Arterial-ventricular coupling with aging and disease

Cardiovascular aging: the unveiled enigma from bench to bedside

: The rapid increase in the median age of the world's population requires particular attention towards older and more fragile people. Cardiovascular risk factors, time and comorbidities play a vicious role in the development of heart failure, both with reduced and preserved ejection fraction, in the elderly. Understanding the mechanisms underlying the pathophysiological processes observed with aging is pivotal to target those patients and their therapeutic needs properly. This review aims to investigate and to dissect the main pathways leading to the aging cardiomyopathy, helping to understand the relationship from bench to bedside of the clinical phenotype.

Left ventricular pumping during the transition-adaptation sequence in preterm infants: impact of the patent ductus arteriosus

BackgroundPostnatally, the immature left ventricle (LV) is subjected to high systemic afterload. Hypothesizing that LV pumping would change during transition-adaptation, we analyzed the LV in preterm infants (GA≤32+6), clinically stable or with a hemodynamically significant patent ductus arteriosus (hPDA) by applying a pump model.MethodsPumping was characterized by E_A (effective arterial elastance, reflecting afterload), E_ES (end-systolic LV elastance, reflecting contractility), E_A/E_ES coupling ratios, descriptive E_A:E_ES relations, and E_A/E_ES graphs. Data calculated from echocardiography and blood pressure were analyzed by diagnosis (S group: clinically stable, no hPDA, n=122; hPDA group, n=53) and by periods (early transition: days of life 1-3; late transition: 4-7; and adaptation: 8-30).ResultsS group: LV pumping was characterized by an increased E_A/E_ES coupling ratio of 0.65 secondary to low E_ES in early transition, a tandem rise of both E_A and E_ES in late transition, and an E_A/E_ES coupling ratio of 0.45 secondary to high E_ES in adaptation; hPDA group: time-trend analyses showed significantly lower E_A (P<0.0001) and E_ES (P=0.006). Therefore, LV pumping was characterized by a lower E_A/E_ES coupling ratio (P=0.088) throughout transition-adaptation.ConclusionsIn stable infants, facing high afterload, the immature LV, enhanced by the physiological PDA, increases its contractility. In hPDA, facing low afterload, the overloaded immature LV exhibits a consistently lower contractility.

New Insights into Cardiac and Vascular Natriuretic Peptides: Findings from Young Adults Born with Very Low Birth Weight

BACKGROUND

In community studies, plasma B-type natriuretic peptide (BNP) is positively associated with cardiovascular disorders. Those born with very low birth weight (VLBW) have increased risk of metabolic and vascular disorders in later life, but plasma concentrations of natriuretic peptides have not been studied. The objectives here were to evaluate BNP and C-type natriuretic peptide (CNP)—a putative marker of vascular risk—in young adults born with VLBW.

METHODS

In all, 220 VLBW cases and 97 matched controls were studied 28 years after birth during a 2-day period at 1 research center. Aminoterminal (NT) products (NTproBNP, NTproCNP) and a range of conventional vascular risk factors including echocardiographic indices were measured along with genetic polymorphisms known to increase plasma NTproBNP.

RESULTS

VLBW individuals were smaller, had smaller hearts, reduced stroke volume and endothelial function, and higher systolic blood pressure and arterial elastance. Of the many humoral vascular and metabolic risk factors measured, including NTproBNP, only plasma NTproCNP (higher in VLBW individuals) differed significantly. Across all individuals, associations of NTproCNP with each of 7 conventional risk factors, as well as with arterial elastance, were positive, whereas associations of NTproBNP with risk were all inverse. In multivariate analysis, the genetic variant rs198358 was independently associated with NTproBNP.

CONCLUSIONS

In young adults at increased risk of cardiovascular disease, higher NTproCNP likely reflects a compensatory vascular response to vascular stress, whereas the negative link with NTproBNP likely reflects beneficial genetic mutations. The ratio of NTproBNP to NTproCNP may provide a novel index of ideal cardiovascular health.

The Role of Vascular Calcification in Heart Failure and Cognitive Decline

Vascular calcification is heterogeneous and triggered by multiple mechanisms. It has been implicated in the development of heart failure with preserved ejection fraction (HFpEF) and cognitive function impairment. Understanding the pathophysiology of vascular calcification may help us improve the management of HFpEF, atherosclerosis, accelerated arterial stiffness, hypertension, and cognitive dysfunction. Currently, there are no effective strategies for treating accelerated arterial stiffness. This may indicate that once arterial stiffness or vascular calcification has developed, it may be less likely to stop the ongoing pathophysiology. Therefore, earlier intervention targeting the probable pathways of vascular calcification may benefit the patients with vascular calcification and related pathological conditions. In this review, we briefly discuss the proposed pathophysiological roles of vascular calcification in the development of heart failure and cognitive decline, the animal models used to study the link between vascular calcification and cardiovascular diseases, and the possible corresponding management strategies.

Prognostic value of left ventricular-arterial coupling in elderly patients with septic shock

PURPOSE

To investigate the predictive value of left ventricular-arterial coupling (VAC) for clinical prognosis of elderly patients with septic shock.

