Impaired endothelium-dependent and -independent vasodilation in elderly patients with chronic heart failure

Effects of medical therapy and age on cardiac output changes following balloon pulmonary angioplasty: Implications for combination therapy in chronic thromboembolic pulmonary hypertension

BACKGROUND

Some patients with chronic thromboembolic pulmonary hypertension (CTEPH) exhibit exercise intolerance due to reduced cardiac output (CO) even after successful balloon pulmonary angioplasty (BPA). Medical therapy is a potential option for such cases; however, it is unclear which patients necessitate it even after BPA.

METHODS

This study included 286 patients with CTEPH who underwent BPA and right heart catheterization 1 year after the final BPA and classified them into no-medication and withdrawal groups. The no-medication group comprised patients without pulmonary hypertension (PH) medications before and after BPA, while the withdrawal group included patients who received PH medications before BPA and discontinued them after BPA. We assessed differences in the changes in CO after BPA from baseline (ΔCO) between the 2 groups. Additionally, we evaluated the ΔCO among different age categories within each group: younger (<60 years), middle-aged (60-70 years), and older adults (≥70 years).

RESULTS

After adjusting baseline covariates, overall CO did not differ significantly. However, ΔCO was significantly positive in the no-medication group but negative in the withdrawal group (0.32 and -0.33, difference in ΔCO: -0.65, 95% confidence intervals: -0.90 to -0.40). A significantly positive effect on ΔCO was observed in younger and middle-aged individuals, with a significant interaction between age and ΔCO in no-medication groups.

CONCLUSIONS

Increasing CO with BPA alone may be challenging with age in patients with CTEPH. Given that discontinuation of PH medication after BPA decreased CO more than the effect of BPA, medical therapy might be necessary even after successful BPA.

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.

Fenofibrate Reverses Dysfunction of EPCs Caused by Chronic Heart Failure

The enhanced activity of endothelial progenitor cells (EPCs) by AMP-activated protein kinase (AMPK) agonists might explain the reversal of chronic heart failure (CHF)-mediated endothelial dysfunction. We studied baseline circulating EPC numbers in patients with heart failure and clarified the effect of fenofibrate on both circulating angiogenic cell (CAC) and late EPC activity. The numbers of circulating EPCs in CHF patients were quantified by flow cytometry. Blood-derived mononuclear cells were cultured, and CAC and late EPC functions, including fibronectin adhesion, tube formation, and migration, were evaluated. We focused on the effect of fenofibrate, an AMPK agonist, on EPC function and Akt/eNOS cascade activation in vitro. The number of circulating EPCs (CD34⁺/KDR⁺) was significantly lower in CHF patients (ischemic cardiomyopathy (ICMP): 0.07%, dilated cardiomyopathy (DCMP): 0.068%; p < 0.05) than in healthy subjects (0.102% of the gating region). In CACs, fibronectin adhesion function was reversed by fenofibrate treatment (p < 0.05). Similar results were also found for tube formation and migration in late EPCs, which were significantly improved by fenofibrate in an AMPK-dependent manner (p < 0.05), suggesting that fenofibrate reversed CACs and late EPC dysfunction in CHF patients. The present findings reveal the potential application of the AMPK agonist fenofibrate to reverse endothelial dysfunction in CHF patients.

Microvascular endothelial function and primary open angle glaucoma

Purpose

To determine the role of microvascular endothelial dysfunction as risk factor for primary open angle glaucoma.

Methods

A cross-sectional study was conducted involving 114 Malay patients with POAG seen at the eye clinic of Hospital Universiti Sains Malaysia. Patients aged between 40 and 80 years who were diagnosed with other types of glaucoma, previous glaucoma filtering surgery or other surgeries except uncomplicated cataract surgery and pterygium surgery were excluded. A total of 101 patients who were followed up for dry eyes, age-related cataracts or post cataracts extraction surgery were recruited as control subjects. Those with family history of glaucoma or glaucoma suspect were excluded. Microvascular endothelial function was assessed using laser Doppler fluximetry and the process of iontophoresis. Iontophoresis with acetylcholine (ACh) and sodium nitroprusside (SNP) was used to measure microvascular endothelium-dependent and endothelium-independent vasodilatations, respectively.

