Flow-mediated Dilation In Patients Research Articles

The Role of NO and H2O2 in Ach-Induced Dilation of Human Arterioles in the Absence and Presence of Coronary Artery Disease

The endothelium regulates vascular tone through the release of various vasodilatory factors such as NO, PGI2, and endothelium-derived hyperpolarizing (EDH) signaling that is more important in resistance arteries and arterioles. Using freshly isolated human arterioles, previous studies indicate that hydrogen peroxide (H2O2), an EDH factor, mediates flow-mediated dilation in patients with coronary artery disease (CAD), whereas NO plays a more prominent role in patients without CAD. However, the mechanisms of receptor agonists (e.g., acetylcholine)-induced dilation remains to be clarified in human arterioles. The objective of this study was to compare the role of NO and H2O2 in acetylcholine (Ach-induced dilation in human adipose arterioles (HAA) from non-CAD and CAD patients. HAA (100-200 μm) dissected from discarded surgical samples of non-CAD and CAD patients, were cannulated onto glass micropipettes and pressurized at 60 mmHg for measurement of diameter changes by using videomicroscopy. Microvessels were incubated with L-NAME (100 μM), an inhibitor of NO synthase, Indomethacin (Indo, 10 μM), an inhibitor of PGI2 synthesis and peg-CAT (500 U/ml), a scavenger of H2O2. To study the dose-dependent response to Ach (log 10-9 – 10-5 M), HAA were preconstricted with endothelin-1 (0.1-0.5 nM). In non-CAD tissues Ach induced potent concentration-dependent dilation (maximal dilation at 10−5 M: 95.6±1.8%). After preincubation with L-NAME, this dilation was partially reduced (maximal dilation at 10−5 M: 77.4±3.1%, P<0.05 vs. control), while the combination of L-NAME and Indo reduced it to the same extent as L-NAME by itself (maximal dilation at 10−5 M: 73.1±7.4%, P<0.05 vs. control). To further determine the role of H2O2 in dilatory response to Ach, we treated HAA with peg-CAT. Incubation of peg-CAT significantly reduced the dilation (maximal dilation at 10−5 M: 74.6±8.1% and 51.3±8.7% in the absence and presence of L-NAME and Indo, P<0.05 vs. control). In HAA obtained from CAD patients, the dilation response to Ach was similar to non-CAD (maximal dilation at 10−5 M: 93.9± 1.8%) and the combination of L-NAME and Indo reduced this dilation to a lesser extent (maximal dilation at 10−5 M: 83.1±3%, P=0.055), compared to non-CAD patients (maximal dilation at 10−5 M: 73.1±7.4%, P<0.05 vs. control). The preincubation with peg-CAT attenuated the dilation only at log -7 M (maximal dilation at 10−7 M: 33.8±9.5%, P<0.05 vs. 54.6±7.5% in control). The large portion of the dilation remaining after the combination of L-NAME and Indo was almost completely abolished in the presence of high K+ concentration (maximal dilation at 10−5 M: 12.9±5.1% P<0.05 vs. control). Together, these results provide new evidence that in non-CAD arterioles both NO and H2O2 play an important role in Ach-induced dilation whereas PGI2 is likely not involved. In CAD arterioles, NO, PGI2 and H2O2 have much less contribution to Ach-induced dilation, while a H2O2-independent EDH signaling plays the major role in the dilatory response. Further studies are required to determine the specific mechanism or factor involved in Ach-induced EDH-dependent dilation in HAA. This work was supported by the National Heart, Lung, and Blood Institute [R01HL096647]. 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.

Evaluation of Endothelial Dysfunction via Flow-Mediated Dilation in Patients with Inflammatory Bowel Disease Referred to Medical Centers in Kerman

Background: By examining flow-mediated dilatation (FMD) as an index for indirect assessment of arterial endothelial function, this study aimed to investigate the relationship between inflammatory bowel disease (IBD) and early atherosclerosis. Methods: This study was performed on 75 patients with ulcerative colitis, 15 patients with Crohn’s disease, and 75 healthy individuals as the control group. Vascular endothelial function was assessed by FMD and Doppler ultrasonography of the right brachial artery. Results: The mean FMD in IBD patients (12.04±3.8) was lower than that of the persons in the control group (16.68±2.2). Besides, the mean FMD in Crohn’s patients was 12.02±3.5 and the corresponding value in the patients with ulcerative colitis was 12.07±4.2, showing no significant difference (P=0.78). There was a significant opposite relationship between age and FMD in the control group, meaning that as age increased, FMD decreased (r=0.6, P=0.01). However, there was no association between age and FMD among IBD patients. Conclusion: Given that this study focused on people without known risk factors for atherosclerosis, the results pointed to endothelial dysfunction in IBD patients, and IBD can be considered an independent factor in the development of atherosclerosis.

