Neighborhood Socioeconomic Status and Readmission in Acute Type A Aortic Dissection Repair.

INTRODUCTION: We examined the association of socioeconomic status as defined by median household income quartile (MHIQ) with mortality and readmission patterns following open repair of acute type A aortic dissection (ATAAD) in a nationally representative registry. METHODS: Adults who underwent open repair of ATAAD were selected using the US Nationwide Readmissions Database and stratified by MHIQ. Patients were selected based on diagnostic and procedural codes. The primary endpoint was 30-d readmission. RESULTS: Between 2016 and 2019, 10,288 individuals (65% male) underwent open repair for ATAAD. Individuals in the lowest income quartile were younger (median: 60 versus 64, P < 0.05) but had greater Elixhauser comorbidity burden (5.9 versus 5.7, P < 0.05). Across all groups, in-hospital mortality was approximately 15% (P = 0.35). On multivariable analysis adjusting for baseline comorbidity burden, low socioeconomic status was associated with increased readmission at 90 d, but not at 30 d. Concomitant renal disease (odds ratio [OR], 1.68; P < 0.001), pulmonary disease (OR, 1.26; P < 0.001), liver failure (OR 1.2, P = 0.04), and heart failure (OR, 1.17; P < 0.001) were all associated with readmission at 90 d. The primary indication for readmission was most commonly cardiac (33%), infectious (16.5%), and respiratory (9%). CONCLUSIONS: In patients who undergo surgery for ATAAD, lower MHIQ was associated with higher odds of readmission following open repair. While early readmission for individuals living in the lowest income communities is likely attributable to greater baseline comorbidity burden, we observed that 90-d readmission rates are associated with lower MHIQ regardless of comorbidity burden. Further investigation is required to determine which patient-level and system-level interventions are needed to reduce readmissions in the immediate postoperative period for resource poor areas.

Global Aortic Pulse Wave Velocity is Unchanged in Bicuspid Aortopathy With Normal Valve Function but Elevated in Patients With Aortic Valve Stenosis: Insights From a 4D Flow MRI Study of 597 Subjects.

BACKGROUND: Aortopathy is common with bicuspid aortic valve (BAV), and underlying intrinsic tissue abnormalities are believed causative. Valve-mediated hemodynamics are altered in BAV and may contribute to aortopathy and its progression. The contribution of intrinsic tissue defects versus altered hemodynamics to aortopathy progression is not known. PURPOSE: To investigate relative contributions of tissue-innate versus hemodynamics in progression of BAV aortopathy. STUDY TYPE: Retrospective. SUBJECTS: Four hundred seventy-three patients with aortic dilatation (diameter ≥40 mm; comprised of 281 BAV with varied AS severity, 192 tricuspid aortic valve [TAV] without AS) and 124 healthy controls. Subjects were 19-91 years (141/24% female). FIELD STRENGTH/SEQUENCE: 1.5T, 3T; time-resolved gradient-echo 3D phase-contrast (4D flow) MRI. ASSESSMENT: A surrogate measure for global aortic wall stiffness, pulse wave velocity (PWV), was quantified from MRI by standardized, automated technique based on through-plane flow cross-correlation maximization. Comparisons were made between BAV patients with aortic dilatation and varying aortic valve stenosis (AS) severity and healthy subjects and aortopathy patients with normal TAV. STATISTICAL TESTS: Multivariable regression, analysis of covariance (ANCOVA), Tukey's, student's (t), Mann-Whitney (U) tests, were used with significance levels P < 0.05 or P < 0.01 for post-hoc Bonferroni-corrected t/U tests. Bland-Altman and ICC calculations were performed. RESULTS: Multivariable regression showed age with the most significant association for increased PWV in all groups (increase 0.073-0.156 m/sec/year, R2  = 0.30-48). No significant differences in aortic PWV were observed between groups without AS (P = 0.20-0.99), nor were associations between PWV and regurgitation or Sievers type observed (P = 0.60, 0.31 respectively). In contrast, BAV AS patients demonstrated elevated PWV and a significant relationship for AS severity with increased PWV (covariate: age, R2  = 0.48). BAV and TAV patients showed no association between aortic diameter and PWV (P = 0.73). DATA CONCLUSION: No significant PWV differences were observed between BAV patients with normal valve function and control groups. However, AS severity and age in BAV patients were directly associated with PWV increases. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY: Stage 3.

