Endothelial control of arterial distensibility is impaired in chronic heart failure

Morphological and Functional Remodeling of Vascular Endothelium in Cardiovascular Diseases

The vascular endothelium plays a vital role during embryogenesis and aging and is a cell monolayer that lines the blood vessels. The immune system recognizes the endothelium as its own. Therefore, an abnormality of the endothelium exposes the tissues to the immune system and provokes inflammation and vascular diseases such as atherosclerosis. Its secretory role allows it to release vasoconstrictors and vasorelaxants as well as cardio-modulatory factors that maintain the proper functioning of the circulatory system. The sealing of the monolayer provided by adhesion molecules plays an important role in cardiovascular physiology and pathology.

Short-term effect of sacubitril/valsartan on endothelial dysfunction and arterial stiffness in patients with chronic heart failure

Heart failure (HF) is associated to endothelial dysfunction that promotes the increase of arterial stiffness thus augmenting myocardial damage. Sacubitril/Valsartan is used in the treatment of HF reduced ejection fraction (HFrEF) and has been proven effective in reducing cardiovascular disease (CVD) progression and all-cause mortality. The aim of this study was to evaluate the effect of Sacubitril/Valsartan on endothelial dysfunction, arterial stiffness, oxidative stress levels and platelets activation in patients with HFrEF, at baseline and after 6 months of treatment. We enrolled 100 Caucasian patients. Endothelial function was evaluated by the reactive hyperemia index (RHI) and arterial stiffness (AS) by the measurement of carotid-femoral pulse wave velocity (PWV), augmentation pressure (AP) and augmentation index (AI). At baseline, among enrolled outpatients, 43% showed a NYHA class II and 57% a NYHA class III. At 6 months, there was a significant improvement of several hemodynamic, clinical and metabolic parameters with a significant reduction in oxidative stress indices such as 8-isoprostane (p < 0.0001) and Nox-2 (p < 0.0001), platelets activity biomarkers such as sP-selectin (p < 0.0001) and Glycoprotein-VI (p < 0.0001), and inflammatory indices. Moreover, we observed a significant improvement in arterial stiffness parameters and in endothelial function indices. Our study demonstrated that 6 months treatment with Sacubitril/Valsartan, in patients with HFrEF, improves endothelial dysfunction and arterial stiffness, by reducing oxidative stress, platelet activation and inflammation circulating biomarkers, without adverse effects.

Increased Risk of Chronic Obstructive Pulmonary Disease in Patients with Hyperlipidemia: A Nationwide Population-Based Cohort Study

The coexistence of chronic obstructive pulmonary disease (COPD) and cardiovascular disease is common and causes poor prognoses. Hyperlipidemia is the most common risk factor for cardiovascular disease, but the association between hyperlipidemia and COPD remains ambiguous. This study aimed to investigate the risk of COPD development in patients with hyperlipidemia. This retrospective cohort study used information from the National Health Insurance Research Database in Taiwan. We enrolled 21,790 patients with hyperlipidemia and 87,160 control patients without hyperlipidemia for comparison, with a follow-up period of over 10 years. The incidence of new-onset COPD was higher in patients with hyperlipidemia (36.14 per 1000 person-years) than in the controls (22.29 per 1000 person-years). Patients with hyperlipidemia were 1.48 times more likely to develop subsequent COPD than the controls without hyperlipidemia (95% confidence interval 1.44 to 1.53, p < 0.001) following adjustments for age, sex, and comorbidities. In addition, nephropathy, hypertension, congestive heart failure, age, and sex (female) were potential risk factors for developing COPD in patients with hyperlipidemia. Patients with hyperlipidemia may have an increased risk of developing COPD.

Pathophysiology and Treatment of Diabetic Cardiomyopathy and Heart Failure in Patients with Diabetes Mellitus

There is a close relationship between diabetes mellitus and heart failure, and diabetes is an independent risk factor for heart failure. Diabetes and heart failure are linked by not only the complication of ischemic heart disease, but also by metabolic disorders such as glucose toxicity and lipotoxicity based on insulin resistance. Cardiac dysfunction in the absence of coronary artery disease, hypertension, and valvular disease is called diabetic cardiomyopathy. Diabetes-induced hyperglycemia and hyperinsulinemia lead to capillary damage, myocardial fibrosis, and myocardial hypertrophy with mitochondrial dysfunction. Lipotoxicity with extensive fat deposits or lipid droplets is observed on cardiomyocytes. Furthermore, increased oxidative stress and inflammation cause cardiac fibrosis and hypertrophy. Treatment with a sodium glucose cotransporter 2 (SGLT2) inhibitor is currently one of the most effective treatments for heart failure associated with diabetes. However, an effective treatment for lipotoxicity of the myocardium has not yet been established, and the establishment of an effective treatment is needed in the future. This review provides an overview of heart failure in diabetic patients for the clinical practice of clinicians.

Neurohormones, inflammatory mediators, and cardiovascular injury in the setting of heart failure

Neurohormones and inflammatory mediators have effects in both the heart and the peripheral vasculature. In patients with heart failure (HF), neurohormonal activation and increased levels of inflammatory mediators promote ventricular remodeling and development of HF, as well as vascular dysfunction and arterial stiffness. These processes may lead to a vicious cycle, whereby arterial stiffness perpetuates further ventricular remodeling leading to exacerbation of symptoms. Although significant advances have been made in the treatment of HF, currently available treatment strategies slow, but do not halt, this cycle. The current treatment for HF patients involves the inhibition of neurohormonal activation, which can reduce morbidity and mortality related to this condition. Beyond benefits associated with neurohormonal blockade, other strategies have focused on inhibition of inflammatory pathways implicated in the pathogenesis of HF. Unfortunately, attempts to target inflammation have not yet been successful to improve prognosis of HF. Further work is required to interrupt key maladaptive mechanisms involved in disease progression.

Abnormal nailfold videocapillaroscopic findings in heart failure patients with preserved ejection fraction

BACKGROUND

Microvascular dysfunction is one of the pathophysiological mechanisms in heart failure. Nailfold videocapillaroscopy is a noninvasive technique used to examine the microvasculature.

OBJECTIVE

In this study, we aimed to investigate the nailfold capillaroscopic abnormalities in heart failure patients with reduced and preserved ejection fraction and compare those with control group.

METHODS

Three groups of patients were recruited for the study: HFrEF group includes the patients with heart failure with reduced ejection fraction (HFrEF), HFpEF group, patients with heart failure with preserved ejection fraction (HFpEF) and control group, healthy asymptomatic individuals. Nailfold videocapillaroscopy was performed with a videodermatoscope and all nailfold images were evaluated for enlargement and hemorrhages.

RESULTS

Abnormal videocapillaroscopic findings including enlargement and/or hemorrhages were present in 7 (24%) patients in HFrEF group, 19 (66%) patients in HFpEF group and 11 (37%) in control group. The number of patients with abnormal videocapillaroscopic findings were significantly greater in HFpEF group compared to HFrEF (p < 0.05) and control groups (p < 0.05). However, no significant difference was observed in videocapillaroscopic findings between HFrEF and control groups.