Non-alcoholic fatty liver disease and compromised endothelial function in people with type 2 diabetes

IntroductionNonalcoholic fatty liver disease (NAFLD) frequently coexists with type 2 diabetes mellitus (T2DM) and synergistically contributes to the development of atherosclerosis. Flow-mediated dilation (FMD) is a commonly used noninvasive test for assessing endothelial function. The main objective of this study was to explore FMD in patients with T2DM with and without NAFLD.MethodsIn this cross-sectional study, conducted on people with T2DM, NAFLD was defined as controlled attenuation parameter (CAP) score > 302 dB/m. Endothelial dysfunction was detected when arterial FMD of brachial artery was equal or less than 0.7%. Regression analyses were applied to assess factors associated with impaired FMD.ResultA total of 147 patients (72 with NAFLD and 75 without NAFLD) were included in the final analysis. Patients with NAFLD were more likely to develop FMD ≤ 7% (77.8% vs. 58.7%, P = 0.01). In multivariate analysis, NAFLD (OR = 2.581, 95% CI (1.18–5.62), P = 0.017) and hypertension (HTN) (OR = 3.114, 95% CI (1.31–7.35), P = 0.010) were associated with an increased risk of impaired FMD. However, female sex was associated with a decreased risk of impaired FMD (OR = 0.371, 95% CI (0.15–0.87), P = 0.024).ConclusionNAFLD is associated with endothelial dysfunction in people with T2DM. This risk is comparable with the risk imposed by HTN, highlighting the importance of screening and management of NAFLD in these patients.

Effects of Omega-3 Fatty Acids on Flow-mediated Dilatation and Carotid Intima Media Thickness: A Meta-analysis.

To investigate the effects of omega-3 fatty acids on flow-mediated dilatation (FMD) and carotid intima-media thickness (CIMT) and explore the factors influencing these effects. FMD was significantly higher in the omega-3 fatty acid group compared to the control group (mean difference = 0.90%; p = 0.0003). In particular, the subgroup with CHD (both EPA + DHA < 1g/day and ≥ 1g/day) and the subgroup without CHD but with CHD risk factors (only EPA + DHA ≥ 1g/day) showed significantly increased FMD after supplementation of omega-3 fatty acids. CIMT was not significantly different between the omega-3 fatty acid and control groups (standardized mean difference = -0.08; p = 0.26). Subgroup analysis of CHD patients was not conducted because of the limited number of studies. Intake of omega-3 fatty acids improved FMD in patients with CHD and patients with risk factors for CHD. Further research is needed on the effects of omega-3 fatty acids on CIMT.

Effect of Sodium TanshinoneⅡA Sulfonate on Uric Acid, Sicam-1, ET-1 and FMD in Patients with Coronary Heart Disease Complicated with Hyperuricemia.

This study was to observe the effect of Sodium TanshinoneⅡA Sulfonate (ST-ⅡAS) on blood uric acid (UA), human Soluble Intercellular Adhesion Molecule-1 (sICAM-1), Endothelin-1 (ET-1) and percentage of brachial artery Flow-Mediated Dilatation (FMD) in individuals with Hyperuricemia Complicated Coronary Heart Disease (HC-CHD). The study's participants were 108 patients with HC-CHD who attended our hospital between January 2020 and June 2022. In the trial, the patients were split into two groups with 54 instances each: the general group and the observation group. The observation group received ST-IIAS therapy, while the general group received standard care. The experiment chose to observe and compare the difference of uric acid, sICAM-1, ET-1, FMD, therapeutic effectiveness and negative effects between the two groups at various times. Results showed that on the 14th day, the observation group's amounts of UA, sICAM-1, and ET-1 were inferior to the general group (P<0.05); On the 7th and 14th days, the observation group's amount of ET-1 was lower than that of the general group (P<0.05); The observation group's FMD of patients on the 14th day was inferior to the general group after treatment (P<0.05); The observation group's overall effective rate was 94.44% higher than the general group's (P<0.05); The observation group experienced fewer negative responses than the general group did (P<0.05). In conclusion, ST-ⅡAS can be used for uric acid, vascular endothelial systolic and diastolic function in patients with HC-CHD, and has better clinical efficacy and lower risk of adverse reactions.

Brachial artery flow-mediated dilation in patients with systemic sclerosis: an experience from tertiary care center from North India.