Hemodynamic Evaluation of Type B Aortic Dissection Using Compressed Sensing Accelerated 4D Flow MRI.

BACKGROUND: 4D Flow MRI is a quantitative imaging technique to evaluate blood flow patterns; however, it is unclear how compressed sensing (CS) acceleration would impact aortic hemodynamic quantification in type B aortic dissection (TBAD). PURPOSE: To investigate CS-accelerated 4D Flow MRI performance compared to GRAPP-accelerated 4D Flow MRI (GRAPPA) to evaluate aortic hemodynamics in TBAD. STUDY TYPE: Prospective. POPULATION: Twelve TBAD patients, two volunteers. FIELD STRENGTH/SEQUENCE: 1.5T, 3D time-resolved cine phase-contrast gradient echo sequence. ASSESSMENT: GRAPPA (acceleration factor [R] = 2) and two CS-accelerated (R = 7.7 [CS7.7] and 10.2 [CS10.2]) 4D Flow MRI scans were acquired twice for interscan reproducibility assessment. Voxelwise kinetic energy (KE), peak velocity (PV), forward flow (FF), reverse flow (RF), and stasis were calculated. Plane-based mid-lumen flows were quantified. Imaging times were recorded. TESTS: Repeated measures analysis of variance, Pearson correlation coefficients (r), intraclass correlation coefficients (ICC). P < 0.05 indicated statistical significance. RESULTS: The KE and FF in true lumen (TL) and PV in false lumen (FL) did not show difference among three acquisition types (P = 0.818, 0.065, 0.284 respectively). The PV and stasis in TL were higher, KE, FF, and RF in FL were lower, and stasis was higher in GRAPPA compared to CS7.7 and CS10.2. The RF was lower in GRAPPA compared to CS10.2. The correlation coefficients were strong in TL (r = [0.781-0.986]), and low to strong in FL (r = [0.347-0.948]). The ICC levels demonstrated moderate to excellent interscan reproducibility (0.732-0.989). The FF and net flow in mid-descending aorta TL were significantly different between CS7.7 and CS10.2. CONCLUSION: CS-accelerated 4D Flow MRI has potential for clinical utilization with shorter scan times in TBAD. Our results suggest similar hemodynamic trends between acceleration types, but CS-acceleration impacts KE, FF, RF, and stasis more in FL. EVIDENCE LEVEL: 1 Technical Efficacy: Stage 2.

Systolic reverse flow derived from 4D flow cardiovascular magnetic resonance in bicuspid aortic valve is associated with aortic dilation and aortic valve stenosis: a cross sectional study in 655 subjects.

