Brachial Artery Flow Research Articles

Acute Effects of Cannabis Inhalation on Arterial Stiffness, Vascular Endothelial Function, and Cardiac Function.

The cardiovascular impact of cannabis use is incompletely understood. Although evidence links chronic use to an increased risk of disease and adverse cardiovascular events, few studies have investigated the acute effects of cannabis inhalation on subclinical dysfunction. Furthermore, it remains unknown how method of inhalation and cannabinoid profile modify risk. While controlling for inhalation method and the effects of either Δ-9-tetrahydrocannabinol (THC) or cannabidiol (CBD), we examined the acute cardiovascular effects of cannabis use on arterial stiffness, vascular endothelial responsiveness, and cardiac function, as markers of cardiovascular impairment. Twenty-two young, healthy, cannabis users were assessed for arterial stiffness via pulse wave velocity, vascular endothelial function via brachial artery flow mediated dilation, and cardiac function via echocardiography, before and after (1) smoking THC-predominant cannabis (S-THC), (2) vaporizing THC-predominant THC (V-THC), and (3) vaporizing cannabidiol-predominant cannabis (V-CBD). S-THC and V-THC increased heart rate (S-THC: ∆17±15 bpm, V-THC: ∆16±16 bpm;both P<0.0001) and mean arterial pressure (S-THC: ∆7±6 mm Hg, V-THC: ∆5±5 mm Hg;both P<0.0001) whereas V-CBDdid not (∆1±4 bpm, ∆3±4 mm Hg;both P>0.05). After inhalation, pulse wave velocity increased (S-THC: ∆0.29±0.75 m/s, V-THC: ∆0.42±0.74 m/s, V-CBD: ∆0.10±0.44 m/s; P=0.002) and diastolic function was reduced ([early/late ratio] S-THC: ∆-0.2±0.53, V-THC: ∆-0.33±58, V-CBD: ∆0.01±66; P=0.03). Differences in heart rate were related to changes in pulse wave velocity (r2=0.2; P=0.0002) and diastolic function (r2=0.26; P<0.0001). Inhalation method did not alter these cannabinoid-dependent responses. THC predominant, but not cannabidiol predominant, cannabis elicits increases in heart rate and blood pressure irrespective of inhalation method, which may increase arterial stiffness and reduce diastolic function. These findings implicate THC as a relevant factor for cannabis-related subclinical cardiovascular dysfunction. URL: https://www.clinicaltrials.gov; Unique identifier: NCT04693884.

Early postoperative resistance index can predict radiocephalic arteriovenous fistula failure.

Ultrasonography is valuable for assessing arteriovenous fistula (AVF) maturation. Brachial artery flow volume (FV) measured at 6 weeks post-AVF creation can predict AVF failure. However, the association between early postoperative FV and AVF failure remains unclear. The resistance index (RI) may also serve as a prognostic factor for AVF maturation; however, it has not been extensively studied. Therefore, we aimed to investigate the relationship between AVF failure and early postoperative FV and RI. We retrospectively analyzed data from 102 patients (mean age, 67.8 ± 14.2 years; male, 68.6%; diabetes mellitus, 52.0%) who underwent new radiocephalic-AVF creation between January 2019 and December 2023 in Japan. An ultrasound device was used to measure brachial artery FV and RI on postoperative days 0 and 1. AVF failure was defined as occlusion or stenosis requiring vascular access intervention or surgical revision before the first cannulation, or cannulation difficulty or FV dysfunction requiring vascular access intervention or surgery at the first cannulation. On postoperative day 0, FV was 383.1 ± 146.8 mL/min, and RI was 0.65 ± 0.11. On postoperative day 1, FV was 466.9 ± 179.2 mL/min, and RI was 0.62 ± 0.11. FV significantly increased, and RI was significantly reduced on postoperative day 1 compared to those on day 0 (p < 0.01). Multivariate analyses revealed that higher RI (per 0.1; odds ratio (OR), 2.16; 95% confidence interval (CI), 1.22-3.82), but not FV, was significantly associated with AVF failure on postoperative day 0. On postoperative day 1, lower FV (per 100 mL/min; OR, 0.63; 95% CI, 0.42-0.95) and higher RI (per 0.1; OR, 2.17; 95% CI, 1.16-4.05) were significantly associated with AVF failure. This study highlights RI as a predictor of AVF failure in the early postoperative period when vasospasm is likely to occur.

The relationship between post-anastomosis brachial artery flow rate and brachiocephalic arteriovenous fistula access maturity in end-stage kidney disease patients with diabetes mellitus.

From previous studies, evaluation of post-anastomosis draining-vein volume flow rate with Doppler ultrasound can be a predictor for arteriovenous fistula maturation. Due to the high variation in measurements by the effect of probe pressure in draining vein, measuring volume flow rate based on post-anastomosis feeding-artery may be an early alternative predictor of arteriovenous fistula maturation. This study aims to investigate the correlation of post-creation brachial artery volume flow rate on maturity of brachiocephalic arteriovenous fistula access in patients with end-stage kidney disease with diabetes mellitus. A retrospective cohort study was conducted on end-stage kidney disease patients with diabetes mellitus who underwent brachiocephalic arteriovenous fistula creation at three hospitals from July 2019 to March 2020. Doppler ultrasound examination of the brachial artery and draining vein volume flow rate was conducted at pre-operative, post-creation, 2 weeks, and 6 weeks post-creation. Maturity was evaluated at 6 weeks post-anastomosis. A total of 71 subjects met the inclusion and exclusion criteria, with 44 (62%) achieving maturation within 6 weeks. There was a correlation between post-anastomosis brachial artery (p < 0.001) and draining vein volume flow rate (p < 0.001) with arteriovenous fistula maturity after 6 weeks post-operatively. Brachial artery volume flow rate of ⩾350 mL/min can predict AVF maturity with a sensitivity of 95.45% (95% confidence interval = 84.86-98.74) and a specificity of 85.19% (95% confidence interval = 67.52-94.08). Post-anastomosis brachial artery flow volume can be a valuable parameter to predict brachiocephalic arteriovenous fistula maturity. It is a potential alternative to draining vein volume flow, which is technically a difficult examination.

