Venous endothelial function in heart failure: Comparison with healthy controls and effect of clinical compensation

The safety and efficacy of compression therapy in patients with stable heart failure

Background

Compression therapy is widely used as a therapeutic option for edema; however, concerns regarding its safety in patients with heart failure (HF) arose, particularly due to increased venous return, which increases pulmonary artery blood pressure. This study aimed to investigate the safety of compression therapy in patients with chronic HF.

Methods

This study retrospectively enrolled patients with stable chronic HF who initiated treatment with compression therapy for lower extremity edema. The primary outcome was New York Heart Association (NYHA) class changes after 1 month of compression therapy, and adverse events were evaluated.

Results

We analyzed 101 patients who initiated compression therapy. The number of patients continuing compression therapy at one month was 86. Overall, 61.6 % were female and the median age was 81 years. The proportion of patients with heart failure and preserved ejection fraction (HFpEF) was 50.4 %. Brain natriuretic peptide levels were significantly lower than baseline levels at 1 month, (baseline vs 1 month: 486 (360-696) vs 311 (211-511), p < 0.001), with a lower NYHA III prevalence (baseline vs 1 month: 53.5 % vs 32.6 %, p < 0.001), without any adverse events related to compression therapy initiation. Additionally, multivariate logistic analysis indicated an association between HFpEF and significant BNP reduction after compression therapy (odds ratio: 4.70; 95 % confidence interval: 1.63-13.6).

Conclusions

Compression therapy was associated with decreased BNP levels and improved symptoms, especially in HFpEF, without any adverse events in stable chronic HF. These findings indicate that compression therapy is safe for patients with stable chronic HF.

Venous endothelial function in cardiovascular disease

The essential role of the endothelium in vascular homeostasis is associated with the release of endothelium-dependent relaxing and contractile factors (EDRF and EDCF, respectively). Different from arteries, where these factors are widely studied, the vasoactive factors derived from the venous endothelium have been given less attention. There is evidence for a role of the nitric oxide (NO), endothelium-dependent hyperpolarization (EDH) mechanism, and cyclooxygenase (COX)-derived metabolites as EDRFs; while the EDCFs need to be better evaluated since no consensus has been reached about their identity in venous vessels. The imbalance between the synthesis, bioavailability, and/or action of EDRFs and/or EDCFs results in a pathological process known as endothelial dysfunction, which leads to reduced vasodilation and/or increased vasoconstriction. In the venous system, endothelial dysfunction is relevant since reduced venodilation may increase venous tone and decrease venous compliance, thus enhancing mean circulatory filling pressure, which maintains or modify cardiac workload contributing to the etiology of cardiovascular diseases. Interestingly, some alterations in venous function appear at the early stages (or even before) the establishment of these diseases. However, if the venous endothelium dysfunction is involved in these alterations is not yet fully understood and requires further studies. In this sense, the present study aims to review the current knowledge on venous endothelial function and dysfunction, and the general state of the venous tone in two important cardiovascular diseases of high incidence and morbimortality worldwide: hypertension and heart failure.

Does the 6-minute walk test in hospitalized COPD patients exclusively correlate with lung function parameters or should psychological factors also be taken into account?

The 6-minute walk test is generally considered a standard test for the evaluation of short-term maximal physical performance. It has not been evaluated whether psychological factors, such as anxiety or depression, affect the performance or the results of the test. The main aim of this study was to investigate whether a correlation exists between psychological factors and the data from the 6-minute walking test. The study cohort consisted of 85 (♀ = 34 and ♂ = 51) 66 ± 10 (mean ± SD) year-old patients with chronic obstructive pulmonary disease (COPD) hospitalized for disease exacerbation. Forced Expiratory Volume in the first second (FEV₁) (% predicted) as predictor for lung function, as well as anxiety and depression symptoms assessed using the Hospital Anxiety and Depression Scale (HADS) as psychological predictors were collected. Bivariate correlations and hierarchical linear regression models were used to analyse the correlations. Walking distance was on average 260m ± 107m and ranged from 64m to 480m. HADS was negatively correlated with 6-min walking distance (r = 0.441, p = .0009, r = -.523, p = 00006). Hierarchical linear regression showed that FEV₁ alone explained 33%, and together with the psychological variables anxiety and depression explained 42% of the variance of results from the 6-minute walking test. These findings demonstrated that 11% of the data correlated with the psychological variables alone (p = .011). The effect size for lung function (f² = .717) and psychological variables (f² = .352) were high, whereas the socio-demographic variables sex, age, educational level and BMI could not explain any additional variance in our cohort. In conclusion, our study indicates that psychological factors such as symptoms of depression and anxiety are associated with lower physical functional performance in the 6-minute walking test. As such, these factors should also be assessed. Future research is needed to show if treatments of anxiety and depression can improve the walking distance in COPD patients.