BACKGROUND: Bicuspid aortic valve (BAV) disease is associated with increased risk of aortopathy. In addition to current intervention guidelines, BAV mediated changes in aortic 3D hemodynamics have been considered as risk stratification measures. We aimed to evaluate the association of 4D flow cardiovascular magnetic resonance (CMR) derived voxel-wise aortic reverse flow with aortic dilation and to investigate the role of aortic valve regurgitation (AR) and stenosis (AS) on reverse flow in systole and diastole. METHODS: 510 patients with BAV (52 ± 14 years) and 120 patients with trileaflet aortic valve (TAV) (61 ± 11 years) and mid-ascending aorta diameter (MAAD) > 35 mm who underwent CMR including 4D flow CMR were retrospectively included. An age and sex-matched healthy control cohort (n = 25, 49 ± 12 years) was selected. Voxel-wise reverse flow was calculated in the aorta and quantified by the mean reverse flow in the ascending aorta (AAo) during systole and diastole. RESULTS: BAV patients without AS and AR demonstrated significantly increased systolic and diastolic reverse flow (222% and 13% increases respectively, p < 0.01) compared to healthy controls and also had significantly increased systolic reverse flow compared to TAV patients with aortic dilation (79% increase, p < 0.01). In patients with isolated AR, systolic and diastolic AAo reverse flow increased significantly with AR severity (c = - 83.2 and c = - 205.6, p < 0.001). In patients with isolated AS, AS severity was associated with an increase in both systolic (c = - 253.1, p < 0.001) and diastolic (c = - 87.0, p = 0.02) AAo reverse flow. Right and left/right and non-coronary fusion phenotype showed elevated systolic reverse flow (> 17% increase, p < 0.01). Right and non-coronary fusion phenotype showed decreased diastolic reverse flow (> 27% decrease, p < 0.01). MAAD was an independent predictor of systolic (p < 0.001), but not diastolic, reverse flow (p > 0.1). CONCLUSION: 4D flow CMR derived reverse flow associated with BAV was successfully captured even in the absence of AR or AS and in comparison to TAV patients with aortic dilation. Diastolic AAo reverse flow increased with AR severity while AS severity strongly correlated with increased systolic reverse flow in the AAo. Additionally, increasing MAAD was independently associated with increasing systolic AAo reverse flow. Thus, systolic AAo reverse flow may be a valuable metric for evaluating disease severity in future longitudinal outcome studies.

Implementation of a direct-to-operating room aortic emergency transfer program: Expedited management of type A aortic dissection.

INTRODUCTION: Type A Aortic Dissection (TAAD) is a surgical emergency with a time-dependent rate of mortality. We hypothesized that a direct-to-operating room (DOR) transfer program for patients with TAAD would reduce time to intervention. METHODS: A DOR program was started at an urban tertiary care hospital in February 2020. We performed a retrospective study of adult patients undergoing treatment for TAAD before (n = 42) and after (n = 84) implementation of DOR. Expected mortality was calculated using the International Registry of Acute Aortic Dissection risk prediction model. RESULTS: Median time from acceptance of transfer from emergency physician to operating room arrival was 1.37 h (82 min) faster in DOR compared to pre-DOR (1.93 h vs 3.30 h, p < 0.001). Median time from arrival to operating room was 1.14 h (72 min) faster after DOR compared to pre-DOR (0.17 h vs 1.31 h, p < 0.001). In-hospital mortality was 16.2% in pre-DOR, with an observed-to-expected (O/E) ratio of 1.03 (p = 0.24) and 12.0% in the DOR group, with an O/E ratio of 0.59 (p < 0.001). CONCLUSION: Creation of a DOR program resulted in decreased time to intervention. This was associated with a decrease in observed-to-expected operative mortality. The transfer of patients with acute type A aortic dissection to centers with direct-to-OR programs may result in decreased time from diagnosis to surgery.

Management of acute aortic syndromes from initial presentation to definitive treatment.

BACKGROUND: Acute aortic syndromes comprise a spectrum of diseases including aortic dissection, intramural hematoma, and penetrating atherosclerotic ulcers. Early diagnosis, rapid intervention, and multidisciplinary team care are vital to efficiently manage time-sensitive aortic emergencies, mobilize appropriate resources, and optimize clinical outcomes. OBJECTIVE: This comprehensive review outlines the multidisciplinary team approach from initial presentation to definitive interventional treatment and post-operative care. DISCUSSION: Acute aortic syndromes can be life-threatening and require prompt diagnosis and aggressive initiation of blood pressure and pain control to prevent subsequent complications. Early time to diagnosis and intervention are associated with improved outcomes. CONCLUSIONS: A multidisciplinary team can help promptly diagnose and manage aortic syndromes.

The Prebiotic Provenance of Semi-Aqueous Solvents.