The feasibility of a novel method to remove circumferentially ruptured balloons during ultrasound-guided percutaneous transluminal angioplasty for arteriovenous dialysis access

Objective: Angioplasty balloon rupture is a rare complication during percutaneous transluminal angioplasty (PTA). Conventional approach to retrieve circumferentially ruptured balloons is open surgery. This study examined the feasibility of a novel approach which can remove ruptured balloon during PTA in vascular access. Methods: This retrospective study analyzed 35 patients of a total 6465 patients that underwent ultrasound-guided PTA with a circumferential balloon rupture from February 2016 and August 2023. The patients underwent surgery (Group I, n = 13) or the novel method (Group II, n = 22) for balloon retrieval. Kaplan–Meier curve was used to assess the primary patency rates of the two groups. Result: The total incidence of circumferential balloon rupture was 0.5% in our center. Balloon retrieval was successful in both groups with no complications except one case had an infection in the surgical wound. Kaplan–Meier curve analysis showed that the post-intervention primary patency rates of the two methods were not significantly different ( p &gt; 0.05). There was a significant difference between pre-operation and post-operation brachial arterial flow ( p &lt; 0.001). Conclusion: The feasibility of the novel technique for retrieval of circumferential ruptured balloons during ultrasound-guided PTA is validated. The technique enables less invasive retrieval and continuation of PTA.

Revisiting the Muscles and Nerves of Anterior Compartment of the Arm: A Case Report.

During routine dissection of the anterior compartment of the arm region, we encountered several variations in the muscular and neural structures in the right upper extremity of a female cadaver. We observed one superiorly positioned extramuscular head with fibers originating from both the biceps brachii (BB) and coracobrachialis (CB) muscles and one inferiorly positioned extramuscular head with fibers solely from the BB muscle. The musculocutaneous nerve did not penetrate the CB muscle, but instead provided a muscular branch that communicated with the median nerve (MN). Both the MN and brachial artery (BA) flow beneath the extra head. This case suggests that the described variations may contribute to the entrapment of the MN and compression of the BA. Understanding these variations is crucial before surgical intervention. The failure to recognize such anatomical nuances could lead to inadvertent nerve injury or compromised vascular perfusion, emphasizing the need for preoperative planning and intraoperative vigilance.

#2515 Optimizing brachial-basilic arteriovenous fistula outcomes: insights from a mapping and pre-transposition review

Abstract Background and Aims Brachial- Basilic arteriovenous fistulas (BBAVF) are an option for our patients when superficial vascular patrimony is lacking, but they pose technical and time challenges due to the necessity of a second-stage surgical transposition. The literature reports a 47% primary patency rate within the first year. BBAVFs are associated with higher incidences of steal syndrome and increased stenosis rates, commonly requiring interventions. This study aims to provide insights about optimizing BBAVF outcomes through a comprehensive mapping and pre-transposition evaluation. Method We developed a retrospective single-centre study from 2016 to 2022 that included 101 patients with BBAVFs mapped and constructed at Centro Hospitalar Universitário de Santo António. Mapping and pre-transposition evaluations data were collected from our digital records and the dialysis centre's provided insights about the BBAVFs outcomes through telephonic contact. A comparative analysis between patients achieving one-year primary patency (1Y-P) and those who did not (No 1Y-P) was performed, considering mapping variables (brachial artery and basilic vein diameters) and pre-transposition variables (brachial artery flow and basilic vein diameter). Results At 12 months our primary patency rate was 72.27%. The 1Y-P and No 1Y-P groups showed no significant differences concerning to baseline characteristics such as sex (p = 0.536), age (p = 0.489), and major comorbidities like diabetes (p = 0.929), ischemic heart disease (p = 0.741), peripheral arterial disease (p = 0.174), kidney transplantation (p = 0.384), and previous haemodialysis (p = 0.384). When the BBAVFs were constructed as the first access, they were significantly associated with less primary patency at 12 months (1Y-P n = 32 (43.84%) vs No 1Y-P n = 23 (82.14%); p &amp;lt; 0.001). In the vascular mapping the brachial artery (1Y-P 4.32 ± 0.86 mm vs No 1Y-P 4.11 ± 0.78 mm; p = 0.454) and basilic vein (1Y-P 3.90 ± 1.11 mm vs No 1Y-P 3.59 ± 0.88 mm; p = 0.249) diameters were larger in the 1Y-P group, although without statistically significance. It is important to emphasise that only 12 BBAVFs were constructed with less than 3 mm basilic veins and we only had 50% 12-month primary patency in those patients. Pre-transposition flow was significantly higher in patients with primary patency at 12 months (1Y-P 1069,77 ± 311,89 ml/min vs No 1Y-P 985,00 ± 500,83 ml/min; p = 0.018) and basilic vein diameter was higher in the same group, but without statistical significance (1Y-P 6.50 ± 1.19 mm vs No 1Y-P 6.14 ± 1.53 mm; p = 0.123). Conclusion Our primary patency rate was higher than the described in the literature, which could be a reflection of the organized mapping process in our centre that excludes limit size veins from the BBAVF construction. Patients with BBAVF as their initial access face worse outcomes with decreased primary patency time, probably due to lack of intrinsic vascular patrimony. Stringent construction criteria are warranted in those cases. Contrary to expectations, vessel diameters did not show significant relevance, prompting consideration of factors like distensibility or vessels calcifications as potentially influential. However, we have to underline that the average mapping basilic vein diameter was greater than 3 mm in both groups, which suggests a pre-selection is already carried out in our centre, and, even though there was not statistical significance, the 1Y-P group had bigger basilic veins in the vascular mapping. Our results were worst in the 12 BBAVFs constructed with less than 3 mm basilic veins. BBAVFs pre-transposition evaluation importance is emphasized by the association of higher pre-transposition brachial artery flow rates with improved outcomes. This research highlights the importance of mapping and pre transposition evaluation for optimal BBAVF outcomes, but further studies need to be done with longer follow up times and including more vascular access mapping criteria.