CONCLUSIONS

Our study showed that microvascular abnormalities demonstrated by videodermatoscopic examination of nailfold capillaries are considerably more common in HFpEF patients compared to HFrEF and control groups.

Aortic Dimensions, Biophysical Properties, and Plasma Biomarkers in Children and Adults with Marfan or Loeys-Dietz Syndrome

Background

Aortic dilation, stiffening, and dissection are common and potentially lethal complications of Marfan syndrome (MFS) and Loeys-Dietz syndrome (LDS), which involve abnormal transforming growth factor beta (TGF-β) signalling. The relation of aortic dimensions, stiffness, and biomarker levels is unknown. The objective of this study was to measure aortic dimensions, stiffness, TGF-β and matrix metalloproteinase (MMP) levels, and endothelial function in patients with MFS, and to compare TGF-β levels in patients with MFS receiving different therapeutic regimens.

Methods

This was a cohort study of 40 MFS and 4 LDS patients and 87 control participants. Aortic dimension and stiffness indexes, including pulse wave velocity (PWV), were measured using echocardiography and Doppler. Total and free TGF-β and MMP blood levels were measured using Quantikine (R&D Systems, Inc, Minneapolis, MN) and Quanterix (Billerica, MA) kits. Endothelial function was measured using brachial artery flow-mediated dilation.

Results

PWV was increased in patients with MFS. There were increased MMP-2 levels in those with MFS but no increase in free or total TGF-β or MMP-9 levels compared with control participants. There was no difference in TGF-β levels between MFS patients receiving no medications, angiotensin receptor blockers, and β-blockers. PWV correlated most strongly with age. Endothelial function showed premature gradual decline in patients with MFS.

Conclusions

Despite the increased PWV, monitoring aortic stiffness or TGF-β levels would not be helpful in patients with MFS. TGF-β levels were not increased and the increased MMP-2 levels suggest consideration of a different therapeutic target.

Role of endothelial dysfunction in heart failure

Coronary artery disease is a major underlying etiology for heart failure. The role of coronary microvascular disease, and endothelial dysfunction, in the pathophysiology of heart failure is poorly appreciated. Endothelial dysfunction, induced by oxidative stress, contributes to the development of heart failure. Alterations of endothelial function and nitric oxide-cyclic guanosine monophosphate (NO-cGMP) pathway are involved in the pathophysiology of heart failure with both reduced and preserved ejection fraction. Indeed, an altered endothelium dependent vasodilatation, causing repeated episodes of ischemia/reperfusion, can induce a chronic stunned myocardium with systolic dysfunction and an increased diastolic stiffness with diastolic dysfunction. Moreover, the altered NO-cGMP pathway directly affects myocardial homeostasis. Endothelial dysfunction is associated with worse prognosis and higher rate of cardiovascular events. Potential therapeutic strategies targeting the NO-cGMP pathway in patients with HF will be discussed in this review article. Although clinical data are still inconclusive, the NO-cGMP pathway represents a promising target for therapy.

Cardio-ankle vascular index predicts the 1-year prognosis of heart failure patients categorized in clinical scenario 1

The sudden increase in blood pressure by vascular dysfunction is associated with the development of acute decompensated heart failure (ADHF) categorized in clinical scenario (CS) 1. However, the relationship between vascular function and prognosis in ADHF patients with CS1 is unclear. 3239 consecutive ADHF patients between January 2012 and June 2018 were enrolled. ADHF patients with CS1 undergoing ankle brachial index/cardio-ankle vascular index (CAVI) were included and patients with peripheral artery disease were excluded. Finally, 113 patients were analyzed. The primary endpoint of the present study was composite endpoint at 1 year (the cardiac death or re-hospitalization by ADHF). Cox proportional hazard analysis was conducted to identify independent predictors of composite endpoint. 25 patients (22.1%) were developed composite endpoint. CAVI in patients who have composite endpoint were significantly higher than without non-composite endpoint (composite endpoint group: 9.9 ± 1.3 non-composite endpoint group 8.7 ± 1.7, P = 0.001). The composite endpoint group was elderly and had higher ejection fraction, lower hemoglobin, and less used beta blockers, and renin angiotensin aldosterone system inhibitors. After adjustment by these confounding factors, CAVI was independently associated with the occurrence of composite endpoint (hazard ratio 1.69, 95% CI 1.05-2.73, P = 0.032). A cut-off value of CAVI for predicting composite endpoint was 8.65 (sensitivity 0.444, specificity 0.920, area under the curve 0.724, 95% CI 0.614-0.834). High CAVI was associated with the occurrence of composite endpoint after CS1 ADHF.

Vascular effects of serelaxin in patients with stable coronary artery disease: a randomized placebo-controlled trial

AIMS

The effects of serelaxin, a recombinant form of human relaxin-2 peptide, on vascular function in the coronary microvascular and systemic macrovascular circulation remain largely unknown. This mechanistic, clinical study assessed the effects of serelaxin on myocardial perfusion, aortic stiffness, and safety in patients with stable coronary artery disease (CAD).

METHODS AND RESULTS

In this multicentre, double-blind, parallel-group, placebo-controlled study, 58 patients were randomized 1:1 to 48 h intravenous infusion of serelaxin (30 µg/kg/day) or matching placebo. The primary endpoints were change from baseline to 47 h post-initiation of the infusion in global myocardial perfusion reserve (MPR) assessed using adenosine stress perfusion cardiac magnetic resonance imaging, and applanation tonometry-derived augmentation index (AIx). Secondary endpoints were: change from baseline in AIx and pulse wave velocity, assessed at 47 h, Day 30, and Day 180; aortic distensibility at 47 h; pharmacokinetics and safety. Exploratory endpoints were the effect on cardiorenal biomarkers [N-terminal pro-brain natriuretic peptide (NT-proBNP), high-sensitivity troponin T (hsTnT), endothelin-1, and cystatin C]. Of 58 patients, 51 were included in the primary analysis (serelaxin, n = 25; placebo, n = 26). After 2 and 6 h of serelaxin infusion, mean placebo-corrected blood pressure reductions of -9.6 mmHg (P = 0.01) and -13.5 mmHg (P = 0.0003) for systolic blood pressure and -5.2 mmHg (P = 0.02) and -8.4 mmHg (P = 0.001) for diastolic blood pressure occurred. There were no between-group differences from baseline to 47 h in global MPR (-0.24 vs. -0.13, P = 0.44) or AIx (3.49% vs. 0.04%, P = 0.21) with serelaxin compared with placebo. Endothelin-1 and cystatin C levels decreased from baseline in the serelaxin group, and there were no clinically relevant changes observed with serelaxin for NT-proBNP or hsTnT. Similar numbers of serious adverse events were observed in both groups (serelaxin, n = 5; placebo, n = 7) to 180-day follow-up.