The numerous and varied roles of phosphorylated organic molecules in biochemistry suggest they may have been important to the origin of life. The prominence of phosphorylated molecules presents a conundrum given that phosphorylation is a thermodynamically unfavorable, endergonic process in water, and most natural sources of phosphate are poorly soluble. We recently demonstrated that a semi-aqueous solvent consisting of urea, ammonium formate, and water (UAFW) supports the dissolution of phosphate and the phosphorylation of nucleosides. However, the prebiotic feasibility and robustness of the UAFW system are unclear. Here, we study the UAFW system as a medium in which phosphate minerals are potentially solubilized. Specifically, we conduct a series of chemical experiments alongside thermodynamic models that simulate the formation of ammonium formate from the hydrolysis of hydrogen cyanide, and demonstrate the stability of formamide in such solvents (as an aqueous mixture). The dissolution of hydroxylapatite requires a liquid medium, and we investigate whether a UAFW system is solid or liquid over varied conditions, finding that this characteristic is controlled by the molar ratios of the three components. For liquid UAFW mixtures, we also find the solubility of phosphate is higher when the quantity of ammonium formate is greater than urea. We suggest the urea within the system can lower the activity of water, help create a stable and persistent solution, and may act as a condensing agent/catalyst to improve nucleoside phosphorylation yields.

NOX2 Activation of Natural Killer T Cells Is Blocked by the Adenosine A2A Receptor to Inhibit Lung Ischemia-Reperfusion Injury.

RATIONALE: Ischemia-reperfusion (IR) injury after lung transplantation, which affects both short- and long-term allograft survival, involves activation of NADPH oxidase 2 (NOX2) and activation of invariant natural killer T (iNKT) cells to produce IL-17. Adenosine A2A receptor (A2AR) agonists are known to potently attenuate lung IR injury and IL-17 production. However, mechanisms for iNKT cell activation after IR and A2AR agonist-mediated protection remain unclear. OBJECTIVES: We tested the hypothesis that NOX2 mediates IL-17 production by iNKT cells after IR and that A2AR agonism prevents IR injury by blocking NOX2 activation in iNKT cells. METHODS: An in vivo murine hilar ligation model of IR injury was used, in which left lungs underwent 1 hour of ischemia and 2 hours of reperfusion. MEASUREMENTS AND MAIN RESULTS: Adoptive transfer of iNKT cells from p47(phox-/-) or NOX2(-/-) mice to Jα18(-/-) (iNKT cell-deficient) mice significantly attenuated lung IR injury and IL-17 production. Treatment with an A2AR agonist attenuated IR injury and IL-17 production in wild-type (WT) mice and in Jα18(-/-) mice reconstituted with WT, but not A2AR(-/-), iNKT cells. Furthermore, the A2AR agonist prevented IL-17 production by murine and human iNKT cells after acute hypoxia-reoxygenation by blocking p47(phox) phosphorylation, a critical step for NOX2 activation. CONCLUSIONS: NOX2 plays a key role in inducing iNKT cell-mediated IL-17 production and subsequent lung injury after IR. A primary mechanism for A2AR agonist-mediated protection entails inhibition of NOX2 in iNKT cells. Therefore, agonism of A2ARs on iNKT cells may be a novel therapeutic strategy to prevent primary graft dysfunction after lung transplantation.

Surgical management of calcific valvular and coronary disease in a patient with alkaptonuria: a case report.