Limb Position Influences Peripheral Arterial Stiffness Reduction with Reactive Hyperemia

Reactive hyperemia can acutely reduce peripheral arterial stiffness. The reduction in peripheral arterial stiffness with reactive hyperemia has been suggested to be flow dependent. However, no previous studies have manipulated the magnitude of hyperemia. We manipulated blood flow by altering limb position to test the hypothesis that a larger increase in blood flow would lead to a greater reduction in peripheral arterial stiffness. Fourteen healthy young adults (5 women; age: 25 ± 5 years; mean ± SD) were included in this study. Peripheral arterial stiffness assessed via brachial to radial pulse wave velocity (PWV) was measured by placing pulse tonometers simultaneously over the brachial and radial arteries. Doppler ultrasound was used to measure brachial arterial blood flow. Arterial blood pressure was continuously monitored via photoplethysmography on the middle finger of the contralateral hand. Reactive hyperemia was performed with the right arm positioned below (≍50°) and above (≍50°) heart level using a rapid-release cuff positioned on the upper arm, inflated to 220 mmHg, sustained for 5 min, then released. Measurements were recorded before cuff inflation and at 5, 15, and 30 min after cuff release. Repeated measures ANOVA revealed a significant condition effect (p&lt;0.01) with peripheral PWV higher with the arm below the heart. There was a significant time x condition interaction (p&lt;.05). At 5-min after reactive hyperemia, peripheral PWV was reduced more with the arm below the heart (9.58 ±1.65 to 7.26 ± 1.51 m/sec) than above the heart (7.08 ± 1.79 to 5.88 ± 1.43 m/sec). Mean arterial pressure did not change across time points (p&gt;0.05). Peak brachial artery blood flow was greater with the arm below the heart (477.37 ± 145 vs 368.64 ± 137 ml/min; p&lt;.001). The results show that reactive hyperemia produces an acute reduction in brachial to radial PWV. The reduction in peripheral arterial stiffness was greater when the arm was below the heart. The mechanism for position-related differences in the reduction in peripheral arterial stiffness with reactive hyperemia may be associated with the magnitude of increase in blood flow. REJ was supported by National Heart, Lung, and Blood Institute (5T32HL134634-04). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Physical Activity Influences the Relationship between Objectively Measured Hot Flashes and Endothelial Function in Perimenopausal Women

Hot flashes (HF) are disruptive symptoms experienced by approximately 80% of women undergoing menopause. The transition to menopause is associated with increases in CVD risk factors. The frequency and severity of HF have been associated with poorer cardiovascular health but most of these studies have quantified HF by self-report and have not considered physical activity (PA), known for its cardiovascular benefits. The association between HFs and CVD risk may be through their effect on endothelial health. The objective of this study was to evaluate the relationship between objectively measured HF and endothelial function and determine the effect of physical activity on the relationship in healthy perimenopausal women. We hypothesized that more HF would be associated with lower endothelial function and PA would influence this relationship. Healthy perimenopausal women (n=52, age 43-54) were included in this analysis. Perimenopause was defined as ≥7d difference in the length of consecutive cycles to &lt;12 months of amenorrhea. Hot flashes were measured objectively using sternal skin conductance for 24 hours. The number of HF experienced and HF rate (normalized to actual wear time) were quantified. Endothelial function was assessed with measures of brachial artery flow mediated dilation (FMD, %) on the non-dominant arm. Moderate to vigorous physical activity (MVPA) was assessed with 7-days of actigraphy monitoring on the non-dominant wrist. The R package GGIR and Hildebrand (2016) cut points were used to quantify PA intensity and reported as sum of the average minutes of moderate and vigorous physical activity per day. Pearson correlations and multiple regression analyses were used to evaluate relationships between variables. Data met all assumptions for statistical tests. Modeling was performed to evaluate whether HFs were predictors of the main outcome of FMD (R version 4.2.3 and RStudio version 2023.06.2+561). Age and BMI were included in all models. Lower FMD was significantly correlated with a higher objective HF rate ( r (52) =-0.27, p=0.05). Objective HF rate predicted FMD (β=-3.91, p=0.04) when controlling for age and BMI (adj R2=0.100, F(3,48) =2.892, p=.05). When MVPA was added to the model, MVPA alone was not a significant predictor but the interaction between MVPA and HF was (β=0.12, p=0.04; adj R2=0.147, F(5,46) =2.761, p&lt;0.03). This interaction was such that higher levels of MVPA were related to a less strongly negative relationship between objective HF rate and FMD. A simple slopes analysis found that the HF rate effect at one SD below the mean MVPA was significantly negative, (β=-8.64, p=0.004), whereas the HF rate effect at one SD above the mean MVPA was not significant, (β=0.18, p=0.95). These data provide strong evidence that support the hypothesis that a greater number of objectively-assessed hot flashes is associated with lower endothelial function in perimenopausal women and that higher amount of physical activity serves as a buffer against the negative relation between hot flashes and FMD. NIH NHLBI R15 Grant 1R15HL145650-01A1 (Witkowski); Smith College McKinley s Honors Fellowship (Tha Ra Wun); Smith College STRIDE (Buszkiewicz). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Poor Sleep Quality Contributes to Vascular Endothelial Dysfunction in Young Adults with Adverse Childhood Experiences