CONCLUSION

In patients with stable CAD, 48 h intravenous serelaxin reduced blood pressure but did not alter myocardial perfusion.

Vascular Parameters for Ambulatory Monitoring of Congestive Heart Failure Patients: Proof of Concept

PURPOSE

Prompt detection of congestion is an essential target in order to prevent heart failure (HF) related hospitalization, being ambulatory monitoring a promising strategy to do so. A successful non-invasive ambulatory monitoring system requires automatic devices for physiological data recording; these data must give information about HF deterioration early enough to predict HF-related adverse events. This work aims to evaluate seven vascular parameters for the ambulatory monitoring of congestive heart failure patients.

METHODS

Seven vascular parameters are proposed as indicators of HF deterioration. These parameters are obtained using venous occlusion plethysmography; a technique that uses hardware able of being miniaturized and easily integrated into wearables for ambulatory monitoring. The ability of the proposed vascular parameters to detect congestion is evaluated in eight healthy volunteers and ten congestive heart failure patients with different congestion levels-mild, moderate and severe.

RESULTS

Most parameters distinguish between healthy volunteers and heart failure patients, and some of them present significant differences between volunteers and low levels of congestion-mild or moderate.

CONCLUSION

Home monitoring of some of the proposed parameters could detect HF deterioration on its onset and alert to health personnel.

Endothelial Dysfunction in Chronic Heart Failure: Assessment, Findings, Significance, and Potential Therapeutic Targets

Chronic heart failure (CHF) is a complex syndrome that results from structural and functional disturbances that affect the ability of the heart to supply oxygen to tissues. It largely affects and reduces the patient's quality of life, socio-economic status, and imposes great costs on health care systems worldwide. Endothelial dysfunction (ED) is a newly discovered phenomenon that contributes greatly to the pathophysiology of numerous cardiovascular conditions and commonly co-exists with chronic heart failure. However, the literature lacks clarity as to which heart failure patients might be affected, its significance in CHF patients, and its reversibility with pharmacological and non-pharmacological means. This review will emphasize all these points and summarize them for future researchers interested in vascular pathophysiology in this particular patient population. It will help to direct future studies for better characterization of these two phenomena for the potential discovery of therapeutic targets that might reduce future morbidity and mortality in this "at risk" population.

Cerebral blood flow changes during intermittent acute hypoxia in patients with heart failure

Objective Heart failure (HF) is associated with intermittent hypoxia, and the effects of this hypoxia on the cardiovascular system are not well understood. This study was performed to compare the effects of acute hypoxia (10% oxygen) between patients with and without HF. Methods Fourteen patients with chronic HF and 17 matched control subjects were enrolled. Carotid artery changes were examined during the first period of hypoxia, and brachial artery changes were examined during the second period of hypoxia. Data were collected at baseline and after 2 and 4 minutes of hypoxia. Norepinephrine, epinephrine, dopamine, and renin were measured at baseline and after 4 minutes hypoxia. Results The carotid blood flow, carotid systolic diameter, and carotid diastolic diameter increased and the carotid resistance decreased in patients with HF. Hypoxia did not change the carotid compliance, distensibility, brachial artery blood flow and diameter, or concentrations of sympathomimetic amines in patients with HF, but hypoxia increased the norepinephrine level in the control group. Hypoxia increased minute ventilation and decreased the oxygen saturation and end-tidal carbon dioxide concentration in both groups. Conclusion Hypoxia-induced changes in the carotid artery suggest an intensification of compensatory mechanisms for preservation of cerebral blood flow in patients with HF.

Magnetic resonance cold pressor test to investigate potential endothelial dysfunction in patients suffering from type 1 diabetes

BACKGROUND

In its course, diabetes impairs microvascular function through endothelial dysfunction. As the response of myocardial perfusion to sympathetic stimulation through cold is modulated by endothelium-related factors, an incipient endothelial dysfunction might be observed noninvasively by investigation of myocardial perfusion with a cold pressor test (CPT). This approach has been used in clinical MRI previously.

PURPOSE

To assess endothelial function of patients suffering from type 1 diabetes by MR CPT.

STUDY TYPE

Prospective cohort study.

SUBJECTS

Twenty type 1 diabetics and 20 healthy volunteers.

FIELD STRENGTH/SEQUENCE

3T, dynamic contrast enhanced perfusion (steady-state free precession).

ASSESSMENT

Absolute quantitative myocardial perfusion values at rest and under CPT.

STATISTICAL TESTS

Kolmogorov-Smirnov test to determine normal distribution of the results. T-test for independent samples.

RESULTS

Patients' mean myocardial perfusion was 0.68 cc/g/min at rest and 0.80 cc/g/min during CPT, respective values of 0.81 cc/g/min and 1.36 cc/g/min were found in healthy volunteers. Perfusion values differed significantly for CPT (P < 0.01) but not for resting conditions (P = 0.06).

DATA CONCLUSION

This study demonstrated that endothelial function might be impaired in type 1 diabetes patients. This fosters the thesis that endothelial function may serve as an early biomarker for coronary artery disease in patients with type 1 diabetes while these patients are still clinically asymptomatic.

LEVEL OF EVIDENCE

2 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2018;48:1595-1601.

Effect of Xanthine Oxidase Inhibition on Arterial Stiffness in Patients With Chronic Heart Failure

BACKGROUND

The xanthine oxidase inhibitor allopurinol improves endothelial function in different populations, including patients with chronic heart failure (CHF). Its effect on arterial stiffness parameters is less clear. We investigated the effect of short-term low-dose allopurinol therapy on arterial stiffness in Saudi patients with stable mild-moderate CHF.

METHODS

A prospective, randomized, double-blind, placebo-controlled study was performed on 73 patients with mild-moderate CHF. In all, 36 patients were randomized to allopurinol 300 mg daily for 3 months, while 37 patients were randomized to placebo. Arterial stiffness parameters, aortic pulse wave velocity (Ao-PWV) and heart rate corrected augmentation index (c-AIx), were assessed before and after treatment along with serum uric acid.

RESULTS

A total of 66 patients completed the study. Both groups were matched for age, sex, severity of heart failure, and arterial stiffness. Compared with placebo, allopurinol recipients had a significant fall in uric acid concentration from 6.31 ± 1.4 (SD) mg/dL to 3.81 ± 1.2 (P < .001). Despite that, there was no significant change in arterial stiffness parameters between allopurinol and placebo groups. Post-treatment Ao-PWV was 9.79 ± 2.6 m/s in the allopurinol group and 10.07 ± 3.4 m/s in the placebo group, P = .723. Post-treatment c-AIx was 24.0% ± 9.1% and 22.0% ± 9.9%, respectively, P = .403.

CONCLUSIONS

We have shown that allopurinol significantly reduced uric acid concentration in Saudi patients with CHF but was not associated with a change in arterial stiffness. Our cohort of patients had worse arterial stiffness values at baseline, which might make them more resistant to change using our study regimen.The study has been registered with the International Standard Randomized Controlled Trial Number registry with an identifier number of ISRCTN58980230.