MATERIALS AND METHODS

This was a single-center prospective cohort study of 63 elderly patients with septic shock treated between August 2014 and January 2016 at the 30-bed intensive care unit (ICU) of Zhejiang Hospital (China). Left VAC was evaluated by transthoracic echocardiography (TTE). End-systolic elastance (Ees) and left ventricular ejection fraction (LVEF) were measured; arterial elastance (Ea) was calculated. The 28-day survival was evaluated.

RESULTS

Compared with non-survivors, survivors had a significantly lower Ea/Ees ratio (P<0.01), mainly because survivors had higher Ees values (P<0.01), but without difference in Ea (P=0.720). LVEF was greater (47.5±7.3 vs. 43.6±6.4, P=0.03); LVESV was smaller in survivors compared to non-survivors (P<0.05). The multivariate Cox proportional regression analysis showed that APACHEII scores (hazard ratio (HR)=1.12, 95% confidence interval (95%CI):1.01-1.25, P=0.04), blood lactate levels (HR=1.21, 95%CI:1.07-1.36, P=0.002), and VAC (HR=2.57, 95%CI:1.29-5.13, P=0.007) were independently associated with 28-day mortality of elderly patients with septic shock. The optimal cutoff point of VAC for predicting 28-day mortality was 2.14 with 56.7% sensibility and 87.9% specificity; the area under the curve was 0.74.

CONCLUSIONS

Left VAC has prognostic value in elderly patients with septic shock.

Should we recommend reductions in saturated fat intake or in red/processed meat consumption? The SUN prospective cohort study

BACKGROUND & AIMS

While most studies have shown increased mortality associated with excessive red/processed meat consumption, the association of saturated fatty acids (SFA) intake with mortality is less homogeneous. We aimed to prospectively assess the association of both, meat consumption (red, processed, red + processed, and total) and SFA intake, with the risk of all-cause death.

METHODS

We assessed 18,540 participants of the SUN (Seguimiento Universidad de Navarra) cohort, followed-up for a mean of 9.5 years. A validated 136-item FFQ was administered at baseline. We used Cox models adjusted for potential confounders.

RESULTS

We observed 255 deaths during 176,916 person-years of follow-up. Age modified the association between meat consumption and all-cause mortality (p for interaction = 0.027, 0.075, and 0.013, for red, total, and processed meat, respectively). Among participants aged >45 years the fully-adjusted HRs (95% CIs) for one additional serving/d of red, total, and red + processed meat consumption were 1.47 (1.06, 2.04), 1.23 (1.05, 1.45), and 1.32 (1.05, 1.65), respectively, with significant linear trends (P for trend 0.022, 0.012, and 0.018, respectively). In these participants, SFA intake was non-significantly associated with mortality. However, isocaloric replacement of monounsaturated fat or carbohydrates by SFA resulted in significantly higher mortality risk. Likewise, replacing 100 g of vegetables, fruits & nuts or cereals by 100 g of red meat resulted in higher mortality risk. No association of meat consumption or SFA with all-cause mortality was observed in participants younger than 46 years.

CONCLUSIONS

Among highly educated persons, aged >45 years, a high consumption of red, total, and red + processed meat was related to increased all-cause mortality, compared with those with low consumption, whereas no significant associations were found for SFA intake. Dietary guidelines should specifically limit meat consumption and not relying only in limiting SFA intake.

Left ventricular functional, structural and energetic effects of normal aging: Comparison with hypertension

Objectives

Both aging and hypertension are significant risk factors for heart failure in the elderly. The purpose of this study was to determine how aging, with and without hypertension, affects left ventricular function.

Methods

Cross-sectional study of magnetic resonance imaging and ³¹P spectroscopy-based measurements of left ventricular structure, global function, strains, pulse wave velocity, high energy phosphate metabolism in 48 normal subjects and 40 treated hypertensive patients (though no other cardiovascular disease or diabetes) stratified into 3 age deciles from 50–79 years.

Results

Normal aging was associated with significant increases in systolic blood pressure, vascular stiffness, torsion, and impaired diastolic function (all P<0.05). Age-matched hypertension exacerbated the effects of aging on systolic pressure, and diastolic function. Hypertension alone, and not aging, was associated with increased left ventricular mass index, reduced energetic reserve, reduced longitudinal shortening and increased endocardial circumferential shortening (all P<0.05). Multiple linear regression analysis showed that these unique hypertensive features were significantly related to systolic blood pressure (P<0.05).

Conclusions

1) Hypertension adds to the age-related changes in systolic blood pressure and diastolic function; 2) hypertension is uniquely associated with changes in several aspects of left ventricular structure, function, systolic strains, and energetics; and 3) these uniquely hypertensive-associated parameters are related to the level of systolic blood pressure and so are potentially modifiable.

Arterial-ventricular coupling and parameters of vascular stiffness in hypertensive patients: Role of gender

Objective

Non-invasive estimation of arterial–ventricular coupling has been extensively used for the evaluation of cardiovascular performance, however, a relative small amount of data is available regarding arterial–ventricular coupling and its components in hypertension. The present study was designed to investigate the relationship between left ventricular elastance, arterial elastance, parameters of vascular stiffness and the influence of gender in a population of hypertensive individuals.