Introduction: Adverse childhood experiences (ACEs) represent severe psychosocial stressors during the first 18 years of life that promote a dose-dependent, lifetime increase in cardiovascular disease risk. ACEs have been associated with impaired vascular endothelial function and poor sleep quality in young adults. However, whether poor sleep quality influences the association between ACEs and vascular endothelial function is unclear. We hypothesized that sleep quality would mediate the association of ACE exposure with impaired vascular function. Purpose: To examine the contribution of sleep quality to ACEs-related impairments in vascular endothelial function in young adults. Methods: We used a cross-sectional cohort study (Study 1) and a single-arm intervention (Study 2) to test our hypothesis. Sleep quality was characterized as sleep effciency (SE%) and calculated as total sleep duration relative to time-in-bed. Vascular endothelial function was assessed using the brachial artery flow mediated dilation technique (FMD). In Study 1, we examined the mediation effect of SE% in the association of ACE exposure with FMD in a cohort of young adults (n=56; age = 25 ± 5 y, BMI = 26 ± 5 kg/m2) using the bootstrapped (1,000 replications) bias-corrected percentile confidence interval method adjusted for sex, and depression and anxiety symptomology. The variance accounted for (VAF) was calculated as the ratio of the indirect effect to total effect β-coeffcients. In Study 2, with a separate sample (n=12; age = 21 ± 2 y, BMI = 23 ± 4 kg/m2) of young adults with high ACE exposure (5 ± 2 ACEs) and poor sleep quality (SE ≤ 90%), we manipulated SE% using 6-weeks of cognitive-behavioral therapy for insomnia (CBTi) and measured FMD before (PRE) and after (POST) the intervention. Change in weekly SE% from daily consensus sleep diary entries was analyzed using a one-way ANOVA with Tukey post hoc comparisons. PRE to POST change in FMD was analyzed with a paired samples t-test. The association between the change (Δ; POST-PRE) in SE% and FMD was examined using a Spearman’s correlation coeffcient (ρ). Results: In Study 1, SE% significantly, partially mediated the association between ACE exposure and FMD (indirect effect standardized β-estimate = -0.11 [95% CI = -0.29 – -0.02]; VAF = 27.4%). In Study 2, there was a treatment effect of CBTi on SE% ( p &lt; 0.001) where SE% improved from baseline to weeks 3, 4, 5, and 6 (weekly improvement range = 8.8 – 10.1%; all p ≤ 0.002). FMD increased PRE to POST (2.85 ± 0.58 to 3.65 ± 1.0 %/SR AUC·104; p = 0.017). There was a moderate, non-significant association between ΔSE% and ΔFMD (ρ = 0.46, p = 0.13). Conclusions: Our findings provide initial evidence that poor sleep quality may contribute to the previously described impairment in vascular endothelial dysfunction observed with increasing ACE exposure in young adults. Funding provided by a grant from the Injury Prevention Research Center through the CDC (R49 CE003095; NDMJ). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Mitochondrial-targeted Antioxidant Enhancing Effects on Vascular Endothelial Function in Middle-aged and Older Adults Is Influenced by Cardiorespiratory Fitness

Vascular endothelial dysfunction in middle-aged and older (MA/O, ≥ 45 y) adults is partly attributable to excess mitochondrial reactive oxygen species (mtROS) production. Aerobic exercise preserves endothelial function in preclinical models via lower mtROS and mitigates the deleterious effects of aging on cardiorespiratory fitness (CRF). However, the acute effects of a mitochondrial-targeted antioxidant on age-related vascular endothelial function in the context of CRF are currently unknown. We hypothesized lower CRF resulting from a physically inactive lifestyle contributing to age-related endothelial dysfunction is mediated via greater mtROS in humans. In a double-blind, randomized, placebo-controlled crossover study design MA/O adults were divided into two groups: exercisers (EX, n=11, age 60.0 ± 4.0 y, BMI 25.0 ± 0.9 kg/m2) and non-exercisers (NEX, n=12, age 64.0 ± 2.8 y, BMI 28.2 ± 1.0 kg/m2). CRF, assessed via VO2max, was measured on a cycle ergometer from an incremental ramp protocol (10 or 20 watts/min). Vascular endothelial function from brachial artery flow mediated dilation (FMDBA) was acquired before (pre-ingestion) and ~1 h after MitoQ (single dose, 80 mg) or placebo supplementation. A two-way repeated measures ANOVA with a Bonferroni post-hoc analysis was used to determine the effects of MitoQ and placebo on FMDBA. Compared to placebo, MitoQ increased FMDBA in NEX (pre: 4.9 ± 0.4 vs post: 7.0 ± 0.4 %, p&lt;0.05) by +37% and brachial artery diameter (pre: 0.18 ± 0.02 vs post: 0.24 ± 0.02 mm, p&lt;0.05) by +34% whereas no changes were observed for FMDBA (pre: 6.8 ± 0.5 vs post: 7.0 ± 0.3 %, p&gt;0.05) or brachial artery diameter (pre: 0.25 ± 0.02 vs post: 0.26 ± 0.02 mm, p&gt;0.05) in EX. CRF was positively correlated with baseline FMDBA (n=17, r=0.56, p=0.01) whereas the change in FMDBA with MitoQ was inversely correlated with CRF (r=-0.54, p=0.02). These data demonstrate the acute MitoQ-enhancing effects on vascular endothelial function in MA/O adults is attributable, in part, to greater mtROS in physically inactive adults with lower CRF. Funding for this study was provided, in part, by Ball State University ASPiRE internal research grant (N.A. Carlini). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Ongoing, Chronic Stress Exposure Is Related to Impaired Vascular Endothelial Function Among Young Adults Irrespective of Subjective Appraisal of Stressor Severity