Results

In general, POAG patients demonstrated lower ACh% and ACh_max values compared with controls. There was significant difference in microvascular endothelial function [ACh%: mean, 95% confidence interval = 503.1 (378.0, 628.3), and ACh_max: mean, 95% confidence interval = 36.8 (30.2, 43.5)] between primary open angle glaucoma cases (p < 0.001) and controls [ACh%: mean, 95% confidence interval = 1378.4 (1245.4, 1511.3), and ACh_max: mean, 95% confidence interval = 79.2 (72.1, 86.2)]; this difference remained significant even after controlling for potential confounders. Similar difference was also found in SNP% and SNP_max between POAG and controls (p < 0.001). Age and diastolic blood pressure were inversely correlated with microvascular endothelial function.

Conclusion

There was an impairment of microvascular endothelial function and endothelial-independent vasodilatation in POAG patients. Microvascular endothelial function is a potential risk factor for POAG.

Exercise training attenuates the pressor response evoked by peripheral chemoreflex in rats with heart failure

The effects of exercise training (ExT) on the pressor response elicited by potassium cyanide (KCN) in the rat model of ischemia-induced heart failure (HF) are unknown. We evaluated the effects of ExT on chemoreflex sensitivity and its interaction with baroreflex in rats with HF. Wistar rats were divided into four groups: trained HF (Tr-HF), sedentary HF (Sed-HF), trained sham (Tr-Sham), and sedentary sham (Sed-Sham). Trained animals underwent to a treadmill running protocol for 8 weeks (60 m/day, 5 days/week, 16 m/min). After ExT, arterial pressure (AP), baroreflex sensitivity (BRS), peripheral chemoreflex (KCN: 100 μg/kg body mass), and cardiac function were evaluated. The results demonstrate that ExT induces an improvement in BRS and attenuates the pressor response to KCN relative to the Sed-HF group (P < 0.05). The improvement in BRS was associated with a reduction in the pressor response following ExT in HF rats (P < 0.05). Moreover, ExT induced a reduction in left ventricular end-diastolic pressure and pulmonary congestion compared with the Sed-HF group (P < 0.05). The pressor response to KCN in the hypotensive state is decreased in sedentary HF rats. These results suggest that ExT improves cardiac function and BRS and attenuates the pressor response evoked by KCN in HF rats.

Acute ingestion of citrulline stimulates nitric oxide synthesis but does not increase blood flow in healthy young and older adults with heart failure

To determine if age-associated vascular dysfunction in older adults with heart failure (HF) is due to insufficient synthesis of nitric oxide (NO), we performed two separate studies: 1) a kinetic study with a stable isotope tracer method to determine in vivo kinetics of NO metabolism, and 2) a vascular function study using a plethysmography method to determine reactive hyperemic forearm blood flow (RH-FBF) in older and young adults in the fasted state and in response to citrulline ingestion. In the fasted state, NO synthesis (per kg body wt) was ∼ 50% lower in older vs. young adults and was related to a decreased rate of appearance of the NO precursor arginine. Citrulline ingestion (3 g) stimulated de novo arginine synthesis in both older [6.88 ± 0.83 to 35.40 ± 4.90 μmol · kg body wt(-1) · h(-1)] and to a greater extent in young adults (12.02 ± 1.01 to 66.26 ± 4.79 μmol · kg body wt(-1) · h(-1)). NO synthesis rate increased correspondingly in older (0.17 ± 0.01 to 2.12 ± 0.36 μmol · kg body wt(-1) · h(-1)) and to a greater extent in young adults (0.36 ± 0.04 to 3.57 ± 0.47 μmol · kg body wt(-1) · h(-1)). Consistent with the kinetic data, RH-FBF in the fasted state was ∼ 40% reduced in older vs. young adults. However, citrulline ingestion (10 g) failed to increase RH-FBF in either older or young adults. In conclusion, citrulline ingestion improved impaired NO synthesis in older HF adults but not RH-FBF, suggesting that factors other than NO synthesis play a role in the impaired RH-FBF in older HF adults, and/or it may require a longer duration of supplementation to be effective in improving RH-FBF.

Further Peripheral Vascular Dysfunction in Heart Failure Patients With a Continuous-Flow Left Ventricular Assist Device: The Role of Pulsatility

OBJECTIVES

Using flow-mediated vasodilation (FMD) and reactive hyperemia (RH), this study aimed to provide greater insight into left ventricular assist device (LVAD)-induced changes in peripheral vascular function.

BACKGROUND

Peripheral endothelial function is recognized to be impaired in patients with heart failure with reduced ejection fraction (HFrEF), but the peripheral vascular effects of continuous-flow LVAD implantation, now used as either a bridge to transplantation or as a destination therapy, remain unclear.

