent with the findings of the in vitro experiments. CONCLUSIONS: This study reveals the haemodynamic mechanisms by which aortic dissection induces aortic aneurysms to produce different risk states. This will contribute to in vitro simulation studies as a new fulcrum in the process of moving from numerical simulation to clinical trials.

Prognostic implications of thyroid hormones in acute aortic dissection: mediating roles of renal function and coagulation.

Background: Thyroid hormones significantly influence cardiovascular pathophysiology, yet their prognostic role in acute aortic dissection (AAD) remains inadequately explored. This study assesses the prognostic value of thyroid hormone levels in AAD, focusing on the mediating roles of renal function and coagulation. Methods: We included 964 AAD patients in this retrospective cohort study. Utilizing logistic regression, restricted cubic splines, and causal mediation analysis, we investigated the association between thyroid hormones and in-hospital mortality and major adverse cardiovascular events (MACEs). Results: In AAD patients overall, an increase of one standard deviation in FT4 levels was associated with a 31.9% increased risk of MACEs (OR 1.319; 95% CI 1.098-1.584) and a 36.1% increase in in-hospital mortality (OR 1.361; 95% CI 1.095-1.690). Conversely, a higher FT3/FT4 ratio was correlated with a 20.2% reduction in risk of MACEs (OR 0.798; 95% CI 0.637-0.999). This correlation was statistically significant predominantly in Type A AAD, while it did not hold statistical significance in Type B AAD. Key renal and coagulation biomarkers, including blood urea nitrogen, creatinine, cystatin C, prothrombin time ratio, prothrombin time, and prothrombin time international normalized ratio, were identified as significant mediators in the interplay between thyroid hormones and MACEs. The FT3/FT4 ratio exerted its prognostic influence primarily through the mediation of renal functions and coagulation, while FT4 levels predominantly impacted outcomes via a partial mediation effect on coagulation. Conclusion: FT4 levels and the FT3/FT4 ratio are crucial prognostic biomarkers in AAD patients. Renal function and coagulation mediate the association between the thyroid hormones and MACEs.

Frozen Elephant Trunk Procedure for Acute Type a Aortic Dissection: Analysis of Distal Aortic Remodeling According to the Society for Vascular Surgery (SVS)/Society of Thoracic Surgeons (STS) Reporting Standard.

BACKGROUND: To investigate impact of frozen elephant trunk (FET) on long-term distal aortic remodeling in acute A aortic dissection (AAD) according to the latest recommended standards from the Society for Vascular Surgery (SVS)/Society of Thoracic Surgeons (STS). METHODS: Clinical data and imaging of patients who underwent FET to treat acute AAD over the last 8 years were retrospectively reviewed. Patients were included if a pre and postoperative computed angio tomographies at least 30 days from surgery was available for comparison. Contrasted postprocessed imaging were analyzed with Aquarius iNtuition (TeraRecon Inc., Foster City, CA, USA) to analyze long-term positive aortic remodeling, false lumen thrombosis, and aortic expansion according to the SVS or STS recommendations. Secondary endpoints were the rate of in-hospital and long-term mortality, spinal cord ischemia (SCI), and aortic-related reinterventions. RESULTS: Out of 75 patients who underwent FET for type A AAD, n = 41 (54.6%) were included. Significant positive aortic remodeling was reported in Ishimaru zone 1-4 but not in visceral or infrarenal aorta (P < 0.001), and the overall rate of false lumen thrombosis was 95.1% (n = 39). Aortic expansion rates were as follows: 4.9% in zones 1-4, 8.3% in zones 5-6, and 15% in zone 7. The rates of in-hospital mortality and long-term mortality were 7.3% (n = 3) and 9.7% (n = 4), respectively. At a median follow-up of 11 months (range 1-141, reintervention rate was 17.1%. CONCLUSIONS: We report positive aortic remodeling of the distal thoracic aorta in patients who underwent FET for acute AAD according to the SVS or STS reporting standards. The positive effect on the distal aorta is limited to the thoracic segments but not in the visceral aorta.

The influence of sex on left ventricular remodeling in patients with aortic dissection.