Methods

In 102 patients, trans-thoracic cardiac ultrasound, parameters of aortic stiffness (carotid-femoral pulse wave velocity) and wave reflection (augmentation index) were recorded. Ultrasound images of common carotid arteries were acquired for the assessment of intima-media thickness as well as carotid compliance and distensibility coefficient.

Results

Mean age was 61 years, 32% diabetes, 56% dyslipidemia, 9% previous cardiovascular events; women (n = 32) and men were superimposable for cardiovascular risk factors prevalence. In the population, ventricular elastance was significantly correlated with arterial elastance (r = 0.887), age (r = 0.334), gender (r = −0.494), BMI (r = −0.313), augmentation index (r = 0.479) (all p < 0.001); and with carotid compliance and distensibility coefficient (r = 0.229 and r = − 0.250, respectively, both p < 0.05); however, only arterial elastance and gender were independently associated with ventricular elastance in multiple regression models adjusted for confounding factors. Gender-specific analysis revealed that arterial elastance and augmentation index remained statistically significant associated with ventricular elastance in men (r = 0.275, p = 0.04); instead augmentation index was no longer significant (r = 0.052, p = 0.77) in the female sex.

Conclusions

In hypertensive patients, main determinants of ventricular elastance are arterial elastance, as an integrated index of arterial vascular load, and gender; however, pressure augmentation might play an additional role in men.

Ventricular-Arterial Coupling in Chronic Heart Failure

Measures of interaction between the left ventricle (LV) and arterial system (ventricular-arterial coupling) are important but under-recognised cardiovascular phenotypes in heart failure. Ventriculo-arterial coupling is commonly assessed in the pressure-volume plane, using the ratio of effective arterial elastance (E_A) to LV end-systolic elastance (E_ES) to provide information on ventricular-arterial system mechanical efficiency and performance when LV ejection fraction is abnormal. These analyses have significant limitations, such as neglecting systolic loading sequence, and are less informative in heart failure with preserved ejection fraction (HFpEF). E_A is almost entirely dependent on vascular resistance and heart rate. Assessment of pulsatile arterial haemodynamics and time-resolved myocardial wall stress provide critical incremental physiological information and should be more widely utilised. Pulsatile arterial load represents a promising therapeutic target in HFpEF. Here, we review various approaches to assess ventricular-arterial interactions, and their pathophysiological and clinical implications in heart failure.

Wave intensity analysis in mice: age-related changes in WIA peaks and correlation with cardiac indexes

Mouse models are increasingly employed in the comprehension of cardiovascular disease. Wave Intensity Analysis (WIA) can provide information about the interaction between the vascular and the cardiac system. We investigate age-associated changes in WIA-derived parameters in mice and correlate them with biomarkers of cardiac function. Sixteen wild-type male mice were imaged with high-resolution ultrasound (US) at 8 weeks (T ₀) and 25 weeks (T ₁) of age. Carotid pulse wave velocity (PWV) was calculated from US images using the diameter-velocity loop and employed to evaluate WIA. Amplitudes of the first (W ₁) and the second (W ₂) local maxima, local minimum (W _b) and the reflection index (RI = W _b/W ₁) were assessed. Cardiac output (CO), ejection fraction (EF), fractional shortening (FS) and stroke volume (SV) were evaluated; longitudinal, radial and circumferential strain and strain rate values (LS, LSR, RS, RSR, CS, CSR) were obtained through strain analysis. W ₁ (T ₀: 4.42e-07 ± 2.32e-07 m²/s; T ₁: 2.21e-07 ± 9.77 m²/s), W ₂ (T ₀: 2.45e-08 ± 9.63e-09 m²/s; T ₁: 1.78e-08 ± 7.82 m²/s), W _b (T ₀: -8.75e-08 ± 5.45e-08 m²/s; T ₁: -4.28e-08 ± 2.22e-08 m²/s), CO (T ₀: 19.27 ± 4.33 ml/min; T ₁: 16.71 ± 2.88 ml/min), LS (T ₀: 17.55 ± 3.67%; T ₁: 15.05 ± 2.89%), LSR (T ₀: 6.02 ± 1.39 s^-1; T ₁: 5.02 ± 1.25 s^-1), CS (T ₀: 27.5 ± 5.18%; T ₁: 22.66 ± 3.09%) and CSR (T ₀: 10.03 ± 2.55 s^-1; T ₁: 7.50 ± 1.84 s^-1) significantly reduced with age. W ₁ was significantly correlated with CO (R = 0.58), EF (R = 0.72), LS (R = 0.65), LSR (R = 0.89), CS (R = 0.61), CSR (R = 0.70) at T ₀; correlations were lost at T ₁. The decrease in W ₁ and W ₂ suggests a cardiac performance reduction, while that in W_b, considering unchanged RI, might indicate a wave energy decrease. The loss of correlation between WIA-derived and cardiac parameters might reflect an alteration in cardiovascular interaction.

Acute ascorbic acid infusion increases left ventricular diastolic function in postmenopausal women

OBJECTIVES

We tested the hypothesis that oxidative stress contributes to reductions in left ventricular diastolic (LV) function in estrogen-deficient postmenopausal women, related in part to reduced nitric oxide (NO) bioavailability.