Role of flow-mediated dilatation (FMD) testing in the assessment of the macrovascular dysfunction in systemic sclerosis (SS) and correlation of FMD values with disease severity. Twenty-five patients of SS and 25 healthy age-matched controls were recruited. Modified Rodnan skin thickness score (MRSS) was used for skin thickness assessment. FMD values were measured in the brachial artery. FMD values done at baseline before the initiation of treatment were lower in SSc patients (4.044 ± 2.742) compared to the healthy controls (11.076 ± 5.896) (P < 0.05). Comparison of FMD values between patients with limited cutaneous systemic sclerosis (LSSc) and diffuse cutaneous systemic sclerosis (DSSc) showed a trend toward lower in LSSc (3.182 ± 2.482) as compared to DSSc patients (5.111 ± 2.711); however, the difference was not statistically significant. Patients with lung manifestations on high-resolution CT chest showed lower FMD values (2.66 ± 2.23) compared to those without HRCT changes (6.45 ± 2.56) (P < 0.05). We demonstrate that FMD values in SSc patients were lower when compared to healthy controls. Patients with SS having pulmonary manifestations showed a lower value of FMD. Key Points • FMD is a simple non-invasive tool to assess the endothelial function in patients with systemic sclerosis. • Lower values of FMD in systemic sclerosis suggest that the endothelial dysfunction and values can also be correlated with other organ involvement such as lung and skin involvement. So, lower FMD values might be a useful marker for disease severity.

Vascular dysfunction in juvenile idiopathic arthritis: a systematic review and meta-analysis.

We performed a systematic review and meta-analysis of studies evaluating vascular function in patients with JIA. Relevant literature published from 1st January 1965 to 1st March 2022 was searched systematically utilizing PubMed, Web of Science, and Embase databases. Observational studies were included-patients with JIA (classified according to the International League of Associations for Rheumatology criteria) were included as cases (study population) and age/sex-matched healthy participants as controls (comparator group). Outcome measures were differences in non-invasive parameters of vascular function. Online Population, Intervention, Comparison, Outcomes Portal was used for deduplication of studies and data extraction. Review Manager, Comprehensive Meta-analysis, and Meta-Essential softwares were used for data synthesis/analysis (encompassing data pooling and evaluation of heterogeneity and publication bias). Newcastle-Ottawa Scale and GRADEpro GDT software were utilized to assess study quality and certainty of evidence, respectively. Of 338 citations, 17 observational studies with 1423 participants (cases = 757, controls = 666) were included. Carotid intima-media thickness (CIMT) was higher [mean difference (MD) 0.02mm {95% confidence interval (CI) 0.01-0.04}, p = 0.0006, I2 = 69%] in patients with JIA. Besides, decreased flow-mediated dilatation (FMD) [MD -2.18% {95%CI -3.69--0.68}, p = 0.004, I2 = 73%] was also observed. Results of studies assessing pulse wave velocity or arterial stiffness could not be pooled due to significant methodological variations. A 'very low' certainty of evidence suggests the presence of vascular dysfunction in JIA. Future longitudinal studies are required to determine whether altered CIMT and FMD in patients with JIA translate to an enhanced risk of (adverse) clinical cardiovascular events. PROSPERO (CRD42022323752).

Serum apolipoprotein A-IV levels are associated with flow-mediated dilation in patients with type 2 diabetes mellitus

BackgroundEndothelial dysfunction is common in diabetes. Apolipoprotein (apo) A-IV functions to antagonize inflammation and oxidative stress. The present study aimed to investigate the relationship between flow-mediated dilation (FMD) and serum apoA-IV level in type 2 diabetes mellitus (T2DM) patients. MethodsA total of 84 T2DM patients with chest discomfort were enrolled in this study. Their baseline characteristics and clinical parameters were documented. Endothelial function of the participants was evaluated by examining FMD of brachial artery. The severity of coronary atherosclerosis was determined by quantitative coronary angiography. Serum apoA-IV levels were measured by ELISA.ResultsThese diabetic patients were dichotomized into low FMD (n = 42) and high FMD (n = 42) groups. Serum apoA-IV levels were significantly higher in high FMD group than in low FMD group (29.96 ± 13.17 vs 17.69 ± 9.16 mg/dL, P < 0.001). Moreover, the patients were also categorized into three apoA-IV tertile groups. FMD was significantly different across three apoA-IV tertiles (P < 0.001). Serum apoA-IV levels were positively correlated to FMD (r = 0.469, P < 0.001). Logistic regression analysis was performed to determine risk factors for low FMD. apoA-IV levels together with the risk factor hsCRP remained significantly to be independent determinants of low FMD (P < 0.01). Linear regression analysis was performed, and apoA-IV levels together with total-to-HDL cholesterol ratio were independently correlated with FMD (P < 0.01).ConclusionsSerum apoA-IV levels are associated with FMD, suggesting that apoA-IV protects endothelial function in patients with T2DM.

Asymmetric Dimethylarginine Is a Marker of Endothelial Dysfunction in Thrombotic Antiphospholipid Syndrome Patients.