AIMS: Patients with aortic dissection have a high prevalence of left ventricular structural alterations, including left ventricular hypertrophy (LVH), but little is known about the impact of sex on this regard. This study compared clinical, cardiac, and prognostic characteristics between men and women with aortic dissection. METHODS: We retrospectively assessed clinical and echocardiographic characteristics, and 1-year mortality in 367 aortic dissection patients (30% women; 66% with Stanford-A) who underwent echocardiography 60 days before or after the diagnosis of aortic dissection from three Brazilian centers. RESULTS: Men and women had similar clinical characteristics, except for higher age (59.4 ±â€Š13.4 vs. 55.9 ±â€Š11.6 years; P  = 0.013) and use of antihypertensive classes (1.4 ±â€Š1.3 vs. 1.1 ±â€Š1.2; P  = 0.024) and diuretics (32 vs. 19%; P  = 0.004) in women compared with men. Women had a higher prevalence of LVH (78 vs. 65%; P  = 0.010) and lower prevalence of normal left ventricular geometry (20 vs. 10%; P  = 0.015) than men. Logistic regression analysis adjusted for confounding factors showed that women were less likely to have normal left ventricular geometry (odds ratio, 95% confidence interval = 0.42, 0.20-0.87; P  = 0.019) and were more likely to have LVH (odds ratio, 95% confidence interval = 1.91, 1.11-3.27; P  = 0.019). Conversely, multivariable Cox-regression analysis showed that women had a similar risk of death compared to men 1 year after aortic dissection diagnosis (hazard ratio, 95% confidence interval = 1.16, 0.77-1.75; P  = 0.49). CONCLUSION: In aortic dissection patients, women were typically older, had higher use of antihypertensive medications, and exhibited a greater prevalence of LVH compared with men. However, 1-year mortality after aortic dissection diagnosis did not differ between men and women.

An efficient procedure for the blood flow computer simulation of patient-specific aortic dissections.

In this work we present a novel methodology for the numerical simulation of patient-specific aortic dissections. Our proposal, which targets the seamless virtual prototyping of customized scenarios, combines an innovative two-step segmentation procedure with a CutFEM technique capable of dealing with thin-walled bodies such as the intimal flap. First, we generate the fluid mesh from the outer aortic wall disregarding the intimal flap, similarly to what would be done in a healthy aorta. Second, we create a surface mesh from the approximate midline of the intimal flap. This approach allows us to decouple the segmentation of the fluid volume from that of the intimal flap, thereby bypassing the need to create a volumetric mesh around a thin-walled body, an operation widely known to be complex and error-prone. Once the two meshes are obtained, the original configuration of the dissection into true and false lumen is recovered by embedding the surface mesh into the volumetric one and calculating a level set function that implicitly represents the intimal flap in terms of the volumetric mesh entities. We then leverage the capabilities of unfitted mesh methods, specifically relying on a CutFEM technique tailored for thin-walled bodies, to impose the wall boundary conditions over the embedded intimal flap. We tested the method by simulating the flow in four patient-specific aortic dissections, all involving intricate geometrical patterns. In all cases, the preprocess is greatly simplified with no impact on the computational times. Additionally, the obtained results are consistent with clinical evidence and previous research.

Admission Left-Arm Systolic Blood Pressure and In-Hospital Mortality After Acute Type A Aortic Dissection Repair.

AIM: Admission systolic blood pressure is a significant predictor of in-hospital mortality in patients with acute type A aortic dissection (ATAAD). While previous studies have focussed on recording the highest blood pressure value from both arms, this study aimed to evaluate the associations between blood pressure in bilateral arms and in-hospital mortality. METHODS: Data were analysed from 262 patients with ATAAD treated at a single centre. The relationship between bilateral arm blood pressure upon admission and in-hospital mortality was assessed in a logistic regression model. To comprehensively evaluate potential non-linear relationships, the association between admission bilateral systolic blood pressure (SBP) and the risk of in-hospital mortality was analysed using restricted cubic splines on a continuous scale. RESULTS: Mean age was 53.6±12.5 years and 194 (74.0%) were male. Baseline and operative data showed that ages, body mass index, smoking, left-arm SBP, left-arm diastolic blood pressure (DBP), right-arm SBP, right-arm DBP, syncope, cerebral/cardiac ischaemia, retrograde brain perfusion, Bentall procedure, coronary artery bypass grafting, and aortic valve replacement significantly differed among the left-arm SBP tertiles. In-hospital mortality was 17.6% (46 of 262). Restricted cubic splines demonstrated that the relationship between presenting left-arm SBP and in-hospital mortality followed a U-shaped curve, whereas non-linearity was not detected in the right arm. CONCLUSION: This study found a U-shaped association between admission left-arm SBP and in-hospital mortality in ATAAD surgery patients, whereas a non-linearity relationship was not detected for right-arm SBP. Low left-arm SBP independently correlated with increased in-hospital mortality, underscoring the significance of bilateral blood pressure differences in ATAAD prognosis.