METHODS

Sixty-eight subjects (13 New York Heart Association [NYHA] functional class II HFrEF patients, 19 NYHA functional class III/IV HFrEF patients, 20 NYHA functional class III/IV HFrEF patients post-LVAD implantation, and 16 healthy age-matched control subjects) underwent FMD and RH testing in the brachial artery with blood flow velocity, artery diameters, and pulsatility index (PI) assessed by ultrasound Doppler.

RESULTS

PI was significantly lower in the LVAD group (2.0 ± 0.4) compared with both the HFrEF II (8.6 ± 0.8) and HFrEF III/IV (8.1 ± 0.9) patients, who, in turn, had significantly lower PI than the control subjects (12.8 ± 0.9). Likewise, LVAD %FMD/shear rate (0.09 ± 0.01 %Δ/s(-1)) was significantly reduced compared with all other groups (control subjects, 0.24 ± 0.03; HFrEF II, 0.17 ± 0.02; and HFrEF III/IV, 0.13 ± 0.02 %Δ/s(-1)), and %FMD/shear rate significantly correlated with PI (r = 0.45). RH was unremarkable across groups.

CONCLUSIONS

Although central hemodynamics are improved in patients with HFrEF by a continuous-flow LVAD, peripheral vascular function is further compromised, which is likely due, at least in part, to the reduction in pulsatility that is a characteristic of such a mechanical assist device.

Acute Dietary Nitrate Intake Improves Muscle Contractile Function in Patients With Heart Failure: A Double-Blind, Placebo-Controlled, Randomized Trial

BACKGROUND

Skeletal muscle strength, velocity, and power are markedly reduced in patients with heart failure, which contributes to their impaired exercise capacity and lower quality of life. This muscle dysfunction may be partially because of decreased nitric oxide (NO) bioavailability. We therefore sought to determine whether ingestion of inorganic nitrate (NO3 (-)) would increase NO production and improve muscle function in patients with heart failure because of systolic dysfunction.

METHODS AND RESULTS

Using a double-blind, placebo-controlled, randomized crossover design, we determined the effects of dietary NO3 (-) in 9 patients with heart failure. After fasting overnight, subjects drank beetroot juice containing or devoid of 11.2 mmol of NO3 (-). Two hours later, muscle function was assessed using isokinetic dynamometry. Dietary NO3 (-) increased (P<0.05-0.001) breath NO by 35% to 50%. This was accompanied by 9% (P=0.07) and 11% (P<0.05) increases in peak knee extensor power at the 2 highest movement velocities tested (ie, 4.71 and 6.28 rad/s). Maximal power (calculated by fitting peak power data with a parabola) was therefore greater (ie, 4.74±0.41 versus 4.20±0.33 W/kg; P<0.05) after dietary NO3 (-) intake. Calculated maximal velocity of knee extension was also higher after NO3 (-) ingestion (ie, 12.48±0.95 versus 11.11±0.53 rad/s; P<0.05). Blood pressure was unchanged, and no adverse clinical events occurred.

CONCLUSIONS

In this pilot study, acute dietary NO3 (-) intake was well tolerated and enhanced NO bioavailability and muscle power in patients with systolic heart failure. Larger-scale studies should be conducted to determine whether the latter translates into an improved quality of life in this population.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01682356.

The TNF-α/sphingosine-1-phosphate signaling axis drives myogenic responsiveness in heart failure

Heart failure (HF) is hallmarked by an increase in total peripheral resistance (TPR) that compensates for the drop in cardiac output. While initially allowing for the maintenance of mean arterial pressure at acceptable levels, the long-term upregulation of TPR is prone to compromise cardiac performance and tissue perfusion, and to ultimately accelerate disease progression. Augmented vasoconstriction of terminal arteries, the site of TPR regulation, is cooperatively driven by mechanisms such as: (i) endothelial dysfunction, (ii) increased sympathetic activity and (iii) enhanced pressure-induced myogenic responsiveness. Herein, we review emerging evidence that the increase in myogenic responsiveness is central to the long-term elevation of TPR in HF. On a molecular level, this augmented intrinsic response is governed by an activation of the tumor necrosis factor-α (TNF-α)/sphingosine-1-phosphate signaling axis in microvascular smooth muscle cells. The beneficial effect of TNF-α scavenging strategies on tissue perfusion in HF mouse models adds to the gaining momentum to revisit the use of anti-TNF-α treatment modalities in discrete HF patient populations.