Background: Alkaptonuria is a rare metabolic disease that causes an increase in homogentisic acid (HGA) due to a lack of enzymatic activity. Commonly, accumulation of HGA presents with dark discoloration of skin and other tissues, also known as ochronosis. Additionally, alkaptonuria can result in other clinical manifestations, including arthritis and cardiac disease. This case highlights alkaptonuria-related cardiac disease and challenges that cardiac surgery teams may face when treating this patient population. Case summary: A 62-year-old male with a history of alkaptonuria, Hodgkin's lymphoma treated with chemoradiation, hypertension, and hyperlipidaemia originally presented with shortness of breath in the setting of known cardiac disease. Cardiac work-up demonstrated aortic stenosis, mitral stenosis, and multivessel coronary artery disease requiring aortic valve replacement, mitral valve replacement, and coronary artery bypass grafting. During the operation, significant discoloration of tissue was observed. This correlated with areas of severe calcification, which was noted throughout both valves. Extensive debridement was required prior to proceeding to valve replacements. Additionally, near-infrared spectroscopy failed to provide accurate measurements of cerebral oxygenation. Discussion: Alkaptonuria is correlated with cardiovascular disease, particularly valvular disease. Intraoperatively, these patients may exhibit noticeable discoloration and severe calcification of various tissues. Additionally, traditional infrared-based methods of cerebral oxygenation monitoring may not be reliable; however, other options of cerebral monitoring may be feasible. With proper pre-operative planning, however, patients with alkaptonuria may safely undergo cardiac surgery.

Implanted size and structural valve deterioration in the Edwards Magna bioprosthesis.

Background: The desire of patients to avoid anticoagulation, together with the potential of valve-in-valve (VIV) transcatheter aortic valve replacement (TAVR), have resulted in the increasing use of bioprosthetic valves for aortic valve replacement (AVR). While patient-prosthesis mismatch (PPM) is known to be an adverse risk after AVR, few studies have addressed the effect of PPM on valve durability. This study evaluates the role of valve size and hemodynamics on long term durability after AVR with a Magna bioprosthesis. Methods: We performed a retrospective, single-center evaluation of patients who underwent a surgical AVR procedure between June 2004 through December 2022 using the Magna bioprosthesis. Perioperative information and long-term follow-up data were sourced from the institution's Society for Thoracic Surgeons Adult Cardiac Surgery Registry and outcomes database. Cumulative incidence of freedom from reintervention were estimated accounting for competing events. Group comparisons used Gray's test. Results: Among 2,100 patients, the mean patient age was 69 years (range, 22-95 years), of whom 98% had native aortic valve disease, 32.5% had concomitant coronary bypass grafting, and 19% had mitral valve surgery. Median follow-up was 5.8 (1.9-9.4) years, during which 116 reinterventions were performed, including 74 explants and 42 VIV procedures. Nine hundred and twenty-eight patients died prior to reintervention. Incidence of all cause reintervention was 1.2%, 4.5%, and 11.7% at 5, 10, and 15 years, respectively. Smaller valve size was associated with worse survival (P<0.001), but not with reintervention. Higher mean gradient at implant was associated with increased late reintervention [sub-distribution hazard ratio: 1.016; 95% confidence interval (CI): 1.005 to 1.028; P=0.0047, n=1,661]. Conclusions: While reintervention rates are low for the Magna prosthesis at 15 years, the analysis is confounded by the competing risk of death. PPM, as reflected physiologically by elevated post-operative valve gradients, portends an increased risk of intervention. Further study is necessary to elucidate the mechanism of early stenosis in patients who progress to reintervention.

Modeling of Valve-in-Valve Transcatheter Aortic Valve Implantation after Aortic Root Replacement Using 3-Dimensional Artificial Intelligence Algorithm.

