Ex vivo biaxial load testing analysis of aortic biomechanics demonstrates variation in elastic energy distribution across the aortic zone zero.

OBJECTIVES: We hypothesized that tissue characteristics vary significantly along zone zero, which may be reflected by regional differences in stored elastic energy. Our objectives were to (1) characterize the regional variation in stored elastic energy within tissues of the aortic zone zero and (2) identify the association between this variation and patient characteristics. METHODS: From February 2018 to January 2021, 123 aortic tissue samples were obtained from the aortic root and proximal and distal ascending aortas of 65 adults undergoing elective ascending aorta replacement. Biaxial biomechanics testing was performed to obtain tissue elastic energy at the inflection point and compared with patient demographics and preoperative computed tomography imaging. Coefficient models were fit using B-spline to interrogate the relationship among elastic energy, region, and patient characteristics. RESULTS: Mean elastic energy at inflection point was 24.3 ± 15.6 kJ/m3. Elastic energy increased significantly between the root and proximal, and root and distal ascending aorta and decreased with increasing age. Differences due to history of connective tissue disorder and bicuspid aortic valve were significant but diminished when controlled for other patient characteristics. Among covariates, age and region were found to be the most important predictors for elastic energy. CONCLUSIONS: Aortic tissue biomechanical metrics varied across regions and with patient characteristics within the aortic zone zero. Assessment of endovascular outcomes in the ascending aorta must closely consider the region of deployment and variable tissue qualities along the length of the landing zone. Regional variation in tissue characteristics should be incorporated into existing patient-specific models of aortic mechanics.

Early results of bare metal extension stent for thoracoabdominal aortic dissection.

Objectives: Debakey type I and IIIb aortic dissections are complicated by extension along the full length of the aorta. Over the long term, the thoracoabdominal aorta in these patients often continues to degenerate, requiring endovascular or open repair. The purpose of this investigation is to determine the early clinical outcome on aortic remodeling using a composite thoracic stent graft and thoracoabdominal bare metal extension stenting strategy. Methods: From April 2019 to April 2021, 73 patients with Debakey I/IIIb aortic dissection underwent endovascular stent graft repair of the descending thoracic aorta and repair of the thoracoabdominal aorta using bare metal extension stenting. Preoperative and follow-up surveillance computed tomography imaging scans were analyzed. Results: Fifty-three (73%) patients had a Debakey I aortic dissection, and 50 (69%) patients underwent surgery during the chronic (time to surgery >30 days) dissection phase. Mortality at 30 days was 4% (3 hyperacute patients). Stroke occurred in 3 (4%), paraparesis in 2 (2.7%), and acute renal failure requiring dialysis occurred in 2 (2.7%) patients. On postoperative and follow-up computed tomography, there was a significant increase in false lumen thrombosis (P < .001). This coincided with a significant increase in true lumen fraction suggestive of positive aortic remodeling (P < .001) at the time of latest follow-up. Conclusions: Altering the course of aortic remodeling, with placement of a dissection stent in the thoracoabdominal aorta simultaneous with descending thoracic aortic repair may promote true lumen re-expansion and false lumen thrombosis during acute and chronic dissection phases.

Performance and Durability of Cryopreserved Allograft Aortic Valve Replacements.

BACKGROUND: The value of allografts for aortic root replacement is controversial, with recent concern about limited durability. Currently, we prefer allografts for invasive infective endocarditis. Purposes of this study were to assess allograft performance and durability in our cumulative experience with aortic allografts. METHODS: From January 1987 to January 2017, 2042 adults received 2110 aortic allograft root replacements at our institution: 986 (47%) for infective endocarditis (669 [68%] for prosthetic valve endocarditis) and 1124 (53%) for other indications. Mean recipient age was 54 ± 15 years, and mean allograft donor age was 35 ± 13 years. Follow-up was 85% complete and comprised 17,253 patient-years of data. Longitudinal allograft performance was extracted from 6339 available echocardiographic studies. Durability was assessed by explant for allograft structural failure. RESULTS: Allograft mean gradient at hospital discharge was 6 mm Hg and 9, 13, and 15 mm Hg at 5, 10, and 15 years post-implant, respectively. Severe aortic regurgitation was 0% at hospital discharge, but 14%, 25%, and 35% at 5, 10, and 15 years, respectively. A total of 405 allografts were explanted for structural failure, actuarially 2%, 14%, 34%, and 51% at 5, 10, 15, and 20 years, respectively. Risk factors for structural failure were younger recipient age, larger body surface area, hypertension, and thoracic aorta disease; donor factors were older age and larger allograft size. Implant for infective endocarditis was not associated with accelerated structural failure. CONCLUSIONS: This study affirms allografts' long-term acceptable hemodynamic performance and durability. Concern about structural failure should not limit allograft use. Recipient hypertension, allograft size, and donor age are modifiable risk factors.

Prevalence of Human Immunodeficiency Virus and Opportunistic Infections Among Transgender Patients in the Clinical Setting: An All-Payer Electronic Health Record Database Study.

We performed a cross-sectional analysis of the prevalence of HIV and opportunistic infections among transgender patients in clinical care. Of 10,160 transgender patients identified, 3.9% had a diagnosis of HIV, compared to 0.32% in the non-transgender cohort (p<0.0001). Transgender patients experience the burden of all opportunistic infection compared to non-transgender patients in this analysis, although prevalence of pneumocystis pneumonia was not significant. This cohort-based, all-payer electronic health record study of HIV patients connected to care revealed that transgender patients have a higher prevalence of HIV infection and opportunistic infections compared to the non-transgender cohort.

Mental Health Diagnoses Among Transgender Patients in the Clinical Setting: An All-Payer Electronic Health Record Study.

We performed a cross-sectional analysis of the prevalence of psychiatric diagnoses among transgender patients in clinical care using an all-payer electronic health record database. Of 10,270 transgender patients identified, 58% (n=5940) had at least one psychiatric diagnosis compared with 13.6% (n=7,311,780) in the control patient population (p<0.0005). Transgender patients had a statistically significant increase in prevalence for all psychiatric diagnoses queried, with major depressive disorder and generalized anxiety disorder being the most common diagnoses (31% and 12%, respectively). Utilizing an all-payer database, although not without limitations, enables assessment of mental health and substance use diagnoses in this otherwise small population.

Assessing the National Prevalence of HIV Screening in the United States using Electronic Health Record Data.

The Centers for Disease Control and Prevention and the U.S. Preventive Services Task Force recommend population-based screening for human immunodeficiency virus (HIV) at least once in each patient's life. National surveys estimate that 42.5% of the population has been screened; however, these studies have relatively low sample sizes and inherent survey biases. Using a national, de-identified cloud-based electronic health record (EHR) information from over 48 million patients, we found that only 6.4% of Americans over the age of 18 had laboratory evidence of a prior HIV test. Further investigation is necessary to determine if single-item questions on national surveys correlate with objective evidence of HIV testing, as well as addressing the numerous limitations related to the use of EHR data that likely grossly underestimates the prevalence of HIV screening nationally.