Effect of Sildenafil on Pressure-Volume Loop Measures of Ventricular Function in Fontan Patients

Sildenafil has been reported to improve exercise capacity in Fontan patients, but the physiologic mechanisms behind these findings are not completely understood. The objective of this study was to study the acute effect of sildenafil on pressure-volume loop (PVL) measures of ventricular function in Fontan patients. Patients after Fontan operation who were presenting for a clinically indicated catheterization were enrolled. Patients were randomized in a double-blinded fashion to receive placebo (n = 9) or sildenafil (n = 10) 30-90 min prior to catheterization. PVLs were recorded using microconductance catheters at baseline and after infusion of dobutamine (10 mcg/kg/min). The primary outcome was change in ventriculoarterial (VA) coupling. For the entire cohort, VA coupling trended toward improvement with dobutamine (1.4 ± 0.4 to 1.8 ± 0.9, p = 0.07). End-systolic elastance showed improvement (2.6 ± 0.9 to 3.8 ± 1.4 mmHg m(2)/ml, p < 0.01) with dobutamine infusion. The cohorts had similar VA coupling at baseline (p = 0.32), but the sildenafil cohort trended toward having less of an improvement in VA coupling with dobutamine stress (p = 0.06). There were no differences between PVL measures of systolic or diastolic function between treatment groups, both at baseline and after dobutamine infusion. Patients with Fontan circulation had improved contractility and trended toward improvement in VA coupling with dobutamine stress. Acute sildenafil administration was not associated with improved PVL measurements of ventricular function in this population. These results suggest that clinical improvements seen with administration of sildenafil in Fontan patients are not associated with an acute improvement in ventricular function.

CLINICAL TRIAL REGISTRATION

www.clinicaltrials.gov ; Clinicaltrials.gov Identifier: NCT01815502.

Increased serum levels of oxidative stress are associated with hospital readmissions due to acute heart failure

OBJECTIVES

Inflammation and serum oxidative stress (OS) are important components in heart failure (HF) deterioration. In this study we tested the hypothesis that an increase in patients' sera OS levels is associated with acute HF (AHF) readmissions.

METHODS

Thirty consecutive patients (mean age 71 ± 10 years) admitted with AHF were included in the study. Serum OS in these patients was measured in-hospital and repeatedly after discharge over a period of 8 weeks of follow-up in which we reordered patients' HF readmissions. Of the 30 patients, 13 (43%) were readmitted (RAD group) and 17 (57%) did not require readmission (NRAD group).

RESULTS

OS levels before discharge from the first hospital admission in the 2 groups were similar (p = 0.84 and p = 0.56, respectively). However, using repeated measures ANOVA, we found that the interaction between the time points and the 2 groups of patients (RAD and NRAD) was statistically significant (p = 0.037). It is important to note that OS serum levels were more predictive of HF readmissions than were repeated simultaneous serum measurements of NT-proBNP (p = 0.97).

CONCLUSIONS

Increased OS levels in AHF patients, after they have been discharged from the hospital, are associated with higher HF readmission rates. In AHF, OS is a dynamic parameter associated with HF deterioration.

Androgenicity and venous endothelial function in post-menopausal women

BACKGROUND

Endothelial dysfunction is one of the early signs of cardiovascular damage. High androgen levels have been related to inflammatory endothelial markers in pre- and post-menopausal women.

AIM

This cross-sectional study aimed at investigating whether free androgen index (FAI) [estimated by dividing total testosterone (nmol/l) by SHBG (nmol/l) x 100] is related to endothelial function during post-menopause.

SUBJECTS AND METHODS

Twenty-six post-menopausal women were assessed with the dorsal hand vein compliance technique. Acetylcholine (Ach) and sodium nitroprusside (SNP) dose-response curves were constructed to test endothelium-dependent and independent relaxation, respectively.

RESULTS

Mean age was 54 yr (+/-4) and median time since menopause was 6 yr (interquartile range: 3-9). Patients were stratified according to FAI levels into two groups: FAI greater than or less than the group median of 2.5. Waist-to-hip ratio (WHR) was significantly higher in the group with FAI>2.5, as well as median dose of Ach for maximal vasodilation [720 (360-3600) ng/min with FAI>2.5 vs 36 (0.36-360) ng/min with FAI<or=2.5; p=0.005]. Maximal vasodilation with SNP was similar in both groups. Positive correlations were observed between Ach doses and maximal vasodilation and FAI (r=0.473, p=0.015), waist (r=0.510, p= 0.011), and WHR (r=0.479, p=0.021). SHBG was negatively correlated with Ach doses (rs=-0.400, p=0.043).

CONCLUSIONS

This study suggests that FAI, even within normal limits, is related to early changes in endothelial function in healthy post-menopausal women. Longitudinal studies are required to determine the clinical relevance of these findings.

Endothelium-dependent and -independent vasodilation is more attenuated in ischaemic than in non-ischaemic heart failure

AIMS

Endothelial dysfunction in chronic heart failure (CHF) contributes to vasoconstriction. Underlying atherosclerosis may increase vascular abnormalities in ischaemic CHF. We aimed to compare flow-mediated dilation (FMD) and nitroglycerin-mediated dilation (NMD) of the brachial artery between patients with ischaemic and non-ischaemic CHF.

METHODS AND RESULTS

A total of 57 patients with systolic CHF participated in the study (mean age 59 +/- 8 years, 81% male). Patients were in stable NYHA class II (40 patients, 70%) and III (17 patients, 30%). Ischaemic aetiology of CHF was confirmed by coronary angiography in 34 (60%) patients and ruled out in 23 (40%). Flow-mediated dilation and NMD of the brachial artery was assessed by high-resolution ultrasound. Endothelium-dependent vasodilation was markedly reduced in patients with ischaemic CHF compared with those with non-ischaemic aetiology of CHF-mean absolute change in artery diameter (Deltad) 0.09 +/- 0.07 mm in ischaemic group vs. 0.18 +/- 0.07 mm in non-ischaemic (P < 0.0001). Nitroglycerin-mediated vasodilation was also significantly different-Deltad = 0.14 +/- 0.06 mm in ischaemic vs. 0.31 +/- 0.10 mm in non-ischaemic CHF (P < 0.0001).

CONCLUSION

Endothelium-dependent and -independent vascular response is more attenuated in ischaemic than in non-ischaemic CHF.