STUDY DESIGN

LV diastolic function - recorded using transthoracic echocardiography and determined as the peak early (E) to late (A) mitral inflow velocity ratio and the E to peak early (e') mitral annular velocity ratio - and brachial artery flow mediated dilation (FMD), a biomarker of NO bioavailability, were measured during acute systemic infusions of saline (control) and ascorbic acid (experimental model to decrease oxidative stress) in healthy premenopausal women (N=14, 18-40 years) and postmenopausal women (N=23, 45-75 years).

RESULTS

The E/A ratio was lower (1.16[1.06-1.33] vs 1.65[1.5-2.3]; median[interquartile range]) and the E/e' ratio was elevated (8.8[7.6-9.9] vs. 6.6[5.5-7.3]) in postmenopausal compared with premenopausal women, indicating reduced LV diastolic function. E/A and E/e' were correlated with FMD (r=0.54 and r=-0.59, respectively, both P<0.01). Ascorbic acid infusion improved both FMD (5.4±2.0% to 7.8±2.6%) and E/e' (to 8.1[7.2-9.7], P=0.01) in postmenopausal women but not in premenopausal women. Ascorbic acid did not change E/A in either group.

CONCLUSION

The current study provides evidence that oxidative stress contributes to reduced LV diastolic function in estrogen-deficient postmenopausal women, possibly by reducing the availability of NO.

Carotid-Ventricular Coupling During Exercise: A Pilot Study

OBJECTIVES

To evaluate carotid elasticity and left ventricular elastance during a graded bicycle semisupine exercise test in patients with known or suspected coronary artery disease and compare them with a control group of healthy young volunteers.

METHODS

Thirty-six elderly patients and 18 young healthy volunteers were recruited. The right carotid diameter was estimated by an automatic system applied to B-mode sonographic sequences, central mean blood and pulse pressures by radial artery tonometry, and cardiac volumes by 2-dimensional transthoracic echocardiography; from these direct measurements, the carotid cross-sectional distensibility coefficient and left ventricular elastance index were obtained. Analyses were performed at rest, at peak stress, and during the recovery phase.

RESULTS

The elderly patients included 20 men (mean age ± SD, 61 ± 8 years); the volunteers included 9 men (mean age, 34 ± 3 years). The mean blood pressure (at rest: patients, 97 ± 7 mm Hg; controls, 93 ± 9 mm Hg; not significant) increased similarly in both groups during exercise and decreased during the recovery phase. The diameter was higher in patients than controls (7.5 ± 1.1 versus 6.2 ± 0.5 mm) and increased significantly with exercise only in the latter group (at peak: 6.5 ± 0.6 mm; P < .05). The distensibility coefficient and elastance index were lower in patients than controls during the test phases [at rest: 24.5 ± 10.2 versus 60.8 ± 21.3 × 10(-3)/kPa and 3.6 ± 1.4 versus 1.6 ± 0.8 mm Hg/(mL/m(2))] and mostly changed in the controls, showing a decreased distensibility coefficient (peak: 40.6 ± 15.1 × 10(-3)/kPa) and an increased elastance index [peak: 5.9 ± 2.8 mm Hg/(mL/m(2))].

CONCLUSIONS

In older patients with multiple cardiovascular risk factors or established coronary artery disease, an abnormal carotid-ventricular adaptation to exercise was observed when compared to young healthy individuals.

Senescent endothelial cells: Potential modulators of immunosenescence and ageing

Recent studies have demonstrated that the accumulation of senescent endothelial cells may be the primary cause of cardiovascular diseases. Because of their multifunctional properties, endothelial cells actively take part in stimulating the immune system and inflammation. In addition, ageing is characterized by the progressive deterioration of immune cells and a decline in the activation of the immune response. This results in a loss of the primary function of the immune system, which is eliminating damaged/senescent cells and neutralizing potential sources of harmful inflammatory reactions. In this review, we discuss cellular senescence and the senescence-associated secretory phenotype (SASP) of endothelial cells and summarize the link between endothelial cells and immunosenescence. We describe the possibility that age-related changes in Toll-like receptors (TLRs) and microRNAs can affect the phenotypes of senescent endothelial cells and immune cells via a negative feedback loop aimed at restraining the excessive pro-inflammatory response. This review also addresses the following questions: how do senescent endothelial cells influence ageing or age-related changes in the inflammatory burden; what is the connection between ECs and immunosenescence, and what are the crucial hypothetical pathways linking endothelial cells and the immune system during ageing.

New diagnostic perspectives on heart failure with preserved ejection fraction: systolic function beyond ejection fraction

Although preserved ejection fraction is found in more than 50% of patients with heart failure, its acceptance as a specific clinical entity is limited. More understanding of the physiopathology, early diagnosis and medical management is needed. With no existing systematic information in the literature, the aim of this review is to provide a comprehensive overview of the new imaging techniques for diagnosing heart failure with preserved ejection fraction, particularly in the early stages of the disease, underlying the pivotal role of new technologies such as two-dimensional speckle tracking echocardiography and vascular stiffness.

