Impact of angiotensin receptor-neprilysin inhibition on vascular function in heart failure with reduced ejection fraction: A pilot study

The mechanisms for the benefits of Angiotensin Receptor Neprilysin Inhibition (ARNi) in heart failure patients with reduced ejection fraction (HFrEF) are likely beyond blood pressure reduction. Measures of vascular function such as arterial stiffness and endothelial function are strong prognostic markers of cardiovascular outcomes in HFrEF, yet the impact of ARNi on vascular health remains to be explored. We hypothesized that arterial stiffness and endothelial function would improve after 12 weeks of ARNi in HFrEF. We tested 10 stable HFrEF patients at baseline and following 12 weeks of ARNi [64 ± 9 years, Men/Women: 9/1, left ventricular ejection fraction (EF): 28 ± 6%] as well as 10 stable HFrEF patients that remained on conventional treatment (CON: 60 ± 7 years, Men/Women: 6/4, EF: 31 ± 5%; all p = NS). Arterial stiffness was assessed via carotid-femoral pulse wave velocity (PWV) and endothelial function was assessed via brachial artery flow-mediated dilation (FMD). PWV decreased after 12 weeks of ARNi (9.0 ± 2.1 vs. 7.1 ± 1.2 m/s; p < 0.01) but not in CON (7.0 ± 2.4 vs. 7.5 ± 2.3 m/s; p = 0.35), an effect that remained when controlling for reductions in mean arterial pressure (p < 0.01). FMD increased after 12 weeks of ARNi (2.2 ± 1.9 vs. 5.5 ± 2.1%; p < 0.001) but not in CON (4.8 ± 3.8 vs. 5.4 ± 3.4%; p = 0.34). Baseline PWV (p = 0.06) and FMD (p = 0.07) were not different between groups. These preliminary data suggest that 12 weeks of ARNi therapy may reduce arterial stiffness and improve endothelial function in HFrEF. Thus, the findings from this pilot study suggest that the benefits of ARNi are beyond blood pressure reduction and include improvements in vascular function.

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.

New indices of arterial stiffness correlate with disease severity and mid-term prognosis in acute decompensated heart failure

Arterial stiffness has been implicated in pathophysiology of heart failure (HF) since it is involved in the ventricular-vascular coupling. Recently, new indices obtained by a cuff oscillometric technique, the arterial velocity pulse index (AVI) for the stiffness of central arteries and the arterial pressure volume index (API) for the stiffness of peripheral arteries have been developed and validated. However, the AVI and API measurement has not been attempted in HF population. This study aimed to investigate the relationship between the AVI, API and clinical parameters and outcomes in HF patients. A prospective cohort of patients with acute decompensated HF were enrolled within 6 months, who were admitted to a tertiary referral hospital in China. Measurement of the AVI and API (AVE-1500, Shisei Datum, Tokyo, Japan) was performed on the day of admission and discharge. Patients were followed up to 6 months for the composite endpoint of all-cause death and rehospitalization for HF. A total of 127 patients were recruited for analysis (60 ± 15 years, 70% male). 80% of the patients were in New York Heart Association (NYHA) Class III or IV at admission with mean left ventricular ejection fraction (LVEF) of 34 ± 9%. During hospitalization, all patients received guideline-directed medical therapy if not contraindicated. The AVI (27.3 ± 5.0 vs. 28.6 ± 6.7, P = 0.002) and API (24.9 ± 4.9 vs. 26.0 ± 6.5, P = 0.05) were lower at discharge than at admission. By dividing the patients into mild to severe group based on systolic blood pressure (SBP) and LVEF or into tertiles according to the amino-terminal pro-brain natriuretic peptide (NT-proBNP), transmitral E velocity over mitral annular e' velocity (E/e' ratio), it was observed that the AVI increased with a higher level of NT-proBNP (P for trend < 0.001), a larger E/e' (P for trend < 0.001) and a lower LVEF (P for trend = 0.0183), while the API increased as the E/e' and systolic blood pressure became higher (both P for trend < 0.05). The improvement in AVI at discharge was correlated with LVEF (R = - 0.3024, P < 0.05) and NT-proBNP improvement (R = 0.3118, P < 0.05), while the change in API was positively correlated with SBP change (R = 0.3897, P < 0.001). In 6 months after discharge, there were 52 predefined events including 15 deaths and 44 rehospitalization for HF. Apart from the level of NT-proBNP, the AVI at discharge of ≥ 26 showed a trend of being associated with the composite outcome (HR 2.747, 95% CI 1.411-5.349, P < 0.001 for univariate analysis; HR 1.864, 95% CI 0.892-3.893, P = 0.09761 for multivariate analysis). New noninvasive arterial stiffness indices as the AVI and API reflected severity of illness and midterm prognosis in admitted HF patients. Further studies are warranted for understanding its mechanisms and developing clinical applications.