Serum levels of nitrite/nitrate, lipid profile, and Fasting Plasma Glucose and their associations in subclinical hypothyroid women before and after a two month treatment by levothyroxine

BACKGROUND

Subclinical hypothyroidism (sHT) is a condition defined by elevated TSH values with normal levels of free thyroid hormones. Altered metabolic status is one of the consequences of sHT which can affect serum levels of FPG, lipid profile, and nitric oxide which propounds cardiovascular consequences per se. The aim of this study was to determine the possible effects of sHT on nitrite/nitrate levels, as a marker of endothelial performance.

MATERIALS AND METHODS

50 females were enrolled in this study, 25 women as control group and 25 women as case group (evaluated two times: before and after levothyroxine therapy). Blood samples were collected and levels of FPG, lipid profile components, and nitric oxide were measured spectrophotometrically. The data were analyzed using SPSS version 18 software.

RESULTS

The levels of lipid profile (except for TG between before and after group, p < 0.05) and nitric oxide did not differ in groups while FPG was significantly higher in case groups in comparison to control group (p < 0.001). Nitric oxide had no correlations with any of variables except for LDL in after treatment group (p < 0.05 and r = 0.397).

CONCLUSION

Nitric oxide does not have correlation with components of lipid profile (except for LDL) or FPG and has no differences in subclinical hypothyroid patients and control group. Levothyroxine therapy during 2 months cannot alter the levels of nitric oxide in subclinical hypothyroid patients.

The Endothelium as a Target for the Treatment of Heart Failure

The functional integrity of endothelial cells is a marker and a prerequisite for vascular health. It is well established that the endothelium not only modulates, but also mediates vascular disease processes. Certain diseases such as diabetes, dyslipidaemia, obesity, and arterial hypertension advance endothelial injury. The disease process induces cellular and functional changes in endothelial cells leading to a pathophysiological phenomenon referred to as endothelial cell dysfunction, which involves abnormal vasomotion, an imbalance in reactive oxygen species and nitric oxide, the activation of inflammation, and disruption of the coagulation process of the endothelial cells. With this knowledge, it is now known that vascular function plays a central role in the development and progression of heart failure (HF). HF is the primary cause of patient hospitalization. There is a strong desire to intervene and prevent the growing HF epidemic. Over the last decade, numerous therapies have been evaluated but few have led to positive results in the later stages of clinical trials. Efforts are currently being made to understand the pathophysiology of endothelial dysfunction and use this knowledge to identify novel agents or therapeutic targets that will improve the outcome of patients with HF and restore the normal function of the endothelium. The purpose of this review is to present a brief summary of the traditional approaches that have been taken to improve endothelial dysfunction and combat HF and, more importantly, to discuss some novel therapeutic approaches that are still under investigation, including the use of gene therapy and nanocarriers as means of delivering targets to the dysfunctional endothelium as treatment for HF.

Experimental Evidences Supporting the Benefits of Exercise Training in Heart Failure

Heart Failure (HF), a common end point for many cardiovascular diseases, is a syndrome with a very poor prognosis. Although clinical trials in HF have achieved important outcomes in reducing mortality, little is known about functional mechanisms conditioning health improvement in HF patients. In parallel with clinical studies, basic science has been providing important discoveries to understand the mechanisms underlying the pathophysiology of HF, as well as to identify potential targets for the treatment of this syndrome. In spite of being the end-point of cardiovascular derangements caused by different etiologies, autonomic dysfunction, sympathetic hyperactivity, oxidative stress, inflammation and hormonal activation are common factors involved in the progression of this syndrome. Together these causal factors create a closed link between three important organs: brain, heart and the skeletal muscle. In the past few years, we and other groups have studied the beneficial effects of aerobic exercise training as a safe therapy to avoid the progression of HF. As summarized in this chapter, exercise training, a non-pharmacological tool without side effects, corrects most of the HF-induced neurohormonal and local dysfunctions within the brain, heart and skeletal muscles. These adaptive responses reverse oxidative stress, reduce inflammation, ameliorate neurohormonal control and improve both cardiovascular and skeletal muscle function, thus increasing the quality of life and reducing patients' morbimortality.

α-Tocopherol and Atherosclerosis

Cardiovascular disease is the leading cause of morbidity and mortality in the Western world. There is compelling evidence incriminating oxidative stress in the pathogenesis of the atherosclerotic lesion. Several lines of evidence suggest that antioxidants, especially α-tocopherol, have potential beneficial effects with regard to cardiovascular disease. In vitro, α-tocopherol has been shown to inhibit platelet adhesion and aggregation and smooth muscle cell proliferation, exert anti-inflammatory effects on monocytes, and improve endothelial function. Also, supplementation with α-tocopherol has been shown to decrease lipid peroxidation, platelet aggregation, and pro-inflammatory activity of monocytes. However, clinical trials with α-tocopherol supplementation to date have been equivocal. Thus, although mounting in vitro evidence and animal models provide a sound scientific basis for α-tocopherol supplementation, further clinical trials are required before a definitive recommendation can be made with respect to the primary and secondary prevention of heart disease.

Review: Type 2 diabetes — implications for macrovascular mechanics and disease

Before macrovascular disease is established, type 2 diabetes is associated with structural and functional changes in large arteries that lead to increased stiffness, abnormal pulse wave travel and systolic hypertension. Structural changes result mainly from glycation of wall components. Functional changes originate in endothelial dysfunction. Increased arterial stiffness, or decreased arterial distensibility, increases pulse wave velocity and the amplitude of reflected waves, so that reflected waves arrive early and augment central systolic pressure. This promotes the development of left ventricular hypertrophy, an independent risk factor for cardiovascular mortality. One of the major mechanisms of arterial stiffening is endothelial dysfunction with reduced nitric oxide (NO)-mediated vasodilatation, the initial lesion in pre-atherosclerotic diabetes. To understand better the mechanisms of endothelial dysfunction will be vital if future therapeutic interventions are targeted to disease prevention. Protein glycation in poorly controlled diabetes is also damaging to blood vessels and must be limited by good diabetic control over the longer term.

Review: Clinical assessment of endothelial function — an update

Endothelial dysfunction precedes clinically detectable vascular disease, suggesting its early detection may allow the targeting of treatment to improve endothelial function and thus inhibit progression of disease.1,2 Although the evidence for a preventive strategy remains circumstantial, there is worldwide interest in the measurement of endothelial function in relation to risk factors and treatment of atherosclerotic vascular disease. Unfortunately, a widely applicable clinical measurement of endothelial function does not yet exist; those that are available remain tools for research. The ideal clinical test of endothelial function should be specific, sensitive and reproducible, as well as simple to perform, painless, and inexpensive. In this review we outline the relative merits and disadvantages of the techniques that are available.