Repair of Dissecting Aortic Aneurysm in Post-LVAD Patient.

Left ventricular assist devices (LVAD) are frequently used in the management of end-stage heart failure, especially given the limited availability of donor hearts. The latest HeartMate 3 LVAD delivers non-physiological continuous flow (CF), although the impact on the aorta is not well established. We highlight a case of aortic aneurysm formation complicated by dissection formation that necessitated high-risk re-operative surgery in a patient post CF-LVAD.

Two surgical strategies (early carotid reperfusion vs. Central aortic repair-first) of acute type a aortic dissection complicated with cerebral malperfusion syndrome: a meta-analysis and systematic review.

OBJECTIVE: Cerebral malperfusion (CM) is a common comorbidity in acute type A aortic dissection (ATAAD), which is associated with high mortality and poor neurological prognosis. This meta-analysis investigated the surgical strategy of ATAAD patients with CM, aiming to compare the difference in therapeutic effectiveness between the central repair-first and the early reperfusion-first according to clinical outcomes. METHODS: The meta-analysis and systematic review was conducted based on studies sourced from the PubMed, Embase, and Cochrane literature database, in which cases of ATAAD with CM underwent surgical repair were included. Data for baseline characteristics, mortality, survival were extracted, and risk ratio (RR) values and the pooled mortality were calculated. RESULTS: A total of 17 retrospective studies were analyzed, including 1010 cases of ATAAD with CM underwent surgical repair. The pooled early mortality in early reperfusion group was lower (8.1%; CI, 0.02 to 0.168) than that in the central repair group (16.2%; CI, 0.115 to 0.216). The pooled long-term mortality was 7.9% in the early reperfusion cohort and 17.4% the central repair-first cohort, without a statistically significant heterogeneity (I [2] = 51.271%; p = 0.056). The mean time of symptom-onset-to-the-operation-room in all the reports was 8.87 ± 12.3 h. CONCLUSION: This meta-analysis suggested that early reperfusion-first may achieved better outcomes compared to central repair-first in ATAAD patients complicated with CM to some extent. Early operation and early restoration of cerebral perfusion may reduce the occurrence of some neurological complications. TRIAL REGISTRATION: The meta-analysis was registered in the International Prospective Register of Systematic Reviews database (No. CRD CRD42023475629) on Nov. 8th, 2023.

Sex-based difference in selected stroke etiologies: cerebral dural sinus venous thrombosis, reversible cerebral vasoconstriction syndrome, dissection, migraine, pregnancy/puerperium/OC use.

Females are at higher risk than males for a multitude of cerebrovascular conditions, both common and rare; partially resulting from a complex interplay between differing process involving genetics, hormonal influences, common cerebrovascular risk factors among others. Specific topics including cervical artery dissection, cerebral dural sinus venous thrombosis, reversible cerebral vasoconstriction syndrome, migraine, along with these disorders in the setting of pregnancy, puerperium and oral contraceptive utilization. Epidemiology, pathophysiology, presentation, basics of management and outcomes are presented, with sex differences throughout.

Spinal cord ischemia and reinterventions following thoracic endovascular repair for acute type B aortic dissections.