Introduction: Chronic stress is associated with cardiovascular morbidity independently of traditional cardiovascular risk factors. Vascular endothelial function (VEF) is predictive of cardiovascular risk and is reduced in response to transient and chronic psychosocial stress. While dominant stress theories (i.e., differential exposure model) posit that stress exposure explains health disparities, it has also been hypothesized that the subjective experience of these stressors — or stress appraisal — may also influence the effects of stress exposure on health. The purpose of this study was to investigate the associations of ongoing, chronic stress exposure and stress appraisal on VEF in young adults. Our hypothesis was that ongoing, chronic stress exposure, rather than stress appraisal, would be more strongly and inversely associated with VEF. We further conceptualized that stress appraisal would moderate the association between stress exposure and VEF. Methods: In 64, healthy young adults (75% Female; age = 25 ± 5 y), we assessed cumulative, chronic stress exposure with a measure that quantified ongoing exposure to 8 specific stressors over the last 12 months. For each chronic stress exposure reported, participants rated the perceived stressor severity using a 3-point Likert scale ( 1 = not upsetting, 2 = somewhat upsetting, 3 = very upsetting). The number of stressors was used as the indicator of ongoing, chronic stress exposure, while the average stressor severity was used as the indicator of stress appraisal. We assessed VEF using the brachial artery flow mediated dilation (FMD) technique normalized to the shear rate stimulus (%·[s1×10−2]) quantified as shear rate area under the curve. Using partial correlations, we examined relations among ongoing, chronic stress exposure and stress appraisal versus VEF, independently of sex. We then conducted an exploratory moderation analysis to assess whether stress appraisal moderated the effect of ongoing, chronic stress exposure on VEF. Results: Ongoing, chronic stress exposure (r=-0.32, p&lt;0.05), but not stress appraisal (r=-0.13, p=0.34) was related to VEF. Further, stress appraisal did not significantly moderate the association between ongoing, chronic stress exposure and VEF (p=0.69). However, the direct effect of ongoing, chronic stress exposure was statistically significant (β = -0.51; p=0.009), whereas the effect of stress appraisal was not (p=0.79), confirming our initial correlation analyses. Conclusions: Our findings indicate that ongoing, chronic stress exposure, rather than the subjective appraisal of this stress, significantly predicts impaired vascular endothelial function among young adults. Thus, our findings provide initial evidence indicating that stressor exposure is suffcient to increase cardiovascular risk independently of the perceived severity of the stressor(s) among young adults. However, the strength of our moderation analysis is limited by sample size, and future larger-scale studies may be necessary to fully understand the degree to which stress appraisal moderates the link between chronic stress and cardiovascular risk. Future studies may also seek to understand how potentially important, modifiable psychological processes influence this relationship, which may also be independent of stress appraisal. Funding provided by a grant from the Injury Prevention Research Center through the CDC (R49 CE003095; NDMJ and EBKT). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Relationships among Gonadotropins, Sex Hormones, and Vascular Function in Adolescents with Normal Weight or Obesity