Enhancement of arterial pulsation during flow-mediated dilation is impaired in the presence of ischemic heart disease

Purpose

The aim of this study is to investigate the relationship between arterial pulse amplitude change under increased shear stress and the presence of ischemic heart disease (IHD).

Methods

This study comprised 31 subjects, including 14 subjects with IHD. We investigated the change in brachial artery pulse amplitude during flow-mediated dilation (FMD) using ultrasonography.

Results

The arterial pulse amplitude increased during FMD in 19 subjects, whereas it decreased in 12 subjects. There was a marked difference in the change in arterial pulse amplitude (the maximum amplitude of the arterial pulse amplitude during FMD/the arterial pulse amplitude at baseline) between subjects with and without IHD (0.98 ± 0.53 and 1.37 ± 0.53, p = 0.028). Furthermore, decreased arterial pulse amplitude during FMD was a significant predictor of IHD after adjustment of age, blood pressure, the presence of each type of coronary risks, the value of FMD and sex (p = 0.0001).

Conclusions

The decrease of arterial pulsation amplitude during FMD was a useful predictive parameter for IHD.

Electronic supplementary material

The online version of this article (doi:10.1186/s40064-016-2794-0) contains supplementary material, which is available to authorized users.

Early Cellular Changes in the Ascending Aorta and Myocardium in a Swine Model of Metabolic Syndrome

Background

Metabolic syndrome is associated with pathological remodeling of the heart and adjacent vessels. The early biochemical and cellular changes underlying the vascular damage are not fully understood. In this study, we sought to establish the nature, extent, and initial timeline of cytochemical derangements underlying reduced ventriculo-arterial compliance in a swine model of metabolic syndrome.

Methods

Yorkshire swine (n = 8 per group) were fed a normal diet (ND) or a high-cholesterol (HCD) for 12 weeks. Myocardial function and blood flow was assessed before harvesting the heart. Immuno-blotting and immuno-histochemical staining were used to assess the cellular changes in the myocardium, ascending aorta and left anterior descending artery (LAD).

Results

There was significant increase in body mass index, blood glucose and mean arterial pressures (p = 0.002, p = 0.001 and p = 0.024 respectively) in HCD group. At the cellular level there was significant increase in anti-apoptotic factors p-Akt (p = 0.007 and p = 0.002) and Bcl-xL (p = 0.05 and p = 0.01) in the HCD aorta and myocardium, respectively. Pro-fibrotic markers TGF-β (p = 0.01), pSmad1/5 (p = 0.03) and MMP-9 (p = 0.005) were significantly increased in the HCD aorta. The levels of pro-apoptotic p38MAPK, Apaf-1 and cleaved Caspase3 were significantly increased in aorta of HCD (p = 0.03, p = 0.04 and p = 0.007 respectively). Similar changes in coronary arteries were not observed in either group. Functionally, the high cholesterol diet resulted in significant increase in ventricular end systolic pressure and–dp/dt (p = 0.05 and p = 0.007 respectively) in the HCD group.

Conclusion

Preclinical metabolic syndrome initiates pro-apoptosis and pro-fibrosis pathways in the heart and ascending aorta, while sparing coronary arteries at this early stage of dietary modification.

Cardiovascular responses to heat stress in chronic heart failure

Clinical reports have suggested that patients with heart diseases may be particularly vulnerable to heat injury. This review examines the effects of heat stress on cardiovascular and autonomic functions in patients with chronic heart failure (CHF). Laboratory investigations have shown that cutaneous vasodilator responses to heating are impaired in patients, whereas activation of skin sympathetic nerve activation is not attenuated in CHF as compared to controls. Attenuated cutaneous vasodilation may increase the risk of a heat related illness when CHF subjects are exposed to hyperthermic conditions.

Vascular health late after Kawasaki disease: implications for accelerated atherosclerosis

Kawasaki disease (KD), an acute vasculitis that primarily affects young children, is the most common acquired paediatric cardiovascular disease in developed countries. While sequelae of arterial inflammation in the acute phase of KD are well documented, its late effects on vascular health are increasingly unveiled. Late vascular dysfunction is characterized by structural alterations and functional impairment in term of arterial stiffening and endothelial dysfunction and shown to involve both coronary and systemic arteries. Further evidence suggests that continuous low grade inflammation and ongoing active remodeling of coronary arterial lesions occur late after acute illness and may play a role in structural and functional alterations of the arteries. Potential importance of genetic modulation on vascular health late after KD is implicated by associations between mannose binding lectin and inflammatory gene polymorphisms with severity of peripheral arterial stiffening and carotid intima-media thickening. The changes in cholesterol and lipoproteins levels late after KD further appear similar to those proposed to be atherogenic. While data on adverse vascular health are less controversial in patients with persistent or regressed coronary arterial aneurysms, data appear conflicting in individuals with no coronary arterial involvements or only transient coronary ectasia. Notwithstanding, concerns have been raised with regard to predisposition of KD in childhood to accelerated atherosclerosis in adulthood. Until further evidence-based data are available, however, it remains important to assess and monitor cardiovascular risk factors and to promote cardiovascular health in children with a history of KD in the long term.

FGF23 directly impairs endothelium-dependent vasorelaxation by increasing superoxide levels and reducing nitric oxide bioavailability

Fibroblast growth factor 23 (FGF23) is secreted primarily by osteocytes and regulates phosphate and vitamin D metabolism. Elevated levels of FGF23 are clinically associated with endothelial dysfunction and arterial stiffness in chronic kidney disease (CKD) patients; however, the direct effects of FGF23 on endothelial function are unknown. We hypothesized that FGF23 directly impairs endothelial vasorelaxation by hindering nitric oxide (NO) bioavailability. We detected expression of all four subtypes of FGF receptors (Fgfr1-4) in male mouse aortas. Exogenous FGF23 (90-9,000 pg/ml) did not induce contraction of aortic rings and did not relax rings precontracted with PGF2α. However, preincubation with FGF23 (9,000 pg/ml) caused a ∼36% inhibition of endothelium-dependent relaxation elicited by acetylcholine (ACh) in precontracted aortic rings, which was prevented by the FGFR antagonist PD166866 (50 nM). Furthermore, in FGF23-pretreated (9,000 pg/ml) aortic rings, we found reductions in NO levels. We also investigated an animal model of CKD (Col4a3(-/-) mice) that displays highly elevated serum FGF23 levels and found they had impaired endothelium-dependent vascular relaxation and reduced nitrate production compared with age-matched wild types. To elucidate a mechanism for the FGF23-induced impairment, we measured superoxide levels in endothelial cells and aortic rings and found that they were increased following FGF23 treatment. Crucially, treatment with the superoxide scavenger tiron reduced superoxide levels and also restored aortic relaxation to ACh. Therefore, our data suggest that FGF23 increases superoxide, inhibits NO bioavailability, and causes endothelial dysfunction in mouse aorta. Together, these data provide evidence that high levels of FGF23 contribute to cardiovascular dysfunction.