Objective: The potential contribution of asymmetric dimethylarginine (ADMA) and high-sensitivity C reactive protein (hsCRP) to endothelial dysfunction in APS patients has not been studied in detail, until now. The study involved 105 APS patients (59 diagnosed with primary APS (PAPS) and 46 APS associated with systemic lupus erythematosus (SAPS)) who were compared to 40 controls. Endothelial dysfunction was assessed by measurement of flow-mediated dilatation (FMD) and glyceryl trinitrate dilatation (NMD) of the brachial artery. ADMA (micromol/L) was analyzed by ELISA. Results: FMD in patients with APS was significantly lower than that of the controls (p < 0.001), with no difference between the PAPS and the SAPS groups. ADMA and hsCRP concentrations were significantly higher in the patient cohort than in the control group (p < 0.001, p = 0.006, respectively), as was the case with the SAPS group as compared to the PAPS group (p < 0.001, p = 0.022, respectively). FMD impairment correlated to ADMA (ρ 0.472, p < 0.001) and to hsCRP (ρ 0.181, p = 0.033). In the regression model, the ADMA concentration confirmed the strength of its association (B 0.518, SE 0.183, Wald 8.041, p = 0.005, Exp(B) 1.679, 95% CI 1.174–2.402) to FMD impairment. The synergistic probability model of ADMA and hsCRP caused FMD impairment when the positivity of β2GPIIgG was added. ADMA may be used as a simple and low-cost tool for verifying the presence of endothelial dysfunction in APS patients. According to the results of the study, we could presume that hsCRP, together with aPL, has a preparatory effect on the endothelium in causing endothelial dysfunction.

Differences in coronary flow reserve and flow-mediated dilation between plaque psoriasis and psoriatic arthritis

Abstract Background/Introduction Psoriatic disease is associated with increased cardiovascular risk through mechanisms of inflammation and oxidative stress. Purpose We aimed to investigate endothelial glycocalyx, coronary microcirculatory function and flow-mediated dilation in patients with plaque psoriasis and psoriatic arthritis. Methods In 311 patients (mean age: 52±12 years) with psoriatic disease (185 with plaque psoriasis and 126 with psoriatic arthritis) and 150 controls with similar age, sex and atherosclerotic risk factors, we assessed: (1) Perfused boundary region (PBR) of the sublingual microvessels with a diameter 5–25μm using Sidestream Dark Field camera (Microscan, Glycocheck). Increased PBR indicates impaired glycocalyx integrity. (2) Coronary flow reserve (CFR) in the distal left anterior descending coronary artery, (3) Flow-mediated dilation (FMD) of the brachial artery, and (4) LV global longitudinal strain (GLS) using speckle-tracking echocardiography. Results Compared with controls, patients with psoriatic disease had higher PBR (2.14±0.29 versus 1.78±0.25μm, p&amp;lt;0.001) and lower CFR (2.86±0.93 versus 3.39±0.68, p&amp;lt;0.001), FMD (6.97±3.9 versus 9.1±2.1, p&amp;lt;0.001) and GLS (−17.4±3.8 versus −21.9±1.5%, p&amp;lt;0.001). There was not significant difference between the two study groups (plaque psoriasis and psoriatic arthritis) in PBR (2.14±0.28 versus 2.14±0.31μm, p=0.990) and GLS (−17.2±3.9 versus −17.6±3.8%, p=0.297). Patients with psoriatic arthritis had more impaired CFR (2.75±0.85 versus 2.96±0.99, p=0.045) and FMD (5.45±3.2 versus 7.76±4, p=0.003) compared to patients with plaque psoriasis. Conclusions Patients with psoriatic disease have impaired endothelial, vascular and myocardial function compared with controls. Coronary microcirculatory function and flow-mediated dilation are more affected in psoriatic arthritis compared with plaque psoriasis. Funding Acknowledgement Type of funding sources: None.

Relationship of arterial tonometry and exercise in patients with chronic heart failure: a systematic review with meta-analysis and trial sequential analysis

BackgroundArterial stiffness is a common characteristic in patients with chronic heart failure (CHF), and arterial tonometric technologies related to arterial stiffness are novel and effective methods and have an important value in the diagnosis and prognosis of CHF. In terms of ameliorating arterial stiffness in patients with CHF, exercise training is considered an adjuvant treatment and also an effective means in the diagnosis and judgment of prognosis. However, there are huge controversies and inconsistencies in these aspects. The objective of this meta-analysis was to systematically test the connection of arterial tonometry and exercise in patients with CHF.MethodsDatabases, including MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, were accessed from inception to 7 March 2022. The meta-analysis was then conducted, and trial sequential analysis (TSA) was performed jointly to further verify our tests and reach more convincing conclusions by using RevMan version 5.4 software, STATA version 16.0 software, and TSA version 0.9.5.10 Beta software.ResultsEighteen articles were included, with a total of 876 participants satisfying the inclusion criteria. The pooling revealed that flow-mediated dilation (FMD) was lower in basal condition [standardized mean difference (SMD): − 2.28%, 95% confidence interval (CI) − 3.47 to − 1.08, P < 0.001] and improved significantly after exercise (SMD: 5.96%, 95% CI 2.81 to 9.05, P < 0.001) in patients with heart failure with reduced ejection fraction (HFrEF) compared with healthy participants. The high-intensity training exercise was more beneficial (SMD: 2.88%, 95% CI 1.78 to 3.97, P < 0.001) than the moderate-intensity training exercise to improve FMD in patients with CHF. For augmentation index (AIx), our study indicated no significant differences (SMD: 0.50%, 95% CI − 0.05 to 1.05, P = 0.074) in patients with heart failure with preserved ejection fraction (HFpEF) compared with healthy participants. However, other outcomes of our study were not identified after further verification using TSA, and more high-quality studies are needed to reach definitive conclusions in the future.ConclusionsThis review shows that FMD is lower in basal condition and improves significantly after exercise in patients with HFrEF compared with healthy population; high-intensity training exercise is more beneficial than moderate-intensity training exercise to improve FMD in patients with CHF; besides, there are no significant differences in AIx in patients with HFpEF compared with the healthy population. More high-quality studies on this topic are warranted.