The effect of cardiac resynchronization therapy on arterial stiffness and central hemodynamic parameters

INTRODUCTION

Cardiac resynchronization therapy (CRT) is a device-based method of treatment which decreases morbidity and mortality in heart failure with reduced ejection fraction (HFrEF). This study was aimed to investigate the effects of CRT on hemodynamic and arterial stiffness parameters evaluated by noninvasive method, and determine whether there is a correlation between the changes after CRT in these parameters and the clinical response to CRT or not.

METHODS

The study included 46 patients with HFrEF who were planned to undergo CRT implantation. Before the CRT implantation, clinical and demographic data were recorded from all patients. Hemodynamic and arterial stiffness parameters were measured oscillometrically by an arteriograph before CRT implantation. The patients were re-evaluated minimum three months after CRT; the above-mentioned parameters were measured again and compared to the pre-CRT period.

RESULTS

Compared to the period before CRT, mean systolic blood pressure (SBP) (116.8 ± 19.1 mm Hg vs 127.7 ± 20.9 mm Hg, P = .005), central SBP (cSBP) (106.2 ± 17.3 mm Hg vs 116.8 ± 18.7 mm Hg, P = .015), cardiac output (CO) (4.6 ± 0.8 lt/min vs 5.1 ± 0.8 lt/min, P = .002), stroke volume (65.6 ± 16.3 mL vs 72.0 ± 14.9 mL), and pulse wave velocity (PWV) (10 ± 1.6 m/sec vs 10.4 ± 1.8 m/sec, P = .004) increased significantly in post-CRT period. In addition, the same parameters were significantly increased post-CRT period in patients with clinical response. However, there was not any similar increase in nonresponder patients.

CONCLUSION

This study demonstrated that SBP, CO, and PWV increased significantly after CRT. The modest increases in these parameters were observed to be associated with positive clinical outcomes.

Assessment of Arterial Stiffness in Patients With Resistant Hypertension: Additional Insights Into the Pathophysiology of This Condition?

BACKGROUND

Good understanding of the pathophysiological mechanism(s) of resistant hypertension (RH) and the relationship to vascular dysfunction is important for optimal blood pressure control.

METHODS AND RESULTS

The aim of this review article is to summarize the available data on the methods of arterial stiffness assessment, and their usefulness in RH. Several studies that provide information on the noninvasive methods of evaluation of arterial stiffness have been discussed; specifically, pulse wave velocity (PWV) and augmentation index (AIx) tests. Increased arterial stiffness, elevated AIx, and impaired endothelial function all act as indicators and predictors of cardiovascular events in patients with hypertension (HTN).

CONCLUSION

Our review suggests that PWV and AIx are impaired in patients with severe HTN. Early assessment of these characteristics can potentially be of value in patients with RH.

The Role of Arterial Stiffness and Central Hemodynamics in Heart Failure

Whereas traditional understanding of left ventricular afterload was focused on a steady-state circulation model with continuous pressures and flow, a more realistic concept is emerging, taking the pulsatile nature of the heart and the arterial system into account. The most simple measure of pulsatility is brachial pulse pressure, representing the pulsatility fluctuating around the mean blood pressure level. Brachial pulse pressure is widely available, fundamentally associated with the development and treatment of heart failure (HF), but its analysis is often confounded in patients with established HF. The next step of analysis consists of arterial stiffness, central (rather than brachial) pressures, and of wave reflections. The latter are closely related to left ventricular late systolic afterload, ventricular remodeling, diastolic dysfunction, exercise capacity, and, in the long term, the risk of new-onset HF. Wave reflection may also evolve as a suitable therapeutic target for HF with preserved and reduced ejection fraction. A full understanding of ventricular-arterial coupling, however, requires dedicated analysis of time-resolved pressure and flow signals. This review provides a summary of current understanding of pulsatile hemodynamics in HF.

Prognostic evaluation of the elastic properties of the ascending aorta in dilated cardiomyopathy

BACKGROUND

Nowadays there is an increased interest in the role of aortic stiffness in the pathophysiology of heart failure (HF), as it is a major determinant of left ventricular (LV) performance. We aimed at assessing the predictive value of the aortic stiffness parameters, measured by echocardiography, in patients affected by nonischaemic dilated cardiomyopathy (DCM) regarding three end-points: death, HF rehospitalization, combined death or HF rehospitalization in a long-term follow-up.