Vascular function and the role of oxidative stress in heart failure, heart transplant, and beyond

Using flow-mediated vasodilation (FMD), reactive hyperemia, and an acute oral antioxidant cocktail (AOC; vitamins C and E and α-lipoic acid), this study aimed to provide greater insight into altered vascular function and the role of oxidative stress in chronic heart failure patients with reduced ejection fraction (HFrEF) and at several time points beyond heart transplantation (HTx). A total of 61 age-matched subjects (12 healthy controls, 14 New York Heart Association class II and III HFrEF, and 35 HTx recipients [<3 years post-HTx, 5-10 years post-HTx, and >14 years post-HTx]) ingested either placebo (PL) or an AOC before FMD and reactive hyperemia testing of the brachial artery. Vascular function, as measured by FMD, was not different among the controls (6.8±1.9%), recent <3-year post-HTx group (8.1±1.2%), and the 5- to 10-year post-HTx group (5.5±1.0%). However, PL FMD was lower in the HFrEF (4.5±0.7%) and in the >14-year post-HTx group (2.9±0.8%). The AOC increased plasma ascorbate levels in all of the groups but only increased FMD in the controls (PL, 6.8±1.9%; AOC, 9.2±1.0%) and >14-year post-HTx recipients (PL, 2.9±0.8%; AOC, 4.5±1.3%). There were no differences in reactive hyperemia in any of the groups with PL or AOC. This cross-sectional study reveals that, compared with controls, vascular function is blunted in HFrEF, is similar soon after HTx, but is decreased with greater time post-HTx with free radicals implicated in this progression.

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.

Low-frequency blood flow oscillations in congestive heart failure and after beta1-blockade treatment

Laser Doppler flowmetry (LDF) of forearm skin blood flow, combined with iontophoretically-administered acetylcholine and sodium nitroprusside and wavelet spectral analysis, was used for noninvasive evaluation of endothelial function in 17 patients newly diagnosed with New York Heart Association class II-III congestive heart failure (CHF). After 20+/-10 weeks' treatment with a beta(1)-blocker (Bisoprolol), the measurements were repeated. Measurements were also made on an age- and sex-matched group of healthy controls (HC). In each case data were recorded for 30 min. In HC, the difference in absolute spectral amplitude of LDF oscillations between the two vasodilators manifests in the frequency interval 0.005-0.0095 Hz (p<0.01); this difference is initially absent in patients with CHF, but appears following the beta(1)-blocker treatment (p<0.01). For HC, the difference between the two vasodilators also manifests in normalised spectral amplitude in 0.0095-0.021 Hz (p<0.05). This latter difference is absent in CHF patients and is unchanged by treatment with beta(1)-blockers. It is concluded that there are two oscillatory skin blood flow components associated with endothelial function. Both are reduced in CHF. Activity in the lower frequency interval is restored by beta(1)-blocker treatment, confirming the association between CHF and endothelial dysfunction but suggesting the involvement of two distinct mechanisms.

Differences in arterial compliance, microvascular function and venous capacitance between patients with heart failure and either preserved or reduced left ventricular systolic function

BACKGROUND

Up to 50% of patients with the clinical syndrome of heart failure have preserved left ventricular systolic function (HF-PSF). These patients may have abnormalities of ventriculo-vascular coupling, due to increased vascular and ventricular stiffness.

METHODS

We compared arterial compliance, microvascular vasodilator function and venous capacitance (VC) in 3 groups of patients (n=12 each) matched for the presence of coronary heart disease: 1) HF and preserved systolic function (HF-PSF), 2) HF and reduced systolic function (HF-RSF) and 3) controls (no HF, PSF). Arterial compliance was assessed by measuring aortic pulse wave velocity (PWV) with applanation tonometry. Cutaneous microvascular function was assessed using Laser Doppler imaging (LDI) coupled with iontophoresis of endothelium-dependent (acetylcholine) and -independent (sodium nitroprusside) vasodilators. VC was measured using venous occlusion plethysmography.

RESULTS

PWV was significantly higher in HF-PSF subjects than in both HF-RSF and control groups (10.7 [1.1], 8.9 [1.7] and 8.6 [2.1] m/s respectively, p<0.05). Acetylcholine and nitroprusside induced vasodilatation were equally impaired in HF-PSF and HF-RSF, as compared to controls (p<0.01). VC was higher in HF-RSF subjects compared with HF-PSF subjects (1.75 [0.41], 1.34 [0.34] ml/100 ml forearm vol. respectively, p<0.05).