Objective: Childhood obesity may lead to premature cardiovascular disease in adulthood. Excess adiposity suppresses gonadotropin [luteinizing hormone (LH), follicle-stimulating hormone (FSH)] production in both adolescent males and females, which act upon the gonads, leading to the release of the sex hormones (estrogen and testosterone). Both estrogen and testosterone have been linked to vascular function. Relationships among gonadotropins, sex hormones, and vascular function are not completely understood in male and female adolescents across the weight-status spectrum. We, therefore, sought to examine associations among gonadotropins, sex hormones, and vascular health in adolescents with normal weight or obesity. We hypothesized that increased levels of gonadotropins would be associated with worsened vascular function, and higher levels of estrogen would be associated with favorable vascular function. Methods and Data: Adolescents (n=58; 12– &lt;18-years of age) were stratified according to body mass index (BMI) percentile into normal weight (5th – &lt;85th BMI percentile; n=25) and obesity (³95th BMI percentile; n=33) categories. Fasting blood samples were collected to measure FSH, LH, testosterone, estradiol, total cholesterol, triglycerides, low-density lipoprotein cholesterol (LDL), very-low-density lipoprotein cholesterol (VLDL), high-density lipoprotein cholesterol (HDL), glucose, and insulin. Insulin resistance was calculated using the homeostatic model assessment (HOMA-IR). Vascular function was measured via ultrasonography for measures of carotid artery compliance and distensibility [i.e., diameter compliance (cDC), incremental elastic modulus (cIEM)], and brachial artery flow mediated dilation (FMD). Results: Female adolescents with obesity had a significantly greater ( p=0.009) FMD compared to females with normal weight. Triglycerides, VLDL, total cholesterol-to-HDL ratio, HOMA-IR, and insulin were also significantly greater (all p&lt;0.05) in adolescents with obesity compared to those with normal weight, while HDL was significantly lower ( p&lt;0.0001). FSH, LH, testosterone, and estradiol did not statistically significantly differ between the normal weight and obesity groups in either sex. After adjusting for age, multiple comparisons, and stratifying by sex, higher testosterone was associated with decreased cDC (p=0.018) in females. Additionally in females, higher testosterone was associated with increased cIEM ( p=0.002). In adolescent males, higher estrogen was associated with decreased cDC ( p=0.006) and increased cIEM ( p=0.003). Conclusion: Adding to previous research showing relationships between sex hormones and vascular health in adults, the current study shows associations between sex hormones and cDC and cIEM in adolescents. That said, we found no associations between gonadotropins and measures of vascular function in adolescents with normal weight or obesity. Future studies are needed to confirm these results in a larger cohort and among those with BMI in the overweight (85th - &lt;95th BMI percentile) category and differentiating severe obesity (&gt;120% of the 95th percentile, or &gt;35 kg/m2). Dr. Kelly serves as an unpaid investigator, consultant, and educator for Eli Lilly, Novo Nordisk, and Vivus; an unpaid consultant for Boehringer Ingelheim; receives donated study medication from Novo Nordisk and Vivus for NIDDK-funded clinical trials. Dr. Bomberg has served as a site principal investigator and site co-investigator for Novo Nordisk. His research program is supported by the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) of the National Institutes of Health (NIH) under award number K23DK125668. The content is solely the responsibility of the authors and does not necessarily represent the offcial views of the NIH. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Open Exploration and Reduction of Paediatric Supracondylar Humerus Fracture with Pink, Pulseless Hand in Resource-Limited Settings.

Background: Supracondylar humerus fractures (SHFs) are common paediatric injuries, with high risk of vascular compromise. Some patients present with a 'pink, pulseless hand', caused by occlusion of brachial artery flow but with collateral circulation preserving distal perfusion. Management of these patients remains controversial, especially when resources may be limited for prolonged hospitalisation and serial monitoring by skilled staff. The aim of this study is to present the intraoperative findings, surgical procedures done and outcomes at 6 weeks for patients with paediatric supracondylar fractures with a pink pulseless hand. Methods: We retrospectively identified 13 patients who presented to a public hospital between January 2019 and May 2023 with a displaced SHF and pink, pulseless hand. All patients underwent an open reduction with an anterior approach allowing for exploration, protection and repair of neurovascular structures. Distal flow was restored in the brachial artery either with topical lidocaine application, thrombectomy or artery reconstruction. Results: Out of 13 patients, all had intact median nerves and 10 had intact arteries (69%), of which seven were interposed at the fracture site and four were in vasospasm. Of the three patients with true arterial injury (23%), two had a crushed artery and one had thrombosis of the artery. Peripheral pulses were restored within an hour of fracture open reduction in all patients. At final follow-up, a mean 6 weeks postoperatively, all patients had recovered without neurovascular deficit, compartment syndrome or Volkmann ischemic contracture. Conclusions: In resource-limited settings, we recommend performing open exploration and reduction for patients with SHFs with pink, pulseless hand. This approach prevents iatrogenic neurovascular injury during closed reduction attempts, allows for immediate repair of a brachial artery injury and avoids unnecessary hospitalisation and serial monitoring. Level of Evidence: Level IV (Therapeutic).

Does central venous stenosis affects the brachial artery flow volume and peripheral vascular resistive index in patients on maintenance hemodialysis? A retrospective study.

A well-functioning vascular access (VA) is crucial for the patients on maintenance hemodialysis (HD). Central venous stenosis (CVS) is a common, yet, overlooked complication of VA as its diagnosis is challenging. Moreover, its effect on the flow volume (FV) and the peripheral resistive index (RI) was not well discussed before. Despite the availability of doppler ultrasound (DUS) in most centers, direct visualization of central veins using DUS is quite difficult. This is a retrospective single-center self-controlled cohort study that was conducted in a specialized vascular access management tertiary center in Japan and included all patients with CVS who underwent percutaneous transluminal angiography (PTA) with or without vascular stenting in the period from January 2014 to September 2022. The patients were divided according to their VA type into arteriovenous fistula (AVF), and arteriovenous graft (AVG) groups, then subdivided, according to the type of stenosis, into two subgroups: CVS, and mixed central and peripheral venous stenosis (MVS) groups. The FV and RI of the feeding artery were compared in the same procedure before and after PTA to assess the impact of the procedure itself. Data of 485 percutaneous transluminal angiography procedures (PTA), performed in 95 patients during the period from January 2014 to September 2022, were collected. FV and RI were significantly affected in the patients with MVS than patients with CVS. After PTA, both FV and RI were significantly improved. The improvement rate of FV and RI after PTA were significantly higher in patients with MVS than patients with CVS. However, it was difficult to determine the cut-off value to diagnose or to assess the improvement of CVS. Our findings suggest that FV and RI measurement by DUS are good tools, along with the clinical findings for assessment of CVS in certain situations.