Comparison of the radial and brachial artery flow-mediated dilation in patients with hypertension.

Blood flow-mediated dilation (FMD) is a noninvasive assessment of vascular endothelial function in humans. The study of the FMD in hypertensive (HT) patients is an important factor supporting the recognition of the early mechanisms of cardiovascular pathologies, and also of the pathogenesis related to hypertension. To investigate whether FMD measured on the radial artery (FMD-RA) using high-frequency ultrasounds can be used as an alternative to FMD assessed with the lower frequency system on the brachial artery in patients with HT. The simultaneous measurements of FMD-RA and FMD measurements in the brachial artery (FMD-BA) were performed on 76 HT patients using 20 MHz and 7-12 MHz linear array probes, and were compared to the FMD measured in healthy groups. All quantitative data are presented as mean ± standard deviation (SD); the p-values of the normality and tests for variables comparisons are listed. The agreement of the FMD-RA and FMD-BA in HT patients was assessed with the Bland-Altman method, and using the intraclass correlation coefficient (ICC). In some statistical calculations, the FMD-RA values were rescaled by dividing them by a factor of 2. The mean FMD-RA and FMD-BA in HT patients were 5.16 ±2.18% (95% confidence interval (95% CI): [4.50%, 5.82%]) and 2.13 ±1.12% (95% CI: [1.76%, 2.49%]), respectively. The FMD-RA and FMD-BA values of HT patients were significantly different than those in respective control groups. The p-values of Mann-Whitney-Wilcoxon tests were less than 0.05. The Bland-Altman coefficient for both measurement methods, FMD-RA and FMD-BA, was 3%, and the ICC was 0.69. Our findings show that FMD-RA, supplementary to FMD-BA measurements, can be used to assess endothelial dysfunction in the group of HT patients. In addition, the FMD-RA measurements met the criteria of high concordance with the FMD-BA measurements.

Study of Endothelial Dysfunction in Patients With Non-alcoholic Fatty Liver Disease.

BackgroundMetabolic syndrome (syndrome X) is the name for a group of risk factors that raises your risk for heart disease and other health problems, such as diabetes and stroke. Dilatation of blood vessels following stress is a function of vasodilators produced by the endothelium. Flow-mediated vasodilation assesses endothelial function. In the case of endothelial dysfunction, flow-mediated vasodilation is impaired, resulting in decreased or even absence of vasodilation following stress. The easy availability of ultrasound machines nowadays and the non-invasive nature of the test make this a practical test for assessing endothelial dysfunction and the risk of cardiovascular diseases. Various studies have confirmed the presence of impaired flow-mediated vasodilation in patients with coronary artery disease. However, the presence of impaired flow-mediated vasodilation in individuals with risk factors but no cardiovascular diseases can prove that this can be used to predict individuals at risk. This study tries to confirm the presence of endothelial dysfunction in patients with non-alcoholic fatty liver disease (NAFLD) attending a tertiary center hospital in Kochi.ObjectivesThe study's main aim is to compare flow-mediated dilatation in patients with NAFLD and normal individuals.Materials and methodsThe comparative study was conducted among 50 patients attending various outpatient departments in Amrita Institute of Medical Sciences, Kochi. History and examination of cases and controls and relevant investigations were done after obtaining consent. In addition, both groups underwent measurement of flow-mediated vasodilation in the radiology department. Data were entered in Microsoft Excel and were analyzed using SPSS.ResultsFlow-mediated vasodilation was found to be less in patients with fatty liver (7.37 ± 2.75) when compared to individuals with normal liver (12.41 ± 3.71). In addition, flow-mediated vasodilatation was inversely proportional to BMI and age.ConclusionThis study has proved that there will be endothelial dysfunction in NAFLD, as shown by the decrease in flow-mediated vasodilation when compared with normal liver.

Comparison of the improvement of flow-mediated dilatation in patients with acute coronary syndrome versus stable angina after six-month cardiac rehabilitation.