Vascular dysfunction and chronic obstructive pulmonary disease: the role of redox balance

Chronic obstructive pulmonary disease (COPD) is characterized by low pulmonary function, inflammation, free radical production, vascular dysfunction, and subsequently a greater incidence of cardiovascular disease. By administering an acute oral antioxidant cocktail to patients with COPD (n=30) and controls (n=30), we sought to determine the role of redox balance in the vascular dysfunction of these patients. Using a double-blind, randomized, placebo-controlled, crossover design, patients with COPD and controls were ingested placebo or the antioxidant cocktail (vitamin C, vitamin E, α-lipoic acid) after which brachial artery flow-mediated dilation and carotid-radial pulse wave velocity were assessed using ultrasound Doppler. The patients exhibited lower baseline antioxidant levels (vitamin C and superoxide dismutase activity) and higher levels of oxidative stress (thiobarbituic acid reactive species) in comparison with controls. The patients also displayed lower basal flow-mediated dilation (P<0.05), which was significantly improved with antioxidant cocktail (3.1±0.5 versus 4.7±0.6%; P<0.05; placebo versus antioxidant cocktail), but not controls (6.7±0.6 versus 6.9±0.7%; P>0.05; placebo versus antioxidant cocktail). The antioxidant cocktail also improved pulse wave velocity in patients with COPD (14±1 versus 11±1 m·s(-1); P<0.05; placebo versus antioxidant cocktail) while not affecting controls (11±2 versus 10±1 m·s(-1); P>0.05; placebo versus antioxidant). Patients with COPD exhibit vascular dysfunction, likely mediated by an altered redox balance, which can be acutely mitigated by an oral antioxidant. Therefore, free radically mediated vascular dysfunction may be an important mechanism contributing to this population's greater risk and incidence of cardiovascular disease.

A novel system for studying mechanical strain waveform-dependent responses in vascular smooth muscle cells

While many studies have examined the effects mechanical forces on vSMCs, there is a limited understanding of how the different arterial strain waveforms that occur in disease and different vascular beds alter vSMC mechanotransduction and phenotype. Here, we present a novel system for applying complex, time-varying strain waveforms to cultured cells and use this system to understand how these waveforms can alter vSMC phenotype and signaling. We have developed a highly adaptable cell culture system that allows the application of mechanical strain to cells in culture and can reproduce the complex dynamic mechanical environment experienced by arterial cells in the body. Using this system, we examined whether the type of applied strain waveform altered phenotypic modulation of vSMCs by mechanical forces. Cells exposed to the brachial waveform had increased phosphorylation of AKT, EGR-1, c-Fos expression and cytoskeletal remodeling in comparison to cells treated with the aortic waveform. In addition, vSMCs exposed to physiological waveforms had adopted a more differentiated phenotype in comparison to those treated with static or sinusoidal cyclic strain, with increased expression of vSMC markers desmin, calponin and SM-22 as well as increased expression of regulatory miRNAs including miR-143, -145 and -221. Taken together, our studies demonstrate the development of a novel system for applying complex, time-varying mechanical forces to cells in culture. In addition, we have shown that physiological strain waveforms have powerful effects on vSMC phenotype.

Soluble guanylate cyclase: a potential therapeutic target for heart failure

The number of annual hospitalizations for heart failure (HF) and the mortality rates among patients hospitalized for HF remains unacceptably high. The search continues for safe and effective agents that improve outcomes when added to standard therapy. The nitric oxide (NO)-soluble guanylate cyclase (sGC)-cyclic guanosine monophosphate (cGMP) pathway serves an important physiologic role in both vascular and non-vascular tissues, including regulation of myocardial and renal function, and is disrupted in the setting of HF, leading to decreased protection against myocardial injury, ventricular remodeling, and the cardio-renal syndrome. The impaired NO-sGC-cGMP pathway signaling in HF is secondary to reduced NO bioavailability and an alteration in the redox state of sGC, making it unresponsive to NO. Accordingly, increasing directly the activity of sGC is an attractive pharmacologic strategy. With the development of two novel classes of drugs, sGC stimulators and sGC activators, the hypothesis that restoration of NO-sGC-cGMP signaling is beneficial in HF patients can now be tested. Characterization of these agents in pre-clinical and clinical studies has begun with investigations suggesting both hemodynamic effects and organ-protective properties independent of hemodynamic changes. The latter could prove valuable in long-term low-dose therapy in HF patients. This review will explain the role of the NO-sGC-cGMP pathway in HF pathophysiology and outcomes, data obtained with sGC stimulators and sGC activators in pre-clinical and clinical studies, and a plan for the further clinical development to study these agents as HF therapy.

Statins in heart failure: do we need another trial?

Statins lower serum cholesterol and are employed for primary and secondary prevention of cardiovascular events. Clinical evidence from observational studies, retrospective data, and post hoc analyses of data from large statin trials in various cardiovascular conditions, as well as small scale randomized trials, suggest survival and other outcome benefits for heart failure. Two recent large randomized controlled trials, however, appear to suggest statins do not have beneficial effects in heart failure. In addition to lowering cholesterol, statins are believed to have many pleotropic effects which could possibly influence the pathophysiology of heart failure. Following the two large trials, evidence from recent studies appears to support the use of statins in heart failure. This review discusses the role of statins in the pathophysiology of heart failure, current evidence for statin use in heart failure, and suggests directions for future research.

Elastic properties of peripheral arteries in heart failure patients in comparison with normal subjects

Understanding the change in elastic properties of peripheral arteries in heart failure patients is of particular importance, especially when compared with normal subjects. To investigate factors associated with their difference, 40 normal subjects and 60 heart failure patients were studied. Electrocardiograms, carotid pulses and radial pulses were simultaneously recorded to determine carotid-radial pulse transit time (carotid-radial PTT), arm pulse wave velocity (PWV), and arterial volume distensibility. In comparison with normal subjects, carotid-radial PTT was lower by 8 ms in heart failure patients, arm PWV higher by 1.4 m/s, and peripheral arterial distensibility lower by 0.04 % per mmHg (all significant, P < 0.01). Peripheral arterial distensibility was significantly related to systolic blood pressure (SBP) and to left ventricular ejection fraction (LVEF) for heart failure patients (both P < 0.001), but the relationship for the normal group was not statistically significant (both 0.05 < P<0.1). Ageing had a significant inverse relationship with arterial distensibility in normal subjects (P < 0.05), but not in heart failure patients (P = 0.59). No subject in the normal group had an arterial distensibility lower than 0.1 % per mmHg, in comparison with 28 % (17/60) in the heart failure group. Peripheral arterial distensibility has been shown to be significantly lower in heart failure patients in comparison with normal subjects. High SBP and low LVEF were the main factors associated with low arterial distensibility in heart failure patients.