MATERIALS AND METHODS

A total of 202 patients affected by nonischaemic DCM underwent an outpatient examination by echocardiography and blood pressure check at the brachial artery, in order to calculate aortic elastic properties (ie, compliance, distensibility, stiffness index, Peterson's elastic modulus, M-mode strain). ROC curves, Kaplan-Meier curves and multivariable Cox regressions (correcting for age, LV ejection fraction (LVEF), atrial fibrillation, cardiac resynchronization therapy (CRT)) were run to assess the predictive ability of aortic elastic properties against the 3 end-points.

RESULTS

Mean follow-up was 9.83 ± 2.80 years. 24.8% of patients died, while 34.7% were rehospitalized for HF cause and 44.6% experienced the combined end-point. LVEF did not correlate with aortic elastic properties. ROC curves and Kaplan-Meier curves were elaborated. Aortic stiffness did not predict death in our cohort. Otherwise, all aortic elastic properties predicted HF rehospitalization and combined death or HF rehospitalization, after correcting for age, LVEF, atrial fibrillation, CRT.

CONCLUSIONS

Elastic properties of the ascending aorta measured by echocardiography in patients with nonischaemic DCM predict long-term HF rehospitalization and combined death or HF rehospitalization, also after correcting for the confounding factors.

Relation between arterial stiffness and aerobic capacity: Importance of proximal aortic stiffness

Brachial-ankle pulse wave velocity (baPWV) has become a popular modality of arterial stiffness measurement. However, its projected arterial segment does not include the proximal aorta which plays important roles for attenuating cardiac pulsation and reducing afterload. We hypothesised that aerobic capacity would be more strongly associated with PWV including the proximal aorta than that omitting the proximal aorta. To test our hypothesis, we compared the association between aerobic capacity and arterial stiffness parameters omitting vs. including the proximal aorta (i.e. baPWV vs. heart-ankle PWV [haPWV]) in 82 apparently healthy men (18-64 years). Estimated VO_2max significantly correlated with baPWV (r = -0.394, P < .001), and more strongly with haPWV (r = -0.546, P < .001). The forward stepwise multi-regression analysis revealed that haPWV (β = -0.335), as well as age, heart rate, and body mass index (β = -0.280 to -0.297), was a significant independent determinant explaining variance of estimated VO_2max. These results suggest that aerobic capacity is influenced more strongly by the proximal aortic stiffness than distal aortic stiffness.

Echocardiographically Derived Pulse Wave Velocity and Diastolic Dysfunction Are Associated with an Increased Incidence of Atrial Fibrillation in Patients with Systolic Heart Failure

BACKGROUND

Chronic heart failure (CHF) is an established risk factor of atrial fibrillation (AF), but the prognostic value of cardiac and hemodynamic parameters in assessing the risk of developing AF among patients with CHF is less defined.

METHODS AND RESULTS

We followed an outpatients cohort of CHF patients secondary to left ventricular (LV) systolic dysfunction, who were free of AF at baseline. All patients underwent clinical evaluation, comprehensive echocardiography, and blood drawing in the same morning. Aortic pulse wave velocity (aPWV), a measure of aortic stiffness, was determined by Doppler echocardiography. A total of 77 patients (age 63 ± 9 years; 79% male) with mean LVEF (34 ± 8%) formed the study population. Fifteen patients developed incidental AF. At baseline, CHF patients who developed AF during follow-up had higher E-wave velocity (75 ± 2 cm/sec vs. 60 ± 2 cm/sec; P = 0.02), higher difference duration between mitral and pulmonary vein A velocity (A'-A), (10 ± 35 msec vs. 43 ± 44 msec P = 0.02), aPWV (7.1 ± 2.6 vs. 5.3 ± 1.9 m/sec P = 0.004), and furosemide dosage (110 ± 145 mg vs. 49 ± 48 mg P = 0.01) than those remaining free from AF. The two groups of patients did not significantly differ in terms of NYHA, LV volumes, ejection fraction, left atrial volume, creatinine, hemoglobin, renin, epinephrine, amino-terminal propeptide of type III and I procollagens, ACE inhibitor, and β-blocker dose (P > 0.1 for all). Notably, higher aPWV (P = 0.01) and longer A-A' duration (P = 0.04) were associated with an increased incidence of AF, independently of potential confounders.