CONCLUSIONS

These findings are consistent with a more marked increase in vascular stiffness in HF-PSF than in HF-RSF and suggest that arterial stiffness, dynamic vasodilator function and venous abnormalities may be implicated in the complex pathophysiology of HF-PSF.

Aging potentiates the effect of congestive heart failure on muscle microvascular oxygenation

Congestive heart failure (CHF) is most prevalent in aged individuals and elicits a spectrum of cardiovascular and muscular perturbations that impairs the ability to deliver (Qo(2)) and utilize (Vo(2)) oxygen in skeletal muscle. Whether aging potentiates the CHF-induced alterations in the Qo(2)-to-Vo(2) relationship [which determines microvascular Po(2) (Pmv(O(2)))] in resting and contracting skeletal muscle is unclear. We tested the hypothesis that old rats with CHF would demonstrate a greater impairment of skeletal muscle Pmv(O(2)) than observed in young rats with CHF. Phosphorescence quenching was utilized to measure spinotrapezius Pmv(O(2)) at rest and across the rest-to-contractions (1-Hz, 4-6 V) transition in young (Y) and old (O) male Fischer 344 Brown-Norway rats with CHF induced by myocardial infarction (mean left ventricular end-diastolic pressure >20 mmHg for Y(CHF) and O(CHF)). In CHF muscle, aging significantly reduced resting Pmv(O(2)) (32.3 +/- 3.4 Torr for Y(CHF) and 21.3 +/- 3.3 Torr for O(CHF); P < 0.05) and in both Y(CHF) and O(CHF) compared with their aged-matched counterparts, CHF reduced the rate of the Pmv(O(2)) fall at the onset of contractions. Moreover, across the on-transient and in the subsequent steady state, Pmv(O(2)) values in O(CHF) vs. Y(CHF) were substantially lower (for steady-state, 20.4 +/- 1.7 Torr for Y(CHF) and 16.4 +/- 2.0 Torr for O(CHF); P < 0.05). At rest and during contractions in CHF, the pressure driving blood-muscle O(2) diffusion (Pmv(O(2))) is substantially decreased in old animals. This finding suggests that muscle dysfunction and exercise intolerance in aged CHF patients might be due, in part, to the failure to maintain a sufficiently high Pmv(O(2)) to facilitate blood-muscle O(2) exchange and support mitochondrial ATP production.

Nebivolol for heart failure in the elderly

Recent analyses in the temporal trends of mortality and hospitalization in patients with chronic heart failure showed marginal changes in the last 20 years, particularly in the elderly. According to the Euro Heart Survey program and other observational reports, only 37-50% of patients with heart failure are treated with beta-blockers, with a dosage that is approximately half the target dose of clinical trials. The most frequent reason for the limited use of beta-blockers and the suboptimal doses prescribed, is age greater than 70 years. Only two multicenter, double-blind, randomized, placebo-controlled, parallel group trials; the Effects of Nebivolol on Left Ventricular Function in Elderly Patients with Chronic Heart Failure (ENECA) and the Study of Effects of Nebivolol Intervention on Outcomes and Rehospitalization Seniors with Heart Failure (SENIORS), both with nebivolol, have been specifically aimed to assess the efficacy of beta-blockade in elderly heart failure patients. The results of such trials demonstrated that the drug is well tolerated and effective in reducing mortality and morbidity, and that the beneficial clinical effect is independent of the baseline ejection fraction.

Efeitos da sauna sobre doenças cardiovasculares e doenças relacionadas com o estilo de vida

Freqüentar a sauna é uma prática popular de jovens, adultos e idosos saudáveis. Os médicos do esporte são, com freqüência, solicitados a opinar sobre o impacto da sauna nas doenças e na saúde de modo geral. A sauna pode ser benéfica ou maléfica, dependendo do uso que fazemos dela. Nos últimos anos, a sauna está sendo considerada benéfica para os portadores de doenças cardiovasculares como a insuficiência cardíaca e doenças relacionadas com o estilo de vida, principalmente por melhorar a função endotelial periférica, via aumento do débito cardíaco e vasodilatação periférica. A disfunção endotelial está presente em quase todas as doenças cardiovasculares. O presente artigo pretende fazer uma revisão sobre os efeitos da sauna sobre o sistema cardiovascular em indivíduos saudáveis e em determinadas doenças cardiovasculares.