OBJECTIVE: The technical aspects of thoracic endovascular aortic repair (TEVAR) for acute type B aortic dissection (TBAD), specifically the location of proximal seal zone (PSZ) (need to cover the left subclavian artery [LSA]), distal seal zone (DSZ) (length of aortic coverage), benefit of LSA revascularization, and prophylactic lumbar drainage are still debated. Each of these issues has potential benefits but also has known risks. This study aims to identify factors associated with reintervention and spinal cord ischemia (SCI) following TEVAR for acute TBAD with a zone 3 entry tear. METHODS: The Vascular Quality Initiative was queried for TEVARs performed for acute TBAD with zone 3 entry tear, zone 3 proximal zone of disease, treated with TEVAR extending between zone 2 and zone 5. The primary outcomes were SCI and related reintervention. Secondary outcomes were stroke, arm ischemia, and retrograde type A dissection (RTAD). The exposure variables were PSZ 2 vs 3, DSZ 4 vs 5, prophylactic lumbar drain, and LSA revascularization. Univariate analyses were conducted with χ2 analysis, and multivariable logistic regression was used to evaluate association with outcomes. RESULTS: Of 583 patients who met inclusion criteria, 266 had PSZ 2 and 317 had PSZ 3. On univariate analysis, PSZ 2 was associated with a higher rate of reintervention, but PSZ2 was not significant on multivariable analysis after accounting for age, sex, race, smoking, PSZ, DSZ, prophylactic lumbar drain, and LSA patency. PSZ 2 was not associated with SCI, arm ischemia, or RTAD. PSZ 2 was associated with a trend towards a higher rate of stroke. DSZ 4 and DSZ 5 were performed in 161 and 422 TEVARs, respectively, and DSZ 5 was associated with a higher rate of SCI on univariate (3 [1.9%] vs 39 [9.2%]; P = .01) and multivariable (odds ratio, 7.384; 95% confidence interval, 2.193-24.867; P = .001) analyses. Prophylactic lumbar drain placement was not statistically significantly associated with SCI, but lack of postoperative LSA patency was associated with SCI (odds ratio, 2.966; 95% confidence interval, 1.016-8.656; P = .05). CONCLUSIONS: This study found that PSZ 2 was not associated with lower reinterventions or higher rates of SCI but trended towards a higher rate of stroke than PSZ 3. Additionally, DSZ 5 was strongly associated with SCI when compared with DSZ 4, highlighting the importance of limiting aortic coverage to coverage of the proximal entry tear when possible.

Fracture mechanics modeling of aortic dissection.

Aortic dissection, a critical cardiovascular condition with life-threatening implications, is distinguished by the development of a tear and its propagation within the aortic wall. A thorough understanding of the initiation and progression of these tears, or cracks, is essential for accurate diagnosis and effective treatment. This paper undertakes a fracture mechanics approach to delve into the mechanics of tear propagation in aortic dissection. Our objective is to elucidate the impact of geometric and material parameters, providing valuable insights into the determinants of this pivotal cardiovascular event. Through our investigation, we have gained an understanding of how various parameters influence the energy release rate for tear propagation in both longitudinal and circumferential directions, aligning our findings with clinical data.

Efficacy and Safety of Sacubitril/Valsartan in Chronic Type B Aortic Dissection Combined With Mild Hypertension.

BACKGROUND: Optimal antihypertensive medication for chronic type B aortic dissection (AD) remains undecided. This study compared the efficacy and safety of sacubitril/valsartan with valsartan to determine suitable antihypertensive drug combinations. METHODS: In this single-center, open-label, randomized, controlled trial, patients with chronic Stanford type B AD and mild hypertension were randomized to receive sacubitril/valsartan 100/200 mg or valsartan 80/160 mg. The primary endpoint was the reduction in mean sitting systolic blood pressure (msSBP) at week 8 in patients with sacubitril/valsartan vs. valsartan. Key secondary endpoints included changes in (i) mean sitting diastolic blood pressure (msDBP); (ii) pulse pressure (PP); and (iii) mean ambulatory blood pressure (BP) for 24-hour, daytime, and nighttime. Safety assessments included adverse events (AEs) and serious AEs. This trial was registered with the Chinese Clinical Trial Registry, identifier: ChiCTR2300073399. RESULTS: A total of 315 patients completed the study. Sacubitril/valsartan provided a significantly greater reduction in msSBP than valsartan at week 8 (between-treatment difference: -5.1 mm Hg [95% confidence interval -5.8 to -4.5], P < 0.001). Reductions in msSBP, msDBP, and PP as well as the mean ambulatory BP for 24-hour, daytime, and nighttime, were significantly greater in sacubitril/valsartan compared with valsartan (all P < 0.001). No excessive episodes of AEs occurred in the sacubitril/valsartan group. CONCLUSIONS: Sacubitril/valsartan and valsartan reduced BP compared with baseline values. However, sacubitril/valsartan improved BP control to a greater extent than valsartan. It may offer a new treatment option for patients with mild hypertension and chronic type B AD.