OBJECTIVE: Aortic root replacement requires construction of a composite valve-graft and reimplantation of coronary arteries. This study assessed the feasibility of valve-in-valve transcatheter aortic valve implantation after aortic root replacement. METHODS: A retrospective review was conducted on 74 consecutive patients who received a composite valve-graft at a single institution from 2019 to 2021. Forty patients had bioprosthetic valves with adequate postoperative gated computed tomographic angiography scans. Computational simulations of balloon and self-expanding transcatheter valve deployments were performed. The modeled coronary distances were compared to traditional, manually measured valve-to-coronary distances. RESULTS: There was a statistically significant difference in the modeled versus manual measurements of valve to coronary distances were for all patients regardless of valve type or coronary artery analyzed (p <0. 05). Most patients are low risk for coronary obstruction per three-dimensional modeling including those with a valve-to-coronary distance <4 millimeters. Only one patient (2.5%) was at risk for coronary obstruction for the left coronary artery using a ballonvalve. No other valve combination was considered high risk of coronary obstruction. Five patients (12.5%) were at risk for possible valve stent deformation at the outflow, due to angulation at the graft anastomosis. CONCLUSIONS: Following aortic root replacement, all patients were candidates for Valve-in-Valve using one or both types of transcatheter heart valves. Self-expanding valves may be at higher risk for stent frame deformation at graft anastomotic lines and balloon-expandable valves may be at higher risk of coronary obstruction.

Age-Stratified Surgical Aortic Valve Replacement for Aortic Stenosis.

BACKGROUND: The management of aortic stenosis has evolved to stratification by age as reflected in recent societal guidelines. We evaluated age-stratified surgical aortic valve replacement (SAVR) trends and outcomes in patients with bicuspid aortic valve (BAV) or tricuspid aortic valve (TAV) from The Society of Thoracic Surgeons Adult Cardiac Surgery Database. METHODS: This cohort included adults (≥18 years) undergoing SAVR for severe aortic stenosis between July 2011 and December 2022. Comparisons were stratified by age (<65 years, 65-79 years, ≥80 years) and BAV or TAV status. Primary end points included operative mortality, composite morbidity and mortality, and permanent stroke. Observed to expected ratios by The Society of Thoracic Surgeons predicted risk of mortality were calculated. RESULTS: In total, 200,849 SAVR patients (55,326 BAV [27.5%], 145,526 TAV [72.5%]) from 1238 participating hospitals met study criteria. Annual SAVR volumes decreased by 45% (19,560 to 10,851) during the study period. The decrease was greatest (96%) for patients ≥80 years of age (4914 to 207). The relative prevalence of BAV was greater in younger patients (<65 years, 69,068 [49.5% BAV]; 65-79 years, 104,382 [19.1% BAV]; ≥80 years, 27,399 [4.5% BAV]). The observed mortality in <80-year-old BAV patients (<65 years, 1.08; 65-79 years, 1.21; ≥80 years, 3.68) was better than the expected mortality rate (<65 years, 1.22; 65-79 years, 1.54; ≥80 years, 3.14). CONCLUSIONS: SAVR volume in the transcatheter era has decreased substantially, particularly for patients ≥80 years old and for those with TAV. Younger patients with BAV have better than expected outcomes, which should be carefully considered during shared decision-making in the treatment of aortic stenosis. SAVR should remain the preferred therapy in this population.

Expanding the role of percutaneous coronary intervention in patients resuscitated from cardiac arrest.

Special attention to post-cardiac arrest management is important to long-term survival and favorable neurological outcome in patients resuscitated from cardiac arrest. The use of emergent percutaneous coronary intervention in resuscitated patients presenting with ST-segment elevation myocardial infarction has long been considered an appropriate approach for coronary revascularization. Recent evidence suggests that other subsets of patients, namely, post-cardiac arrest patients without ST-segment elevation myocardial infarction, may benefit from immediate percutaneous coronary intervention following resuscitation. These findings could eventually have important implications for the care of resuscitated patients, including transportation of resuscitated patients to appropriate cardiac interventional facilities, access to treatment modalities such as therapeutic hypothermia, and coordinated care with cardiac catheterization laboratories.

Successful surgical treatment of Stanford type A aortic dissection due to Salmonella aortitis.