Flow cytometric assessment of circulating platelet and erythrocytes microparticles in young thalassemia major patients: relation to pulmonary hypertension and aortic wall stiffness

Heart disease is the leading cause of mortality and morbidity in β-thalassemia major (β-TM). Aggregability of abnormal red cells and membrane-derived microparticles (MPs) stemming from activated platelets and erythrocytes are responsible for thrombotic risk. We measured platelet and erythrocyte MPs (PMPs and ErMPs) in 60 young β-TM patients compared with 40 age- and sex-matched healthy controls and assessed their relation to clinicopathological characteristics and aortic elastic properties. Patients were studied stressing on transfusion history, splenectomy, thrombotic events, chelation therapy, hematological and coagulation profiles, flow cytometric measurement of PMPs (CD41b(+) ) and ErMPs (glycophorin A(+) ) as well as echocardiographic assessment of aortic elastic properties. Aortic stiffness index and pulmonary artery pressure were significantly higher, whereas aortic strain and distensibility were lower in TM patients than controls (P < 0.001). Both PMPs and ErMPs were significantly elevated in TM patients compared with controls, particularly patients with risk of pulmonary hypertension, history of thrombosis, splenectomy or serum ferritin >2500 μg/L (P < 0.001). Compliant patients on chelation therapy had lower MPs levels than non-compliant patients (P < 0.001). PMPs and ErMPs were positively correlated to markers of hemolysis, serum ferritin, D-dimer, vWF Ag, and aortic stiffness, whereas negatively correlated to hemoglobin level and aortic distensibility (P < 0.05). We suggest that increased MPs may be implicated in vascular dysfunction, pulmonary hypertension risk, and aortic wall stiffness observed in thalassemia patients. Their quantification could provide utility for early detection of cardiovascular abnormalities and monitoring the biological efficacy of chelation therapy.

Chronic heart failure does not attenuate the total activity of sympathetic outflow to skin during whole-body heating

BACKGROUND

Previous studies show that the rise in skin blood flow and cutaneous vascular conductance during heat stress is substantially attenuated in chronic heart failure (CHF) patients. The mechanisms responsible for this finding are not clear. In particular, little is known regarding the responses of skin sympathetic nerve activity (SSNA) that control the skin blood flow during heat stress in CHF patients. We examined the effects of a modest heat stress to test the hypothesis that SSNA responses could be attenuated in CHF.

METHODS AND RESULTS

We assessed SSNA (microneurography) from the peroneal nerve and skin blood flow (forearm laser Doppler) in 9 patients with stable class II-III CHF and in matched healthy subjects during passive whole-body heating with a water-perfused suit. Whole-body heating induced similar increases in internal temperature (≈0.6 °C) in both groups. Whole-body heat stress evoked similar SSNA activation in CHF patients (Δ891±110 U/min) and the control subjects (Δ787±84 U/min; P=0.66), whereas the elevation in forearm cutaneous vascular conductance in patients with CHF was significantly lower than that in healthy control subjects (Δ131±29% vs. Δ623±131%; P=0.001).

CONCLUSIONS

The present data show that SSNA activation during a modest whole-body heat stress is not attenuated in CHF. Thus, the attenuated skin vasodilator response in CHF patients is not attributable to a reduction in total activity of sympathetic outflow to skin.

Endothelial dysfunction, arterial stiffness, and heart failure

Outcomes for heart failure (HF) patients remain suboptimal. No known therapy improves mortality in acute HF and HF with preserved ejection fraction; the most recent HF trial results have been negative or neutral. Improvement in surrogate markers has not necessarily translated into better outcomes. To translate breakthroughs with potential therapies into clinical benefit, a better understanding of the pathophysiology establishing the foundation of benefit is necessary. Vascular function plays a central role in the development and progression of HF. Endothelial function and nitric oxide availability affect myocardial function, systemic and pulmonary hemodynamics, and coronary and renal circulation. Arterial stiffness modulates ventricular loading conditions and diastolic function, key components of HF with preserved ejection. Endothelial function and arterial stiffness may therefore serve as important physiological targets for new HF therapies and facilitate patient selection for improved application of existing agents.

Hyperemia-Related Changes in Arterial Stiffness: Comparison between Pulse Wave Velocity and Stiffness Index in the Vascular Reactivity Assessment

Carotid-to-radial pulse wave velocity (PWV_cr) has been proposed to evaluate endothelial function. However, the measurement of PWV_cr is not without limitations. A new simple approach could have wide application. Stiffness index (SI) is obtained by analysis of the peripheral pulse wave and gives reproducible information about stiffness of large arteries. This study assessed the effects of hyperemia on SI and compared it with PWV_cr in 14 healthy subjects. Both were measured at rest and during 8 minutes after ischemia. SI temporal course was determined. At 1 minute, SI and PWV_cr decreased (5.58 ± 0.24 to 5.34 ± 0.23 m/s, P < 0.05; 7.8 ± 1.0 to 7.2 ± 0.9 m/s; P < 0.05, resp.). SI was positively related to PWV_cr in baseline (r = 0.62 , P < 0.05), at 1 minute (r = 0.79, P < 0.05), and during the whole experimental session (r = 0.52, P < 0.05). Conclusion. Hyperemia significantly decreases SI in healthy subjects. SI was related to PWV_cr and could be used to facilitate the evaluation of hyperemia-related changes in arterial stiffness.

Chunghyul-Dan (Qingxie-Dan) Improves Arterial Stiffness in Patients with Increased baPWV

Arterial stiffness is an important, independent determinant of cardiovascular risk. Pulse wave velocity (PWV) has been used as a valuable index of arterial stiffness and as a surrogate marker for atherosclerosis. Chunghyul-dan (CHD) has anti-hyperlipidemic activity, anti-inflammatory activity and anti-atherogenic effects. To determine its clinical effect on increased arterial stiffness, we examined whether CHD improves arterial stiffness in patients with increased brachial-ankle PWV (baPWV). Thirty-five subjects with increased baPWV (> 1400 cm/sec) were recruited and randomized to a treatment group (20 subjects) or a control group (15 subjects). The treatment group was administered CHD at a dose of 600 mg three times a day for 8 weeks, and the control group received no medication (observation only). baPWV was assessed using a pulse pressure analyzer at baseline and after 8 weeks. Blood pressure and serum lipid profile were monitored in the treatment group. Our results indicate that baPWV was lowered significantly in the treatment group after 8 weeks of medication ( p < 0.05), but not in the control group. Moreover, there were no significant changes in blood pressure and serum lipids profile except triglyceride level suggesting that the effect is largely independent of CHD's lipid-lowering effect or a blood pressure change. In conclusion, CHD appears to improve arterial stiffness in patients with increased PWV.

Comparison of flow-mediated vasodilation in femoral and brachial arteries in healthy dogs

OBJECTIVE

To compare flow-mediated vasodilation (FMD) measurements in brachial and femoral arteries of healthy dogs habituated to the assessment method, evaluate repeatability of these measurements, and investigate effects of blood pressure cuff inflation time on femoral artery FMD measurements.

ANIMALS

11 healthy adult Miniature Schnauzers.