Investigation of the Association between Bilateral Selective Anterograde Cerebral Perfusion and Postoperative Ischemic Stroke in Obese Patients with Emergency Surgery for Acute Type A Aortic Dissection.

Background and objectives: The relationship between cerebral perfusion and new postoperative ischemic stroke in obese patients is not well defined. The aim of this study was to investigate the association between selective bilateral anterograde cerebral perfusion and new postoperative ischemic stroke in obese patients with emergency surgery for acute type A aortic dissection. Materials and methods: A total of 292 patients with emergency surgery for acute type A aortic dissection were included in this study. Patients with hemorrhagic stroke or ischemic stroke with severe neurological dysfunction at admission that were not candidates for surgery; patients who died in the first 48 h after intensive care admission and patients with incomplete medical records were excluded. Results: The mean age was 59.42 ± 10.68 years and the mean Euroscore was 9.12 ± 1.63. Obesity was present in 76.4%, the incidence of new postoperative ischemic stroke was 27.5%, and the postoperative mortality rate was 26.7%. The mean cardiopulmonary bypass time was 206.81 ± 75.48 min, the aortic cross-clamp time was 118.2 ± 46.42 min, and 90% of cases required cerebral perfusion. The mean cerebral perfusion time was 30.8 ± 24.41 min. Obese patients had a higher frequency of in-hospital death (p = 0.009), smoking (p = 0.036), hypertension (p = 0.023), left common carotid artery dissection (p < 0.001), right common carotid artery dissection (p = 0.029), femoral artery cannulation (p = 0.026), aortic root replacement (p = 0.009), aortic valve replacement (p = 0.005) and early reintervention for bleeding (p = 0.004). Using logistic regression, selective bilateral anterograde cerebral perfusion over 40 min in obese patients was independently associated with new postoperative ischemic stroke (OR = 2.35; 95%CI = 1.36-4.86; p = 0.021). Conclusions: A patient-tailored strategy for cerebral perfusion should be considered in obese patients, considering the high atheromatous burden of the supra-aortic vessels in these patients and the potential risk of atheromatous embolization associated with this technique.

Patient-Specific Haemodynamic Analysis of Virtual Grafting Strategies in Type-B Aortic Dissection: Impact of Compliance Mismatch.

INTRODUCTION: Compliance mismatch between the aortic wall and Dacron Grafts is a clinical problem concerning aortic haemodynamics and morphological degeneration. The aortic stiffness introduced by grafts can lead to an increased left ventricular (LV) afterload. This study quantifies the impact of compliance mismatch by virtually testing different Type-B aortic dissection (TBAD) surgical grafting strategies in patient-specific, compliant computational fluid dynamics (CFD) simulations. MATERIALS AND METHODS: A post-operative case of TBAD was segmented from computed tomography angiography data. Three virtual surgeries were generated using different grafts; two additional cases with compliant grafts were assessed. Compliant CFD simulations were performed using a patient-specific inlet flow rate and three-element Windkessel outlet boundary conditions informed by 2D-Flow MRI data. The wall compliance was calibrated using Cine-MRI images. Pressure, wall shear stress (WSS) indices and energy loss (EL) were computed. RESULTS: Increased aortic stiffness and longer grafts increased aortic pressure and EL. Implementing a compliant graft matching the aortic compliance of the patient reduced the pulse pressure by 11% and EL by 4%. The endothelial cell activation potential (ECAP) differed the most within the aneurysm, where the maximum percentage difference between the reference case and the mid (MDA) and complete (CDA) descending aorta replacements increased by 16% and 20%, respectively. CONCLUSION: This study suggests that by minimising graft length and matching its compliance to the native aorta whilst aligning with surgical requirements, the risk of LV hypertrophy may be reduced. This provides evidence that compliance-matching grafts may enhance patient outcomes.