BACKGROUND: Salmonella spp. cause infectious aortitis through the hematogenous spread of an intestinal Salmonella infection. Salmonella aortitis can result in extensive tissue damage in the aorta leading to complications including dissection, abscess formation, pseudoaneurysms, and rupture, which require early diagnosis and treatment with both surgery and antibiotic therapy. CASE PRESENTATION: We report a case of Salmonella aortitis complicated by Stanford type A aortic dissection. A 62-year-old man with a history of heroin use presented with chest pain, epigastric pain and vomiting. The computed tomography scan showed Stanford type A aortic dissection without malperfusion. At the time of surgery, an aortic dissection with purulent fluid and contained rupture was noted in the ascending aorta. Fluid culture was consistent with Salmonella. A composite valve-graft conduit aortic root replacement with ascending aorta and hemiarch replacement was performed. The patient recovered well and was discharged on long-term antibiotics. CONCLUSIONS: This rare case of a Stanford type A aortic dissection with contained rupture due to Salmonella aortitis was successfully treated with emergent surgery and antibiotic therapy.

Aortic arch and frozen elephant trunk repair of a right-sided aortic arch with pseudoaneurysm rupture.

A 53-year-old man with a history of vascular ring repair secondary to a right-sided aortic arch with a retroesophageal subclavian artery and ligamentum arteriosum to the descending thoracic aorta presented to our institution with a large aortic pseudoaneurysm of the distal aortic arch. Computed tomography demonstrated a right-sided aortic arch with a 5.8-cm pseudoaneurysm arising from the distal arch with concern for rupture. The patient underwent successful two-stage repair, including a left carotid artery to subclavian artery bypass, followed by total arch replacement with the frozen elephant trunk technique. He recovered well postoperatively, and computed tomography showed complete, successful repair of the pseudoaneurysm.

Verticalization Therapy for Acute Respiratory Distress Syndrome Patients Receiving Veno-Venous Extracorporeal Membrane Oxygenation.

Persistent hypoxemia during veno-venous extracorporeal membrane oxygenation (VV-ECMO) for supporting acute respiratory distress syndrome (ARDS) patients is a clinical challenge for intensive care medical providers. Prone positioning is an effective strategy to treat persistent hypoxemia; however, placing a patient in a prone position is resource intensive with significant risks to the patient. We present a patient with severe ARDS receiving VV-ECMO who underwent verticalization therapy and subsequently recovered pulmonary function.

Entry tear hemodynamics using 4D flow MRI in a patient with acute type B aortic dissection.

Stanford type B aortic dissection (TBAD) is a potentially fatal condition involving a tear in the descending aorta. As TBAD can be managed with medical therapy or surgical repair, identifying predictors of adverse outcomes is important to risk-stratify patients for preemptive surgical procedures. 4D flow magnetic resonance imaging (MRI) has shown to be useful in characterizing the complex hemodynamics seen in TBAD patients and correlating flow patterns with adverse outcomes. We report a case of a 58-year-old man who presented to the hospital with acute TBAD and a large primary entry tear. He was initially managed with medical therapy due to his stable clinical status and computed tomographic angiography showing a stable dissection. However, 4D flow MRI showed high velocity flow through the entry tear, which foreshadowed the later clinical decompensation of the patient. Our case demonstrates that performing 4D flow MRI on TBAD patients is feasible and can provide valuable information in the decision to pursue medical or surgical management.

Conformational changes during in vitro balloon fracture of internal aortic annuloplasty ring.