PROCEDURES

Arterial luminal diameter and blood flow velocity integral (FVI) were measured before and after cuff inflation of 5 minutes' (brachial and femoral arteries) or 3 minutes' duration (femoral artery) in separate experiments. A blood pressure cuff was inflated to > 200 mm Hg distal to each imaging site to increase local blood flow to induce reactive hyperemia. Changes in FVI after cuff deflation, FMD, and between-dog and within-dog coefficients of variation (CVs) were determined.

RESULTS

After cuff inflation of 5 minutes' duration, greater changes were detected in median change in FVI and FMD of brachial arteries (174.0% and 8.0%, respectively), compared with values determined for femoral arteries (32.0% and 2.1%, respectively). Between-dog CV for brachial artery FMD was 34.0%, compared with 89.6% for femoral arteries, and within-dog CV was 32.5% for brachial arteries versus 51.6% for femoral arteries after cuff inflation of 5 minutes' duration.

CONCLUSIONS AND CLINICAL RELEVANCE

In healthy Miniature Schnauzers, FMD was greater and more repeatable in brachial arteries than in femoral arteries. Reactive hyperemia was inconsistently induced in femoral arteries following 3- or 5-minute cuff inflation times. Brachial, but not femoral, artery FMD measurement is a potentially useful research technique for measurement of endothelial function in dogs.

Exercise as a nonpharmacologic intervention in patients with heart failure

For patients with heart failure (HF), dyspnea and fatigue resulting in diminished exercise tolerance are among the main factors that contribute to decreased social and physical functioning and quality of life. There has long been evidence to suggest that measures of cardiac function, such as ejection fraction and cardiac output, only poorly correlate with a patient's exercise capacity, indicating the involvement of factors other than those impacting central circulation. The lack of a close correlation between central hemodynamics and exercise tolerance has led to investigations into alterations in the periphery, such as abnormalities in vascular endothelial function, hyperactivation of the sympathetic nervous system, and changes in structure and oxidative capacity of skeletal muscle, which are commonly seen in patients with HF. Over the past 2 decades, numerous clinical trials have demonstrated the beneficial impact of exercise training on skeletal muscle energy metabolism, vascular function, and ventilatory capacity, which correlate with improvements in exercise tolerance, hospitalization rates, and quality of life of patients with HF. In accordance with recent guidelines established by the leading cardiology societies in the United States and Europe, physicians are urged to emphasize exercise training for all clinically stable patients with HF using individualized protocols that feature early mobilization after acute exacerbations of the disease and gradual increases in intensity.

Effects of interval cycle training with or without strength training on vascular reactivity in heart failure patients

BACKGROUND

Exercise training confers beneficial effects on vascular reactivity in patients with chronic heart failure (CHF). This randomized study compares the effects of interval cycle training combined with strength training versus interval training alone on vascular reactivity in CHF patients.

METHODS

Twenty-eight consecutive stable CHF patients (23 males, 53 ± 10 years, 28.4 ± 4.1 kg/m(2), left ventricular ejection fraction of 37 ± 12%) were randomly assigned to 3 times' weekly training sessions for 3 months, consisting of a) 40 minutes of interval cycle training (n = 14), versus b) 20 minutes of similar interval training plus 20 minutes of strength training of the quadriceps, hamstrings, muscles of the shoulder and biceps brachialis (n = 14). The work/recovery ratio of each session was 30/60 seconds. The intensity of interval training was set at 50% of the peak workload achieved at the steep ramp test (consisted of a 25-Watt increase on a cycle ergometer every 10 seconds until exhaustion). All patients underwent maximal, symptom-limited cardiopulmonary exercise testing and ultrasound evaluation of vascular reactivity by flow-mediated vasodilation (FMD) before and after the program.

RESULTS

A significant improvement in FMD was observed in the combined training group (P = 0.002), in contrast to the interval training alone group (P = NS); the improvement was significantly greater in the combined training than in the interval training alone group (P < .05). Peak oxygen uptake increased significantly and similarly in both groups, in the interval training group (P = .03), and in the combined training group (P = .006). No significant correlation was found between FMD improvement and cardiopulmonary exercise parameters.

CONCLUSIONS

A combined high-intensity, interval cycle exercise with strength training induces a greater beneficial effect on vascular reactivity rather than interval exercise training alone in CHF patients.

Age effect on vascular reactivity in Type 1 diabetes

AIM

The objective of this study was to assess the effect of age on vascular reactivity in patients with Type 1 diabetes.

METHODS

Forty-five patients with Type 1 diabetes and 71 healthy control subjects, divided into three age groups (18-30, 31-45 and 46-60 years old), underwent assessment of vascular reactivity based on ultrasound examination of a brachial artery after nitric oxide donor administration.

RESULTS

The vasodilative and haemodynamic effect was most pronounced in the youngest control subjects, where lumen widening of 0.51 ± 0.16 mm (13.9 ± 4.2%) and increase in early velocity of 28.4 ± 6.5 cm/s (237 ± 55%) were observed, while, in the control subjects from the middle and oldest age groups, the increase in artery diameter was 0.4 ± 0.11 and 0.22 ± 0.12 mm (9.8 ± 2.6 and 5.0 ± 2.6%), respectively. In the youngest patients with diabetes, lumen widening by 0.35 ± 0.13 mm (8.6 ± 3.4%) and increase in early diastolic velocity by 16.9 ± 5.6 cm/s (158 ± 52%) were noted (P < 0.05 vs. control subjects). In patients with diabetes from the middle and oldest age groups, the increase in artery diameter was 0.26 ± 0.06 and 0.16 ± 0.09 mm (5.5 ± 1.4 and 3.2 ± 1.8%), respectively.

CONCLUSIONS

Vascular reactivity is strongly age dependent in all subjects; however, responses are delayed and occur over a longer time period in the patients with diabetes. Vasodilation test protocols should take into account the age of the subjects.

Comparison of Hyperemic Changes in Carotid-Radial Pulse Wave Velocity by Upper and Lower Arm Cuff Occlusion

Carotid-radial pulse wave velocity (PWV) normally decreases following release of upper arm cuff occlusion (hyperemia). Lower arm (LA) elicits less brachial artery dilation than upper arm (UA) occlusion but more closely reflects endothelial function. Using applanation tonometry, we compared changes (Δ) in PWV induced by UA and LA hyperemia in 65 healthy participants. Pulse wave velocity was measured serially. Both techniques decreased PWV maximally at 1 minute with gradual return to baseline by 9 minutes. ΔPWV1min was greater for UA than LA occlusion (-11.5% vs -6.8%, P = .02). Multivariate analysis showed arm location independently related to ΔPWV (P = .036). In participants with variable cardiovascular risk, PWV decline lessened with increasing Framingham risk for both techniques. In conclusion: UA and LA occlusion decrease PWV maximally at 1 minute after release of arterial occlusion. PWV 1 min decline are more marked after UA than LA occlusion and progressively lessens with increasing Framingham risk.