A Cross-Sectional Study Evaluating the Association of Brachial Artery Flow Mediated Vasodilation with Physical Activity Measured by Accelerometry in Patients with the Overlap of Obstructive Sleep Apnea and Chronic Obstructive Pulmonary Disease.

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in Overlap Syndrome (OS), the co-occurrence of Obstructive Sleep Apnea and Chronic Obstructive Pulmonary Disease. Clustering of patients in subgroups with similar pre-clinical manifestations (ie, endothelial dysfunction) may identify relevant therapeutic phenotype categories for patients with OS who are at high risk of CVD. We therefore conducted a cross-sectional pilot study of endothelial function in 7 patients with OS (Forced Expiratory Volume in 1 second/Forced Vital Capacity < 0.7) on continuous positive airway pressure therapy (n = 7) to assess the relationship between FMD and physical activity. We found a strong association between FMD and step counts (rho = 0.77, p = 0.04); and FMD and moderate physical activity (rho = 0.9, p = 0.005). Further, larger studies are needed to confirm that FMD may identify patients with OS at high risk of CVD who benefit from increased physical activity.

Lower limb blood flow occlusion increases systemic pressor response without increasing brachial arterial blood flow redistribution in women.

This study was conducted to investigate the systemic hemodynamic and vascular changes in women during and after two commonly used clinical blood flow restriction (BFR) pressures at rest. There are minimal data regarding the independent effects of BFR on hemodynamic and systemic vascular changes due to pressor response, particularly among women. Therefore, this study investigated BFR-induced alterations in pressor response and systemic flow redistribution at rest during two commonly used pressures (50% and 80% limb occlusion pressure [LOP]). Fifteen women (22.1 ± 4.2 years) completed two randomised sessions involving 8-min of bilateral, lower limb restriction at 50% or 80% LOP followed by 8-min of recovery post-deflation. Changes in vascular (arterial diameter [DIA], time-averaged mean velocity [TAMV], volume flow [VF], and area) and hemodynamic (heart rate [HR] and blood pressure) measures over time (pre-, during, post-occlusion) and by session (50% vs. 80% LOP) were tested using repeated measures analysis of variance. Repeated measures correlations (rrm) quantified common intraindividual associations between BFR-induced hemodynamic and vascular responses. HR increased from baseline during 50% LOP and remained elevated during recovery (p < 0.05). HR increased from baseline during 80% LOP, while tibial VF and TAMV decreased (p < 0.03 for all). HR and TAMV values returned to baseline during recovery, while brachial artery VF decreased (p < 0.05). Changes in HR, brachial VF, and brachial TAMV were similar between 50% and 80% LOP (rrm = 0.32-0.70, p < 0.05 for all). At 80% LOP, changes in HR were positively correlated with brachial VF (rrm = 0.38) and TAMV (rrm = 0.43) and negatively correlated with tibial VF (rrm = -0.36) and TAMV (rrm = -0.30) (p < 0.05 for all). Results suggest that BFR at 80% LOP elicits an acute systemic pressor reflex without concomitant increases in brachial arterial flow, while 50% LOP elicits a subdued response.

Two-Year Cumulative and Functional Patency after Creation of Endovascular Arteriovenous Hemodialysis Fistulae

PurposeTo assess 2-year cumulative and functional patency of endovascular arteriovenous fistulae (endoAVF) created with the WavelinQ device. Materials and MethodsPatients who had fistulae created at a single center from December 2019 to December 2020 were included in this retrospective study. Forty-three patients underwent endoAVF creation (22 females, 21 males). Data collected included patient demographics, location of fistula creation, interventions performed, and brachial artery flow before and after creation. Two-year cumulative and functional patency rates were assessed with Kaplan–Meier method, and variables that affected patency and maturation were examined using Cox proportional hazards model. ResultsTechnical success was 95% (41/43), and in 4 patients, the fistula did not mature for dialysis use (9.7%). For the remaining 37 patients with endoAVF maturation, 25 had ulnar–ulnar fistulae, 10 had radial–radial fistulae, and 2 had interosseous artery–vein fistulae. Mean maturity time was 73 days, and brachial artery flow of >886 mL/min was predictive of maturation. Mean tunneled dialysis catheter removal time was 133 days. Number of interventions per patient-year was 0.38, where 8 were maturation procedures (5 vein elevations/transpositions and 3 coil embolizations) and 21 were maintenance angioplasties. Two-year cumulative/secondary and functional patency rates were 89.4% and 92.1%, respectively, with a mean follow-up of 665.7 days. Examined variables did not impact cumulative or functional patency. One adverse event was migration of coil to the heart, which was successfully retrieved at time of procedure. ConclusionsTwo-year patency of 89.4% and functional patency of 92.1% were observed after endoAVF creation with WavelinQ device.