Galectin-3: A Link between Myocardial and Arterial Stiffening in Patients with Acute Decompensated Heart Failure?

BACKGROUND

Heart failure is accompanied by abnormalities in ventricular-vascular interaction due to increased myocardial and arterial stiffness. Galectin-3 is a recently discovered biomarker that plays an important role in myocardial and vascular fibrosis and heart failure progression.

OBJECTIVES

The aim of this study was to determine whether galectin-3 is correlated with arterial stiffening markers and impaired ventricular-arterial coupling in decompensated heart failure patients.

METHODS

A total of 79 inpatients with acute decompensated heart failure were evaluated. Serum galectin-3 was determined at baseline, and during admission, transthoracic echocardiography and measurements of vascular indices by Doppler ultrasonography were performed.

RESULTS

Elevated pulse wave velocity and low arterial carotid distensibility are associated with heart failure in patients with preserved ejection fraction (p = 0.04, p = 0.009). Pulse wave velocity, carotid distensibility and Young's modulus did not correlate with serum galectin-3 levels. Conversely, raised galectin-3 levels correlated with an increased ventricular-arterial coupling ratio (Ea/Elv) p = 0.047, OR = 1.9, 95% CI (1.0‑3.6). Increased galectin-3 levels were associated with lower rates of left ventricular pressure rise in early systole (dp/dt) (p=0.018) and raised pulmonary artery pressure (p = 0.046). High galectin-3 levels (p = 0.038, HR = 3.07) and arterial pulmonary pressure (p = 0.007, HR = 1.06) were found to be independent risk factors for all-cause mortality and readmissions.

CONCLUSIONS

This study showed no significant correlation between serum galectin-3 levels and arterial stiffening markers. Instead, high galectin-3 levels predicted impaired ventricular-arterial coupling. Galectin-3 may be predictive of raised pulmonary artery pressures. Elevated galectin-3 levels correlate with severe systolic dysfunction and together with pulmonary hypertension are independent markers of outcome.

Association between baseline cardiovascular mechanics and exercise capacity in patients with coronary artery disease

OBJECTIVE

Functional capacity is one of the cardinal determinants of morbidity and mortality in patients with coronary artery disease (CAD). We hypothesized that baseline cardiovascular mechanics, including cardiac systolic and diastolic functions, arterial mechanics, and ventriculoarterial interaction, may play a role in predicting exercise capacity in patients with CAD.

METHODS

Fifty consecutive patients with CAD who were referred to cardiac rehabilitation were prospectively included in the study. Patients with non-sinus rhythms or severe valvular disease were excluded. Full left ventricular pressure-volume loops were constructed and arterial mechanics was evaluated using echocardiographic and tonometric measurements. Cardiopulmonary exercise tests were performed to measure exercise capacity.

RESULTS

Fifty patients were enrolled in the study. Ventriculo-arterial coupling showed a moderate correlation with peak oxygen consumption (VO2) (r=0.410, p=0.04) in patients with reduced left ventricular ejection fraction (LVEF). Only left ventricular volume at 15 mm Hg (r=0.514, p<0.01) in diastolic parameters (stiffness constant, p=0.75; ventricular compliance, p=0.17) and arterial compliance (r=0.467, p=0.01) in arterial parameters [arterial elastance, p=0.27; systemic vascular resistance, p=0.45; augmentation pressure, p=0.85; augmentation index (AIx), p=0.63; heart rate-corrected AIx, p=0.68] emerged as significant factors correlated with peak VO2 in patients with normal LVEF.

CONCLUSION

Comprehensive evaluation of resting cardiovascular mechanics can give clues about exercise-recruited reserves of the cardiovascular system. Optimization of ventriculo-arterial coupling in patients with reduced LVEF and arterial compliance in patients with normal LVEF should be the main target in patients with CAD and limited functional capacity.

Compensatory Effect between Aortic Stiffening and Remodelling during Ageing

The arterial tree exhibits a complex spatio-temporal wave pattern, whose healthy behaviour depends on a subtle balance between mechanical and geometrical properties. Several clinical studies demonstrated that such a balance progressively breaks down during ageing, when the aorta stiffens and remodels by increasing its diameter. These two degenerative processes however, have different impacts on the arterial wave pattern. They both tend to compensate for each other, thus reducing the detrimental effect they would have had if they had arisen individually. This remarkable compensatory mechanism is investigated by a validated multi-scale model, with the aim to elucidate how aortic stiffening and remodelling quantitatively impact the complex interplay between forward and reflected backward waves in the arterial network. We focus on the aorta and on the pressure at the ventricular-aortic interface, which epidemiological studies demonstrate to play a key role in cardiovascular diseases.