We investigated whether the improvement in endothelial function, measured using flow-mediated dilatation (FMD), an important predictor of cardiovascular outcomes, was comparable in acute coronary syndrome (ACS) versus stable angina patients after percutaneous coronary intervention (PCI) and a six-month cardiac rehabilitation (CR) programme. We analysed the results from 119 patients who completed a six-month CR programme after successful PCI for stable angina (n = 50) and ACS (n = 69). After six months of CR, the results of FMD were significantly improved in both groups. There were no significant between-group differences in the FMD results at the six-month follow up. After successful PCI and a six-month CR programme, FMD values were equally improved in both stable angina and ACS patients.

Vitamin D Repletion Mitigates Oxidative Stress Induced Pulmonary Artery Remodeling in Sickle Cell Disease

The lung is a primary target of end organ pathology in patients with sickle cell disease (SCD). Pulmonary artery remodeling, a common feature at autopsy in SCD, is characteristic of the pulmonary hypertension of SCD. In an autopsy cohort of 20 patients with SCD, we found that pulmonary artery remodeling was a pathology of the young patient. Patients with severe remodeling had less than a 15% probability of surviving to 25 years of age, whereas those with milder remodeling had an 80% probability of living beyond 50. Therefore, we wanted to understand the mechanisms underpinning pulmonary artery remodeling.Using benchtop ion trap mass spectrometry on extracted pulmonary proteins from the autopsy study, we screened for oxidative “fingerprints” (protein modifications) that were specific for SCD. We found that the lungs from patients with SCD carried a profound oxidative burden. Oxidative modifications arising from the hydroxyl (∙OH), superoxide (∙O2-) peroxynitrite (ONOO-),and eosinophil peroxidase were all significantly elevated compared to samples prepared from identical lung blocks from unaffected controls at autopsy. However, of the oxidative modifications detected, only the signature from peroxynitrite, 3-nitro tyrosine, (3-NT) could differentiate those SCD patients with profound pulmonary artery remodeling from those with milder forms of this pathology. After adjusting for age, the 3-NT content was increased 16 fold in the severely remodeled pulmonary tissues. Using immunohistochemistry, we found that 3NT was exquisitely localized to remodeling vessels and areas of smooth muscle proliferation. We assayed plasma proteins from patients with SCD at steady state and found a consistently elevated 3-NT content when compared to control plasma. The 3-NT containing proteins in living patients correlated strongly with NT-proBNP, but inversely with plasma free hemoglobin at steady state.Peroxynitrite, a strong smooth muscle mitogen, is formed via the reaction of NO with ∙O2-, therefore we reasoned that the presence of the superoxide radical was transforming NO into ONOO-. Extracellular (EC) superoxides are neutralized by EC-superoxide dismutases (SODs) to preserve the vaso-regulatory effects of NO. EC-SOD is tethered to the outer membrane of cells to allow for diffusion of NO without superoxide attack. Using immunohistochemistry, electron microscopy, and linear-ion trap mass spectrometry with comparative proteomics on paraffin-free lung tissue we noted, that pulmonary EC-SOD was 60-fold depleted in the remodeling pulmonary vessels and endothelium in patients with SCD at autopsy. The plasma of patients at steady state, compared to unaffected controls, however, contained increased, but inactive EC-SOD indicating an SCD-specific release of EC-SOD from the outer membrane of endothelial surfaces and into the plasma compartment.Using an in vitro culture of human pulmonary endothelial cells, we quantified EC-SOD on the cell surface using ELISA. Plasma from patients with SCD significantly reduced the amount of EC-SOD detectable on the endothelial cells. Plasma from healthy control subjects was without effect.We, and many other groups have demonstrated that patients with SCD have compromised flow mediated dilation (FMD) - an NO mediated process. We found that both plasma EC-SOD and 3-NT content of plasma proteins inversely correlated with FMD in patients with SCD. However, high dose vitamin D repletion (100,000 units ergocalciferol weekly) improved FMD within 8 weeks and reduced both plasma EC-SOD and 3NT content of plasma proteins, thus restoring NO function. After an 8 week washout period of the ergocalciferol, FMD values, plasma EC-SOD, and plasma 3-NT content returned to baseline, pathological steady state levels.Furthermore, plasma from the 8 week ergocalciferol treated patients lost the ability to deplete EC-SOD from the endothelial cell surface in vitro, whereas after the washout, plasma from the same subject effectively removed EC-SOD from the endothelial cells.Taken together these data suggest a new mechanism of pulmonary hypertension in patients with SCD, one in which NO in the presence of superoxide radical promotes pulmonary artery remodeling and predicts an early death. Vitamin D, through an as yet undetermined mechanism, appears to restore NO function, and re-localize EC-SOD to the appropriate vascular compartment. DisclosuresKutlar:Sancilio & Co (OMEG-411-02): Other: Chair of Data and Safety Monitoring Board; BlueBird Bio: Other: Member of Data Monitoring Committee; Reprixys Pharmaceuticals Corporation (formerly known as Selexys Pharmaceuticals Corporation, which is not affiliated with Selexis S.A.): Research Funding; Novartis: Research Funding.