CONCLUSIONS

Increased aortic stiffness and LV diastolic dysfunction are strong predictors of new onset of AF among patients with systolic CHF.

The effect of aldosterone-antagonist therapy on aortic elastic properties in patients with nonischemic dilated cardiomyopathy

BACKGROUND

Many studies proved the prognostic importance of aortic stiffness as an independent predictor of cardiovascular morbidity and all-cause mortality. The decrease of arterial compliance has a high prevalence in patients with heart failure and affects both hemodynamics and prognosis. Aortic stiffness is partially caused by excessive activation of the renin-angiotensin-aldosterone system. Spironolactone, a mineralcorticoid receptor antagonist (MRA), has been shown to decrease aortic stiffness and fibrosis in experimental models. However, there are few studies that describe the effects of MRA on aortic stiffness in patients with nonischemic dilated cardiomyopathy.

AIMS

To evaluate the effect of spironolactone on aortic stiffness in patients with nonischemic dilated cardiomyopathy.

MATERIALS AND METHODS

We randomized (1 : 1) 102 patients with nonischemic dilated cardiomyopathy with New York Heart Association class I-II to receive spironolactone 25 mg/day (up to 100 mg/day) or placebo, in addition to recommended therapy. Aortic stiffness index, aortic strain, aortic distensibility and aortic dimensions were assessed at baseline and after 6 months. All measures were obtained with echocardiography M-mode at 3 cm above the aortic valve on parasternal long axis view and simultaneous brachial arterial pressure with sphygmomanometer.

RESULTS

Ascending aorta diameters, aortic stiffness index, aortic distensibility and aortic strain were similar at randomization in the two groups. After 6 months of therapy in the treated group, we found a reduction of aortic stiffness index (7.2 ± 3.5 versus 9.6 ± 4.8 mmHg; P = 0.03) and an increase of aortic distensibility (3.77 ± 1.0 versus 2.92 ± 0.55 mmHg; P = 0.01) and systolic aortic strain (10.0 ± 5.0 versus 8.0% ± 2.1%; P = 0.01). There were no difference in systolic arterial pressure, diastolic arterial pressure and differential pressure in the two groups.

CONCLUSION

Therapy with spironolactone is effective in reducing aortic stiffness in patients with nonischemic dilated cardiomyopathy. This effect could improve hemodynamics supporting the use of MRAs in patients with low New York Heart Association class (I-II).

Relation of Central Arterial Stiffness to Incident Heart Failure in the Community

BACKGROUND

Arterial stiffness, pressure pulsatility, and wave reflection are associated with cardiovascular disease. Left ventricular function is coupled to proximal aortic properties, but the association of central aortic stiffness and hemodynamics with incident clinical heart failure (HF) is not well described.

METHODS AND RESULTS

Framingham Study participants without clinical HF (n=2539, mean age 64 years, 56% women) underwent applanation tonometry to measure carotid-femoral pulse wave velocity (CFPWV), central pulse pressure, forward wave amplitude, and augmentation index. CFPWV was inverse-transformed to reduce heteroscedasticity and multiplied by -1 to restore effect direction (iCFPWV). Over 10.1 (range 0.04-12.9) years, 170 HF events developed. In multivariable-adjusted analyses, iCFPWV was associated with incident HF in a continuous, graded fashion (hazards ratio [HR] per SD unit [SDU] 1.29, 95% confidence interval [CI] 1.02-1.64, P=0.037). iCFPWV was associated with HF with reduced ejection fraction (HR=1.69/SDU, 95% CI 1.19-2.42, P=0.0037) in age- and sex-adjusted models, which was attenuated in multivariable-adjusted models (P=0.065). Central pulse pressure and forward wave amplitude were associated with HF in age- and sex-adjusted models (per SDU, HR=1.20, 95% CI 1.06-1.37, P=0.006, and HR=1.15, 95% CI 1.01-1.31, P=0.036, respectively), but not in multivariable-adjusted models (both P≥0.28). Augmentation index was not associated with HF risk (P≥0.19 in all models).

CONCLUSIONS

In our prospective investigation of a large community-based sample of middle-aged to elderly individuals, greater aortic stiffness (reflected by higher iCFPWV) was associated with increased risk of HF. Future studies may investigate the impact of modifying aortic stiffness in reducing the community burden of HF.

Echocardiographic elastic properties of ascending aorta and their relationship with exercise capacity in patients with non-ischemic dilated cardiomyopathy

Background

: Aortic stiffness, an independent predictor of mortality and cardiovascular events, is common among patients affected by non-ischemic dilated cardiomyopathy (NIDC) and heart failure (HF).