(228) Cell-Based Therapy Can Restore Erectile Function in Men with Type 2 Diabetes and Metabolic Syndrome by Promoting Angiogenesis and Endothelial Repair

Abstract Introduction Although there has been a growing interest in restorative therapies for erectile dysfunction (ED) in recent years, there is still limited mechanistic evidence to support their effectiveness in the clinical setting. Objective The goal of this research was to investigate the mechanistic impact of cell-based therapy in men with ED secondary to Type 2 Diabetes Mellitus (DM2) and Metabolic Syndrome (MetS) through analysis of plasma biomarkers. Methods International Index of Erectile Function (IIEF) was completed by all men in the ACESO (NCT02886884) and CERES (NCT03059355) clinical trials. ACESO and CERES were both randomized, blinded, pilot phase clinical trials in which all participants received cellular therapy at varying doses and sources to treat endothelial dysfunction secondary to either DM2 or MetS, respectively. The intervention in both trials was peripheral intravenous infusion of allogeneic Mesenchymal Stem Cells (MSCs) of either 20 or 100 million cells derived from either bone marrow (BM) or umbilical cord tissue (UC). Follow-up was for 1 year. Endothelial function was measured via Brachial Artery Flow Mediated Vasodilation (FMD) and Endothelial Progenitor Cell-Colony Forming Units (EPC-CFU) assay. Plasma aliquots were isolated from blood samples and subjected to multiplex ELISA assay for analysis of angiogenic biomarkers. Results Data was pooled from all 20 men in the ACESO and CERES clinical trials. Overall, 7 received 20 million BM-MSCs, 9 received 100 million BM-MSCs, 2 received 20 million UC-MSCs, and 2 received 100 million UC-MSCs. There were no treatment emergent serious adverse effects (TE-SAEs) within 30 days following infusion in any of the participants. Among men with ED (IIEF-EF&amp;lt;25), 31.25% achieved MCID in erectile function. Participants with mild or moderate ED at baseline showed greater improvements in erectile function and endothelial function compared to those with severe ED. Participants who achieved MCID following cell therapy also experienced statistically significant improvements in FMD (P=0.05), whereas those who did not achieve MCID or had normal erectile function at baseline did not experience an improvement in FMD. Furthermore, men with Metabolic Syndrome who met MCID criteria were found to have increased Angiopoietin 1 and decreased Angiopoietin 2 following cell therapy. Conclusions The findings of this study demonstrate the potential of cell-based therapies in improving erectile function, angiogenic, and endothelial function. Future studies should aim to identify the causative mechanisms underlying these restorative effects in humans, paving the way for enhanced understanding and optimization of such therapies. Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: Longeveron LLC.

Preoperative and postoperative vascular characteristics in AVF creation surgery

Background: Early postoperative vascular ultrasound can predict the maturity of arteriovenous fistulas as well as detect complications.&#x0D; Objective: To present the characteristics of upper extremity vessels on ultrasound prior to AVF surgery and to analyze the changes in vessel size and flow rate postoperatively.&#x0D; Subjects and methods: We prospectively describe 80 cases of AVF formation at Dong Nai General Hospital from April 2022 to April 2023. Vascular ultrasound evaluations were conducted preoperatively and at 1 day, 2 weeks and 6 weeks postoperatively to evaluate the diameter and the blood flow of vessels used to create AVFs.&#x0D; Results: Eighty patients underwent AVF surgery. In forearm AVFs, the median diameter of the feeding artery and the draining vein were 2.12 (1.83 – 2.5) mm and 3.38 (2.9 – 3.80) mm, respectively. In upper-arm AVFs, the median diameter of the feeding artery and the draining vein were 3.67 (3.45 – 3.99) mm and 4.0 (3.64 – 4.05) mm, respectively. The draining vein flow rate showed a strong correlation with the brachial artery flow rate (R2 = 0.94, correlation coefficient = 0.88). The diameter and flow rate of the draining vein at 6 weeks post-surgery displayed significant correlations with their respective values at 2 weeks post-surgery, with correlation coefficients of 0.92 (R2 = 0.66) and 1.04 (R2 = 0.86), respectively. After 6 weeks post-surgery, non-diabetic patients exhibited larger draining vein diameters and higher flow rates compared with diabetic patients.&#x0D; Conclusions: The study highlighted the predictive potential of vascular ultrasound at the 2-week postoperative mark for AVF maturation The brachial artery flow rate can serve as a reliable indicator of AVF flow rate. Given the tendency for diabetic patients to exhibit smaller draining vein diameter and lower AVF flow rate than non-diabetic patients, particular caution is recommended when performing preoperative ultrasound mapping in this patient population.

High dietary salt intake attenuates nitric oxide mediated endothelium-dependent vasodilation and increases oxidative stress in pregnancy.

This study aimed to investigate the impact of dietary salt intake during normal pregnancy on maternal microvascular and macrovascular endothelium-dependent reactivity and oxidative stress level. In this cross-sectional study, based on their 24-h urinary sodium excretion, pregnant women (37-40 weeks of gestation) were divided into three groups: normal salt (<5.75 g/day, N = 12), high salt (5.75-10.25 g/day, N = 36), and very high salt (VHS;>10.25 g/day, N = 17). Forearm skin microvascular reactivity in response to vascular occlusion, local heating (LTH) and iontophoresis of acetylcholine (AChID), as well as brachial artery flow mediated dilation (FMD) were measured. Serum nitric oxide, endocan, 8-iso-prostaglandin F2α (8-iso-PGF2α), thiobarbituric acid reactive substances (TBARS), and ferric-reducing ability of plasma assay were measured as biomarkers of endothelial function/activation and oxidative stress. Brachial artery FMD, microvascular AChID, and LTH were significantly decreased in VHS compared with NS group, while LTH was also decreased in normal salt compared with high salt group. Nitric oxide was significantly decreased in both high salt and VHS groups compared with normal salt. Endocan, 8-iso-PGF2α, and TBARS were significantly increased in VHS compared with the normal salt group. High dietary salt intake is associated with decreased nitric oxide mediated endothelium-dependent vasodilation in peripheral microcirculation and macrocirculation of healthy pregnant women due to increased oxidative stress.