Characterizing heart failure in the ventricular volume domain

Heart failure (HF) may be accompanied by considerable alterations of left ventricular (LV) volume, depending on the particular phenotype. Two major types of HF have been identified, although heterogeneity within each category may be considerable. All variants of HF show substantially elevated LV filling pressures, which tend to induce changes in LV size and shape. Yet, one type of HF is characterized by near-normal values for LV end-diastolic volume (EDV) and even a smaller end-systolic volume (ESV) than in matched groups of persons without cardiac disease. Furthermore, accumulating evidence indicates that, both in terms of shape and size, in men and women, the heart reacts differently to adaptive stimuli as well as to certain pharmacological interventions. Adjustments of ESV and EDV such as in HF patients are associated with (reverse) remodeling mechanisms. Therefore, it is logical to analyze HF subtypes in a graphical representation that relates ESV to EDV. Following this route, one may expect that the two major phenotypes of HF are identified as distinct entities localized in different areas of the LV volume domain. The precise coordinates of this position imply unique characteristics in terms of the actual operating point for LV volume regulation. Evidently, ejection fraction (EF; equal to 1 minus the ratio of ESV and EDV) carries little information within the LV volume representation. Thus far, classification of HF is based on information regarding EF combined with EDV. Our analysis shows that ESV in the two HF groups follows different patterns in dependency of EDV. This observation suggests that a superior HF classification system should primarily be founded on information embodied by ESV.

Age-associated pro-inflammatory remodeling and functional phenotype in the heart and large arteries

The aging population is increasing dramatically. Aging–associated stress simultaneously drives proinflammatory remodeling, involving angiotensin II and other factors, in both the heart and large arteries. The structural remodeling and functional changes that occur with aging include cardiac and vascular wall stiffening, systolic hypertension and suboptimal ventricular-arterial coupling, features that are often clinically silent and thus termed a silent syndrome. These age-related effects are the result of responses initiated by cardiovascular proinflammatory cells. Local proinflammatory signals are coupled between the heart and arteries due to common mechanical and humoral messengers within a closed circulating system. Thus, targeting proinflammatory signaling molecules would be a promising approach to improve age-associated suboptimal ventricular-arterial coupling, a major predisposing factor for the pathogenesis of clinical cardiovascular events such as heart failure.

Abnormal stress-related measures of arterial stiffness in middle-aged and elderly men and women with impaired fasting glucose at risk for a first episode of symptomatic heart failure

Background

Abnormal resting arterial stiffness is present in middle‐aged and elderly persons with abnormalities of fasting glucose (diabetes or impaired fasting glucose) and is associated with exercise intolerance. We sought to determine whether these same persons exhibited stress‐related abnormalities of arterial stiffness.

Methods and Results

We analyzed dobutamine magnetic resonance stress imaging results from 373 consecutively recruited persons aged 55 to 85 years with normal fasting glucose, impaired fasting glucose, or diabetes who were at risk for but without symptomatic heart failure. Personnel blinded to participant identifiers measured arterial stiffness (brachial pulse pressure/left ventricular stroke volume indexed to body surface area, the aortic elastance index [brachial end‐systolic pressure/left ventricular stroke volume indexed to body surface area], and thoracic aortic distensibility) at 80% of the maximum predicted heart rate response for age. Participants averaged 69±8 years of age; 79% were white, 92% were hypertensive, and 66% were women. After accounting for hypertension, sex, coronary artery disease, smoking, medications, hypercholesterolemia, and visceral fat, we observed an effect of glycemic status for stress measures of arterial stiffness in those with diabetes and impaired fasting glucose relative to those with normal fasting glucose (P=0.002, P=0.02, and P=0.003, respectively).

Conclusion

Middle‐ and older‐aged individuals with diabetes or impaired fasting glucose have higher stress measures of arterial stiffness than those with normal fasting glucose. These data emphasize the need for future studies with larger sample sizes to determine whether stress‐related elevations in arterial stiffness are related to exercise intolerance and future episodes of heart failure experienced by those with abnormalities of fasting glucose.

Clinical Trial Registration

URL: http://clinicaltrials.gov/. Unique identifier: NCT00542503.

Visit-to-visit blood pressure variability is a marker of cardiac diastolic function and carotid atherosclerosis

Background

The associations between visit-to-visit blood pressure (BP) variability and cardiac function and carotid atherosclerosis is not clear.

Methods

Study subjects were 144 subjects (80 were female, aged 73 ± 9 years) who underwent echocardiography and cervical ultrasonography. The ratio of early ventricular filling velocity to early diastolic mitral annular velocity (E/e’), ejection fraction, left ventricular mass index (LVMI), and maximum intima-media thickness (max-IMT) of the carotid artery were compared between the highest (high variability) and lowest (low variability) tertiles of the standard deviation of systolic BP (9.9 ± 3.5 mmHg).

Results

E/e’ and max-IMT were significantly greater in the high variability group than in the low variability group after adjusting for age, sex, baseline systolic BP, and other covariates (high variability vs. low variability; E/e’: 13.03 ± 5.33 vs. 10.66 ± 3.30, multivariate-adjusted difference (β) = 1.82, 95% confidence interval 0.06–3.58; max-IMT: 1.65 ± 0.43 mm vs. 1.42 ± 0.46 mm, β = 0.20 mm, 95% confidence interval 0.03–0.36 mm). There were no significant differences in LVMI or ejection fraction.

Conclusion

These results indicate that high visit-to-visit BP variability is associated with diastolic function and carotid atherosclerosis, and is a possible risk factor for diastolic dysfunction and atherosclerosis.