Methods

: A total of 55 patients with diagnosis of NIDC (aged 60 ± 11 years, mean ejection fraction (EF) 35.2% ± 7.7%) admitted consecutively to our department for mild to moderate HF (NYHA class II–III) underwent an echocardiographic study and cardiopulmonary exercise test (CPX). We evaluated elastic properties of ascending aorta, i.e. aortic stiffness and aortic distensibility (mm Hg^{− 1}), derived from ascending aorta systolic and diastolic diameter (mm/m²) measured 3 cm above the valvular plane through 2D-guided M-mode echocardiography.

Results

: Mean aortic stiffness was 15.63 ± 14.53 and aortic distensibility was 2.61 ± 2.39 mm Hg^{− 1}. Collected parameters at CPX were peak oxygen consumption (pVO₂) (ml/kg/min), anaerobic threshold (AT) and the slope of the relation between minute ventilation (VE) and carbon dioxide production (VCO₂). Mean pVO₂ was 15.4 ± 3.9 ml/kg/min, VE/VCO₂ ratio at AT was 36.1 ± 6.1. Functional capacity measured through peak VO₂ was found to be directly correlated with aortic distensibility (r = 0.47, p = − 0.0002) and negatively correlated to aortic stiffness index (r = − 0.51, p = − 0.0001). These results were the same at multivariate analysis, corrected by age, hypertension, diabetes mellitus and ejection fraction (respectively r = 0.27, p = 0.008 and r = − 1.75, p = 0.0002).

Conclusions

: HF patients due to NIDC elastic properties of ascending aorta, evaluated by echocardiography, are correlated with a reduced functional capacity.

Mineralocorticoid receptor antagonist in heart failure: Past, present and future perspectives

Aldosterone is involved in various deleterious effects on the cardiovascular system, including sodium and fluid retention, myocardial fibrosis, vascular stiffening, endothelial dysfunction, catecholamine release and stimulation of cardiac arrhythmias. Therefore, aldosterone receptor blockade may have several potential benefits in patients with cardiovascular disease. Mineralocorticoid receptor antagonists (MRAs) have been shown to prevent many of the maladaptive effects of aldosterone, in particular among patients with heart failure (HF). Randomized controlled trials have demonstrated efficacy of MRA in heart failure with reduced ejection fraction, both in patients with NYHA functional classes III and IV and in asymptomatic and mildly symptomatic patients (NYHA classes I and II). Recent data in patients with heart failure with preserved ejection fraction are encouraging. MRA could also have anti-arrhythmic effects on atrial and ventricular arrhythmias and may be helpful in patient ischemic heart disease through prevention of myocardial fibrosis and vascular damage. This article aims to discuss the pathophysiological effects of aldosterone in patients with cardiovascular disease and to review the current data that support the use of MRA in heart failure.

Arterial wave reflection and subclinical left ventricular systolic dysfunction

OBJECTIVES

Increased arterial wave reflection is a predictor of cardiovascular events and has been hypothesized to be a cofactor in the pathophysiology of heart failure. Whether increased wave reflection is inversely associated with left-ventricular (LV) systolic function in individuals without heart failure is not clear.

METHODS

Arterial wave reflection and LV systolic function were assessed in 301 participants from the Cardiovascular Abnormalities and Brain Lesions (CABL) study using two-dimensional echocardiography and applanation tonometry of the radial artery to derive central arterial waveform by a validated transfer function. Aortic augmentation index (AIx) and wasted energy index (WEi) were used as indices of wave reflection. LV systolic function was measured by LV ejection fraction (LVEF) and tissue Doppler imaging (TDI). Mitral annulus peak systolic velocity (Sm), peak longitudinal strain and strain rate were measured. Participants with history of coronary artery disease, atrial fibrillation, LVEF less than 50% or wall motion abnormalities were excluded.

RESULTS

Mean age of the study population was 68.3 ± 10.2 years (64.1% women, 65% hypertensive). LV systolic function by TDI was lower with increasing wave reflection, whereas LVEF was not. In multivariate analysis, TDI parameters of LV longitudinal systolic function were significantly and inversely correlated to AIx and WEi (P values from 0.05 to 0.002).

CONCLUSIONS

In a community cohort without heart failure and with normal LVEF, an increased arterial wave reflection was associated with subclinical reduction in LV systolic function assessed by novel TDI techniques. Further studies are needed to investigate the prognostic implications of this relationship.