Disturbed Blood Flow Acutely Increases Endothelial Microparticles and Decreases Flow Mediated Dilation in Patients With Heart Failure With Reduced Ejection Fraction.

IntroductionDisturbed blood flow, characterized by high retrograde and oscillatory shear rate (SR), is associated with a proatherogenic phenotype. The impact of disturbed blood flow in patients with heart failure with reduced ejection fraction (HFrEF) remains unknown. We tested the hypothesis that acute elevation to retrograde and oscillatory SR provoked by local circulatory occlusion would increase endothelial microparticles (EMPs) and decrease brachial artery flow-mediated dilation (FMD) in patients with HFrEF.MethodsEighteen patients with HFrEF aged 55 ± 2 years, with left ventricular ejection fraction (LVEF) 26 ± 1%, and 14 control subjects aged 49 ± 2 years with LVEF 65 ± 1 randomly underwent experimental and control sessions. Brachial artery FMD (Doppler) was evaluated before and after 30 min of disturbed forearm blood flow provoked by pneumatic cuff (Hokanson) inflation to 75 mm Hg. Venous blood samples were collected at rest, after 15 and 30 min of disturbed blood flow to assess circulating EMP levels (CD42b−/CD31+; flow cytometry).ResultsAt rest, FMD was lower in patients with HFrEF compared with control subjects (P < 0.001), but blood flow patterns and EMPs had no differences (P > 0.05). The cuff inflation provoked a greater retrograde SR both groups (P < 0.0001). EMPs responses to disturbed blood flow significantly increased in patients with HFrEF (P = 0.03). No changes in EMPs were found in control subjects (P > 0.05). Disturbed blood flow decreased FMD both groups. No changes occurred in control condition.ConclusionCollectively, our findings suggest that disturbed blood flow acutely decreases FMD and increases EMP levels in patients with HFrEF, which may indicate that this set of patients are vulnerable to blood flow disturbances.

The impact of interval vs. continuous training on exercise capacity and endothelial function in post-myocardial patients: a randomised control trial

Abstract Introduction High-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) are two most common and well established exercise modalities for cardiac rehabilitation in patients after myocardial infarction. Yet, data on their effects on cardiovascular parameters beyond exercise capacity (e.g. endothelial function) are scarce. Methods Patients referred to cardiac rehabilitation (CR) after myocardial infarction were randomised to HIIT or MICT. HIIT consisted of 7 cycles of 1.5 min of 80–90% VO2peak and 3 min of 65–70% VO2peak intensity; MICT consisted of 32 min of 75% VO2peak intensity. We ultrasonographically appraised flow-mediated dilation (FMD) – a marker of endothelial function – before (resting), immediately after and one hour after (a) the first and (b) the last exercise training session, in order to appraise the specific effects of HIIT vs. MICT on acute and long-term vascular response to training. Cardiopulmonary exercise testing was performed in all patients. We compared the effects of training modalities with ANCOVA using baseline values as covariates, and examined the improvement after CR in each intervention group with paired-samples t-test. Results Eighty-six patients were included (55±10 years of age, 19% females), 43 in each group. There were no differences between HIIT and MICT groups in baseline characteristics. VO2peak improved in both groups (HIIT: 22.8 to 24.9 ml/kg/min, p=0.016 and MICT: 21.9 to 24.5 ml/kg/min, p&amp;lt;0.001), with no significant between-group differences (p=0.571). Also, resting FMD improved after both HIIT and MICT (4.6 to 6.7%, p=0.016, and 4.7 to 8.0%, p=0.001, respectively), with no significant between-group differences (p=0.177). Acute vascular response to training, however, improved with HIIT (FMD one hour after the last training session: 4.1 to 7.1%, p=0.022), but not MICT (5.9 to 6.4%, p=0.584). Conclusion Both HIIT and MICT significantly and comparably improve exercise capacity and resting FMD in patients after myocardial infarction. In addition, however, HIIT is associated with improved vascular response during recovery period after exercise. Funding Acknowledgement Type of funding source: None

Predictors of endothelial function improvement in patients with mild hypertriglyceridemia without evidence of coronary artery disease treated with purified eicosapentaenoic acid