In vivo assessment of arterial stiffness in the isoflurane anesthetized spontaneously hypertensive rat

Background

Rodent models are increasingly used to study the development and progression of arterial stiffness. Both the non-invasive Doppler derived Pulse Wave Velocity (PWV) and the invasively determined arterial elastance index (EaI) have been used to assess arterial stiffness in rats and mice, but the need for anesthetic agents to make these in vivo estimates may limit their utility. Thus, we sought to determine: 1) if known differences in arterial stiffness in spontaneously hypertensive rats (SHR) are detectable by PWV and EaI measurements when made under isoflurane anesthesia, and 2) if these two uniquely acquired assessments of arterial elasticity correlate.

Methods

We obtained PWV and EaI measurements in isoflurane anesthetized young and old SHRs, which are known to have significant differences in arterial stiffness. Doppler pulse waves were recorded from carotid and iliac arteries and the distance (D) between probe applantation sites was recorded. Simultaneously, an EKG was obtained, and the time intervals between the R-wave of the EKG to the foot of the Doppler waveforms were measured and averaged over three cardiac cycles. Pulse-transit time (T) of the carotid to iliac artery was determined, and PWV was calculated as Distance (D)/Time (T), where D = the distance from the carotid to the iliac notch and T = (R to iliac foot) - (R to carotid foot). EaI was subsequently determined from pressure volumes loops obtained via left ventricle catheterization.

Results

PWV and EaI were found to be significantly faster in the older rats (13.2 ± 2.0 vs. 8.0 ± 0.8 m/sec, p < 0.001; 120 ± 20 vs. 97 ± 16 mmHg/μl/g, p <0.05). Bland-Altman analyses of intra- and inter-observer measures demonstrate a statistically significant relationship between readings (p < 0.0001). PWV and EaI measurements were found to be significantly and positively correlated with a correlation coefficient of 0.53 (p < 0.05).

Conclusion

Our study suggests that isoflurane administration does not limit Doppler PWV or EaI measures in their ability to provide accurate, in vivo assessments of relative arterial stiffness in isoflurane anesthetised SHR rats. Furthermore, PWV data obtained in these rats correlate well with invasively determined EaI.

The decay of stem cell nourishment at the niche

One of the main features of human aging is the loss of adult stem cell homeostasis. Organs that are very dependent on adult stem cells show increased susceptibility to aging, particularly organs that present a vascular stem cell niche. Reduced regenerative capacity in tissues correlates with reduced stem cell function, which parallels a loss of microvascular density (rarefraction) and plasticity. Moreover, the age-related loss of microvascular plasticity and rarefaction has significance beyond metabolic support for tissues because stem cell niches are regulated co-ordinately with the vascular cells. In addition, microvascular rarefaction is related to increased inflammatory signals that may negatively regulate the stem cell population. Thus, the processes of microvascular rarefaction, adult stem cell dysfunction, and inflammation underlie the cycle of physiological decline that we call aging. Observations from new mouse models and humans are discussed here to support the vascular aging theory. We develop a novel theory to explain the complexity of aging in mammals and perhaps in other organisms. The connection between vascular endothelial tissue and organismal aging provides a potential evolutionary conserved mechanism that is an ideal target for the development of therapies to prevent or delay age-related processes in humans.

Ventriculo-arterial coupling in children with Still's murmur

Still's murmur is the most common innocent heart murmur in children and considered flow related; however, so far the cause of the murmur has not yet been fully explained. Assessment of the hemodynamic ventriculo‐arterial interaction and the proportional anatomical dimensions of the left ventricle and the aortic root were the objective for this study. This case–control study was conducted at the Division of Pediatric Cardiology, Vienna Medical University, including healthy children with and without Still's murmur. To assess ventriculo‐arterial interaction, the model of ventriculo‐arterial coupling (VAC) was applied. The model describes the interaction between the left ventricle (left ventricular contractility, E_LV) and the arterial system (effective arterial elastance, E_A) by the VAC ratio E_A/E_LV. The parameters E_A and E_LV can be derived from M‐mode echocardiography thereby allowing a noninvasive pressure–volume analysis. Outcomes comprised VAC ratio and diameters of both the aortic root (AOD) and the left ventricle in end diastole (LVED) and end systole (LVES) as well as their relative proportions, ejection fraction (EF), stroke volume (SV), blood pressure (BP), and heart rate (HR). Forty‐three healthy children with Still's murmur (mean age 5.2 years) and 42 healthy children without murmur (mean age 5.8 years) participated in this study. Children with Still's murmur had a significantly lower VAC ratio E_A/E_LV (0.5 ± 0.13 vs. 0.59 ± 0.15; P < 0.005), a significantly higher EF% (67.1 ± 5.8 vs. 63.3 ± 5.6; P < 0.005, P < 0.01), and a larger SV per kg bodyweight (1.84 ± 0.33 vs. 1.68 ± 0.38; P < 0.05) than controls. BP, HR, and diameters of AOD, LVED, and LVES as well as their relative anatomic proportions did not differ between children with Still's murmur and controls. Still's murmur seems to be generated by a subtle alteration in ventriculo‐arterial coupling in healthy children. This result can be translated to parents, as they may be informed that their child's innocent murmur is caused by a more “lively interplay between the heart and the aorta.”