Objective: HAART 300 300 (BioStable Science and Engineering, Inc) aortic annuloplasty rings restore physiologic annular geometry during aortic valve repair. Transcatheter valve-in-ring implantation is appealing for recurrent valve dysfunction but may necessitate balloon fracture of downsized annuloplasty rings. We characterized the feasibility of ring fracture and changes in ring geometry preceding fracture. Methods: The 19-mm, 21-mm, and 23-mm HAART 300 annuloplasty rings were obtained, and 23-mm, 24-mm, 25-mm, and 26-mm valvuloplasty balloons were obtained. Under continuous fluoroscopy and video recording, a 23-mm balloon was inflated within a 19-mm ring at 1 atm/s until ring fracture or balloon failure occurred. If balloon failure occurred, experiments were sequentially repeated with 1-mm upsized balloons until ring fracture occurred or no larger-sized balloons were available. Results: Upon balloon inflation, all rings exhibited an irreversible conformational change from an elliptical, annular geometry to a circular shape with ring posts flaring outward. A 23-mm balloon burst at 21 atm without fracturing the 19-mm ring. The 24-mm balloon fractured the 19-mm ring at 15 atm. Likewise, a 24-mm balloon ruptured at 18 atm without fracturing the 21-mm annuloplasty ring. A 25-mm balloon fractured the 21-mm ring at 18 atm. Finally, a 26-mm balloon burst at 20 atm without fracturing a 23-mm annuloplasty ring, but it did elicit the confirmational changes described. All fractures occurred along the upslope of a ring post. The exposed metal frame was visible after the 21-mm ring fracture. Conclusions: Fracture of HAART 300 aortic annuloplasty rings is possible with an oversized, high-pressure balloon. However, the geometrical changes in the ring and subsequent rupture of its fabric covering may be obstacles to safe, in vivo ring fracture.

Veno-Venous Extracorporeal Rewarming Using Dual-Lumen Cannula in Accidental Hypothermia.

Accidental hypothermia with a core temperature below 28°C is associated with an increased risk of hemodynamic instability. It is difficult to predict which patients will survive with a favorable neurologic outcome; therefore, decision-making regarding extracorporeal support is not straightforward. We report a case of rewarming using veno-venous dual-lumen cannula as an alternative to veno-arterial support with full recovery and normal neurologic examination. In centers where extracorporeal membrane oxygenation is available, rewarming using veno-venous dual-lumen extracorporeal support may be a useful strategy to mitigate the risks associated with veno-arterial extracorporeal support.

Baseline 4D Flow-Derived in vivo Hemodynamic Parameters Stratify Descending Aortic Dissection Patients With Enlarging Aortas.

Purpose: The purpose of our study was to assess the value of true lumen and false lumen hemodynamics compared to aortic morphological measurements for predicting adverse-aorta related outcomes (AARO) and aortic growth in patients with type B aortic dissection (TBAD). Materials and Methods: Using an IRB approved protocol, we retrospectively identified patients with descending aorta (DAo) dissection at a large tertiary center. Inclusion criteria includes known TBAD with ≥ 6 months of clinical follow-up after initial presentation for TBAD or after ascending aorta intervention for patients with repaired type A dissection with residual type B aortic dissection (rTAAD). Patients with prior descending aorta intervention were excluded. The FL and TL of each patient were manually segmented from 4D flow MRI data, and 3D parametric maps of aortic hemodynamics were generated. Groups were divided based on (1) presence vs. absence of AARO and (2) growth rate ≥ vs. < 3 mm/year. True and false lumen kinetic energy (KE), stasis, peak velocity (PV), reverse/forward flow (RF/FF), FL to TL KE ratio, as well as index aortic diameter were compared between groups using the Mann-Whitney U or independent t-test. Results: A total of n = 51 patients (age: 58.4 ± 15.0 years, M/F: 31/20) were included for analysis of AARO. This group contained n = 26 patients with TBAD and n = 25 patients with rTAAD. In the overall cohort, AARO patients had larger baseline diameters, lower FL-RF, FL stasis, TL-KE, TL-FF and TL-PV. Among patients with de novo TBAD, those with AAROs had larger baseline diameter, lower FL stasis and TL-PV. In both the overall cohort and in the subgroup of de novo TBAD, subjects with aortic growth ≥ 3mm/year, patients had a higher KE ratio. Conclusion: Our study suggests that 4D flow MRI is a promising tool for TBAD evaluation that can provide information beyond traditional MRA or CTA. 4D flow has the potential to become an integral aspect of TBAD work-up, as hemodynamic assessment may allow earlier identification of at-risk patients who could benefit from earlier intervention.