Background and aimsEicosapentaenoic acid (EPA) has been reported to reduce cardiovascular risk in patients with hypertriglyceridemia. Although several mechanisms underlying the effects of EPA have been demonstrated, those responsible for its beneficial role in patients with hypertriglyceridemia without evidence of coronary artery disease (CAD) have not been fully elucidated. We sought to clarify the main factors associated with EPA administration that led to improved endothelial function. MethodsForty-seven consecutive patients with mild hypertriglyceridemia (mean age, 59 ± 13 years) without evidence of CAD were prospectively enrolled and administered purified EPA (1800 mg/day). Forty-four patients who were not administered EPA were enrolled as age- and sex-matched controls. Clinical variables and flow-mediated dilation (FMD) were examined before and after 6 months of treatment. Univariate and multivariate regression analyses were performed between FMD changes and clinical variables. ResultsEPA treatment decreased triglyceride levels (from 224.6 ± 58.8 to 151.8 ± 54.5 mg/dl, p < 0.001) and increased FMD (from 4.21% ± 1.91% to 6.21% ± 2.30%, p < 0.001). Multivariate analysis showed that the change in FMD was associated with the baseline high-density lipoprotein cholesterol (HDL-C) level (β = −0.331, p = 0.027) and the change in EPA/arachidonic acid (AA) ratio (β = 0.301, p = 0.048). ConclusionsEPA treatment improved triglyceride levels and FMD in patients with mild hypertriglyceridemia and without evidence of CAD. The baseline HDL-C level and the change in EPA/AA ratio predicted FMD improvement. The beneficial effects of EPA on triglyceride-rich lipoproteins and vascular endothelium may help improve endothelial function.

Chronic antioxidant administration restores macrovascular function in patients with heart failure with reduced ejection fraction.

What is the central question of this study? We aimed to examine oxidative stress, antioxidant capacity and macro- and microvascular function in response to 30 days of oral antioxidant administration in patients with heart failure with reduced ejection fraction. What is the main finding and its importance? We observed an approximately twofold improvement in macrovascular function, assessed via brachial artery flow-mediated dilatation, and a reduction in oxidative stress after antioxidant administration in patients with heart failure with reduced ejection fraction. The improvement in macrovascular function was reversed 1week after treatment cessation. These findings have identified the potential of oral antioxidant administration to optimize macrovascular health in this patient group. Heart failure with reduced ejection fraction (HFrEF) is characterized by macrovascular dysfunction and elevated oxidative stress that may be mitigated by antioxidant (AOx) administration. In this prospective study, we assessed flow-mediated dilatation (FMD) and reactive hyperaemia responses in 14 healthy, older control participants and 14 patients with HFrEF, followed by 30days of oral AOx administration (1g vitaminC, 600I.U. vitaminE and 0.6g α-lipoic acid) in the patient group. Blood biomarkers of oxidative stress (malondialdehyde) and AOx capacity (ferric reducing ability of plasma) were also assessed. Patients with HFrEF had a lower %FMD (2.63±1.57%) than control participants (5.62±2.60%), and AOx administration improved %FMD in patients with HFrEF (30days, 4.90±2.38%), effectively restoring macrovascular function to that of control participants. In a subset of patients, we observed a progressive improvement in %FMD across the treatment period (2.62±1.62, 4.23±2.69, 4.33±2.24 and 4.97±2.56% at days 0, 10, 20 and 30, respectively, n=12) that was abolished 7days after treatment cessation (2.99±1.78%, n=9). No difference in reactive hyperaemia was evident between groups or as a consequence of the AOx treatment. Ferric reducing ability of plasma levels increased (from 6.08±2.80 to 6.70±1.59mm, day0versus 30) and malondialdehyde levels decreased (from 6.81±2.80 to 6.22±2.84μm, day 0versus 30) after treatment. These findings demonstrate the efficacy of chronic AOx administration in attenuating oxidative stress, improving AOx capacity and restoring macrovascular function in patients with HFrEF.

Retinol-binding protein 4 as a biomarker of cardiometabolic risk in rheumatoid arthritis

Background Retinol-binding protein 4 (RBP4) has been implicated in the pathogenesis of cardiovascular disease. Higher circulating RBP4 concentrations have been observed in patients with previous clinical arteriosclerosis. RBP4 concentrations are positively related to the early endothelial dysfunction measured using marker flow-mediated dilation in patients with rheumatoid arthritis (RA). Aim This study was done to measure the serum RBP4 level in patients with RA and to assess its clinical relevance to cardiometabolic risk and carotid atherosclerosis in RA. Patients and methods The current study enrolled 50 patients with RA, fulfilling the American College of Rheumatology criteria for the diagnosis of RA, who were divided into three groups: group Ia (severe disease activity), group Ib (moderate disease activity), and group Ic (mild disease activity), together with 40 apparently healthy participants as a control group (group II). Clinical symptoms, disease activity using disease activity score 28, BMI, and blood pressure were assessed. RBP4 levels were measured by enzyme-linked immunosorbent assay technique. Complete blood count; C-reactive protein; fasting blood glucose; lipid profile including total cholesterol, high-density lipoprotein, low-density lipoprotein, and triglycerides; fasting plasma insulin level; calculation of insulin resistance by homeostatic model assessment of insulin resistance; autoantibody profiles; ECG; and carotid artery ultrasound were done. Results RBP4 levels were highly significantly increased in all patients with RA when compared with the control group (P Conclusion Our data suggest that the level of RBP4 was increased in patients with RA compared with control, and increased level of RBP4 is associated with presence of atherosclerosis in patients with RA as demonstrated by CIMT. RBP4 could be used as a marker for early prediction of premature atherosclerosis in patients with RA.