So far, the physiology of Still's murmur has not yet been defined. This study is the first to describe a significant difference in ventriculo‐arterial coupling in healthy children with and without Still's murmur.

Causes and pathophysiology of heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFPEF) is frequently associated with multiple disorders complicating both the clinical management and the understanding of the underlying mechanisms. This review focuses on the causes and pathophysiology of HFPEF and overviews how cellular and molecular changes related to various comorbidities may influence the age-dependent and gender-dependent hemodynamic alterations of diastolic ventricular function.

Exercise reveals impairments in left ventricular systolic function in patients with metabolic syndrome

Metabolic syndrome (MetS) is the manifestation of a cluster of cardiovascular risk factors and is associated with a threefold increase in the risk of cardiovascular morbidity and mortality, which is suggested to be mediated, in part, by resting left ventricular (LV) systolic dysfunction. However, to what extent resting LV systolic function is impaired in MetS is controversial, and there are no data indicating whether LV systolic function is impaired during exercise. Accordingly, the objective of this study was to examine comprehensively the LV and arterial responses to exercise in individuals with MetS without diabetes and/or overt cardiovascular disease in comparison to a healthy control population. Cardiovascular function was characterized using Doppler echocardiography and gas exchange in individuals with MetS (n = 27) versus healthy control subjects (n = 20) at rest and during peak exercise. At rest, individuals with MetS displayed normal LV systolic function but reduced LV diastolic function compared with healthy control subjects. During peak exercise, individuals with MetS had impaired contractility, pump performance and vasodilator reserve capacity versus control subjects. A blunted contractile reserve response resulted in diminished arterial-ventricular coupling reserve and limited aerobic capacity in individuals with MetS versus control subjects. These findings are of clinical importance, because they provide insight into the pathophysiological changes in MetS that may predispose this population of individuals to an increased risk of cardiovascular morbidity and mortality.

Aortic distensibility in type 1 diabetes

OBJECTIVE

To evaluate the relationship between long-term glycemia, traditional cardiovascular disease (CVD) risk factors, and ascending aortic stiffness in type 1 diabetes.

RESEARCH DESIGN AND METHODS

Eight hundred seventy-nine subjects in the Diabetes Control and Complications Trial (DCCT)/Epidemiology of Diabetes Interventions and Complications (EDIC) study were evaluated. The stiffness/distensibility of the ascending thoracic aorta (AA) was measured with magnetic resonance imaging. Associations of AA distensibility and CVD risk factors, mean HbA1c, and cardiovascular complications including macroalbuminuria were assessed using multivariate linear regression models.

RESULTS

The mean age of the subjects was 50 ± 7 years (47% women, mean diabetes duration of 28 years). Over 22 years of follow-up, 27% of participants had cardiovascular complications. After adjusting for gender and cohort, AA distensibility was lower with increasing age, mean systolic blood pressure, LDL, and HbA1c measured over an average of 22 years (-26.3% per 10 years, -11.0% per 10 mmHg SBP, -1.8% per 10 mg/dL of LDL, and -9.3% per unit mean HbA1c [%], respectively). Patients with macroalbuminuria had 25% lower AA distensibility compared with those without (P < 0.0001). Lower AA distensibility also was associated with greater ratio of left ventricular mass to volume (-3.4% per 0.1 g/mL; P < 0.0001).

CONCLUSIONS

Our findings indicate strong adverse effects of hypertension, chronic hyperglycemia and macroalbuminuria on AA stiffness in type 1 diabetes in the DCCT/EDIC cohort.

Ventricular-arterial coupling: Invasive and non-invasive assessment

Interactions between the left ventricle (LV) and the arterial system, (ventricular-arterial coupling) are key determinants of cardiovascular function. Ventricularearterial coupling is most frequently assessed in the pressure-volume plane using the ratio of effective arterial elastance (E_A) to LV end-systolic elastance (E_ES). E_A (usually interpreted as a lumped index of arterial load) can be computed as end-systolic pressure/stroke volume, whereas E_ES (a load-independent measure of LV chamber systolic stiffness and contractility) is ideally assessed invasively using data from a family of pressure-volume loops obtained during an acute preload alteration. Single-beat methods have also been proposed, allowing for non-invasive estimations of E_ES using simple echocardiographic measurements. The E_A/E_ES ratio is useful because it provides information regarding the operating mechanical efficiency and performance of the ventricular-arterial system. However, it should be recognized that analyses in the pressure-volume plane have several limitations and that "ventricular-arterial coupling" encompasses multiple physiologic aspects, many of which are not captured in the pressure-volume plane. Therefore, additional assessments provide important incremental physiologic information about the cardiovascular system and should be more widely used. In particular, it should be recognized that: (1) comprehensive analyses of arterial load are important because E_A poorly characterizes pulsatile LV load and does not depend exclusively on arterial properties; (2) The systolic loading sequence, an important aspect of ventricular-arterial coupling, is neglected by pressure-volume analyses, and can profoundly impact LV function, remodeling and progression to heart failure. This brief review summarizes methods for the assessment of ventricular-arterial interactions, as discussed at the Artery 12 meeting (October 2012).